sftp: add required packages to vendor

Godeps/Godeps.json

@@ -220,6 +220,10 @@
 			"Comment": "v0.8.0-2-g248dadf",
 			"Rev": "248dadf4e9068a0b3e79f02ed0a610d935de5302"
 		},
+		{
+			"ImportPath": "github.com/pkg/sftp",
+			"Rev": "bf1c2bb0012cdea62d6c5ae7212a1bb04cfa4d89"
+		},
 		{
 			"ImportPath": "github.com/pmezard/go-difflib/difflib",
 			"Rev": "792786c7400a136282c1664665ae0a8db921c6c2"
@@ -466,6 +470,10 @@
 			"ImportPath": "google.golang.org/grpc/transport",
 			"Comment": "v1.0.5-9-gc810507",
 			"Rev": "c8105071640ef29fce843ed96983e864bb18eb0e"
+		},
+		{
+			"ImportPath": "github.com/kr/fs",
+			"Rev": "2788f0dbd16903de03cb8186e5c7d97b69ad387b"
 		}
 	]
 }

vendor/github.com/kr/fs/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/kr/fs/Readme

@@ -0,0 +1,3 @@
+Filesystem Package
+
+http://godoc.org/github.com/kr/fs

vendor/github.com/kr/fs/filesystem.go

@@ -0,0 +1,36 @@
+package fs
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+// FileSystem defines the methods of an abstract filesystem.
+type FileSystem interface {
+
+	// ReadDir reads the directory named by dirname and returns a
+	// list of directory entries.
+	ReadDir(dirname string) ([]os.FileInfo, error)
+
+	// Lstat returns a FileInfo describing the named file. If the file is a
+	// symbolic link, the returned FileInfo describes the symbolic link. Lstat
+	// makes no attempt to follow the link.
+	Lstat(name string) (os.FileInfo, error)
+
+	// Join joins any number of path elements into a single path, adding a
+	// separator if necessary. The result is Cleaned; in particular, all
+	// empty strings are ignored.
+	//
+	// The separator is FileSystem specific.
+	Join(elem ...string) string
+}
+
+// fs represents a FileSystem provided by the os package.
+type fs struct{}
+
+func (f *fs) ReadDir(dirname string) ([]os.FileInfo, error) { return ioutil.ReadDir(dirname) }
+
+func (f *fs) Lstat(name string) (os.FileInfo, error) { return os.Lstat(name) }
+
+func (f *fs) Join(elem ...string) string { return filepath.Join(elem...) }

vendor/github.com/kr/fs/walk.go

@@ -0,0 +1,95 @@
+// Package fs provides filesystem-related functions.
+package fs
+
+import (
+	"os"
+)
+
+// Walker provides a convenient interface for iterating over the
+// descendants of a filesystem path.
+// Successive calls to the Step method will step through each
+// file or directory in the tree, including the root. The files
+// are walked in lexical order, which makes the output deterministic
+// but means that for very large directories Walker can be inefficient.
+// Walker does not follow symbolic links.
+type Walker struct {
+	fs      FileSystem
+	cur     item
+	stack   []item
+	descend bool
+}
+
+type item struct {
+	path string
+	info os.FileInfo
+	err  error
+}
+
+// Walk returns a new Walker rooted at root.
+func Walk(root string) *Walker {
+	return WalkFS(root, new(fs))
+}
+
+// WalkFS returns a new Walker rooted at root on the FileSystem fs.
+func WalkFS(root string, fs FileSystem) *Walker {
+	info, err := fs.Lstat(root)
+	return &Walker{
+		fs:    fs,
+		stack: []item{{root, info, err}},
+	}
+}
+
+// Step advances the Walker to the next file or directory,
+// which will then be available through the Path, Stat,
+// and Err methods.
+// It returns false when the walk stops at the end of the tree.
+func (w *Walker) Step() bool {
+	if w.descend && w.cur.err == nil && w.cur.info.IsDir() {
+		list, err := w.fs.ReadDir(w.cur.path)
+		if err != nil {
+			w.cur.err = err
+			w.stack = append(w.stack, w.cur)
+		} else {
+			for i := len(list) - 1; i >= 0; i-- {
+				path := w.fs.Join(w.cur.path, list[i].Name())
+				w.stack = append(w.stack, item{path, list[i], nil})
+			}
+		}
+	}
+
+	if len(w.stack) == 0 {
+		return false
+	}
+	i := len(w.stack) - 1
+	w.cur = w.stack[i]
+	w.stack = w.stack[:i]
+	w.descend = true
+	return true
+}
+
+// Path returns the path to the most recent file or directory
+// visited by a call to Step. It contains the argument to Walk
+// as a prefix; that is, if Walk is called with "dir", which is
+// a directory containing the file "a", Path will return "dir/a".
+func (w *Walker) Path() string {
+	return w.cur.path
+}
+
+// Stat returns info for the most recent file or directory
+// visited by a call to Step.
+func (w *Walker) Stat() os.FileInfo {
+	return w.cur.info
+}
+
+// Err returns the error, if any, for the most recent attempt
+// by Step to visit a file or directory. If a directory has
+// an error, w will not descend into that directory.
+func (w *Walker) Err() error {
+	return w.cur.err
+}
+
+// SkipDir causes the currently visited directory to be skipped.
+// If w is not on a directory, SkipDir has no effect.
+func (w *Walker) SkipDir() {
+	w.descend = false
+}

vendor/github.com/pkg/sftp/.gitignore

@@ -0,0 +1,8 @@
+.*.swo
+.*.swp
+
+server_standalone/server_standalone
+
+examples/sftp-server/id_rsa
+examples/sftp-server/id_rsa.pub
+examples/sftp-server/sftp-server

vendor/github.com/pkg/sftp/.travis.yml

@@ -0,0 +1,29 @@
+language: go
+go_import_path: github.com/pkg/sftp
+go:
+  - 1.5.x
+  - 1.6.x
+  - 1.7.x
+  - tip
+
+os:
+  - linux
+  - osx
+
+sudo: false
+
+addons:
+  ssh_known_hosts:
+      - bitbucket.org
+
+install:
+  - go get -t -v ./...
+  - ssh-keygen -t rsa -q -P "" -f $HOME/.ssh/id_rsa
+
+script:
+  - go test -integration -v ./...
+  - go test -testserver -v ./...
+  - go test -integration -testserver -v ./...
+  - go test -race -integration -v ./...
+  - go test -race -testserver -v ./...
+  - go test -race -integration -testserver -v ./...

vendor/github.com/pkg/sftp/CONTRIBUTORS

@@ -0,0 +1,3 @@
+Dave Cheney <dave@cheney.net>
+Saulius Gurklys <s4uliu5@gmail.com>
+John Eikenberry <jae@zhar.net>

vendor/github.com/pkg/sftp/LICENSE

@@ -0,0 +1,9 @@
+Copyright (c) 2013, Dave Cheney
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/pkg/sftp/README.md

@@ -0,0 +1,48 @@
+sftp
+----
+
+The `sftp` package provides support for file system operations on remote ssh
+servers using the SFTP subsystem. It also implements an SFTP server for serving
+files from the filesystem.
+
+[![UNIX Build Status](https://travis-ci.org/pkg/sftp.svg?branch=master)](https://travis-ci.org/pkg/sftp) [![GoDoc](http://godoc.org/github.com/pkg/sftp?status.svg)](http://godoc.org/github.com/pkg/sftp)
+
+usage and examples
+------------------
+
+See [godoc.org/github.com/pkg/sftp](http://godoc.org/github.com/pkg/sftp) for
+examples and usage.
+
+The basic operation of the package mirrors the facilities of the
+[os](http://golang.org/pkg/os) package.
+
+The Walker interface for directory traversal is heavily inspired by Keith
+Rarick's [fs](http://godoc.org/github.com/kr/fs) package.
+
+roadmap
+-------
+
+ * There is way too much duplication in the Client methods. If there was an
+   unmarshal(interface{}) method this would reduce a heap of the duplication.
+
+contributing
+------------
+
+We welcome pull requests, bug fixes and issue reports.
+
+Before proposing a large change, first please discuss your change by raising an
+issue.
+
+For API/code bugs, please include a small, self contained code example to
+reproduce the issue. For pull requests, remember test coverage.
+
+We handle issues and pull requests with a 0 open philosophy. That means we will
+try to address the submission as soon as possible and will work toward a
+resolution. If progress can no longer be made (eg. unreproducible bug) or stops
+(eg. unresponsive submitter), we will close the bug.
+
+Please remember that we don't have infinite time and so it is a good guideline
+that the less time it takes us to work with you on your idea/issue the greater
+the chance we will have the time to do it.
+
+Thanks.

vendor/github.com/pkg/sftp/attrs.go

@@ -0,0 +1,237 @@
+package sftp
+
+// ssh_FXP_ATTRS support
+// see http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02#section-5
+
+import (
+	"os"
+	"syscall"
+	"time"
+)
+
+const (
+	ssh_FILEXFER_ATTR_SIZE        = 0x00000001
+	ssh_FILEXFER_ATTR_UIDGID      = 0x00000002
+	ssh_FILEXFER_ATTR_PERMISSIONS = 0x00000004
+	ssh_FILEXFER_ATTR_ACMODTIME   = 0x00000008
+	ssh_FILEXFER_ATTR_EXTENDED    = 0x80000000
+)
+
+// fileInfo is an artificial type designed to satisfy os.FileInfo.
+type fileInfo struct {
+	name  string
+	size  int64
+	mode  os.FileMode
+	mtime time.Time
+	sys   interface{}
+}
+
+// Name returns the base name of the file.
+func (fi *fileInfo) Name() string { return fi.name }
+
+// Size returns the length in bytes for regular files; system-dependent for others.
+func (fi *fileInfo) Size() int64 { return fi.size }
+
+// Mode returns file mode bits.
+func (fi *fileInfo) Mode() os.FileMode { return fi.mode }
+
+// ModTime returns the last modification time of the file.
+func (fi *fileInfo) ModTime() time.Time { return fi.mtime }
+
+// IsDir returns true if the file is a directory.
+func (fi *fileInfo) IsDir() bool { return fi.Mode().IsDir() }
+
+func (fi *fileInfo) Sys() interface{} { return fi.sys }
+
+// FileStat holds the original unmarshalled values from a call to READDIR or *STAT.
+// It is exported for the purposes of accessing the raw values via os.FileInfo.Sys()
+type FileStat struct {
+	Size     uint64
+	Mode     uint32
+	Mtime    uint32
+	Atime    uint32
+	UID      uint32
+	GID      uint32
+	Extended []StatExtended
+}
+
+// StatExtended contains additional, extended information for a FileStat.
+type StatExtended struct {
+	ExtType string
+	ExtData string
+}
+
+func fileInfoFromStat(st *FileStat, name string) os.FileInfo {
+	fs := &fileInfo{
+		name:  name,
+		size:  int64(st.Size),
+		mode:  toFileMode(st.Mode),
+		mtime: time.Unix(int64(st.Mtime), 0),
+		sys:   st,
+	}
+	return fs
+}
+
+func fileStatFromInfo(fi os.FileInfo) (uint32, FileStat) {
+	mtime := fi.ModTime().Unix()
+	atime := mtime
+	var flags uint32 = ssh_FILEXFER_ATTR_SIZE |
+		ssh_FILEXFER_ATTR_PERMISSIONS |
+		ssh_FILEXFER_ATTR_ACMODTIME
+
+	fileStat := FileStat{
+		Size:  uint64(fi.Size()),
+		Mode:  fromFileMode(fi.Mode()),
+		Mtime: uint32(mtime),
+		Atime: uint32(atime),
+	}
+
+	// os specific file stat decoding
+	fileStatFromInfoOs(fi, &flags, &fileStat)
+
+	return flags, fileStat
+}
+
+func unmarshalAttrs(b []byte) (*FileStat, []byte) {
+	flags, b := unmarshalUint32(b)
+	var fs FileStat
+	if flags&ssh_FILEXFER_ATTR_SIZE == ssh_FILEXFER_ATTR_SIZE {
+		fs.Size, b = unmarshalUint64(b)
+	}
+	if flags&ssh_FILEXFER_ATTR_UIDGID == ssh_FILEXFER_ATTR_UIDGID {
+		fs.UID, b = unmarshalUint32(b)
+	}
+	if flags&ssh_FILEXFER_ATTR_UIDGID == ssh_FILEXFER_ATTR_UIDGID {
+		fs.GID, b = unmarshalUint32(b)
+	}
+	if flags&ssh_FILEXFER_ATTR_PERMISSIONS == ssh_FILEXFER_ATTR_PERMISSIONS {
+		fs.Mode, b = unmarshalUint32(b)
+	}
+	if flags&ssh_FILEXFER_ATTR_ACMODTIME == ssh_FILEXFER_ATTR_ACMODTIME {
+		fs.Atime, b = unmarshalUint32(b)
+		fs.Mtime, b = unmarshalUint32(b)
+	}
+	if flags&ssh_FILEXFER_ATTR_EXTENDED == ssh_FILEXFER_ATTR_EXTENDED {
+		var count uint32
+		count, b = unmarshalUint32(b)
+		ext := make([]StatExtended, count, count)
+		for i := uint32(0); i < count; i++ {
+			var typ string
+			var data string
+			typ, b = unmarshalString(b)
+			data, b = unmarshalString(b)
+			ext[i] = StatExtended{typ, data}
+		}
+		fs.Extended = ext
+	}
+	return &fs, b
+}
+
+func marshalFileInfo(b []byte, fi os.FileInfo) []byte {
+	// attributes variable struct, and also variable per protocol version
+	// spec version 3 attributes:
+	// uint32   flags
+	// uint64   size           present only if flag SSH_FILEXFER_ATTR_SIZE
+	// uint32   uid            present only if flag SSH_FILEXFER_ATTR_UIDGID
+	// uint32   gid            present only if flag SSH_FILEXFER_ATTR_UIDGID
+	// uint32   permissions    present only if flag SSH_FILEXFER_ATTR_PERMISSIONS
+	// uint32   atime          present only if flag SSH_FILEXFER_ACMODTIME
+	// uint32   mtime          present only if flag SSH_FILEXFER_ACMODTIME
+	// uint32   extended_count present only if flag SSH_FILEXFER_ATTR_EXTENDED
+	// string   extended_type
+	// string   extended_data
+	// ...      more extended data (extended_type - extended_data pairs),
+	// 	   so that number of pairs equals extended_count
+
+	flags, fileStat := fileStatFromInfo(fi)
+
+	b = marshalUint32(b, flags)
+	if flags&ssh_FILEXFER_ATTR_SIZE != 0 {
+		b = marshalUint64(b, fileStat.Size)
+	}
+	if flags&ssh_FILEXFER_ATTR_UIDGID != 0 {
+		b = marshalUint32(b, fileStat.UID)
+		b = marshalUint32(b, fileStat.GID)
+	}
+	if flags&ssh_FILEXFER_ATTR_PERMISSIONS != 0 {
+		b = marshalUint32(b, fileStat.Mode)
+	}
+	if flags&ssh_FILEXFER_ATTR_ACMODTIME != 0 {
+		b = marshalUint32(b, fileStat.Atime)
+		b = marshalUint32(b, fileStat.Mtime)
+	}
+
+	return b
+}
+
+// toFileMode converts sftp filemode bits to the os.FileMode specification
+func toFileMode(mode uint32) os.FileMode {
+	var fm = os.FileMode(mode & 0777)
+	switch mode & syscall.S_IFMT {
+	case syscall.S_IFBLK:
+		fm |= os.ModeDevice
+	case syscall.S_IFCHR:
+		fm |= os.ModeDevice | os.ModeCharDevice
+	case syscall.S_IFDIR:
+		fm |= os.ModeDir
+	case syscall.S_IFIFO:
+		fm |= os.ModeNamedPipe
+	case syscall.S_IFLNK:
+		fm |= os.ModeSymlink
+	case syscall.S_IFREG:
+		// nothing to do
+	case syscall.S_IFSOCK:
+		fm |= os.ModeSocket
+	}
+	if mode&syscall.S_ISGID != 0 {
+		fm |= os.ModeSetgid
+	}
+	if mode&syscall.S_ISUID != 0 {
+		fm |= os.ModeSetuid
+	}
+	if mode&syscall.S_ISVTX != 0 {
+		fm |= os.ModeSticky
+	}
+	return fm
+}
+
+// fromFileMode converts from the os.FileMode specification to sftp filemode bits
+func fromFileMode(mode os.FileMode) uint32 {
+	ret := uint32(0)
+
+	if mode&os.ModeDevice != 0 {
+		if mode&os.ModeCharDevice != 0 {
+			ret |= syscall.S_IFCHR
+		} else {
+			ret |= syscall.S_IFBLK
+		}
+	}
+	if mode&os.ModeDir != 0 {
+		ret |= syscall.S_IFDIR
+	}
+	if mode&os.ModeSymlink != 0 {
+		ret |= syscall.S_IFLNK
+	}
+	if mode&os.ModeNamedPipe != 0 {
+		ret |= syscall.S_IFIFO
+	}
+	if mode&os.ModeSetgid != 0 {
+		ret |= syscall.S_ISGID
+	}
+	if mode&os.ModeSetuid != 0 {
+		ret |= syscall.S_ISUID
+	}
+	if mode&os.ModeSticky != 0 {
+		ret |= syscall.S_ISVTX
+	}
+	if mode&os.ModeSocket != 0 {
+		ret |= syscall.S_IFSOCK
+	}
+
+	if mode&os.ModeType == 0 {
+		ret |= syscall.S_IFREG
+	}
+	ret |= uint32(mode & os.ModePerm)
+
+	return ret
+}

vendor/github.com/pkg/sftp/attrs_stubs.go

@@ -0,0 +1,11 @@
+// +build !cgo,!plan9 windows android
+
+package sftp
+
+import (
+	"os"
+)
+
+func fileStatFromInfoOs(fi os.FileInfo, flags *uint32, fileStat *FileStat) {
+	// todo
+}

vendor/github.com/pkg/sftp/attrs_unix.go

@@ -0,0 +1,17 @@
+// +build darwin dragonfly freebsd !android,linux netbsd openbsd solaris
+// +build cgo
+
+package sftp
+
+import (
+	"os"
+	"syscall"
+)
+
+func fileStatFromInfoOs(fi os.FileInfo, flags *uint32, fileStat *FileStat) {
+	if statt, ok := fi.Sys().(*syscall.Stat_t); ok {
+		*flags |= ssh_FILEXFER_ATTR_UIDGID
+		fileStat.UID = statt.Uid
+		fileStat.GID = statt.Gid
+	}
+}

vendor/github.com/pkg/sftp/conn.go

@@ -0,0 +1,126 @@
+package sftp
+
+import (
+	"encoding"
+	"io"
+	"sync"
+
+	"github.com/pkg/errors"
+)
+
+// conn implements a bidirectional channel on which client and server
+// connections are multiplexed.
+type conn struct {
+	io.Reader
+	io.WriteCloser
+	sync.Mutex // used to serialise writes to sendPacket
+}
+
+func (c *conn) recvPacket() (uint8, []byte, error) {
+	return recvPacket(c)
+}
+
+func (c *conn) sendPacket(m encoding.BinaryMarshaler) error {
+	c.Lock()
+	defer c.Unlock()
+	return sendPacket(c, m)
+}
+
+type clientConn struct {
+	conn
+	wg         sync.WaitGroup
+	sync.Mutex                          // protects inflight
+	inflight   map[uint32]chan<- result // outstanding requests
+}
+
+// Close closes the SFTP session.
+func (c *clientConn) Close() error {
+	defer c.wg.Wait()
+	return c.conn.Close()
+}
+
+func (c *clientConn) loop() {
+	defer c.wg.Done()
+	err := c.recv()
+	if err != nil {
+		c.broadcastErr(err)
+	}
+}
+
+// recv continuously reads from the server and forwards responses to the
+// appropriate channel.
+func (c *clientConn) recv() error {
+	defer func() {
+		c.Lock()
+		c.conn.Close()
+		c.Unlock()
+	}()
+	for {
+		typ, data, err := c.recvPacket()
+		if err != nil {
+			return err
+		}
+		sid, _ := unmarshalUint32(data)
+		c.Lock()
+		ch, ok := c.inflight[sid]
+		delete(c.inflight, sid)
+		c.Unlock()
+		if !ok {
+			// This is an unexpected occurrence. Send the error
+			// back to all listeners so that they terminate
+			// gracefully.
+			return errors.Errorf("sid: %v not fond", sid)
+		}
+		ch <- result{typ: typ, data: data}
+	}
+}
+
+// result captures the result of receiving the a packet from the server
+type result struct {
+	typ  byte
+	data []byte
+	err  error
+}
+
+type idmarshaler interface {
+	id() uint32
+	encoding.BinaryMarshaler
+}
+
+func (c *clientConn) sendPacket(p idmarshaler) (byte, []byte, error) {
+	ch := make(chan result, 1)
+	c.dispatchRequest(ch, p)
+	s := <-ch
+	return s.typ, s.data, s.err
+}
+
+func (c *clientConn) dispatchRequest(ch chan<- result, p idmarshaler) {
+	c.Lock()
+	c.inflight[p.id()] = ch
+	if err := c.conn.sendPacket(p); err != nil {
+		delete(c.inflight, p.id())
+		ch <- result{err: err}
+	}
+	c.Unlock()
+}
+
+// broadcastErr sends an error to all goroutines waiting for a response.
+func (c *clientConn) broadcastErr(err error) {
+	c.Lock()
+	listeners := make([]chan<- result, 0, len(c.inflight))
+	for _, ch := range c.inflight {
+		listeners = append(listeners, ch)
+	}
+	c.Unlock()
+	for _, ch := range listeners {
+		ch <- result{err: err}
+	}
+}
+
+type serverConn struct {
+	conn
+}
+
+func (s *serverConn) sendError(p id, err error) error {
+	return s.sendPacket(statusFromError(p, err))
+}

vendor/github.com/pkg/sftp/debug.go

@@ -0,0 +1,9 @@
+// +build debug
+
+package sftp
+
+import "log"
+
+func debug(fmt string, args ...interface{}) {
+	log.Printf(fmt, args...)
+}

vendor/github.com/pkg/sftp/packet.go

@@ -0,0 +1,901 @@
+package sftp
+
+import (
+	"bytes"
+	"encoding"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+
+	"github.com/pkg/errors"
+)
+
+var (
+	errShortPacket           = errors.New("packet too short")
+	errUnknownExtendedPacket = errors.New("unknown extended packet")
+)
+
+const (
+	debugDumpTxPacket      = false
+	debugDumpRxPacket      = false
+	debugDumpTxPacketBytes = false
+	debugDumpRxPacketBytes = false
+)
+
+func marshalUint32(b []byte, v uint32) []byte {
+	return append(b, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
+}
+
+func marshalUint64(b []byte, v uint64) []byte {
+	return marshalUint32(marshalUint32(b, uint32(v>>32)), uint32(v))
+}
+
+func marshalString(b []byte, v string) []byte {
+	return append(marshalUint32(b, uint32(len(v))), v...)
+}
+
+func marshal(b []byte, v interface{}) []byte {
+	if v == nil {
+		return b
+	}
+	switch v := v.(type) {
+	case uint8:
+		return append(b, v)
+	case uint32:
+		return marshalUint32(b, v)
+	case uint64:
+		return marshalUint64(b, v)
+	case string:
+		return marshalString(b, v)
+	case os.FileInfo:
+		return marshalFileInfo(b, v)
+	default:
+		switch d := reflect.ValueOf(v); d.Kind() {
+		case reflect.Struct:
+			for i, n := 0, d.NumField(); i < n; i++ {
+				b = append(marshal(b, d.Field(i).Interface()))
+			}
+			return b
+		case reflect.Slice:
+			for i, n := 0, d.Len(); i < n; i++ {
+				b = append(marshal(b, d.Index(i).Interface()))
+			}
+			return b
+		default:
+			panic(fmt.Sprintf("marshal(%#v): cannot handle type %T", v, v))
+		}
+	}
+}
+
+func unmarshalUint32(b []byte) (uint32, []byte) {
+	v := uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24
+	return v, b[4:]
+}
+
+func unmarshalUint32Safe(b []byte) (uint32, []byte, error) {
+	var v uint32
+	if len(b) < 4 {
+		return 0, nil, errShortPacket
+	}
+	v, b = unmarshalUint32(b)
+	return v, b, nil
+}
+
+func unmarshalUint64(b []byte) (uint64, []byte) {
+	h, b := unmarshalUint32(b)
+	l, b := unmarshalUint32(b)
+	return uint64(h)<<32 | uint64(l), b
+}
+
+func unmarshalUint64Safe(b []byte) (uint64, []byte, error) {
+	var v uint64
+	if len(b) < 8 {
+		return 0, nil, errShortPacket
+	}
+	v, b = unmarshalUint64(b)
+	return v, b, nil
+}
+
+func unmarshalString(b []byte) (string, []byte) {
+	n, b := unmarshalUint32(b)
+	return string(b[:n]), b[n:]
+}
+
+func unmarshalStringSafe(b []byte) (string, []byte, error) {
+	n, b, err := unmarshalUint32Safe(b)
+	if err != nil {
+		return "", nil, err
+	}
+	if int64(n) > int64(len(b)) {
+		return "", nil, errShortPacket
+	}
+	return string(b[:n]), b[n:], nil
+}
+
+// sendPacket marshals p according to RFC 4234.
+func sendPacket(w io.Writer, m encoding.BinaryMarshaler) error {
+	bb, err := m.MarshalBinary()
+	if err != nil {
+		return errors.Errorf("binary marshaller failed: %v", err)
+	}
+	if debugDumpTxPacketBytes {
+		debug("send packet: %s %d bytes %x", fxp(bb[0]), len(bb), bb[1:])
+	} else if debugDumpTxPacket {
+		debug("send packet: %s %d bytes", fxp(bb[0]), len(bb))
+	}
+	l := uint32(len(bb))
+	hdr := []byte{byte(l >> 24), byte(l >> 16), byte(l >> 8), byte(l)}
+	_, err = w.Write(hdr)
+	if err != nil {
+		return errors.Errorf("failed to send packet header: %v", err)
+	}
+	_, err = w.Write(bb)
+	if err != nil {
+		return errors.Errorf("failed to send packet body: %v", err)
+	}
+	return nil
+}
+
+func recvPacket(r io.Reader) (uint8, []byte, error) {
+	var b = []byte{0, 0, 0, 0}
+	if _, err := io.ReadFull(r, b); err != nil {
+		return 0, nil, err
+	}
+	l, _ := unmarshalUint32(b)
+	b = make([]byte, l)
+	if _, err := io.ReadFull(r, b); err != nil {
+		debug("recv packet %d bytes: err %v", l, err)
+		return 0, nil, err
+	}
+	if debugDumpRxPacketBytes {
+		debug("recv packet: %s %d bytes %x", fxp(b[0]), l, b[1:])
+	} else if debugDumpRxPacket {
+		debug("recv packet: %s %d bytes", fxp(b[0]), l)
+	}
+	return b[0], b[1:], nil
+}
+
+type extensionPair struct {
+	Name string
+	Data string
+}
+
+func unmarshalExtensionPair(b []byte) (extensionPair, []byte, error) {
+	var ep extensionPair
+	var err error
+	ep.Name, b, err = unmarshalStringSafe(b)
+	if err != nil {
+		return ep, b, err
+	}
+	ep.Data, b, err = unmarshalStringSafe(b)
+	if err != nil {
+		return ep, b, err
+	}
+	return ep, b, err
+}
+
+// Here starts the definition of packets along with their MarshalBinary
+// implementations.
+// Manually writing the marshalling logic wins us a lot of time and
+// allocation.
+
+type sshFxInitPacket struct {
+	Version    uint32
+	Extensions []extensionPair
+}
+
+func (p sshFxInitPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 // byte + uint32
+	for _, e := range p.Extensions {
+		l += 4 + len(e.Name) + 4 + len(e.Data)
+	}
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_INIT)
+	b = marshalUint32(b, p.Version)
+	for _, e := range p.Extensions {
+		b = marshalString(b, e.Name)
+		b = marshalString(b, e.Data)
+	}
+	return b, nil
+}
+
+func (p *sshFxInitPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.Version, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	}
+	for len(b) > 0 {
+		var ep extensionPair
+		ep, b, err = unmarshalExtensionPair(b)
+		if err != nil {
+			return err
+		}
+		p.Extensions = append(p.Extensions, ep)
+	}
+	return nil
+}
+
+type sshFxVersionPacket struct {
+	Version    uint32
+	Extensions []struct {
+		Name, Data string
+	}
+}
+
+func (p sshFxVersionPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 // byte + uint32
+	for _, e := range p.Extensions {
+		l += 4 + len(e.Name) + 4 + len(e.Data)
+	}
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_VERSION)
+	b = marshalUint32(b, p.Version)
+	for _, e := range p.Extensions {
+		b = marshalString(b, e.Name)
+		b = marshalString(b, e.Data)
+	}
+	return b, nil
+}
+
+func marshalIDString(packetType byte, id uint32, str string) ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(str)
+
+	b := make([]byte, 0, l)
+	b = append(b, packetType)
+	b = marshalUint32(b, id)
+	b = marshalString(b, str)
+	return b, nil
+}
+
+func unmarshalIDString(b []byte, id *uint32, str *string) error {
+	var err error
+	*id, b, err = unmarshalUint32Safe(b)
+	if err != nil {
+		return err
+	}
+	*str, b, err = unmarshalStringSafe(b)
+	return err
+}
+
+type sshFxpReaddirPacket struct {
+	ID     uint32
+	Handle string
+}
+
+func (p sshFxpReaddirPacket) id() uint32 { return p.ID }
+
+func (p sshFxpReaddirPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_READDIR, p.ID, p.Handle)
+}
+
+func (p *sshFxpReaddirPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Handle)
+}
+
+type sshFxpOpendirPacket struct {
+	ID   uint32
+	Path string
+}
+
+func (p sshFxpOpendirPacket) id() uint32 { return p.ID }
+
+func (p sshFxpOpendirPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_OPENDIR, p.ID, p.Path)
+}
+
+func (p *sshFxpOpendirPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Path)
+}
+
+type sshFxpLstatPacket struct {
+	ID   uint32
+	Path string
+}
+
+func (p sshFxpLstatPacket) id() uint32 { return p.ID }
+
+func (p sshFxpLstatPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_LSTAT, p.ID, p.Path)
+}
+
+func (p *sshFxpLstatPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Path)
+}
+
+type sshFxpStatPacket struct {
+	ID   uint32
+	Path string
+}
+
+func (p sshFxpStatPacket) id() uint32 { return p.ID }
+
+func (p sshFxpStatPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_STAT, p.ID, p.Path)
+}
+
+func (p *sshFxpStatPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Path)
+}
+
+type sshFxpFstatPacket struct {
+	ID     uint32
+	Handle string
+}
+
+func (p sshFxpFstatPacket) id() uint32 { return p.ID }
+
+func (p sshFxpFstatPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_FSTAT, p.ID, p.Handle)
+}
+
+func (p *sshFxpFstatPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Handle)
+}
+
+type sshFxpClosePacket struct {
+	ID     uint32
+	Handle string
+}
+
+func (p sshFxpClosePacket) id() uint32 { return p.ID }
+
+func (p sshFxpClosePacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_CLOSE, p.ID, p.Handle)
+}
+
+func (p *sshFxpClosePacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Handle)
+}
+
+type sshFxpRemovePacket struct {
+	ID       uint32
+	Filename string
+}
+
+func (p sshFxpRemovePacket) id() uint32 { return p.ID }
+
+func (p sshFxpRemovePacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_REMOVE, p.ID, p.Filename)
+}
+
+func (p *sshFxpRemovePacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Filename)
+}
+
+type sshFxpRmdirPacket struct {
+	ID   uint32
+	Path string
+}
+
+func (p sshFxpRmdirPacket) id() uint32 { return p.ID }
+
+func (p sshFxpRmdirPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_RMDIR, p.ID, p.Path)
+}
+
+func (p *sshFxpRmdirPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Path)
+}
+
+type sshFxpSymlinkPacket struct {
+	ID         uint32
+	Targetpath string
+	Linkpath   string
+}
+
+func (p sshFxpSymlinkPacket) id() uint32 { return p.ID }
+
+func (p sshFxpSymlinkPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(p.Targetpath) +
+		4 + len(p.Linkpath)
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_SYMLINK)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Targetpath)
+	b = marshalString(b, p.Linkpath)
+	return b, nil
+}
+
+func (p *sshFxpSymlinkPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Targetpath, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Linkpath, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+type sshFxpReadlinkPacket struct {
+	ID   uint32
+	Path string
+}
+
+func (p sshFxpReadlinkPacket) id() uint32 { return p.ID }
+
+func (p sshFxpReadlinkPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_READLINK, p.ID, p.Path)
+}
+
+func (p *sshFxpReadlinkPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Path)
+}
+
+type sshFxpRealpathPacket struct {
+	ID   uint32
+	Path string
+}
+
+func (p sshFxpRealpathPacket) id() uint32 { return p.ID }
+
+func (p sshFxpRealpathPacket) MarshalBinary() ([]byte, error) {
+	return marshalIDString(ssh_FXP_REALPATH, p.ID, p.Path)
+}
+
+func (p *sshFxpRealpathPacket) UnmarshalBinary(b []byte) error {
+	return unmarshalIDString(b, &p.ID, &p.Path)
+}
+
+type sshFxpNameAttr struct {
+	Name     string
+	LongName string
+	Attrs    []interface{}
+}
+
+func (p sshFxpNameAttr) MarshalBinary() ([]byte, error) {
+	b := []byte{}
+	b = marshalString(b, p.Name)
+	b = marshalString(b, p.LongName)
+	for _, attr := range p.Attrs {
+		b = marshal(b, attr)
+	}
+	return b, nil
+}
+
+type sshFxpNamePacket struct {
+	ID        uint32
+	NameAttrs []sshFxpNameAttr
+}
+
+func (p sshFxpNamePacket) MarshalBinary() ([]byte, error) {
+	b := []byte{}
+	b = append(b, ssh_FXP_NAME)
+	b = marshalUint32(b, p.ID)
+	b = marshalUint32(b, uint32(len(p.NameAttrs)))
+	for _, na := range p.NameAttrs {
+		ab, err := na.MarshalBinary()
+		if err != nil {
+			return nil, err
+		}
+
+		b = append(b, ab...)
+	}
+	return b, nil
+}
+
+type sshFxpOpenPacket struct {
+	ID     uint32
+	Path   string
+	Pflags uint32
+	Flags  uint32 // ignored
+}
+
+func (p sshFxpOpenPacket) id() uint32 { return p.ID }
+
+func (p sshFxpOpenPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 +
+		4 + len(p.Path) +
+		4 + 4
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_OPEN)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Path)
+	b = marshalUint32(b, p.Pflags)
+	b = marshalUint32(b, p.Flags)
+	return b, nil
+}
+
+func (p *sshFxpOpenPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Path, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Pflags, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Flags, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+type sshFxpReadPacket struct {
+	ID     uint32
+	Handle string
+	Offset uint64
+	Len    uint32
+}
+
+func (p sshFxpReadPacket) id() uint32 { return p.ID }
+
+func (p sshFxpReadPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(p.Handle) +
+		8 + 4 // uint64 + uint32
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_READ)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Handle)
+	b = marshalUint64(b, p.Offset)
+	b = marshalUint32(b, p.Len)
+	return b, nil
+}
+
+func (p *sshFxpReadPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Handle, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Offset, b, err = unmarshalUint64Safe(b); err != nil {
+		return err
+	} else if p.Len, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+type sshFxpRenamePacket struct {
+	ID      uint32
+	Oldpath string
+	Newpath string
+}
+
+func (p sshFxpRenamePacket) id() uint32 { return p.ID }
+
+func (p sshFxpRenamePacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(p.Oldpath) +
+		4 + len(p.Newpath)
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_RENAME)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Oldpath)
+	b = marshalString(b, p.Newpath)
+	return b, nil
+}
+
+func (p *sshFxpRenamePacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Oldpath, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Newpath, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+type sshFxpWritePacket struct {
+	ID     uint32
+	Handle string
+	Offset uint64
+	Length uint32
+	Data   []byte
+}
+
+func (p sshFxpWritePacket) id() uint32 { return p.ID }
+
+func (p sshFxpWritePacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(p.Handle) +
+		8 + 4 + // uint64 + uint32
+		len(p.Data)
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_WRITE)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Handle)
+	b = marshalUint64(b, p.Offset)
+	b = marshalUint32(b, p.Length)
+	b = append(b, p.Data...)
+	return b, nil
+}
+
+func (p *sshFxpWritePacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Handle, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Offset, b, err = unmarshalUint64Safe(b); err != nil {
+		return err
+	} else if p.Length, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if uint32(len(b)) < p.Length {
+		return errShortPacket
+	}
+
+	p.Data = append([]byte{}, b[:p.Length]...)
+	return nil
+}
+
+type sshFxpMkdirPacket struct {
+	ID    uint32
+	Path  string
+	Flags uint32 // ignored
+}
+
+func (p sshFxpMkdirPacket) id() uint32 { return p.ID }
+
+func (p sshFxpMkdirPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(p.Path) +
+		4 // uint32
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_MKDIR)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Path)
+	b = marshalUint32(b, p.Flags)
+	return b, nil
+}
+
+func (p *sshFxpMkdirPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Path, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Flags, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+type sshFxpSetstatPacket struct {
+	ID    uint32
+	Path  string
+	Flags uint32
+	Attrs interface{}
+}
+
+type sshFxpFsetstatPacket struct {
+	ID     uint32
+	Handle string
+	Flags  uint32
+	Attrs  interface{}
+}
+
+func (p sshFxpSetstatPacket) id() uint32  { return p.ID }
+func (p sshFxpFsetstatPacket) id() uint32 { return p.ID }
+
+func (p sshFxpSetstatPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(p.Path) +
+		4 // uint32 + uint64
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_SETSTAT)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Path)
+	b = marshalUint32(b, p.Flags)
+	b = marshal(b, p.Attrs)
+	return b, nil
+}
+
+func (p sshFxpFsetstatPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		4 + len(p.Handle) +
+		4 // uint32 + uint64
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_FSETSTAT)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Handle)
+	b = marshalUint32(b, p.Flags)
+	b = marshal(b, p.Attrs)
+	return b, nil
+}
+
+func (p *sshFxpSetstatPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Path, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Flags, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	}
+	p.Attrs = b
+	return nil
+}
+
+func (p *sshFxpFsetstatPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Handle, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Flags, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	}
+	p.Attrs = b
+	return nil
+}
+
+type sshFxpHandlePacket struct {
+	ID     uint32
+	Handle string
+}
+
+func (p sshFxpHandlePacket) MarshalBinary() ([]byte, error) {
+	b := []byte{ssh_FXP_HANDLE}
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, p.Handle)
+	return b, nil
+}
+
+type sshFxpStatusPacket struct {
+	ID uint32
+	StatusError
+}
+
+func (p sshFxpStatusPacket) MarshalBinary() ([]byte, error) {
+	b := []byte{ssh_FXP_STATUS}
+	b = marshalUint32(b, p.ID)
+	b = marshalStatus(b, p.StatusError)
+	return b, nil
+}
+
+type sshFxpDataPacket struct {
+	ID     uint32
+	Length uint32
+	Data   []byte
+}
+
+func (p sshFxpDataPacket) MarshalBinary() ([]byte, error) {
+	b := []byte{ssh_FXP_DATA}
+	b = marshalUint32(b, p.ID)
+	b = marshalUint32(b, p.Length)
+	b = append(b, p.Data[:p.Length]...)
+	return b, nil
+}
+
+func (p *sshFxpDataPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.Length, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if uint32(len(b)) < p.Length {
+		return errors.New("truncated packet")
+	}
+
+	p.Data = make([]byte, p.Length)
+	copy(p.Data, b)
+	return nil
+}
+
+type sshFxpStatvfsPacket struct {
+	ID   uint32
+	Path string
+}
+
+func (p sshFxpStatvfsPacket) id() uint32 { return p.ID }
+
+func (p sshFxpStatvfsPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		len(p.Path) +
+		len("statvfs@openssh.com")
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_EXTENDED)
+	b = marshalUint32(b, p.ID)
+	b = marshalString(b, "statvfs@openssh.com")
+	b = marshalString(b, p.Path)
+	return b, nil
+}
+
+// A StatVFS contains statistics about a filesystem.
+type StatVFS struct {
+	ID      uint32
+	Bsize   uint64 /* file system block size */
+	Frsize  uint64 /* fundamental fs block size */
+	Blocks  uint64 /* number of blocks (unit f_frsize) */
+	Bfree   uint64 /* free blocks in file system */
+	Bavail  uint64 /* free blocks for non-root */
+	Files   uint64 /* total file inodes */
+	Ffree   uint64 /* free file inodes */
+	Favail  uint64 /* free file inodes for to non-root */
+	Fsid    uint64 /* file system id */
+	Flag    uint64 /* bit mask of f_flag values */
+	Namemax uint64 /* maximum filename length */
+}
+
+// TotalSpace calculates the amount of total space in a filesystem.
+func (p *StatVFS) TotalSpace() uint64 {
+	return p.Frsize * p.Blocks
+}
+
+// FreeSpace calculates the amount of free space in a filesystem.
+func (p *StatVFS) FreeSpace() uint64 {
+	return p.Frsize * p.Bfree
+}
+
+// Convert to ssh_FXP_EXTENDED_REPLY packet binary format
+func (p *StatVFS) MarshalBinary() ([]byte, error) {
+	var buf bytes.Buffer
+	buf.Write([]byte{ssh_FXP_EXTENDED_REPLY})
+	err := binary.Write(&buf, binary.BigEndian, p)
+	return buf.Bytes(), err
+}
+
+type sshFxpExtendedPacket struct {
+	ID              uint32
+	ExtendedRequest string
+	SpecificPacket  interface {
+		serverRespondablePacket
+		readonly() bool
+	}
+}
+
+func (p sshFxpExtendedPacket) id() uint32     { return p.ID }
+func (p sshFxpExtendedPacket) readonly() bool { return p.SpecificPacket.readonly() }
+
+func (p sshFxpExtendedPacket) respond(svr *Server) error {
+	return p.SpecificPacket.respond(svr)
+}
+
+func (p *sshFxpExtendedPacket) UnmarshalBinary(b []byte) error {
+	var err error
+	bOrig := b
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.ExtendedRequest, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	}
+
+	// specific unmarshalling
+	switch p.ExtendedRequest {
+	case "statvfs@openssh.com":
+		p.SpecificPacket = &sshFxpExtendedPacketStatVFS{}
+	default:
+		return errUnknownExtendedPacket
+	}
+
+	return p.SpecificPacket.UnmarshalBinary(bOrig)
+}
+
+type sshFxpExtendedPacketStatVFS struct {
+	ID              uint32
+	ExtendedRequest string
+	Path            string
+}
+
+func (p sshFxpExtendedPacketStatVFS) id() uint32     { return p.ID }
+func (p sshFxpExtendedPacketStatVFS) readonly() bool { return true }
+func (p *sshFxpExtendedPacketStatVFS) UnmarshalBinary(b []byte) error {
+	var err error
+	if p.ID, b, err = unmarshalUint32Safe(b); err != nil {
+		return err
+	} else if p.ExtendedRequest, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	} else if p.Path, b, err = unmarshalStringSafe(b); err != nil {
+		return err
+	}
+	return nil
+}

vendor/github.com/pkg/sftp/release.go

@@ -0,0 +1,5 @@
+// +build !debug
+
+package sftp
+
+func debug(fmt string, args ...interface{}) {}

vendor/github.com/pkg/sftp/server.go

@@ -0,0 +1,607 @@
+package sftp
+
+// sftp server counterpart
+
+import (
+	"encoding"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"sync"
+	"syscall"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	sftpServerWorkerCount = 8
+)
+
+// Server is an SSH File Transfer Protocol (sftp) server.
+// This is intended to provide the sftp subsystem to an ssh server daemon.
+// This implementation currently supports most of sftp server protocol version 3,
+// as specified at http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02
+type Server struct {
+	serverConn
+	debugStream   io.Writer
+	readOnly      bool
+	pktChan       chan rxPacket
+	openFiles     map[string]*os.File
+	openFilesLock sync.RWMutex
+	handleCount   int
+	maxTxPacket   uint32
+}
+
+func (svr *Server) nextHandle(f *os.File) string {
+	svr.openFilesLock.Lock()
+	defer svr.openFilesLock.Unlock()
+	svr.handleCount++
+	handle := strconv.Itoa(svr.handleCount)
+	svr.openFiles[handle] = f
+	return handle
+}
+
+func (svr *Server) closeHandle(handle string) error {
+	svr.openFilesLock.Lock()
+	defer svr.openFilesLock.Unlock()
+	if f, ok := svr.openFiles[handle]; ok {
+		delete(svr.openFiles, handle)
+		return f.Close()
+	}
+
+	return syscall.EBADF
+}
+
+func (svr *Server) getHandle(handle string) (*os.File, bool) {
+	svr.openFilesLock.RLock()
+	defer svr.openFilesLock.RUnlock()
+	f, ok := svr.openFiles[handle]
+	return f, ok
+}
+
+type serverRespondablePacket interface {
+	encoding.BinaryUnmarshaler
+	id() uint32
+	respond(svr *Server) error
+}
+
+// NewServer creates a new Server instance around the provided streams, serving
+// content from the root of the filesystem.  Optionally, ServerOption
+// functions may be specified to further configure the Server.
+//
+// A subsequent call to Serve() is required to begin serving files over SFTP.
+func NewServer(rwc io.ReadWriteCloser, options ...ServerOption) (*Server, error) {
+	s := &Server{
+		serverConn: serverConn{
+			conn: conn{
+				Reader:      rwc,
+				WriteCloser: rwc,
+			},
+		},
+		debugStream: ioutil.Discard,
+		pktChan:     make(chan rxPacket, sftpServerWorkerCount),
+		openFiles:   make(map[string]*os.File),
+		maxTxPacket: 1 << 15,
+	}
+
+	for _, o := range options {
+		if err := o(s); err != nil {
+			return nil, err
+		}
+	}
+
+	return s, nil
+}
+
+// A ServerOption is a function which applies configuration to a Server.
+type ServerOption func(*Server) error
+
+// WithDebug enables Server debugging output to the supplied io.Writer.
+func WithDebug(w io.Writer) ServerOption {
+	return func(s *Server) error {
+		s.debugStream = w
+		return nil
+	}
+}
+
+// ReadOnly configures a Server to serve files in read-only mode.
+func ReadOnly() ServerOption {
+	return func(s *Server) error {
+		s.readOnly = true
+		return nil
+	}
+}
+
+type rxPacket struct {
+	pktType  fxp
+	pktBytes []byte
+}
+
+// Up to N parallel servers
+func (svr *Server) sftpServerWorker() error {
+	for p := range svr.pktChan {
+		var pkt interface {
+			encoding.BinaryUnmarshaler
+			id() uint32
+		}
+		var readonly = true
+		switch p.pktType {
+		case ssh_FXP_INIT:
+			pkt = &sshFxInitPacket{}
+		case ssh_FXP_LSTAT:
+			pkt = &sshFxpLstatPacket{}
+		case ssh_FXP_OPEN:
+			pkt = &sshFxpOpenPacket{}
+			// readonly handled specially below
+		case ssh_FXP_CLOSE:
+			pkt = &sshFxpClosePacket{}
+		case ssh_FXP_READ:
+			pkt = &sshFxpReadPacket{}
+		case ssh_FXP_WRITE:
+			pkt = &sshFxpWritePacket{}
+			readonly = false
+		case ssh_FXP_FSTAT:
+			pkt = &sshFxpFstatPacket{}
+		case ssh_FXP_SETSTAT:
+			pkt = &sshFxpSetstatPacket{}
+			readonly = false
+		case ssh_FXP_FSETSTAT:
+			pkt = &sshFxpFsetstatPacket{}
+			readonly = false
+		case ssh_FXP_OPENDIR:
+			pkt = &sshFxpOpendirPacket{}
+		case ssh_FXP_READDIR:
+			pkt = &sshFxpReaddirPacket{}
+		case ssh_FXP_REMOVE:
+			pkt = &sshFxpRemovePacket{}
+			readonly = false
+		case ssh_FXP_MKDIR:
+			pkt = &sshFxpMkdirPacket{}
+			readonly = false
+		case ssh_FXP_RMDIR:
+			pkt = &sshFxpRmdirPacket{}
+			readonly = false
+		case ssh_FXP_REALPATH:
+			pkt = &sshFxpRealpathPacket{}
+		case ssh_FXP_STAT:
+			pkt = &sshFxpStatPacket{}
+		case ssh_FXP_RENAME:
+			pkt = &sshFxpRenamePacket{}
+			readonly = false
+		case ssh_FXP_READLINK:
+			pkt = &sshFxpReadlinkPacket{}
+		case ssh_FXP_SYMLINK:
+			pkt = &sshFxpSymlinkPacket{}
+			readonly = false
+		case ssh_FXP_EXTENDED:
+			pkt = &sshFxpExtendedPacket{}
+		default:
+			return errors.Errorf("unhandled packet type: %s", p.pktType)
+		}
+		if err := pkt.UnmarshalBinary(p.pktBytes); err != nil {
+			return err
+		}
+
+		// handle FXP_OPENDIR specially
+		switch pkt := pkt.(type) {
+		case *sshFxpOpenPacket:
+			readonly = pkt.readonly()
+		case *sshFxpExtendedPacket:
+			readonly = pkt.SpecificPacket.readonly()
+		}
+
+		// If server is operating read-only and a write operation is requested,
+		// return permission denied
+		if !readonly && svr.readOnly {
+			if err := svr.sendError(pkt, syscall.EPERM); err != nil {
+				return errors.Wrap(err, "failed to send read only packet response")
+			}
+			continue
+		}
+
+		if err := handlePacket(svr, pkt); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func handlePacket(s *Server, p interface{}) error {
+	switch p := p.(type) {
+	case *sshFxInitPacket:
+		return s.sendPacket(sshFxVersionPacket{sftpProtocolVersion, nil})
+	case *sshFxpStatPacket:
+		// stat the requested file
+		info, err := os.Stat(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+		return s.sendPacket(sshFxpStatResponse{
+			ID:   p.ID,
+			info: info,
+		})
+	case *sshFxpLstatPacket:
+		// stat the requested file
+		info, err := os.Lstat(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+		return s.sendPacket(sshFxpStatResponse{
+			ID:   p.ID,
+			info: info,
+		})
+	case *sshFxpFstatPacket:
+		f, ok := s.getHandle(p.Handle)
+		if !ok {
+			return s.sendError(p, syscall.EBADF)
+		}
+
+		info, err := f.Stat()
+		if err != nil {
+			return s.sendError(p, err)
+		}
+
+		return s.sendPacket(sshFxpStatResponse{
+			ID:   p.ID,
+			info: info,
+		})
+	case *sshFxpMkdirPacket:
+		// TODO FIXME: ignore flags field
+		err := os.Mkdir(p.Path, 0755)
+		return s.sendError(p, err)
+	case *sshFxpRmdirPacket:
+		err := os.Remove(p.Path)
+		return s.sendError(p, err)
+	case *sshFxpRemovePacket:
+		err := os.Remove(p.Filename)
+		return s.sendError(p, err)
+	case *sshFxpRenamePacket:
+		err := os.Rename(p.Oldpath, p.Newpath)
+		return s.sendError(p, err)
+	case *sshFxpSymlinkPacket:
+		err := os.Symlink(p.Targetpath, p.Linkpath)
+		return s.sendError(p, err)
+	case *sshFxpClosePacket:
+		return s.sendError(p, s.closeHandle(p.Handle))
+	case *sshFxpReadlinkPacket:
+		f, err := os.Readlink(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+
+		return s.sendPacket(sshFxpNamePacket{
+			ID: p.ID,
+			NameAttrs: []sshFxpNameAttr{{
+				Name:     f,
+				LongName: f,
+				Attrs:    emptyFileStat,
+			}},
+		})
+
+	case *sshFxpRealpathPacket:
+		f, err := filepath.Abs(p.Path)
+		if err != nil {
+			return s.sendError(p, err)
+		}
+		f = filepath.Clean(f)
+		return s.sendPacket(sshFxpNamePacket{
+			ID: p.ID,
+			NameAttrs: []sshFxpNameAttr{{
+				Name:     f,
+				LongName: f,
+				Attrs:    emptyFileStat,
+			}},
+		})
+	case *sshFxpOpendirPacket:
+		return sshFxpOpenPacket{
+			ID:     p.ID,
+			Path:   p.Path,
+			Pflags: ssh_FXF_READ,
+		}.respond(s)
+	case *sshFxpReadPacket:
+		f, ok := s.getHandle(p.Handle)
+		if !ok {
+			return s.sendError(p, syscall.EBADF)
+		}
+
+		data := make([]byte, clamp(p.Len, s.maxTxPacket))
+		n, err := f.ReadAt(data, int64(p.Offset))
+		if err != nil && (err != io.EOF || n == 0) {
+			return s.sendError(p, err)
+		}
+		return s.sendPacket(sshFxpDataPacket{
+			ID:     p.ID,
+			Length: uint32(n),
+			Data:   data[:n],
+		})
+	case *sshFxpWritePacket:
+		f, ok := s.getHandle(p.Handle)
+		if !ok {
+			return s.sendError(p, syscall.EBADF)
+		}
+
+		_, err := f.WriteAt(p.Data, int64(p.Offset))
+		return s.sendError(p, err)
+	case serverRespondablePacket:
+		err := p.respond(s)
+		return errors.Wrap(err, "pkt.respond failed")
+	default:
+		return errors.Errorf("unexpected packet type %T", p)
+	}
+}
+
+// Serve serves SFTP connections until the streams stop or the SFTP subsystem
+// is stopped.
+func (svr *Server) Serve() error {
+	var wg sync.WaitGroup
+	wg.Add(sftpServerWorkerCount)
+	for i := 0; i < sftpServerWorkerCount; i++ {
+		go func() {
+			defer wg.Done()
+			if err := svr.sftpServerWorker(); err != nil {
+				svr.conn.Close() // shuts down recvPacket
+			}
+		}()
+	}
+
+	var err error
+	var pktType uint8
+	var pktBytes []byte
+	for {
+		pktType, pktBytes, err = svr.recvPacket()
+		if err != nil {
+			break
+		}
+		svr.pktChan <- rxPacket{fxp(pktType), pktBytes}
+	}
+
+	close(svr.pktChan) // shuts down sftpServerWorkers
+	wg.Wait()          // wait for all workers to exit
+
+	// close any still-open files
+	for handle, file := range svr.openFiles {
+		fmt.Fprintf(svr.debugStream, "sftp server file with handle %q left open: %v\n", handle, file.Name())
+		file.Close()
+	}
+	return err // error from recvPacket
+}
+
+type id interface {
+	id() uint32
+}
+
+// The init packet has no ID, so we just return a zero-value ID
+func (p sshFxInitPacket) id() uint32 { return 0 }
+
+type sshFxpStatResponse struct {
+	ID   uint32
+	info os.FileInfo
+}
+
+func (p sshFxpStatResponse) MarshalBinary() ([]byte, error) {
+	b := []byte{ssh_FXP_ATTRS}
+	b = marshalUint32(b, p.ID)
+	b = marshalFileInfo(b, p.info)
+	return b, nil
+}
+
+var emptyFileStat = []interface{}{uint32(0)}
+
+func (p sshFxpOpenPacket) readonly() bool {
+	return !p.hasPflags(ssh_FXF_WRITE)
+}
+
+func (p sshFxpOpenPacket) hasPflags(flags ...uint32) bool {
+	for _, f := range flags {
+		if p.Pflags&f == 0 {
+			return false
+		}
+	}
+	return true
+}
+
+func (p sshFxpOpenPacket) respond(svr *Server) error {
+	var osFlags int
+	if p.hasPflags(ssh_FXF_READ, ssh_FXF_WRITE) {
+		osFlags |= os.O_RDWR
+	} else if p.hasPflags(ssh_FXF_WRITE) {
+		osFlags |= os.O_WRONLY
+	} else if p.hasPflags(ssh_FXF_READ) {
+		osFlags |= os.O_RDONLY
+	} else {
+		// how are they opening?
+		return svr.sendError(p, syscall.EINVAL)
+	}
+
+	if p.hasPflags(ssh_FXF_APPEND) {
+		osFlags |= os.O_APPEND
+	}
+	if p.hasPflags(ssh_FXF_CREAT) {
+		osFlags |= os.O_CREATE
+	}
+	if p.hasPflags(ssh_FXF_TRUNC) {
+		osFlags |= os.O_TRUNC
+	}
+	if p.hasPflags(ssh_FXF_EXCL) {
+		osFlags |= os.O_EXCL
+	}
+
+	f, err := os.OpenFile(p.Path, osFlags, 0644)
+	if err != nil {
+		return svr.sendError(p, err)
+	}
+
+	handle := svr.nextHandle(f)
+	return svr.sendPacket(sshFxpHandlePacket{p.ID, handle})
+}
+
+func (p sshFxpReaddirPacket) respond(svr *Server) error {
+	f, ok := svr.getHandle(p.Handle)
+	if !ok {
+		return svr.sendError(p, syscall.EBADF)
+	}
+
+	dirname := f.Name()
+	dirents, err := f.Readdir(128)
+	if err != nil {
+		return svr.sendError(p, err)
+	}
+
+	ret := sshFxpNamePacket{ID: p.ID}
+	for _, dirent := range dirents {
+		ret.NameAttrs = append(ret.NameAttrs, sshFxpNameAttr{
+			Name:     dirent.Name(),
+			LongName: runLs(dirname, dirent),
+			Attrs:    []interface{}{dirent},
+		})
+	}
+	return svr.sendPacket(ret)
+}
+
+func (p sshFxpSetstatPacket) respond(svr *Server) error {
+	// additional unmarshalling is required for each possibility here
+	b := p.Attrs.([]byte)
+	var err error
+
+	debug("setstat name \"%s\"", p.Path)
+	if (p.Flags & ssh_FILEXFER_ATTR_SIZE) != 0 {
+		var size uint64
+		if size, b, err = unmarshalUint64Safe(b); err == nil {
+			err = os.Truncate(p.Path, int64(size))
+		}
+	}
+	if (p.Flags & ssh_FILEXFER_ATTR_PERMISSIONS) != 0 {
+		var mode uint32
+		if mode, b, err = unmarshalUint32Safe(b); err == nil {
+			err = os.Chmod(p.Path, os.FileMode(mode))
+		}
+	}
+	if (p.Flags & ssh_FILEXFER_ATTR_ACMODTIME) != 0 {
+		var atime uint32
+		var mtime uint32
+		if atime, b, err = unmarshalUint32Safe(b); err != nil {
+		} else if mtime, b, err = unmarshalUint32Safe(b); err != nil {
+		} else {
+			atimeT := time.Unix(int64(atime), 0)
+			mtimeT := time.Unix(int64(mtime), 0)
+			err = os.Chtimes(p.Path, atimeT, mtimeT)
+		}
+	}
+	if (p.Flags & ssh_FILEXFER_ATTR_UIDGID) != 0 {
+		var uid uint32
+		var gid uint32
+		if uid, b, err = unmarshalUint32Safe(b); err != nil {
+		} else if gid, b, err = unmarshalUint32Safe(b); err != nil {
+		} else {
+			err = os.Chown(p.Path, int(uid), int(gid))
+		}
+	}
+
+	return svr.sendError(p, err)
+}
+
+func (p sshFxpFsetstatPacket) respond(svr *Server) error {
+	f, ok := svr.getHandle(p.Handle)
+	if !ok {
+		return svr.sendError(p, syscall.EBADF)
+	}
+
+	// additional unmarshalling is required for each possibility here
+	b := p.Attrs.([]byte)
+	var err error
+
+	debug("fsetstat name \"%s\"", f.Name())
+	if (p.Flags & ssh_FILEXFER_ATTR_SIZE) != 0 {
+		var size uint64
+		if size, b, err = unmarshalUint64Safe(b); err == nil {
+			err = f.Truncate(int64(size))
+		}
+	}
+	if (p.Flags & ssh_FILEXFER_ATTR_PERMISSIONS) != 0 {
+		var mode uint32
+		if mode, b, err = unmarshalUint32Safe(b); err == nil {
+			err = f.Chmod(os.FileMode(mode))
+		}
+	}
+	if (p.Flags & ssh_FILEXFER_ATTR_ACMODTIME) != 0 {
+		var atime uint32
+		var mtime uint32
+		if atime, b, err = unmarshalUint32Safe(b); err != nil {
+		} else if mtime, b, err = unmarshalUint32Safe(b); err != nil {
+		} else {
+			atimeT := time.Unix(int64(atime), 0)
+			mtimeT := time.Unix(int64(mtime), 0)
+			err = os.Chtimes(f.Name(), atimeT, mtimeT)
+		}
+	}
+	if (p.Flags & ssh_FILEXFER_ATTR_UIDGID) != 0 {
+		var uid uint32
+		var gid uint32
+		if uid, b, err = unmarshalUint32Safe(b); err != nil {
+		} else if gid, b, err = unmarshalUint32Safe(b); err != nil {
+		} else {
+			err = f.Chown(int(uid), int(gid))
+		}
+	}
+
+	return svr.sendError(p, err)
+}
+
+// translateErrno translates a syscall error number to a SFTP error code.
+func translateErrno(errno syscall.Errno) uint32 {
+	switch errno {
+	case 0:
+		return ssh_FX_OK
+	case syscall.ENOENT:
+		return ssh_FX_NO_SUCH_FILE
+	case syscall.EPERM:
+		return ssh_FX_PERMISSION_DENIED
+	}
+
+	return ssh_FX_FAILURE
+}
+
+func statusFromError(p id, err error) sshFxpStatusPacket {
+	ret := sshFxpStatusPacket{
+		ID: p.id(),
+		StatusError: StatusError{
+			// ssh_FX_OK                = 0
+			// ssh_FX_EOF               = 1
+			// ssh_FX_NO_SUCH_FILE      = 2 ENOENT
+			// ssh_FX_PERMISSION_DENIED = 3
+			// ssh_FX_FAILURE           = 4
+			// ssh_FX_BAD_MESSAGE       = 5
+			// ssh_FX_NO_CONNECTION     = 6
+			// ssh_FX_CONNECTION_LOST   = 7
+			// ssh_FX_OP_UNSUPPORTED    = 8
+			Code: ssh_FX_OK,
+		},
+	}
+	if err != nil {
+		debug("statusFromError: error is %T %#v", err, err)
+		ret.StatusError.Code = ssh_FX_FAILURE
+		ret.StatusError.msg = err.Error()
+		if err == io.EOF {
+			ret.StatusError.Code = ssh_FX_EOF
+		} else if errno, ok := err.(syscall.Errno); ok {
+			ret.StatusError.Code = translateErrno(errno)
+		} else if pathError, ok := err.(*os.PathError); ok {
+			debug("statusFromError: error is %T %#v", pathError.Err, pathError.Err)
+			if errno, ok := pathError.Err.(syscall.Errno); ok {
+				ret.StatusError.Code = translateErrno(errno)
+			}
+		}
+	}
+	return ret
+}
+
+func clamp(v, max uint32) uint32 {
+	if v > max {
+		return max
+	}
+	return v
+}

vendor/github.com/pkg/sftp/server_statvfs_darwin.go

@@ -0,0 +1,21 @@
+package sftp
+
+import (
+	"syscall"
+)
+
+func statvfsFromStatfst(stat *syscall.Statfs_t) (*StatVFS, error) {
+	return &StatVFS{
+		Bsize:   uint64(stat.Bsize),
+		Frsize:  uint64(stat.Bsize), // fragment size is a linux thing; use block size here
+		Blocks:  stat.Blocks,
+		Bfree:   stat.Bfree,
+		Bavail:  stat.Bavail,
+		Files:   stat.Files,
+		Ffree:   stat.Ffree,
+		Favail:  stat.Ffree,                                                      // not sure how to calculate Favail
+		Fsid:    uint64(uint64(stat.Fsid.Val[1])<<32 | uint64(stat.Fsid.Val[0])), // endianness?
+		Flag:    uint64(stat.Flags),                                              // assuming POSIX?
+		Namemax: 1024,                                                            // man 2 statfs shows: #define MAXPATHLEN      1024
+	}, nil
+}

vendor/github.com/pkg/sftp/server_statvfs_impl.go

@@ -0,0 +1,25 @@
+// +build darwin linux,!gccgo
+
+// fill in statvfs structure with OS specific values
+// Statfs_t is different per-kernel, and only exists on some unixes (not Solaris for instance)
+
+package sftp
+
+import (
+	"syscall"
+)
+
+func (p sshFxpExtendedPacketStatVFS) respond(svr *Server) error {
+	stat := &syscall.Statfs_t{}
+	if err := syscall.Statfs(p.Path, stat); err != nil {
+		return svr.sendPacket(statusFromError(p, err))
+	}
+
+	retPkt, err := statvfsFromStatfst(stat)
+	if err != nil {
+		return svr.sendPacket(statusFromError(p, err))
+	}
+	retPkt.ID = p.ID
+
+	return svr.sendPacket(retPkt)
+}

vendor/github.com/pkg/sftp/server_statvfs_linux.go

@@ -0,0 +1,22 @@
+// +build !gccgo,linux
+
+package sftp
+
+import (
+	"syscall"
+)
+
+func statvfsFromStatfst(stat *syscall.Statfs_t) (*StatVFS, error) {
+	return &StatVFS{
+		Bsize:   uint64(stat.Bsize),
+		Frsize:  uint64(stat.Frsize),
+		Blocks:  stat.Blocks,
+		Bfree:   stat.Bfree,
+		Bavail:  stat.Bavail,
+		Files:   stat.Files,
+		Ffree:   stat.Ffree,
+		Favail:  stat.Ffree,         // not sure how to calculate Favail
+		Flag:    uint64(stat.Flags), // assuming POSIX?
+		Namemax: uint64(stat.Namelen),
+	}, nil
+}

vendor/github.com/pkg/sftp/server_statvfs_stubs.go

@@ -0,0 +1,11 @@
+// +build !darwin,!linux gccgo
+
+package sftp
+
+import (
+	"syscall"
+)
+
+func (p sshFxpExtendedPacketStatVFS) respond(svr *Server) error {
+	return syscall.ENOTSUP
+}

vendor/github.com/pkg/sftp/server_stubs.go

@@ -0,0 +1,12 @@
+// +build !cgo,!plan9 windows android
+
+package sftp
+
+import (
+	"os"
+	"path"
+)
+
+func runLs(dirname string, dirent os.FileInfo) string {
+	return path.Join(dirname, dirent.Name())
+}

vendor/github.com/pkg/sftp/server_unix.go

@@ -0,0 +1,143 @@
+// +build darwin dragonfly freebsd !android,linux netbsd openbsd solaris
+// +build cgo
+
+package sftp
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"syscall"
+	"time"
+)
+
+func runLsTypeWord(dirent os.FileInfo) string {
+	// find first character, the type char
+	// b     Block special file.
+	// c     Character special file.
+	// d     Directory.
+	// l     Symbolic link.
+	// s     Socket link.
+	// p     FIFO.
+	// -     Regular file.
+	tc := '-'
+	mode := dirent.Mode()
+	if (mode & os.ModeDir) != 0 {
+		tc = 'd'
+	} else if (mode & os.ModeDevice) != 0 {
+		tc = 'b'
+		if (mode & os.ModeCharDevice) != 0 {
+			tc = 'c'
+		}
+	} else if (mode & os.ModeSymlink) != 0 {
+		tc = 'l'
+	} else if (mode & os.ModeSocket) != 0 {
+		tc = 's'
+	} else if (mode & os.ModeNamedPipe) != 0 {
+		tc = 'p'
+	}
+
+	// owner
+	orc := '-'
+	if (mode & 0400) != 0 {
+		orc = 'r'
+	}
+	owc := '-'
+	if (mode & 0200) != 0 {
+		owc = 'w'
+	}
+	oxc := '-'
+	ox := (mode & 0100) != 0
+	setuid := (mode & os.ModeSetuid) != 0
+	if ox && setuid {
+		oxc = 's'
+	} else if setuid {
+		oxc = 'S'
+	} else if ox {
+		oxc = 'x'
+	}
+
+	// group
+	grc := '-'
+	if (mode & 040) != 0 {
+		grc = 'r'
+	}
+	gwc := '-'
+	if (mode & 020) != 0 {
+		gwc = 'w'
+	}
+	gxc := '-'
+	gx := (mode & 010) != 0
+	setgid := (mode & os.ModeSetgid) != 0
+	if gx && setgid {
+		gxc = 's'
+	} else if setgid {
+		gxc = 'S'
+	} else if gx {
+		gxc = 'x'
+	}
+
+	// all / others
+	arc := '-'
+	if (mode & 04) != 0 {
+		arc = 'r'
+	}
+	awc := '-'
+	if (mode & 02) != 0 {
+		awc = 'w'
+	}
+	axc := '-'
+	ax := (mode & 01) != 0
+	sticky := (mode & os.ModeSticky) != 0
+	if ax && sticky {
+		axc = 't'
+	} else if sticky {
+		axc = 'T'
+	} else if ax {
+		axc = 'x'
+	}
+
+	return fmt.Sprintf("%c%c%c%c%c%c%c%c%c%c", tc, orc, owc, oxc, grc, gwc, gxc, arc, awc, axc)
+}
+
+func runLsStatt(dirname string, dirent os.FileInfo, statt *syscall.Stat_t) string {
+	// example from openssh sftp server:
+	// crw-rw-rw-    1 root     wheel           0 Jul 31 20:52 ttyvd
+	// format:
+	// {directory / char device / etc}{rwxrwxrwx}  {number of links} owner group size month day [time (this year) | year (otherwise)] name
+
+	typeword := runLsTypeWord(dirent)
+	numLinks := statt.Nlink
+	uid := statt.Uid
+	gid := statt.Gid
+	username := fmt.Sprintf("%d", uid)
+	groupname := fmt.Sprintf("%d", gid)
+	// TODO FIXME: uid -> username, gid -> groupname lookup for ls -l format output
+
+	mtime := dirent.ModTime()
+	monthStr := mtime.Month().String()[0:3]
+	day := mtime.Day()
+	year := mtime.Year()
+	now := time.Now()
+	isOld := mtime.Before(now.Add(-time.Hour * 24 * 365 / 2))
+
+	yearOrTime := fmt.Sprintf("%02d:%02d", mtime.Hour(), mtime.Minute())
+	if isOld {
+		yearOrTime = fmt.Sprintf("%d", year)
+	}
+
+	return fmt.Sprintf("%s %4d %-8s %-8s %8d %s %2d %5s %s", typeword, numLinks, username, groupname, dirent.Size(), monthStr, day, yearOrTime, dirent.Name())
+}
+
+// ls -l style output for a file, which is in the 'long output' section of a readdir response packet
+// this is a very simple (lazy) implementation, just enough to look almost like openssh in a few basic cases
+func runLs(dirname string, dirent os.FileInfo) string {
+	dsys := dirent.Sys()
+	if dsys == nil {
+	} else if statt, ok := dsys.(*syscall.Stat_t); !ok {
+	} else {
+		return runLsStatt(dirname, dirent, statt)
+	}
+
+	return path.Join(dirname, dirent.Name())
+}

vendor/github.com/pkg/sftp/sftp.go

@@ -0,0 +1,217 @@
+// Package sftp implements the SSH File Transfer Protocol as described in
+// https://filezilla-project.org/specs/draft-ietf-secsh-filexfer-02.txt
+package sftp
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	ssh_FXP_INIT           = 1
+	ssh_FXP_VERSION        = 2
+	ssh_FXP_OPEN           = 3
+	ssh_FXP_CLOSE          = 4
+	ssh_FXP_READ           = 5
+	ssh_FXP_WRITE          = 6
+	ssh_FXP_LSTAT          = 7
+	ssh_FXP_FSTAT          = 8
+	ssh_FXP_SETSTAT        = 9
+	ssh_FXP_FSETSTAT       = 10
+	ssh_FXP_OPENDIR        = 11
+	ssh_FXP_READDIR        = 12
+	ssh_FXP_REMOVE         = 13
+	ssh_FXP_MKDIR          = 14
+	ssh_FXP_RMDIR          = 15
+	ssh_FXP_REALPATH       = 16
+	ssh_FXP_STAT           = 17
+	ssh_FXP_RENAME         = 18
+	ssh_FXP_READLINK       = 19
+	ssh_FXP_SYMLINK        = 20
+	ssh_FXP_STATUS         = 101
+	ssh_FXP_HANDLE         = 102
+	ssh_FXP_DATA           = 103
+	ssh_FXP_NAME           = 104
+	ssh_FXP_ATTRS          = 105
+	ssh_FXP_EXTENDED       = 200
+	ssh_FXP_EXTENDED_REPLY = 201
+)
+
+const (
+	ssh_FX_OK                = 0
+	ssh_FX_EOF               = 1
+	ssh_FX_NO_SUCH_FILE      = 2
+	ssh_FX_PERMISSION_DENIED = 3
+	ssh_FX_FAILURE           = 4
+	ssh_FX_BAD_MESSAGE       = 5
+	ssh_FX_NO_CONNECTION     = 6
+	ssh_FX_CONNECTION_LOST   = 7
+	ssh_FX_OP_UNSUPPORTED    = 8
+
+	// see draft-ietf-secsh-filexfer-13
+	// https://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-9.1
+	ssh_FX_INVALID_HANDLE              = 9
+	ssh_FX_NO_SUCH_PATH                = 10
+	ssh_FX_FILE_ALREADY_EXISTS         = 11
+	ssh_FX_WRITE_PROTECT               = 12
+	ssh_FX_NO_MEDIA                    = 13
+	ssh_FX_NO_SPACE_ON_FILESYSTEM      = 14
+	ssh_FX_QUOTA_EXCEEDED              = 15
+	ssh_FX_UNKNOWN_PRINCIPAL           = 16
+	ssh_FX_LOCK_CONFLICT               = 17
+	ssh_FX_DIR_NOT_EMPTY               = 18
+	ssh_FX_NOT_A_DIRECTORY             = 19
+	ssh_FX_INVALID_FILENAME            = 20
+	ssh_FX_LINK_LOOP                   = 21
+	ssh_FX_CANNOT_DELETE               = 22
+	ssh_FX_INVALID_PARAMETER           = 23
+	ssh_FX_FILE_IS_A_DIRECTORY         = 24
+	ssh_FX_BYTE_RANGE_LOCK_CONFLICT    = 25
+	ssh_FX_BYTE_RANGE_LOCK_REFUSED     = 26
+	ssh_FX_DELETE_PENDING              = 27
+	ssh_FX_FILE_CORRUPT                = 28
+	ssh_FX_OWNER_INVALID               = 29
+	ssh_FX_GROUP_INVALID               = 30
+	ssh_FX_NO_MATCHING_BYTE_RANGE_LOCK = 31
+)
+
+const (
+	ssh_FXF_READ   = 0x00000001
+	ssh_FXF_WRITE  = 0x00000002
+	ssh_FXF_APPEND = 0x00000004
+	ssh_FXF_CREAT  = 0x00000008
+	ssh_FXF_TRUNC  = 0x00000010
+	ssh_FXF_EXCL   = 0x00000020
+)
+
+type fxp uint8
+
+func (f fxp) String() string {
+	switch f {
+	case ssh_FXP_INIT:
+		return "SSH_FXP_INIT"
+	case ssh_FXP_VERSION:
+		return "SSH_FXP_VERSION"
+	case ssh_FXP_OPEN:
+		return "SSH_FXP_OPEN"
+	case ssh_FXP_CLOSE:
+		return "SSH_FXP_CLOSE"
+	case ssh_FXP_READ:
+		return "SSH_FXP_READ"
+	case ssh_FXP_WRITE:
+		return "SSH_FXP_WRITE"
+	case ssh_FXP_LSTAT:
+		return "SSH_FXP_LSTAT"
+	case ssh_FXP_FSTAT:
+		return "SSH_FXP_FSTAT"
+	case ssh_FXP_SETSTAT:
+		return "SSH_FXP_SETSTAT"
+	case ssh_FXP_FSETSTAT:
+		return "SSH_FXP_FSETSTAT"
+	case ssh_FXP_OPENDIR:
+		return "SSH_FXP_OPENDIR"
+	case ssh_FXP_READDIR:
+		return "SSH_FXP_READDIR"
+	case ssh_FXP_REMOVE:
+		return "SSH_FXP_REMOVE"
+	case ssh_FXP_MKDIR:
+		return "SSH_FXP_MKDIR"
+	case ssh_FXP_RMDIR:
+		return "SSH_FXP_RMDIR"
+	case ssh_FXP_REALPATH:
+		return "SSH_FXP_REALPATH"
+	case ssh_FXP_STAT:
+		return "SSH_FXP_STAT"
+	case ssh_FXP_RENAME:
+		return "SSH_FXP_RENAME"
+	case ssh_FXP_READLINK:
+		return "SSH_FXP_READLINK"
+	case ssh_FXP_SYMLINK:
+		return "SSH_FXP_SYMLINK"
+	case ssh_FXP_STATUS:
+		return "SSH_FXP_STATUS"
+	case ssh_FXP_HANDLE:
+		return "SSH_FXP_HANDLE"
+	case ssh_FXP_DATA:
+		return "SSH_FXP_DATA"
+	case ssh_FXP_NAME:
+		return "SSH_FXP_NAME"
+	case ssh_FXP_ATTRS:
+		return "SSH_FXP_ATTRS"
+	case ssh_FXP_EXTENDED:
+		return "SSH_FXP_EXTENDED"
+	case ssh_FXP_EXTENDED_REPLY:
+		return "SSH_FXP_EXTENDED_REPLY"
+	default:
+		return "unknown"
+	}
+}
+
+type fx uint8
+
+func (f fx) String() string {
+	switch f {
+	case ssh_FX_OK:
+		return "SSH_FX_OK"
+	case ssh_FX_EOF:
+		return "SSH_FX_EOF"
+	case ssh_FX_NO_SUCH_FILE:
+		return "SSH_FX_NO_SUCH_FILE"
+	case ssh_FX_PERMISSION_DENIED:
+		return "SSH_FX_PERMISSION_DENIED"
+	case ssh_FX_FAILURE:
+		return "SSH_FX_FAILURE"
+	case ssh_FX_BAD_MESSAGE:
+		return "SSH_FX_BAD_MESSAGE"
+	case ssh_FX_NO_CONNECTION:
+		return "SSH_FX_NO_CONNECTION"
+	case ssh_FX_CONNECTION_LOST:
+		return "SSH_FX_CONNECTION_LOST"
+	case ssh_FX_OP_UNSUPPORTED:
+		return "SSH_FX_OP_UNSUPPORTED"
+	default:
+		return "unknown"
+	}
+}
+
+type unexpectedPacketErr struct {
+	want, got uint8
+}
+
+func (u *unexpectedPacketErr) Error() string {
+	return fmt.Sprintf("sftp: unexpected packet: want %v, got %v", fxp(u.want), fxp(u.got))
+}
+
+func unimplementedPacketErr(u uint8) error {
+	return errors.Errorf("sftp: unimplemented packet type: got %v", fxp(u))
+}
+
+type unexpectedIDErr struct{ want, got uint32 }
+
+func (u *unexpectedIDErr) Error() string {
+	return fmt.Sprintf("sftp: unexpected id: want %v, got %v", u.want, u.got)
+}
+
+func unimplementedSeekWhence(whence int) error {
+	return errors.Errorf("sftp: unimplemented seek whence %v", whence)
+}
+
+func unexpectedCount(want, got uint32) error {
+	return errors.Errorf("sftp: unexpected count: want %v, got %v", want, got)
+}
+
+type unexpectedVersionErr struct{ want, got uint32 }
+
+func (u *unexpectedVersionErr) Error() string {
+	return fmt.Sprintf("sftp: unexpected server version: want %v, got %v", u.want, u.got)
+}
+
+// A StatusError is returned when an SFTP operation fails, and provides
+// additional information about the failure.
+type StatusError struct {
+	Code      uint32
+	msg, lang string
+}
+
+func (s *StatusError) Error() string { return fmt.Sprintf("sftp: %q (%v)", s.msg, fx(s.Code)) }

vendor/golang.org/x/crypto/curve25519/const_amd64.s

@@ -0,0 +1,20 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This code was translated into a form compatible with 6a from the public
+// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+
+// +build amd64,!gccgo,!appengine
+
+DATA ·REDMASK51(SB)/8, $0x0007FFFFFFFFFFFF
+GLOBL ·REDMASK51(SB), 8, $8
+
+DATA ·_121666_213(SB)/8, $996687872
+GLOBL ·_121666_213(SB), 8, $8
+
+DATA ·_2P0(SB)/8, $0xFFFFFFFFFFFDA
+GLOBL ·_2P0(SB), 8, $8
+
+DATA ·_2P1234(SB)/8, $0xFFFFFFFFFFFFE
+GLOBL ·_2P1234(SB), 8, $8

vendor/golang.org/x/crypto/curve25519/cswap_amd64.s

@@ -0,0 +1,88 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This code was translated into a form compatible with 6a from the public
+// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+
+// +build amd64,!gccgo,!appengine
+
+// func cswap(inout *[5]uint64, v uint64)
+TEXT ·cswap(SB),7,$0
+	MOVQ inout+0(FP),DI
+	MOVQ v+8(FP),SI
+
+	CMPQ SI,$1
+	MOVQ 0(DI),SI
+	MOVQ 80(DI),DX
+	MOVQ 8(DI),CX
+	MOVQ 88(DI),R8
+	MOVQ SI,R9
+	CMOVQEQ DX,SI
+	CMOVQEQ R9,DX
+	MOVQ CX,R9
+	CMOVQEQ R8,CX
+	CMOVQEQ R9,R8
+	MOVQ SI,0(DI)
+	MOVQ DX,80(DI)
+	MOVQ CX,8(DI)
+	MOVQ R8,88(DI)
+	MOVQ 16(DI),SI
+	MOVQ 96(DI),DX
+	MOVQ 24(DI),CX
+	MOVQ 104(DI),R8
+	MOVQ SI,R9
+	CMOVQEQ DX,SI
+	CMOVQEQ R9,DX
+	MOVQ CX,R9
+	CMOVQEQ R8,CX
+	CMOVQEQ R9,R8
+	MOVQ SI,16(DI)
+	MOVQ DX,96(DI)
+	MOVQ CX,24(DI)
+	MOVQ R8,104(DI)
+	MOVQ 32(DI),SI
+	MOVQ 112(DI),DX
+	MOVQ 40(DI),CX
+	MOVQ 120(DI),R8
+	MOVQ SI,R9
+	CMOVQEQ DX,SI
+	CMOVQEQ R9,DX
+	MOVQ CX,R9
+	CMOVQEQ R8,CX
+	CMOVQEQ R9,R8
+	MOVQ SI,32(DI)
+	MOVQ DX,112(DI)
+	MOVQ CX,40(DI)
+	MOVQ R8,120(DI)
+	MOVQ 48(DI),SI
+	MOVQ 128(DI),DX
+	MOVQ 56(DI),CX
+	MOVQ 136(DI),R8
+	MOVQ SI,R9
+	CMOVQEQ DX,SI
+	CMOVQEQ R9,DX
+	MOVQ CX,R9
+	CMOVQEQ R8,CX
+	CMOVQEQ R9,R8
+	MOVQ SI,48(DI)
+	MOVQ DX,128(DI)
+	MOVQ CX,56(DI)
+	MOVQ R8,136(DI)
+	MOVQ 64(DI),SI
+	MOVQ 144(DI),DX
+	MOVQ 72(DI),CX
+	MOVQ 152(DI),R8
+	MOVQ SI,R9
+	CMOVQEQ DX,SI
+	CMOVQEQ R9,DX
+	MOVQ CX,R9
+	CMOVQEQ R8,CX
+	CMOVQEQ R9,R8
+	MOVQ SI,64(DI)
+	MOVQ DX,144(DI)
+	MOVQ CX,72(DI)
+	MOVQ R8,152(DI)
+	MOVQ DI,AX
+	MOVQ SI,DX
+	RET

vendor/golang.org/x/crypto/curve25519/curve25519.go

@@ -0,0 +1,841 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// We have a implementation in amd64 assembly so this code is only run on
+// non-amd64 platforms. The amd64 assembly does not support gccgo.
+// +build !amd64 gccgo appengine
+
+package curve25519
+
+// This code is a port of the public domain, "ref10" implementation of
+// curve25519 from SUPERCOP 20130419 by D. J. Bernstein.
+
+// fieldElement represents an element of the field GF(2^255 - 19). An element
+// t, entries t[0]...t[9], represents the integer t[0]+2^26 t[1]+2^51 t[2]+2^77
+// t[3]+2^102 t[4]+...+2^230 t[9]. Bounds on each t[i] vary depending on
+// context.
+type fieldElement [10]int32
+
+func feZero(fe *fieldElement) {
+	for i := range fe {
+		fe[i] = 0
+	}
+}
+
+func feOne(fe *fieldElement) {
+	feZero(fe)
+	fe[0] = 1
+}
+
+func feAdd(dst, a, b *fieldElement) {
+	for i := range dst {
+		dst[i] = a[i] + b[i]
+	}
+}
+
+func feSub(dst, a, b *fieldElement) {
+	for i := range dst {
+		dst[i] = a[i] - b[i]
+	}
+}
+
+func feCopy(dst, src *fieldElement) {
+	for i := range dst {
+		dst[i] = src[i]
+	}
+}
+
+// feCSwap replaces (f,g) with (g,f) if b == 1; replaces (f,g) with (f,g) if b == 0.
+//
+// Preconditions: b in {0,1}.
+func feCSwap(f, g *fieldElement, b int32) {
+	var x fieldElement
+	b = -b
+	for i := range x {
+		x[i] = b & (f[i] ^ g[i])
+	}
+
+	for i := range f {
+		f[i] ^= x[i]
+	}
+	for i := range g {
+		g[i] ^= x[i]
+	}
+}
+
+// load3 reads a 24-bit, little-endian value from in.
+func load3(in []byte) int64 {
+	var r int64
+	r = int64(in[0])
+	r |= int64(in[1]) << 8
+	r |= int64(in[2]) << 16
+	return r
+}
+
+// load4 reads a 32-bit, little-endian value from in.
+func load4(in []byte) int64 {
+	var r int64
+	r = int64(in[0])
+	r |= int64(in[1]) << 8
+	r |= int64(in[2]) << 16
+	r |= int64(in[3]) << 24
+	return r
+}
+
+func feFromBytes(dst *fieldElement, src *[32]byte) {
+	h0 := load4(src[:])
+	h1 := load3(src[4:]) << 6
+	h2 := load3(src[7:]) << 5
+	h3 := load3(src[10:]) << 3
+	h4 := load3(src[13:]) << 2
+	h5 := load4(src[16:])
+	h6 := load3(src[20:]) << 7
+	h7 := load3(src[23:]) << 5
+	h8 := load3(src[26:]) << 4
+	h9 := load3(src[29:]) << 2
+
+	var carry [10]int64
+	carry[9] = (h9 + 1<<24) >> 25
+	h0 += carry[9] * 19
+	h9 -= carry[9] << 25
+	carry[1] = (h1 + 1<<24) >> 25
+	h2 += carry[1]
+	h1 -= carry[1] << 25
+	carry[3] = (h3 + 1<<24) >> 25
+	h4 += carry[3]
+	h3 -= carry[3] << 25
+	carry[5] = (h5 + 1<<24) >> 25
+	h6 += carry[5]
+	h5 -= carry[5] << 25
+	carry[7] = (h7 + 1<<24) >> 25
+	h8 += carry[7]
+	h7 -= carry[7] << 25
+
+	carry[0] = (h0 + 1<<25) >> 26
+	h1 += carry[0]
+	h0 -= carry[0] << 26
+	carry[2] = (h2 + 1<<25) >> 26
+	h3 += carry[2]
+	h2 -= carry[2] << 26
+	carry[4] = (h4 + 1<<25) >> 26
+	h5 += carry[4]
+	h4 -= carry[4] << 26
+	carry[6] = (h6 + 1<<25) >> 26
+	h7 += carry[6]
+	h6 -= carry[6] << 26
+	carry[8] = (h8 + 1<<25) >> 26
+	h9 += carry[8]
+	h8 -= carry[8] << 26
+
+	dst[0] = int32(h0)
+	dst[1] = int32(h1)
+	dst[2] = int32(h2)
+	dst[3] = int32(h3)
+	dst[4] = int32(h4)
+	dst[5] = int32(h5)
+	dst[6] = int32(h6)
+	dst[7] = int32(h7)
+	dst[8] = int32(h8)
+	dst[9] = int32(h9)
+}
+
+// feToBytes marshals h to s.
+// Preconditions:
+//   |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+//
+// Write p=2^255-19; q=floor(h/p).
+// Basic claim: q = floor(2^(-255)(h + 19 2^(-25)h9 + 2^(-1))).
+//
+// Proof:
+//   Have |h|<=p so |q|<=1 so |19^2 2^(-255) q|<1/4.
+//   Also have |h-2^230 h9|<2^230 so |19 2^(-255)(h-2^230 h9)|<1/4.
+//
+//   Write y=2^(-1)-19^2 2^(-255)q-19 2^(-255)(h-2^230 h9).
+//   Then 0<y<1.
+//
+//   Write r=h-pq.
+//   Have 0<=r<=p-1=2^255-20.
+//   Thus 0<=r+19(2^-255)r<r+19(2^-255)2^255<=2^255-1.
+//
+//   Write x=r+19(2^-255)r+y.
+//   Then 0<x<2^255 so floor(2^(-255)x) = 0 so floor(q+2^(-255)x) = q.
+//
+//   Have q+2^(-255)x = 2^(-255)(h + 19 2^(-25) h9 + 2^(-1))
+//   so floor(2^(-255)(h + 19 2^(-25) h9 + 2^(-1))) = q.
+func feToBytes(s *[32]byte, h *fieldElement) {
+	var carry [10]int32
+
+	q := (19*h[9] + (1 << 24)) >> 25
+	q = (h[0] + q) >> 26
+	q = (h[1] + q) >> 25
+	q = (h[2] + q) >> 26
+	q = (h[3] + q) >> 25
+	q = (h[4] + q) >> 26
+	q = (h[5] + q) >> 25
+	q = (h[6] + q) >> 26
+	q = (h[7] + q) >> 25
+	q = (h[8] + q) >> 26
+	q = (h[9] + q) >> 25
+
+	// Goal: Output h-(2^255-19)q, which is between 0 and 2^255-20.
+	h[0] += 19 * q
+	// Goal: Output h-2^255 q, which is between 0 and 2^255-20.
+
+	carry[0] = h[0] >> 26
+	h[1] += carry[0]
+	h[0] -= carry[0] << 26
+	carry[1] = h[1] >> 25
+	h[2] += carry[1]
+	h[1] -= carry[1] << 25
+	carry[2] = h[2] >> 26
+	h[3] += carry[2]
+	h[2] -= carry[2] << 26
+	carry[3] = h[3] >> 25
+	h[4] += carry[3]
+	h[3] -= carry[3] << 25
+	carry[4] = h[4] >> 26
+	h[5] += carry[4]
+	h[4] -= carry[4] << 26
+	carry[5] = h[5] >> 25
+	h[6] += carry[5]
+	h[5] -= carry[5] << 25
+	carry[6] = h[6] >> 26
+	h[7] += carry[6]
+	h[6] -= carry[6] << 26
+	carry[7] = h[7] >> 25
+	h[8] += carry[7]
+	h[7] -= carry[7] << 25
+	carry[8] = h[8] >> 26
+	h[9] += carry[8]
+	h[8] -= carry[8] << 26
+	carry[9] = h[9] >> 25
+	h[9] -= carry[9] << 25
+	// h10 = carry9
+
+	// Goal: Output h[0]+...+2^255 h10-2^255 q, which is between 0 and 2^255-20.
+	// Have h[0]+...+2^230 h[9] between 0 and 2^255-1;
+	// evidently 2^255 h10-2^255 q = 0.
+	// Goal: Output h[0]+...+2^230 h[9].
+
+	s[0] = byte(h[0] >> 0)
+	s[1] = byte(h[0] >> 8)
+	s[2] = byte(h[0] >> 16)
+	s[3] = byte((h[0] >> 24) | (h[1] << 2))
+	s[4] = byte(h[1] >> 6)
+	s[5] = byte(h[1] >> 14)
+	s[6] = byte((h[1] >> 22) | (h[2] << 3))
+	s[7] = byte(h[2] >> 5)
+	s[8] = byte(h[2] >> 13)
+	s[9] = byte((h[2] >> 21) | (h[3] << 5))
+	s[10] = byte(h[3] >> 3)
+	s[11] = byte(h[3] >> 11)
+	s[12] = byte((h[3] >> 19) | (h[4] << 6))
+	s[13] = byte(h[4] >> 2)
+	s[14] = byte(h[4] >> 10)
+	s[15] = byte(h[4] >> 18)
+	s[16] = byte(h[5] >> 0)
+	s[17] = byte(h[5] >> 8)
+	s[18] = byte(h[5] >> 16)
+	s[19] = byte((h[5] >> 24) | (h[6] << 1))
+	s[20] = byte(h[6] >> 7)
+	s[21] = byte(h[6] >> 15)
+	s[22] = byte((h[6] >> 23) | (h[7] << 3))
+	s[23] = byte(h[7] >> 5)
+	s[24] = byte(h[7] >> 13)
+	s[25] = byte((h[7] >> 21) | (h[8] << 4))
+	s[26] = byte(h[8] >> 4)
+	s[27] = byte(h[8] >> 12)
+	s[28] = byte((h[8] >> 20) | (h[9] << 6))
+	s[29] = byte(h[9] >> 2)
+	s[30] = byte(h[9] >> 10)
+	s[31] = byte(h[9] >> 18)
+}
+
+// feMul calculates h = f * g
+// Can overlap h with f or g.
+//
+// Preconditions:
+//    |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
+//    |g| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
+//
+// Postconditions:
+//    |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+//
+// Notes on implementation strategy:
+//
+// Using schoolbook multiplication.
+// Karatsuba would save a little in some cost models.
+//
+// Most multiplications by 2 and 19 are 32-bit precomputations;
+// cheaper than 64-bit postcomputations.
+//
+// There is one remaining multiplication by 19 in the carry chain;
+// one *19 precomputation can be merged into this,
+// but the resulting data flow is considerably less clean.
+//
+// There are 12 carries below.
+// 10 of them are 2-way parallelizable and vectorizable.
+// Can get away with 11 carries, but then data flow is much deeper.
+//
+// With tighter constraints on inputs can squeeze carries into int32.
+func feMul(h, f, g *fieldElement) {
+	f0 := f[0]
+	f1 := f[1]
+	f2 := f[2]
+	f3 := f[3]
+	f4 := f[4]
+	f5 := f[5]
+	f6 := f[6]
+	f7 := f[7]
+	f8 := f[8]
+	f9 := f[9]
+	g0 := g[0]
+	g1 := g[1]
+	g2 := g[2]
+	g3 := g[3]
+	g4 := g[4]
+	g5 := g[5]
+	g6 := g[6]
+	g7 := g[7]
+	g8 := g[8]
+	g9 := g[9]
+	g1_19 := 19 * g1 // 1.4*2^29
+	g2_19 := 19 * g2 // 1.4*2^30; still ok
+	g3_19 := 19 * g3
+	g4_19 := 19 * g4
+	g5_19 := 19 * g5
+	g6_19 := 19 * g6
+	g7_19 := 19 * g7
+	g8_19 := 19 * g8
+	g9_19 := 19 * g9
+	f1_2 := 2 * f1
+	f3_2 := 2 * f3
+	f5_2 := 2 * f5
+	f7_2 := 2 * f7
+	f9_2 := 2 * f9
+	f0g0 := int64(f0) * int64(g0)
+	f0g1 := int64(f0) * int64(g1)
+	f0g2 := int64(f0) * int64(g2)
+	f0g3 := int64(f0) * int64(g3)
+	f0g4 := int64(f0) * int64(g4)
+	f0g5 := int64(f0) * int64(g5)
+	f0g6 := int64(f0) * int64(g6)
+	f0g7 := int64(f0) * int64(g7)
+	f0g8 := int64(f0) * int64(g8)
+	f0g9 := int64(f0) * int64(g9)
+	f1g0 := int64(f1) * int64(g0)
+	f1g1_2 := int64(f1_2) * int64(g1)
+	f1g2 := int64(f1) * int64(g2)
+	f1g3_2 := int64(f1_2) * int64(g3)
+	f1g4 := int64(f1) * int64(g4)
+	f1g5_2 := int64(f1_2) * int64(g5)
+	f1g6 := int64(f1) * int64(g6)
+	f1g7_2 := int64(f1_2) * int64(g7)
+	f1g8 := int64(f1) * int64(g8)
+	f1g9_38 := int64(f1_2) * int64(g9_19)
+	f2g0 := int64(f2) * int64(g0)
+	f2g1 := int64(f2) * int64(g1)
+	f2g2 := int64(f2) * int64(g2)
+	f2g3 := int64(f2) * int64(g3)
+	f2g4 := int64(f2) * int64(g4)
+	f2g5 := int64(f2) * int64(g5)
+	f2g6 := int64(f2) * int64(g6)
+	f2g7 := int64(f2) * int64(g7)
+	f2g8_19 := int64(f2) * int64(g8_19)
+	f2g9_19 := int64(f2) * int64(g9_19)
+	f3g0 := int64(f3) * int64(g0)
+	f3g1_2 := int64(f3_2) * int64(g1)
+	f3g2 := int64(f3) * int64(g2)
+	f3g3_2 := int64(f3_2) * int64(g3)
+	f3g4 := int64(f3) * int64(g4)
+	f3g5_2 := int64(f3_2) * int64(g5)
+	f3g6 := int64(f3) * int64(g6)
+	f3g7_38 := int64(f3_2) * int64(g7_19)
+	f3g8_19 := int64(f3) * int64(g8_19)
+	f3g9_38 := int64(f3_2) * int64(g9_19)
+	f4g0 := int64(f4) * int64(g0)
+	f4g1 := int64(f4) * int64(g1)
+	f4g2 := int64(f4) * int64(g2)
+	f4g3 := int64(f4) * int64(g3)
+	f4g4 := int64(f4) * int64(g4)
+	f4g5 := int64(f4) * int64(g5)
+	f4g6_19 := int64(f4) * int64(g6_19)
+	f4g7_19 := int64(f4) * int64(g7_19)
+	f4g8_19 := int64(f4) * int64(g8_19)
+	f4g9_19 := int64(f4) * int64(g9_19)
+	f5g0 := int64(f5) * int64(g0)
+	f5g1_2 := int64(f5_2) * int64(g1)
+	f5g2 := int64(f5) * int64(g2)
+	f5g3_2 := int64(f5_2) * int64(g3)
+	f5g4 := int64(f5) * int64(g4)
+	f5g5_38 := int64(f5_2) * int64(g5_19)
+	f5g6_19 := int64(f5) * int64(g6_19)
+	f5g7_38 := int64(f5_2) * int64(g7_19)
+	f5g8_19 := int64(f5) * int64(g8_19)
+	f5g9_38 := int64(f5_2) * int64(g9_19)
+	f6g0 := int64(f6) * int64(g0)
+	f6g1 := int64(f6) * int64(g1)
+	f6g2 := int64(f6) * int64(g2)
+	f6g3 := int64(f6) * int64(g3)
+	f6g4_19 := int64(f6) * int64(g4_19)
+	f6g5_19 := int64(f6) * int64(g5_19)
+	f6g6_19 := int64(f6) * int64(g6_19)
+	f6g7_19 := int64(f6) * int64(g7_19)
+	f6g8_19 := int64(f6) * int64(g8_19)
+	f6g9_19 := int64(f6) * int64(g9_19)
+	f7g0 := int64(f7) * int64(g0)
+	f7g1_2 := int64(f7_2) * int64(g1)
+	f7g2 := int64(f7) * int64(g2)
+	f7g3_38 := int64(f7_2) * int64(g3_19)
+	f7g4_19 := int64(f7) * int64(g4_19)
+	f7g5_38 := int64(f7_2) * int64(g5_19)
+	f7g6_19 := int64(f7) * int64(g6_19)
+	f7g7_38 := int64(f7_2) * int64(g7_19)
+	f7g8_19 := int64(f7) * int64(g8_19)
+	f7g9_38 := int64(f7_2) * int64(g9_19)
+	f8g0 := int64(f8) * int64(g0)
+	f8g1 := int64(f8) * int64(g1)
+	f8g2_19 := int64(f8) * int64(g2_19)
+	f8g3_19 := int64(f8) * int64(g3_19)
+	f8g4_19 := int64(f8) * int64(g4_19)
+	f8g5_19 := int64(f8) * int64(g5_19)
+	f8g6_19 := int64(f8) * int64(g6_19)
+	f8g7_19 := int64(f8) * int64(g7_19)
+	f8g8_19 := int64(f8) * int64(g8_19)
+	f8g9_19 := int64(f8) * int64(g9_19)
+	f9g0 := int64(f9) * int64(g0)
+	f9g1_38 := int64(f9_2) * int64(g1_19)
+	f9g2_19 := int64(f9) * int64(g2_19)
+	f9g3_38 := int64(f9_2) * int64(g3_19)
+	f9g4_19 := int64(f9) * int64(g4_19)
+	f9g5_38 := int64(f9_2) * int64(g5_19)
+	f9g6_19 := int64(f9) * int64(g6_19)
+	f9g7_38 := int64(f9_2) * int64(g7_19)
+	f9g8_19 := int64(f9) * int64(g8_19)
+	f9g9_38 := int64(f9_2) * int64(g9_19)
+	h0 := f0g0 + f1g9_38 + f2g8_19 + f3g7_38 + f4g6_19 + f5g5_38 + f6g4_19 + f7g3_38 + f8g2_19 + f9g1_38
+	h1 := f0g1 + f1g0 + f2g9_19 + f3g8_19 + f4g7_19 + f5g6_19 + f6g5_19 + f7g4_19 + f8g3_19 + f9g2_19
+	h2 := f0g2 + f1g1_2 + f2g0 + f3g9_38 + f4g8_19 + f5g7_38 + f6g6_19 + f7g5_38 + f8g4_19 + f9g3_38
+	h3 := f0g3 + f1g2 + f2g1 + f3g0 + f4g9_19 + f5g8_19 + f6g7_19 + f7g6_19 + f8g5_19 + f9g4_19
+	h4 := f0g4 + f1g3_2 + f2g2 + f3g1_2 + f4g0 + f5g9_38 + f6g8_19 + f7g7_38 + f8g6_19 + f9g5_38
+	h5 := f0g5 + f1g4 + f2g3 + f3g2 + f4g1 + f5g0 + f6g9_19 + f7g8_19 + f8g7_19 + f9g6_19
+	h6 := f0g6 + f1g5_2 + f2g4 + f3g3_2 + f4g2 + f5g1_2 + f6g0 + f7g9_38 + f8g8_19 + f9g7_38
+	h7 := f0g7 + f1g6 + f2g5 + f3g4 + f4g3 + f5g2 + f6g1 + f7g0 + f8g9_19 + f9g8_19
+	h8 := f0g8 + f1g7_2 + f2g6 + f3g5_2 + f4g4 + f5g3_2 + f6g2 + f7g1_2 + f8g0 + f9g9_38
+	h9 := f0g9 + f1g8 + f2g7 + f3g6 + f4g5 + f5g4 + f6g3 + f7g2 + f8g1 + f9g0
+	var carry [10]int64
+
+	// |h0| <= (1.1*1.1*2^52*(1+19+19+19+19)+1.1*1.1*2^50*(38+38+38+38+38))
+	//   i.e. |h0| <= 1.2*2^59; narrower ranges for h2, h4, h6, h8
+	// |h1| <= (1.1*1.1*2^51*(1+1+19+19+19+19+19+19+19+19))
+	//   i.e. |h1| <= 1.5*2^58; narrower ranges for h3, h5, h7, h9
+
+	carry[0] = (h0 + (1 << 25)) >> 26
+	h1 += carry[0]
+	h0 -= carry[0] << 26
+	carry[4] = (h4 + (1 << 25)) >> 26
+	h5 += carry[4]
+	h4 -= carry[4] << 26
+	// |h0| <= 2^25
+	// |h4| <= 2^25
+	// |h1| <= 1.51*2^58
+	// |h5| <= 1.51*2^58
+
+	carry[1] = (h1 + (1 << 24)) >> 25
+	h2 += carry[1]
+	h1 -= carry[1] << 25
+	carry[5] = (h5 + (1 << 24)) >> 25
+	h6 += carry[5]
+	h5 -= carry[5] << 25
+	// |h1| <= 2^24; from now on fits into int32
+	// |h5| <= 2^24; from now on fits into int32
+	// |h2| <= 1.21*2^59
+	// |h6| <= 1.21*2^59
+
+	carry[2] = (h2 + (1 << 25)) >> 26
+	h3 += carry[2]
+	h2 -= carry[2] << 26
+	carry[6] = (h6 + (1 << 25)) >> 26
+	h7 += carry[6]
+	h6 -= carry[6] << 26
+	// |h2| <= 2^25; from now on fits into int32 unchanged
+	// |h6| <= 2^25; from now on fits into int32 unchanged
+	// |h3| <= 1.51*2^58
+	// |h7| <= 1.51*2^58
+
+	carry[3] = (h3 + (1 << 24)) >> 25
+	h4 += carry[3]
+	h3 -= carry[3] << 25
+	carry[7] = (h7 + (1 << 24)) >> 25
+	h8 += carry[7]
+	h7 -= carry[7] << 25
+	// |h3| <= 2^24; from now on fits into int32 unchanged
+	// |h7| <= 2^24; from now on fits into int32 unchanged
+	// |h4| <= 1.52*2^33
+	// |h8| <= 1.52*2^33
+
+	carry[4] = (h4 + (1 << 25)) >> 26
+	h5 += carry[4]
+	h4 -= carry[4] << 26
+	carry[8] = (h8 + (1 << 25)) >> 26
+	h9 += carry[8]
+	h8 -= carry[8] << 26
+	// |h4| <= 2^25; from now on fits into int32 unchanged
+	// |h8| <= 2^25; from now on fits into int32 unchanged
+	// |h5| <= 1.01*2^24
+	// |h9| <= 1.51*2^58
+
+	carry[9] = (h9 + (1 << 24)) >> 25
+	h0 += carry[9] * 19
+	h9 -= carry[9] << 25
+	// |h9| <= 2^24; from now on fits into int32 unchanged
+	// |h0| <= 1.8*2^37
+
+	carry[0] = (h0 + (1 << 25)) >> 26
+	h1 += carry[0]
+	h0 -= carry[0] << 26
+	// |h0| <= 2^25; from now on fits into int32 unchanged
+	// |h1| <= 1.01*2^24
+
+	h[0] = int32(h0)
+	h[1] = int32(h1)
+	h[2] = int32(h2)
+	h[3] = int32(h3)
+	h[4] = int32(h4)
+	h[5] = int32(h5)
+	h[6] = int32(h6)
+	h[7] = int32(h7)
+	h[8] = int32(h8)
+	h[9] = int32(h9)
+}
+
+// feSquare calculates h = f*f. Can overlap h with f.
+//
+// Preconditions:
+//    |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
+//
+// Postconditions:
+//    |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+func feSquare(h, f *fieldElement) {
+	f0 := f[0]
+	f1 := f[1]
+	f2 := f[2]
+	f3 := f[3]
+	f4 := f[4]
+	f5 := f[5]
+	f6 := f[6]
+	f7 := f[7]
+	f8 := f[8]
+	f9 := f[9]
+	f0_2 := 2 * f0
+	f1_2 := 2 * f1
+	f2_2 := 2 * f2
+	f3_2 := 2 * f3
+	f4_2 := 2 * f4
+	f5_2 := 2 * f5
+	f6_2 := 2 * f6
+	f7_2 := 2 * f7
+	f5_38 := 38 * f5 // 1.31*2^30
+	f6_19 := 19 * f6 // 1.31*2^30
+	f7_38 := 38 * f7 // 1.31*2^30
+	f8_19 := 19 * f8 // 1.31*2^30
+	f9_38 := 38 * f9 // 1.31*2^30
+	f0f0 := int64(f0) * int64(f0)
+	f0f1_2 := int64(f0_2) * int64(f1)
+	f0f2_2 := int64(f0_2) * int64(f2)
+	f0f3_2 := int64(f0_2) * int64(f3)
+	f0f4_2 := int64(f0_2) * int64(f4)
+	f0f5_2 := int64(f0_2) * int64(f5)
+	f0f6_2 := int64(f0_2) * int64(f6)
+	f0f7_2 := int64(f0_2) * int64(f7)
+	f0f8_2 := int64(f0_2) * int64(f8)
+	f0f9_2 := int64(f0_2) * int64(f9)
+	f1f1_2 := int64(f1_2) * int64(f1)
+	f1f2_2 := int64(f1_2) * int64(f2)
+	f1f3_4 := int64(f1_2) * int64(f3_2)
+	f1f4_2 := int64(f1_2) * int64(f4)
+	f1f5_4 := int64(f1_2) * int64(f5_2)
+	f1f6_2 := int64(f1_2) * int64(f6)
+	f1f7_4 := int64(f1_2) * int64(f7_2)
+	f1f8_2 := int64(f1_2) * int64(f8)
+	f1f9_76 := int64(f1_2) * int64(f9_38)
+	f2f2 := int64(f2) * int64(f2)
+	f2f3_2 := int64(f2_2) * int64(f3)
+	f2f4_2 := int64(f2_2) * int64(f4)
+	f2f5_2 := int64(f2_2) * int64(f5)
+	f2f6_2 := int64(f2_2) * int64(f6)
+	f2f7_2 := int64(f2_2) * int64(f7)
+	f2f8_38 := int64(f2_2) * int64(f8_19)
+	f2f9_38 := int64(f2) * int64(f9_38)
+	f3f3_2 := int64(f3_2) * int64(f3)
+	f3f4_2 := int64(f3_2) * int64(f4)
+	f3f5_4 := int64(f3_2) * int64(f5_2)
+	f3f6_2 := int64(f3_2) * int64(f6)
+	f3f7_76 := int64(f3_2) * int64(f7_38)
+	f3f8_38 := int64(f3_2) * int64(f8_19)
+	f3f9_76 := int64(f3_2) * int64(f9_38)
+	f4f4 := int64(f4) * int64(f4)
+	f4f5_2 := int64(f4_2) * int64(f5)
+	f4f6_38 := int64(f4_2) * int64(f6_19)
+	f4f7_38 := int64(f4) * int64(f7_38)
+	f4f8_38 := int64(f4_2) * int64(f8_19)
+	f4f9_38 := int64(f4) * int64(f9_38)
+	f5f5_38 := int64(f5) * int64(f5_38)
+	f5f6_38 := int64(f5_2) * int64(f6_19)
+	f5f7_76 := int64(f5_2) * int64(f7_38)
+	f5f8_38 := int64(f5_2) * int64(f8_19)
+	f5f9_76 := int64(f5_2) * int64(f9_38)
+	f6f6_19 := int64(f6) * int64(f6_19)
+	f6f7_38 := int64(f6) * int64(f7_38)
+	f6f8_38 := int64(f6_2) * int64(f8_19)
+	f6f9_38 := int64(f6) * int64(f9_38)
+	f7f7_38 := int64(f7) * int64(f7_38)
+	f7f8_38 := int64(f7_2) * int64(f8_19)
+	f7f9_76 := int64(f7_2) * int64(f9_38)
+	f8f8_19 := int64(f8) * int64(f8_19)
+	f8f9_38 := int64(f8) * int64(f9_38)
+	f9f9_38 := int64(f9) * int64(f9_38)
+	h0 := f0f0 + f1f9_76 + f2f8_38 + f3f7_76 + f4f6_38 + f5f5_38
+	h1 := f0f1_2 + f2f9_38 + f3f8_38 + f4f7_38 + f5f6_38
+	h2 := f0f2_2 + f1f1_2 + f3f9_76 + f4f8_38 + f5f7_76 + f6f6_19
+	h3 := f0f3_2 + f1f2_2 + f4f9_38 + f5f8_38 + f6f7_38
+	h4 := f0f4_2 + f1f3_4 + f2f2 + f5f9_76 + f6f8_38 + f7f7_38
+	h5 := f0f5_2 + f1f4_2 + f2f3_2 + f6f9_38 + f7f8_38
+	h6 := f0f6_2 + f1f5_4 + f2f4_2 + f3f3_2 + f7f9_76 + f8f8_19
+	h7 := f0f7_2 + f1f6_2 + f2f5_2 + f3f4_2 + f8f9_38
+	h8 := f0f8_2 + f1f7_4 + f2f6_2 + f3f5_4 + f4f4 + f9f9_38
+	h9 := f0f9_2 + f1f8_2 + f2f7_2 + f3f6_2 + f4f5_2
+	var carry [10]int64
+
+	carry[0] = (h0 + (1 << 25)) >> 26
+	h1 += carry[0]
+	h0 -= carry[0] << 26
+	carry[4] = (h4 + (1 << 25)) >> 26
+	h5 += carry[4]
+	h4 -= carry[4] << 26
+
+	carry[1] = (h1 + (1 << 24)) >> 25
+	h2 += carry[1]
+	h1 -= carry[1] << 25
+	carry[5] = (h5 + (1 << 24)) >> 25
+	h6 += carry[5]
+	h5 -= carry[5] << 25
+
+	carry[2] = (h2 + (1 << 25)) >> 26
+	h3 += carry[2]
+	h2 -= carry[2] << 26
+	carry[6] = (h6 + (1 << 25)) >> 26
+	h7 += carry[6]
+	h6 -= carry[6] << 26
+
+	carry[3] = (h3 + (1 << 24)) >> 25
+	h4 += carry[3]
+	h3 -= carry[3] << 25
+	carry[7] = (h7 + (1 << 24)) >> 25
+	h8 += carry[7]
+	h7 -= carry[7] << 25
+
+	carry[4] = (h4 + (1 << 25)) >> 26
+	h5 += carry[4]
+	h4 -= carry[4] << 26
+	carry[8] = (h8 + (1 << 25)) >> 26
+	h9 += carry[8]
+	h8 -= carry[8] << 26
+
+	carry[9] = (h9 + (1 << 24)) >> 25
+	h0 += carry[9] * 19
+	h9 -= carry[9] << 25
+
+	carry[0] = (h0 + (1 << 25)) >> 26
+	h1 += carry[0]
+	h0 -= carry[0] << 26
+
+	h[0] = int32(h0)
+	h[1] = int32(h1)
+	h[2] = int32(h2)
+	h[3] = int32(h3)
+	h[4] = int32(h4)
+	h[5] = int32(h5)
+	h[6] = int32(h6)
+	h[7] = int32(h7)
+	h[8] = int32(h8)
+	h[9] = int32(h9)
+}
+
+// feMul121666 calculates h = f * 121666. Can overlap h with f.
+//
+// Preconditions:
+//    |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
+//
+// Postconditions:
+//    |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
+func feMul121666(h, f *fieldElement) {
+	h0 := int64(f[0]) * 121666
+	h1 := int64(f[1]) * 121666
+	h2 := int64(f[2]) * 121666
+	h3 := int64(f[3]) * 121666
+	h4 := int64(f[4]) * 121666
+	h5 := int64(f[5]) * 121666
+	h6 := int64(f[6]) * 121666
+	h7 := int64(f[7]) * 121666
+	h8 := int64(f[8]) * 121666
+	h9 := int64(f[9]) * 121666
+	var carry [10]int64
+
+	carry[9] = (h9 + (1 << 24)) >> 25
+	h0 += carry[9] * 19
+	h9 -= carry[9] << 25
+	carry[1] = (h1 + (1 << 24)) >> 25
+	h2 += carry[1]
+	h1 -= carry[1] << 25
+	carry[3] = (h3 + (1 << 24)) >> 25
+	h4 += carry[3]
+	h3 -= carry[3] << 25
+	carry[5] = (h5 + (1 << 24)) >> 25
+	h6 += carry[5]
+	h5 -= carry[5] << 25
+	carry[7] = (h7 + (1 << 24)) >> 25
+	h8 += carry[7]
+	h7 -= carry[7] << 25
+
+	carry[0] = (h0 + (1 << 25)) >> 26
+	h1 += carry[0]
+	h0 -= carry[0] << 26
+	carry[2] = (h2 + (1 << 25)) >> 26
+	h3 += carry[2]
+	h2 -= carry[2] << 26
+	carry[4] = (h4 + (1 << 25)) >> 26
+	h5 += carry[4]
+	h4 -= carry[4] << 26
+	carry[6] = (h6 + (1 << 25)) >> 26
+	h7 += carry[6]
+	h6 -= carry[6] << 26
+	carry[8] = (h8 + (1 << 25)) >> 26
+	h9 += carry[8]
+	h8 -= carry[8] << 26
+
+	h[0] = int32(h0)
+	h[1] = int32(h1)
+	h[2] = int32(h2)
+	h[3] = int32(h3)
+	h[4] = int32(h4)
+	h[5] = int32(h5)
+	h[6] = int32(h6)
+	h[7] = int32(h7)
+	h[8] = int32(h8)
+	h[9] = int32(h9)
+}
+
+// feInvert sets out = z^-1.
+func feInvert(out, z *fieldElement) {
+	var t0, t1, t2, t3 fieldElement
+	var i int
+
+	feSquare(&t0, z)
+	for i = 1; i < 1; i++ {
+		feSquare(&t0, &t0)
+	}
+	feSquare(&t1, &t0)
+	for i = 1; i < 2; i++ {
+		feSquare(&t1, &t1)
+	}
+	feMul(&t1, z, &t1)
+	feMul(&t0, &t0, &t1)
+	feSquare(&t2, &t0)
+	for i = 1; i < 1; i++ {
+		feSquare(&t2, &t2)
+	}
+	feMul(&t1, &t1, &t2)
+	feSquare(&t2, &t1)
+	for i = 1; i < 5; i++ {
+		feSquare(&t2, &t2)
+	}
+	feMul(&t1, &t2, &t1)
+	feSquare(&t2, &t1)
+	for i = 1; i < 10; i++ {
+		feSquare(&t2, &t2)
+	}
+	feMul(&t2, &t2, &t1)
+	feSquare(&t3, &t2)
+	for i = 1; i < 20; i++ {
+		feSquare(&t3, &t3)
+	}
+	feMul(&t2, &t3, &t2)
+	feSquare(&t2, &t2)
+	for i = 1; i < 10; i++ {
+		feSquare(&t2, &t2)
+	}
+	feMul(&t1, &t2, &t1)
+	feSquare(&t2, &t1)
+	for i = 1; i < 50; i++ {
+		feSquare(&t2, &t2)
+	}
+	feMul(&t2, &t2, &t1)
+	feSquare(&t3, &t2)
+	for i = 1; i < 100; i++ {
+		feSquare(&t3, &t3)
+	}
+	feMul(&t2, &t3, &t2)
+	feSquare(&t2, &t2)
+	for i = 1; i < 50; i++ {
+		feSquare(&t2, &t2)
+	}
+	feMul(&t1, &t2, &t1)
+	feSquare(&t1, &t1)
+	for i = 1; i < 5; i++ {
+		feSquare(&t1, &t1)
+	}
+	feMul(out, &t1, &t0)
+}
+
+func scalarMult(out, in, base *[32]byte) {
+	var e [32]byte
+
+	copy(e[:], in[:])
+	e[0] &= 248
+	e[31] &= 127
+	e[31] |= 64
+
+	var x1, x2, z2, x3, z3, tmp0, tmp1 fieldElement
+	feFromBytes(&x1, base)
+	feOne(&x2)
+	feCopy(&x3, &x1)
+	feOne(&z3)
+
+	swap := int32(0)
+	for pos := 254; pos >= 0; pos-- {
+		b := e[pos/8] >> uint(pos&7)
+		b &= 1
+		swap ^= int32(b)
+		feCSwap(&x2, &x3, swap)
+		feCSwap(&z2, &z3, swap)
+		swap = int32(b)
+
+		feSub(&tmp0, &x3, &z3)
+		feSub(&tmp1, &x2, &z2)
+		feAdd(&x2, &x2, &z2)
+		feAdd(&z2, &x3, &z3)
+		feMul(&z3, &tmp0, &x2)
+		feMul(&z2, &z2, &tmp1)
+		feSquare(&tmp0, &tmp1)
+		feSquare(&tmp1, &x2)
+		feAdd(&x3, &z3, &z2)
+		feSub(&z2, &z3, &z2)
+		feMul(&x2, &tmp1, &tmp0)
+		feSub(&tmp1, &tmp1, &tmp0)
+		feSquare(&z2, &z2)
+		feMul121666(&z3, &tmp1)
+		feSquare(&x3, &x3)
+		feAdd(&tmp0, &tmp0, &z3)
+		feMul(&z3, &x1, &z2)
+		feMul(&z2, &tmp1, &tmp0)
+	}
+
+	feCSwap(&x2, &x3, swap)
+	feCSwap(&z2, &z3, swap)
+
+	feInvert(&z2, &z2)
+	feMul(&x2, &x2, &z2)
+	feToBytes(out, &x2)
+}

vendor/golang.org/x/crypto/curve25519/curve25519_test.go

@@ -0,0 +1,29 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package curve25519
+
+import (
+	"fmt"
+	"testing"
+)
+
+const expectedHex = "89161fde887b2b53de549af483940106ecc114d6982daa98256de23bdf77661a"
+
+func TestBaseScalarMult(t *testing.T) {
+	var a, b [32]byte
+	in := &a
+	out := &b
+	a[0] = 1
+
+	for i := 0; i < 200; i++ {
+		ScalarBaseMult(out, in)
+		in, out = out, in
+	}
+
+	result := fmt.Sprintf("%x", in[:])
+	if result != expectedHex {
+		t.Errorf("incorrect result: got %s, want %s", result, expectedHex)
+	}
+}

vendor/golang.org/x/crypto/curve25519/doc.go

@@ -0,0 +1,23 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package curve25519 provides an implementation of scalar multiplication on
+// the elliptic curve known as curve25519. See http://cr.yp.to/ecdh.html
+package curve25519 // import "golang.org/x/crypto/curve25519"
+
+// basePoint is the x coordinate of the generator of the curve.
+var basePoint = [32]byte{9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+
+// ScalarMult sets dst to the product in*base where dst and base are the x
+// coordinates of group points and all values are in little-endian form.
+func ScalarMult(dst, in, base *[32]byte) {
+	scalarMult(dst, in, base)
+}
+
+// ScalarBaseMult sets dst to the product in*base where dst and base are the x
+// coordinates of group points, base is the standard generator and all values
+// are in little-endian form.
+func ScalarBaseMult(dst, in *[32]byte) {
+	ScalarMult(dst, in, &basePoint)
+}

vendor/golang.org/x/crypto/curve25519/freeze_amd64.s

@@ -0,0 +1,71 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This code was translated into a form compatible with 6a from the public
+// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+
+// +build amd64,!gccgo,!appengine
+
+// func freeze(inout *[5]uint64)
+TEXT ·freeze(SB),7,$0-8
+	MOVQ inout+0(FP), DI
+
+	MOVQ 0(DI),SI
+	MOVQ 8(DI),DX
+	MOVQ 16(DI),CX
+	MOVQ 24(DI),R8
+	MOVQ 32(DI),R9
+	MOVQ ·REDMASK51(SB),AX
+	MOVQ AX,R10
+	SUBQ $18,R10
+	MOVQ $3,R11
+REDUCELOOP:
+	MOVQ SI,R12
+	SHRQ $51,R12
+	ANDQ AX,SI
+	ADDQ R12,DX
+	MOVQ DX,R12
+	SHRQ $51,R12
+	ANDQ AX,DX
+	ADDQ R12,CX
+	MOVQ CX,R12
+	SHRQ $51,R12
+	ANDQ AX,CX
+	ADDQ R12,R8
+	MOVQ R8,R12
+	SHRQ $51,R12
+	ANDQ AX,R8
+	ADDQ R12,R9
+	MOVQ R9,R12
+	SHRQ $51,R12
+	ANDQ AX,R9
+	IMUL3Q $19,R12,R12
+	ADDQ R12,SI
+	SUBQ $1,R11
+	JA REDUCELOOP
+	MOVQ $1,R12
+	CMPQ R10,SI
+	CMOVQLT R11,R12
+	CMPQ AX,DX
+	CMOVQNE R11,R12
+	CMPQ AX,CX
+	CMOVQNE R11,R12
+	CMPQ AX,R8
+	CMOVQNE R11,R12
+	CMPQ AX,R9
+	CMOVQNE R11,R12
+	NEGQ R12
+	ANDQ R12,AX
+	ANDQ R12,R10
+	SUBQ R10,SI
+	SUBQ AX,DX
+	SUBQ AX,CX
+	SUBQ AX,R8
+	SUBQ AX,R9
+	MOVQ SI,0(DI)
+	MOVQ DX,8(DI)
+	MOVQ CX,16(DI)
+	MOVQ R8,24(DI)
+	MOVQ R9,32(DI)
+	RET

vendor/golang.org/x/crypto/curve25519/mont25519_amd64.go

@@ -0,0 +1,240 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build amd64,!gccgo,!appengine
+
+package curve25519
+
+// These functions are implemented in the .s files. The names of the functions
+// in the rest of the file are also taken from the SUPERCOP sources to help
+// people following along.
+
+//go:noescape
+
+func cswap(inout *[5]uint64, v uint64)
+
+//go:noescape
+
+func ladderstep(inout *[5][5]uint64)
+
+//go:noescape
+
+func freeze(inout *[5]uint64)
+
+//go:noescape
+
+func mul(dest, a, b *[5]uint64)
+
+//go:noescape
+
+func square(out, in *[5]uint64)
+
+// mladder uses a Montgomery ladder to calculate (xr/zr) *= s.
+func mladder(xr, zr *[5]uint64, s *[32]byte) {
+	var work [5][5]uint64
+
+	work[0] = *xr
+	setint(&work[1], 1)
+	setint(&work[2], 0)
+	work[3] = *xr
+	setint(&work[4], 1)
+
+	j := uint(6)
+	var prevbit byte
+
+	for i := 31; i >= 0; i-- {
+		for j < 8 {
+			bit := ((*s)[i] >> j) & 1
+			swap := bit ^ prevbit
+			prevbit = bit
+			cswap(&work[1], uint64(swap))
+			ladderstep(&work)
+			j--
+		}
+		j = 7
+	}
+
+	*xr = work[1]
+	*zr = work[2]
+}
+
+func scalarMult(out, in, base *[32]byte) {
+	var e [32]byte
+	copy(e[:], (*in)[:])
+	e[0] &= 248
+	e[31] &= 127
+	e[31] |= 64
+
+	var t, z [5]uint64
+	unpack(&t, base)
+	mladder(&t, &z, &e)
+	invert(&z, &z)
+	mul(&t, &t, &z)
+	pack(out, &t)
+}
+
+func setint(r *[5]uint64, v uint64) {
+	r[0] = v
+	r[1] = 0
+	r[2] = 0
+	r[3] = 0
+	r[4] = 0
+}
+
+// unpack sets r = x where r consists of 5, 51-bit limbs in little-endian
+// order.
+func unpack(r *[5]uint64, x *[32]byte) {
+	r[0] = uint64(x[0]) |
+		uint64(x[1])<<8 |
+		uint64(x[2])<<16 |
+		uint64(x[3])<<24 |
+		uint64(x[4])<<32 |
+		uint64(x[5])<<40 |
+		uint64(x[6]&7)<<48
+
+	r[1] = uint64(x[6])>>3 |
+		uint64(x[7])<<5 |
+		uint64(x[8])<<13 |
+		uint64(x[9])<<21 |
+		uint64(x[10])<<29 |
+		uint64(x[11])<<37 |
+		uint64(x[12]&63)<<45
+
+	r[2] = uint64(x[12])>>6 |
+		uint64(x[13])<<2 |
+		uint64(x[14])<<10 |
+		uint64(x[15])<<18 |
+		uint64(x[16])<<26 |
+		uint64(x[17])<<34 |
+		uint64(x[18])<<42 |
+		uint64(x[19]&1)<<50
+
+	r[3] = uint64(x[19])>>1 |
+		uint64(x[20])<<7 |
+		uint64(x[21])<<15 |
+		uint64(x[22])<<23 |
+		uint64(x[23])<<31 |
+		uint64(x[24])<<39 |
+		uint64(x[25]&15)<<47
+
+	r[4] = uint64(x[25])>>4 |
+		uint64(x[26])<<4 |
+		uint64(x[27])<<12 |
+		uint64(x[28])<<20 |
+		uint64(x[29])<<28 |
+		uint64(x[30])<<36 |
+		uint64(x[31]&127)<<44
+}
+
+// pack sets out = x where out is the usual, little-endian form of the 5,
+// 51-bit limbs in x.
+func pack(out *[32]byte, x *[5]uint64) {
+	t := *x
+	freeze(&t)
+
+	out[0] = byte(t[0])
+	out[1] = byte(t[0] >> 8)
+	out[2] = byte(t[0] >> 16)
+	out[3] = byte(t[0] >> 24)
+	out[4] = byte(t[0] >> 32)
+	out[5] = byte(t[0] >> 40)
+	out[6] = byte(t[0] >> 48)
+
+	out[6] ^= byte(t[1]<<3) & 0xf8
+	out[7] = byte(t[1] >> 5)
+	out[8] = byte(t[1] >> 13)
+	out[9] = byte(t[1] >> 21)
+	out[10] = byte(t[1] >> 29)
+	out[11] = byte(t[1] >> 37)
+	out[12] = byte(t[1] >> 45)
+
+	out[12] ^= byte(t[2]<<6) & 0xc0
+	out[13] = byte(t[2] >> 2)
+	out[14] = byte(t[2] >> 10)
+	out[15] = byte(t[2] >> 18)
+	out[16] = byte(t[2] >> 26)
+	out[17] = byte(t[2] >> 34)
+	out[18] = byte(t[2] >> 42)
+	out[19] = byte(t[2] >> 50)
+
+	out[19] ^= byte(t[3]<<1) & 0xfe
+	out[20] = byte(t[3] >> 7)
+	out[21] = byte(t[3] >> 15)
+	out[22] = byte(t[3] >> 23)
+	out[23] = byte(t[3] >> 31)
+	out[24] = byte(t[3] >> 39)
+	out[25] = byte(t[3] >> 47)
+
+	out[25] ^= byte(t[4]<<4) & 0xf0
+	out[26] = byte(t[4] >> 4)
+	out[27] = byte(t[4] >> 12)
+	out[28] = byte(t[4] >> 20)
+	out[29] = byte(t[4] >> 28)
+	out[30] = byte(t[4] >> 36)
+	out[31] = byte(t[4] >> 44)
+}
+
+// invert calculates r = x^-1 mod p using Fermat's little theorem.
+func invert(r *[5]uint64, x *[5]uint64) {
+	var z2, z9, z11, z2_5_0, z2_10_0, z2_20_0, z2_50_0, z2_100_0, t [5]uint64
+
+	square(&z2, x)        /* 2 */
+	square(&t, &z2)       /* 4 */
+	square(&t, &t)        /* 8 */
+	mul(&z9, &t, x)       /* 9 */
+	mul(&z11, &z9, &z2)   /* 11 */
+	square(&t, &z11)      /* 22 */
+	mul(&z2_5_0, &t, &z9) /* 2^5 - 2^0 = 31 */
+
+	square(&t, &z2_5_0)      /* 2^6 - 2^1 */
+	for i := 1; i < 5; i++ { /* 2^20 - 2^10 */
+		square(&t, &t)
+	}
+	mul(&z2_10_0, &t, &z2_5_0) /* 2^10 - 2^0 */
+
+	square(&t, &z2_10_0)      /* 2^11 - 2^1 */
+	for i := 1; i < 10; i++ { /* 2^20 - 2^10 */
+		square(&t, &t)
+	}
+	mul(&z2_20_0, &t, &z2_10_0) /* 2^20 - 2^0 */
+
+	square(&t, &z2_20_0)      /* 2^21 - 2^1 */
+	for i := 1; i < 20; i++ { /* 2^40 - 2^20 */
+		square(&t, &t)
+	}
+	mul(&t, &t, &z2_20_0) /* 2^40 - 2^0 */
+
+	square(&t, &t)            /* 2^41 - 2^1 */
+	for i := 1; i < 10; i++ { /* 2^50 - 2^10 */
+		square(&t, &t)
+	}
+	mul(&z2_50_0, &t, &z2_10_0) /* 2^50 - 2^0 */
+
+	square(&t, &z2_50_0)      /* 2^51 - 2^1 */
+	for i := 1; i < 50; i++ { /* 2^100 - 2^50 */
+		square(&t, &t)
+	}
+	mul(&z2_100_0, &t, &z2_50_0) /* 2^100 - 2^0 */
+
+	square(&t, &z2_100_0)      /* 2^101 - 2^1 */
+	for i := 1; i < 100; i++ { /* 2^200 - 2^100 */
+		square(&t, &t)
+	}
+	mul(&t, &t, &z2_100_0) /* 2^200 - 2^0 */
+
+	square(&t, &t)            /* 2^201 - 2^1 */
+	for i := 1; i < 50; i++ { /* 2^250 - 2^50 */
+		square(&t, &t)
+	}
+	mul(&t, &t, &z2_50_0) /* 2^250 - 2^0 */
+
+	square(&t, &t) /* 2^251 - 2^1 */
+	square(&t, &t) /* 2^252 - 2^2 */
+	square(&t, &t) /* 2^253 - 2^3 */
+
+	square(&t, &t) /* 2^254 - 2^4 */
+
+	square(&t, &t)   /* 2^255 - 2^5 */
+	mul(r, &t, &z11) /* 2^255 - 21 */
+}

vendor/golang.org/x/crypto/curve25519/mul_amd64.s

@@ -0,0 +1,167 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This code was translated into a form compatible with 6a from the public
+// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+
+// +build amd64,!gccgo,!appengine
+
+// func mul(dest, a, b *[5]uint64)
+TEXT ·mul(SB),0,$16-24
+	MOVQ dest+0(FP), DI
+	MOVQ a+8(FP), SI
+	MOVQ b+16(FP), DX
+
+	MOVQ DX,CX
+	MOVQ 24(SI),DX
+	IMUL3Q $19,DX,AX
+	MOVQ AX,0(SP)
+	MULQ 16(CX)
+	MOVQ AX,R8
+	MOVQ DX,R9
+	MOVQ 32(SI),DX
+	IMUL3Q $19,DX,AX
+	MOVQ AX,8(SP)
+	MULQ 8(CX)
+	ADDQ AX,R8
+	ADCQ DX,R9
+	MOVQ 0(SI),AX
+	MULQ 0(CX)
+	ADDQ AX,R8
+	ADCQ DX,R9
+	MOVQ 0(SI),AX
+	MULQ 8(CX)
+	MOVQ AX,R10
+	MOVQ DX,R11
+	MOVQ 0(SI),AX
+	MULQ 16(CX)
+	MOVQ AX,R12
+	MOVQ DX,R13
+	MOVQ 0(SI),AX
+	MULQ 24(CX)
+	MOVQ AX,R14
+	MOVQ DX,R15
+	MOVQ 0(SI),AX
+	MULQ 32(CX)
+	MOVQ AX,BX
+	MOVQ DX,BP
+	MOVQ 8(SI),AX
+	MULQ 0(CX)
+	ADDQ AX,R10
+	ADCQ DX,R11
+	MOVQ 8(SI),AX
+	MULQ 8(CX)
+	ADDQ AX,R12
+	ADCQ DX,R13
+	MOVQ 8(SI),AX
+	MULQ 16(CX)
+	ADDQ AX,R14
+	ADCQ DX,R15
+	MOVQ 8(SI),AX
+	MULQ 24(CX)
+	ADDQ AX,BX
+	ADCQ DX,BP
+	MOVQ 8(SI),DX
+	IMUL3Q $19,DX,AX
+	MULQ 32(CX)
+	ADDQ AX,R8
+	ADCQ DX,R9
+	MOVQ 16(SI),AX
+	MULQ 0(CX)
+	ADDQ AX,R12
+	ADCQ DX,R13
+	MOVQ 16(SI),AX
+	MULQ 8(CX)
+	ADDQ AX,R14
+	ADCQ DX,R15
+	MOVQ 16(SI),AX
+	MULQ 16(CX)
+	ADDQ AX,BX
+	ADCQ DX,BP
+	MOVQ 16(SI),DX
+	IMUL3Q $19,DX,AX
+	MULQ 24(CX)
+	ADDQ AX,R8
+	ADCQ DX,R9
+	MOVQ 16(SI),DX
+	IMUL3Q $19,DX,AX
+	MULQ 32(CX)
+	ADDQ AX,R10
+	ADCQ DX,R11
+	MOVQ 24(SI),AX
+	MULQ 0(CX)
+	ADDQ AX,R14
+	ADCQ DX,R15
+	MOVQ 24(SI),AX
+	MULQ 8(CX)
+	ADDQ AX,BX
+	ADCQ DX,BP
+	MOVQ 0(SP),AX
+	MULQ 24(CX)
+	ADDQ AX,R10
+	ADCQ DX,R11
+	MOVQ 0(SP),AX
+	MULQ 32(CX)
+	ADDQ AX,R12
+	ADCQ DX,R13
+	MOVQ 32(SI),AX
+	MULQ 0(CX)
+	ADDQ AX,BX
+	ADCQ DX,BP
+	MOVQ 8(SP),AX
+	MULQ 16(CX)
+	ADDQ AX,R10
+	ADCQ DX,R11
+	MOVQ 8(SP),AX
+	MULQ 24(CX)
+	ADDQ AX,R12
+	ADCQ DX,R13
+	MOVQ 8(SP),AX
+	MULQ 32(CX)
+	ADDQ AX,R14
+	ADCQ DX,R15
+	MOVQ ·REDMASK51(SB),SI
+	SHLQ $13,R9:R8
+	ANDQ SI,R8
+	SHLQ $13,R11:R10
+	ANDQ SI,R10
+	ADDQ R9,R10
+	SHLQ $13,R13:R12
+	ANDQ SI,R12
+	ADDQ R11,R12
+	SHLQ $13,R15:R14
+	ANDQ SI,R14
+	ADDQ R13,R14
+	SHLQ $13,BP:BX
+	ANDQ SI,BX
+	ADDQ R15,BX
+	IMUL3Q $19,BP,DX
+	ADDQ DX,R8
+	MOVQ R8,DX
+	SHRQ $51,DX
+	ADDQ R10,DX
+	MOVQ DX,CX
+	SHRQ $51,DX
+	ANDQ SI,R8
+	ADDQ R12,DX
+	MOVQ DX,R9
+	SHRQ $51,DX
+	ANDQ SI,CX
+	ADDQ R14,DX
+	MOVQ DX,AX
+	SHRQ $51,DX
+	ANDQ SI,R9
+	ADDQ BX,DX
+	MOVQ DX,R10
+	SHRQ $51,DX
+	ANDQ SI,AX
+	IMUL3Q $19,DX,DX
+	ADDQ DX,R8
+	ANDQ SI,R10
+	MOVQ R8,0(DI)
+	MOVQ CX,8(DI)
+	MOVQ R9,16(DI)
+	MOVQ AX,24(DI)
+	MOVQ R10,32(DI)
+	RET

vendor/golang.org/x/crypto/curve25519/square_amd64.s

@@ -0,0 +1,130 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This code was translated into a form compatible with 6a from the public
+// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+
+// +build amd64,!gccgo,!appengine
+
+// func square(out, in *[5]uint64)
+TEXT ·square(SB),7,$0-16
+	MOVQ out+0(FP), DI
+	MOVQ in+8(FP), SI
+
+	MOVQ 0(SI),AX
+	MULQ 0(SI)
+	MOVQ AX,CX
+	MOVQ DX,R8
+	MOVQ 0(SI),AX
+	SHLQ $1,AX
+	MULQ 8(SI)
+	MOVQ AX,R9
+	MOVQ DX,R10
+	MOVQ 0(SI),AX
+	SHLQ $1,AX
+	MULQ 16(SI)
+	MOVQ AX,R11
+	MOVQ DX,R12
+	MOVQ 0(SI),AX
+	SHLQ $1,AX
+	MULQ 24(SI)
+	MOVQ AX,R13
+	MOVQ DX,R14
+	MOVQ 0(SI),AX
+	SHLQ $1,AX
+	MULQ 32(SI)
+	MOVQ AX,R15
+	MOVQ DX,BX
+	MOVQ 8(SI),AX
+	MULQ 8(SI)
+	ADDQ AX,R11
+	ADCQ DX,R12
+	MOVQ 8(SI),AX
+	SHLQ $1,AX
+	MULQ 16(SI)
+	ADDQ AX,R13
+	ADCQ DX,R14
+	MOVQ 8(SI),AX
+	SHLQ $1,AX
+	MULQ 24(SI)
+	ADDQ AX,R15
+	ADCQ DX,BX
+	MOVQ 8(SI),DX
+	IMUL3Q $38,DX,AX
+	MULQ 32(SI)
+	ADDQ AX,CX
+	ADCQ DX,R8
+	MOVQ 16(SI),AX
+	MULQ 16(SI)
+	ADDQ AX,R15
+	ADCQ DX,BX
+	MOVQ 16(SI),DX
+	IMUL3Q $38,DX,AX
+	MULQ 24(SI)
+	ADDQ AX,CX
+	ADCQ DX,R8
+	MOVQ 16(SI),DX
+	IMUL3Q $38,DX,AX
+	MULQ 32(SI)
+	ADDQ AX,R9
+	ADCQ DX,R10
+	MOVQ 24(SI),DX
+	IMUL3Q $19,DX,AX
+	MULQ 24(SI)
+	ADDQ AX,R9
+	ADCQ DX,R10
+	MOVQ 24(SI),DX
+	IMUL3Q $38,DX,AX
+	MULQ 32(SI)
+	ADDQ AX,R11
+	ADCQ DX,R12
+	MOVQ 32(SI),DX
+	IMUL3Q $19,DX,AX
+	MULQ 32(SI)
+	ADDQ AX,R13
+	ADCQ DX,R14
+	MOVQ ·REDMASK51(SB),SI
+	SHLQ $13,R8:CX
+	ANDQ SI,CX
+	SHLQ $13,R10:R9
+	ANDQ SI,R9
+	ADDQ R8,R9
+	SHLQ $13,R12:R11
+	ANDQ SI,R11
+	ADDQ R10,R11
+	SHLQ $13,R14:R13
+	ANDQ SI,R13
+	ADDQ R12,R13
+	SHLQ $13,BX:R15
+	ANDQ SI,R15
+	ADDQ R14,R15
+	IMUL3Q $19,BX,DX
+	ADDQ DX,CX
+	MOVQ CX,DX
+	SHRQ $51,DX
+	ADDQ R9,DX
+	ANDQ SI,CX
+	MOVQ DX,R8
+	SHRQ $51,DX
+	ADDQ R11,DX
+	ANDQ SI,R8
+	MOVQ DX,R9
+	SHRQ $51,DX
+	ADDQ R13,DX
+	ANDQ SI,R9
+	MOVQ DX,AX
+	SHRQ $51,DX
+	ADDQ R15,DX
+	ANDQ SI,AX
+	MOVQ DX,R10
+	SHRQ $51,DX
+	IMUL3Q $19,DX,DX
+	ADDQ DX,CX
+	ANDQ SI,R10
+	MOVQ CX,0(DI)
+	MOVQ R8,8(DI)
+	MOVQ R9,16(DI)
+	MOVQ AX,24(DI)
+	MOVQ R10,32(DI)
+	RET

vendor/golang.org/x/crypto/ed25519/ed25519.go

@@ -0,0 +1,181 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package ed25519 implements the Ed25519 signature algorithm. See
+// http://ed25519.cr.yp.to/.
+//
+// These functions are also compatible with the “Ed25519” function defined in
+// https://tools.ietf.org/html/draft-irtf-cfrg-eddsa-05.
+package ed25519
+
+// This code is a port of the public domain, “ref10” implementation of ed25519
+// from SUPERCOP.
+
+import (
+	"crypto"
+	cryptorand "crypto/rand"
+	"crypto/sha512"
+	"crypto/subtle"
+	"errors"
+	"io"
+	"strconv"
+
+	"golang.org/x/crypto/ed25519/internal/edwards25519"
+)
+
+const (
+	// PublicKeySize is the size, in bytes, of public keys as used in this package.
+	PublicKeySize = 32
+	// PrivateKeySize is the size, in bytes, of private keys as used in this package.
+	PrivateKeySize = 64
+	// SignatureSize is the size, in bytes, of signatures generated and verified by this package.
+	SignatureSize = 64
+)
+
+// PublicKey is the type of Ed25519 public keys.
+type PublicKey []byte
+
+// PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
+type PrivateKey []byte
+
+// Public returns the PublicKey corresponding to priv.
+func (priv PrivateKey) Public() crypto.PublicKey {
+	publicKey := make([]byte, PublicKeySize)
+	copy(publicKey, priv[32:])
+	return PublicKey(publicKey)
+}
+
+// Sign signs the given message with priv.
+// Ed25519 performs two passes over messages to be signed and therefore cannot
+// handle pre-hashed messages. Thus opts.HashFunc() must return zero to
+// indicate the message hasn't been hashed. This can be achieved by passing
+// crypto.Hash(0) as the value for opts.
+func (priv PrivateKey) Sign(rand io.Reader, message []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	if opts.HashFunc() != crypto.Hash(0) {
+		return nil, errors.New("ed25519: cannot sign hashed message")
+	}
+
+	return Sign(priv, message), nil
+}
+
+// GenerateKey generates a public/private key pair using entropy from rand.
+// If rand is nil, crypto/rand.Reader will be used.
+func GenerateKey(rand io.Reader) (publicKey PublicKey, privateKey PrivateKey, err error) {
+	if rand == nil {
+		rand = cryptorand.Reader
+	}
+
+	privateKey = make([]byte, PrivateKeySize)
+	publicKey = make([]byte, PublicKeySize)
+	_, err = io.ReadFull(rand, privateKey[:32])
+	if err != nil {
+		return nil, nil, err
+	}
+
+	digest := sha512.Sum512(privateKey[:32])
+	digest[0] &= 248
+	digest[31] &= 127
+	digest[31] |= 64
+
+	var A edwards25519.ExtendedGroupElement
+	var hBytes [32]byte
+	copy(hBytes[:], digest[:])
+	edwards25519.GeScalarMultBase(&A, &hBytes)
+	var publicKeyBytes [32]byte
+	A.ToBytes(&publicKeyBytes)
+
+	copy(privateKey[32:], publicKeyBytes[:])
+	copy(publicKey, publicKeyBytes[:])
+
+	return publicKey, privateKey, nil
+}
+
+// Sign signs the message with privateKey and returns a signature. It will
+// panic if len(privateKey) is not PrivateKeySize.
+func Sign(privateKey PrivateKey, message []byte) []byte {
+	if l := len(privateKey); l != PrivateKeySize {
+		panic("ed25519: bad private key length: " + strconv.Itoa(l))
+	}
+
+	h := sha512.New()
+	h.Write(privateKey[:32])
+
+	var digest1, messageDigest, hramDigest [64]byte
+	var expandedSecretKey [32]byte
+	h.Sum(digest1[:0])
+	copy(expandedSecretKey[:], digest1[:])
+	expandedSecretKey[0] &= 248
+	expandedSecretKey[31] &= 63
+	expandedSecretKey[31] |= 64
+
+	h.Reset()
+	h.Write(digest1[32:])
+	h.Write(message)
+	h.Sum(messageDigest[:0])
+
+	var messageDigestReduced [32]byte
+	edwards25519.ScReduce(&messageDigestReduced, &messageDigest)
+	var R edwards25519.ExtendedGroupElement
+	edwards25519.GeScalarMultBase(&R, &messageDigestReduced)
+
+	var encodedR [32]byte
+	R.ToBytes(&encodedR)
+
+	h.Reset()
+	h.Write(encodedR[:])
+	h.Write(privateKey[32:])
+	h.Write(message)
+	h.Sum(hramDigest[:0])
+	var hramDigestReduced [32]byte
+	edwards25519.ScReduce(&hramDigestReduced, &hramDigest)
+
+	var s [32]byte
+	edwards25519.ScMulAdd(&s, &hramDigestReduced, &expandedSecretKey, &messageDigestReduced)
+
+	signature := make([]byte, SignatureSize)
+	copy(signature[:], encodedR[:])
+	copy(signature[32:], s[:])
+
+	return signature
+}
+
+// Verify reports whether sig is a valid signature of message by publicKey. It
+// will panic if len(publicKey) is not PublicKeySize.
+func Verify(publicKey PublicKey, message, sig []byte) bool {
+	if l := len(publicKey); l != PublicKeySize {
+		panic("ed25519: bad public key length: " + strconv.Itoa(l))
+	}
+
+	if len(sig) != SignatureSize || sig[63]&224 != 0 {
+		return false
+	}
+
+	var A edwards25519.ExtendedGroupElement
+	var publicKeyBytes [32]byte
+	copy(publicKeyBytes[:], publicKey)
+	if !A.FromBytes(&publicKeyBytes) {
+		return false
+	}
+	edwards25519.FeNeg(&A.X, &A.X)
+	edwards25519.FeNeg(&A.T, &A.T)
+
+	h := sha512.New()
+	h.Write(sig[:32])
+	h.Write(publicKey[:])
+	h.Write(message)
+	var digest [64]byte
+	h.Sum(digest[:0])
+
+	var hReduced [32]byte
+	edwards25519.ScReduce(&hReduced, &digest)
+
+	var R edwards25519.ProjectiveGroupElement
+	var b [32]byte
+	copy(b[:], sig[32:])
+	edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &b)
+
+	var checkR [32]byte
+	R.ToBytes(&checkR)
+	return subtle.ConstantTimeCompare(sig[:32], checkR[:]) == 1
+}

vendor/golang.org/x/crypto/ed25519/ed25519_test.go

@@ -0,0 +1,183 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ed25519
+
+import (
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"crypto"
+	"crypto/rand"
+	"encoding/hex"
+	"os"
+	"strings"
+	"testing"
+
+	"golang.org/x/crypto/ed25519/internal/edwards25519"
+)
+
+type zeroReader struct{}
+
+func (zeroReader) Read(buf []byte) (int, error) {
+	for i := range buf {
+		buf[i] = 0
+	}
+	return len(buf), nil
+}
+
+func TestUnmarshalMarshal(t *testing.T) {
+	pub, _, _ := GenerateKey(rand.Reader)
+
+	var A edwards25519.ExtendedGroupElement
+	var pubBytes [32]byte
+	copy(pubBytes[:], pub)
+	if !A.FromBytes(&pubBytes) {
+		t.Fatalf("ExtendedGroupElement.FromBytes failed")
+	}
+
+	var pub2 [32]byte
+	A.ToBytes(&pub2)
+
+	if pubBytes != pub2 {
+		t.Errorf("FromBytes(%v)->ToBytes does not round-trip, got %x\n", pubBytes, pub2)
+	}
+}
+
+func TestSignVerify(t *testing.T) {
+	var zero zeroReader
+	public, private, _ := GenerateKey(zero)
+
+	message := []byte("test message")
+	sig := Sign(private, message)
+	if !Verify(public, message, sig) {
+		t.Errorf("valid signature rejected")
+	}
+
+	wrongMessage := []byte("wrong message")
+	if Verify(public, wrongMessage, sig) {
+		t.Errorf("signature of different message accepted")
+	}
+}
+
+func TestCryptoSigner(t *testing.T) {
+	var zero zeroReader
+	public, private, _ := GenerateKey(zero)
+
+	signer := crypto.Signer(private)
+
+	publicInterface := signer.Public()
+	public2, ok := publicInterface.(PublicKey)
+	if !ok {
+		t.Fatalf("expected PublicKey from Public() but got %T", publicInterface)
+	}
+
+	if !bytes.Equal(public, public2) {
+		t.Errorf("public keys do not match: original:%x vs Public():%x", public, public2)
+	}
+
+	message := []byte("message")
+	var noHash crypto.Hash
+	signature, err := signer.Sign(zero, message, noHash)
+	if err != nil {
+		t.Fatalf("error from Sign(): %s", err)
+	}
+
+	if !Verify(public, message, signature) {
+		t.Errorf("Verify failed on signature from Sign()")
+	}
+}
+
+func TestGolden(t *testing.T) {
+	// sign.input.gz is a selection of test cases from
+	// http://ed25519.cr.yp.to/python/sign.input
+	testDataZ, err := os.Open("testdata/sign.input.gz")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer testDataZ.Close()
+	testData, err := gzip.NewReader(testDataZ)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer testData.Close()
+
+	scanner := bufio.NewScanner(testData)
+	lineNo := 0
+
+	for scanner.Scan() {
+		lineNo++
+
+		line := scanner.Text()
+		parts := strings.Split(line, ":")
+		if len(parts) != 5 {
+			t.Fatalf("bad number of parts on line %d", lineNo)
+		}
+
+		privBytes, _ := hex.DecodeString(parts[0])
+		pubKey, _ := hex.DecodeString(parts[1])
+		msg, _ := hex.DecodeString(parts[2])
+		sig, _ := hex.DecodeString(parts[3])
+		// The signatures in the test vectors also include the message
+		// at the end, but we just want R and S.
+		sig = sig[:SignatureSize]
+
+		if l := len(pubKey); l != PublicKeySize {
+			t.Fatalf("bad public key length on line %d: got %d bytes", lineNo, l)
+		}
+
+		var priv [PrivateKeySize]byte
+		copy(priv[:], privBytes)
+		copy(priv[32:], pubKey)
+
+		sig2 := Sign(priv[:], msg)
+		if !bytes.Equal(sig, sig2[:]) {
+			t.Errorf("different signature result on line %d: %x vs %x", lineNo, sig, sig2)
+		}
+
+		if !Verify(pubKey, msg, sig2) {
+			t.Errorf("signature failed to verify on line %d", lineNo)
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		t.Fatalf("error reading test data: %s", err)
+	}
+}
+
+func BenchmarkKeyGeneration(b *testing.B) {
+	var zero zeroReader
+	for i := 0; i < b.N; i++ {
+		if _, _, err := GenerateKey(zero); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkSigning(b *testing.B) {
+	var zero zeroReader
+	_, priv, err := GenerateKey(zero)
+	if err != nil {
+		b.Fatal(err)
+	}
+	message := []byte("Hello, world!")
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Sign(priv, message)
+	}
+}
+
+func BenchmarkVerification(b *testing.B) {
+	var zero zeroReader
+	pub, priv, err := GenerateKey(zero)
+	if err != nil {
+		b.Fatal(err)
+	}
+	message := []byte("Hello, world!")
+	signature := Sign(priv, message)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Verify(pub, message, signature)
+	}
+}

vendor/golang.org/x/crypto/ssh/agent/client.go

@@ -0,0 +1,659 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package agent implements the ssh-agent protocol, and provides both
+// a client and a server. The client can talk to a standard ssh-agent
+// that uses UNIX sockets, and one could implement an alternative
+// ssh-agent process using the sample server.
+//
+// References:
+//  [PROTOCOL.agent]:    http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL.agent?rev=HEAD
+package agent // import "golang.org/x/crypto/ssh/agent"
+
+import (
+	"bytes"
+	"crypto/dsa"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"encoding/base64"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"sync"
+
+	"golang.org/x/crypto/ed25519"
+	"golang.org/x/crypto/ssh"
+)
+
+// Agent represents the capabilities of an ssh-agent.
+type Agent interface {
+	// List returns the identities known to the agent.
+	List() ([]*Key, error)
+
+	// Sign has the agent sign the data using a protocol 2 key as defined
+	// in [PROTOCOL.agent] section 2.6.2.
+	Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error)
+
+	// Add adds a private key to the agent.
+	Add(key AddedKey) error
+
+	// Remove removes all identities with the given public key.
+	Remove(key ssh.PublicKey) error
+
+	// RemoveAll removes all identities.
+	RemoveAll() error
+
+	// Lock locks the agent. Sign and Remove will fail, and List will empty an empty list.
+	Lock(passphrase []byte) error
+
+	// Unlock undoes the effect of Lock
+	Unlock(passphrase []byte) error
+
+	// Signers returns signers for all the known keys.
+	Signers() ([]ssh.Signer, error)
+}
+
+// AddedKey describes an SSH key to be added to an Agent.
+type AddedKey struct {
+	// PrivateKey must be a *rsa.PrivateKey, *dsa.PrivateKey or
+	// *ecdsa.PrivateKey, which will be inserted into the agent.
+	PrivateKey interface{}
+	// Certificate, if not nil, is communicated to the agent and will be
+	// stored with the key.
+	Certificate *ssh.Certificate
+	// Comment is an optional, free-form string.
+	Comment string
+	// LifetimeSecs, if not zero, is the number of seconds that the
+	// agent will store the key for.
+	LifetimeSecs uint32
+	// ConfirmBeforeUse, if true, requests that the agent confirm with the
+	// user before each use of this key.
+	ConfirmBeforeUse bool
+}
+
+// See [PROTOCOL.agent], section 3.
+const (
+	agentRequestV1Identities   = 1
+	agentRemoveAllV1Identities = 9
+
+	// 3.2 Requests from client to agent for protocol 2 key operations
+	agentAddIdentity         = 17
+	agentRemoveIdentity      = 18
+	agentRemoveAllIdentities = 19
+	agentAddIdConstrained    = 25
+
+	// 3.3 Key-type independent requests from client to agent
+	agentAddSmartcardKey            = 20
+	agentRemoveSmartcardKey         = 21
+	agentLock                       = 22
+	agentUnlock                     = 23
+	agentAddSmartcardKeyConstrained = 26
+
+	// 3.7 Key constraint identifiers
+	agentConstrainLifetime = 1
+	agentConstrainConfirm  = 2
+)
+
+// maxAgentResponseBytes is the maximum agent reply size that is accepted. This
+// is a sanity check, not a limit in the spec.
+const maxAgentResponseBytes = 16 << 20
+
+// Agent messages:
+// These structures mirror the wire format of the corresponding ssh agent
+// messages found in [PROTOCOL.agent].
+
+// 3.4 Generic replies from agent to client
+const agentFailure = 5
+
+type failureAgentMsg struct{}
+
+const agentSuccess = 6
+
+type successAgentMsg struct{}
+
+// See [PROTOCOL.agent], section 2.5.2.
+const agentRequestIdentities = 11
+
+type requestIdentitiesAgentMsg struct{}
+
+// See [PROTOCOL.agent], section 2.5.2.
+const agentIdentitiesAnswer = 12
+
+type identitiesAnswerAgentMsg struct {
+	NumKeys uint32 `sshtype:"12"`
+	Keys    []byte `ssh:"rest"`
+}
+
+// See [PROTOCOL.agent], section 2.6.2.
+const agentSignRequest = 13
+
+type signRequestAgentMsg struct {
+	KeyBlob []byte `sshtype:"13"`
+	Data    []byte
+	Flags   uint32
+}
+
+// See [PROTOCOL.agent], section 2.6.2.
+
+// 3.6 Replies from agent to client for protocol 2 key operations
+const agentSignResponse = 14
+
+type signResponseAgentMsg struct {
+	SigBlob []byte `sshtype:"14"`
+}
+
+type publicKey struct {
+	Format string
+	Rest   []byte `ssh:"rest"`
+}
+
+// Key represents a protocol 2 public key as defined in
+// [PROTOCOL.agent], section 2.5.2.
+type Key struct {
+	Format  string
+	Blob    []byte
+	Comment string
+}
+
+func clientErr(err error) error {
+	return fmt.Errorf("agent: client error: %v", err)
+}
+
+// String returns the storage form of an agent key with the format, base64
+// encoded serialized key, and the comment if it is not empty.
+func (k *Key) String() string {
+	s := string(k.Format) + " " + base64.StdEncoding.EncodeToString(k.Blob)
+
+	if k.Comment != "" {
+		s += " " + k.Comment
+	}
+
+	return s
+}
+
+// Type returns the public key type.
+func (k *Key) Type() string {
+	return k.Format
+}
+
+// Marshal returns key blob to satisfy the ssh.PublicKey interface.
+func (k *Key) Marshal() []byte {
+	return k.Blob
+}
+
+// Verify satisfies the ssh.PublicKey interface.
+func (k *Key) Verify(data []byte, sig *ssh.Signature) error {
+	pubKey, err := ssh.ParsePublicKey(k.Blob)
+	if err != nil {
+		return fmt.Errorf("agent: bad public key: %v", err)
+	}
+	return pubKey.Verify(data, sig)
+}
+
+type wireKey struct {
+	Format string
+	Rest   []byte `ssh:"rest"`
+}
+
+func parseKey(in []byte) (out *Key, rest []byte, err error) {
+	var record struct {
+		Blob    []byte
+		Comment string
+		Rest    []byte `ssh:"rest"`
+	}
+
+	if err := ssh.Unmarshal(in, &record); err != nil {
+		return nil, nil, err
+	}
+
+	var wk wireKey
+	if err := ssh.Unmarshal(record.Blob, &wk); err != nil {
+		return nil, nil, err
+	}
+
+	return &Key{
+		Format:  wk.Format,
+		Blob:    record.Blob,
+		Comment: record.Comment,
+	}, record.Rest, nil
+}
+
+// client is a client for an ssh-agent process.
+type client struct {
+	// conn is typically a *net.UnixConn
+	conn io.ReadWriter
+	// mu is used to prevent concurrent access to the agent
+	mu sync.Mutex
+}
+
+// NewClient returns an Agent that talks to an ssh-agent process over
+// the given connection.
+func NewClient(rw io.ReadWriter) Agent {
+	return &client{conn: rw}
+}
+
+// call sends an RPC to the agent. On success, the reply is
+// unmarshaled into reply and replyType is set to the first byte of
+// the reply, which contains the type of the message.
+func (c *client) call(req []byte) (reply interface{}, err error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	msg := make([]byte, 4+len(req))
+	binary.BigEndian.PutUint32(msg, uint32(len(req)))
+	copy(msg[4:], req)
+	if _, err = c.conn.Write(msg); err != nil {
+		return nil, clientErr(err)
+	}
+
+	var respSizeBuf [4]byte
+	if _, err = io.ReadFull(c.conn, respSizeBuf[:]); err != nil {
+		return nil, clientErr(err)
+	}
+	respSize := binary.BigEndian.Uint32(respSizeBuf[:])
+	if respSize > maxAgentResponseBytes {
+		return nil, clientErr(err)
+	}
+
+	buf := make([]byte, respSize)
+	if _, err = io.ReadFull(c.conn, buf); err != nil {
+		return nil, clientErr(err)
+	}
+	reply, err = unmarshal(buf)
+	if err != nil {
+		return nil, clientErr(err)
+	}
+	return reply, err
+}
+
+func (c *client) simpleCall(req []byte) error {
+	resp, err := c.call(req)
+	if err != nil {
+		return err
+	}
+	if _, ok := resp.(*successAgentMsg); ok {
+		return nil
+	}
+	return errors.New("agent: failure")
+}
+
+func (c *client) RemoveAll() error {
+	return c.simpleCall([]byte{agentRemoveAllIdentities})
+}
+
+func (c *client) Remove(key ssh.PublicKey) error {
+	req := ssh.Marshal(&agentRemoveIdentityMsg{
+		KeyBlob: key.Marshal(),
+	})
+	return c.simpleCall(req)
+}
+
+func (c *client) Lock(passphrase []byte) error {
+	req := ssh.Marshal(&agentLockMsg{
+		Passphrase: passphrase,
+	})
+	return c.simpleCall(req)
+}
+
+func (c *client) Unlock(passphrase []byte) error {
+	req := ssh.Marshal(&agentUnlockMsg{
+		Passphrase: passphrase,
+	})
+	return c.simpleCall(req)
+}
+
+// List returns the identities known to the agent.
+func (c *client) List() ([]*Key, error) {
+	// see [PROTOCOL.agent] section 2.5.2.
+	req := []byte{agentRequestIdentities}
+
+	msg, err := c.call(req)
+	if err != nil {
+		return nil, err
+	}
+
+	switch msg := msg.(type) {
+	case *identitiesAnswerAgentMsg:
+		if msg.NumKeys > maxAgentResponseBytes/8 {
+			return nil, errors.New("agent: too many keys in agent reply")
+		}
+		keys := make([]*Key, msg.NumKeys)
+		data := msg.Keys
+		for i := uint32(0); i < msg.NumKeys; i++ {
+			var key *Key
+			var err error
+			if key, data, err = parseKey(data); err != nil {
+				return nil, err
+			}
+			keys[i] = key
+		}
+		return keys, nil
+	case *failureAgentMsg:
+		return nil, errors.New("agent: failed to list keys")
+	}
+	panic("unreachable")
+}
+
+// Sign has the agent sign the data using a protocol 2 key as defined
+// in [PROTOCOL.agent] section 2.6.2.
+func (c *client) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
+	req := ssh.Marshal(signRequestAgentMsg{
+		KeyBlob: key.Marshal(),
+		Data:    data,
+	})
+
+	msg, err := c.call(req)
+	if err != nil {
+		return nil, err
+	}
+
+	switch msg := msg.(type) {
+	case *signResponseAgentMsg:
+		var sig ssh.Signature
+		if err := ssh.Unmarshal(msg.SigBlob, &sig); err != nil {
+			return nil, err
+		}
+
+		return &sig, nil
+	case *failureAgentMsg:
+		return nil, errors.New("agent: failed to sign challenge")
+	}
+	panic("unreachable")
+}
+
+// unmarshal parses an agent message in packet, returning the parsed
+// form and the message type of packet.
+func unmarshal(packet []byte) (interface{}, error) {
+	if len(packet) < 1 {
+		return nil, errors.New("agent: empty packet")
+	}
+	var msg interface{}
+	switch packet[0] {
+	case agentFailure:
+		return new(failureAgentMsg), nil
+	case agentSuccess:
+		return new(successAgentMsg), nil
+	case agentIdentitiesAnswer:
+		msg = new(identitiesAnswerAgentMsg)
+	case agentSignResponse:
+		msg = new(signResponseAgentMsg)
+	case agentV1IdentitiesAnswer:
+		msg = new(agentV1IdentityMsg)
+	default:
+		return nil, fmt.Errorf("agent: unknown type tag %d", packet[0])
+	}
+	if err := ssh.Unmarshal(packet, msg); err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+type rsaKeyMsg struct {
+	Type        string `sshtype:"17|25"`
+	N           *big.Int
+	E           *big.Int
+	D           *big.Int
+	Iqmp        *big.Int // IQMP = Inverse Q Mod P
+	P           *big.Int
+	Q           *big.Int
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+type dsaKeyMsg struct {
+	Type        string `sshtype:"17|25"`
+	P           *big.Int
+	Q           *big.Int
+	G           *big.Int
+	Y           *big.Int
+	X           *big.Int
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+type ecdsaKeyMsg struct {
+	Type        string `sshtype:"17|25"`
+	Curve       string
+	KeyBytes    []byte
+	D           *big.Int
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+type ed25519KeyMsg struct {
+	Type        string `sshtype:"17|25"`
+	Pub         []byte
+	Priv        []byte
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+// Insert adds a private key to the agent.
+func (c *client) insertKey(s interface{}, comment string, constraints []byte) error {
+	var req []byte
+	switch k := s.(type) {
+	case *rsa.PrivateKey:
+		if len(k.Primes) != 2 {
+			return fmt.Errorf("agent: unsupported RSA key with %d primes", len(k.Primes))
+		}
+		k.Precompute()
+		req = ssh.Marshal(rsaKeyMsg{
+			Type:        ssh.KeyAlgoRSA,
+			N:           k.N,
+			E:           big.NewInt(int64(k.E)),
+			D:           k.D,
+			Iqmp:        k.Precomputed.Qinv,
+			P:           k.Primes[0],
+			Q:           k.Primes[1],
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	case *dsa.PrivateKey:
+		req = ssh.Marshal(dsaKeyMsg{
+			Type:        ssh.KeyAlgoDSA,
+			P:           k.P,
+			Q:           k.Q,
+			G:           k.G,
+			Y:           k.Y,
+			X:           k.X,
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	case *ecdsa.PrivateKey:
+		nistID := fmt.Sprintf("nistp%d", k.Params().BitSize)
+		req = ssh.Marshal(ecdsaKeyMsg{
+			Type:        "ecdsa-sha2-" + nistID,
+			Curve:       nistID,
+			KeyBytes:    elliptic.Marshal(k.Curve, k.X, k.Y),
+			D:           k.D,
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	case *ed25519.PrivateKey:
+		req = ssh.Marshal(ed25519KeyMsg{
+			Type:        ssh.KeyAlgoED25519,
+			Pub:         []byte(*k)[32:],
+			Priv:        []byte(*k),
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	default:
+		return fmt.Errorf("agent: unsupported key type %T", s)
+	}
+
+	// if constraints are present then the message type needs to be changed.
+	if len(constraints) != 0 {
+		req[0] = agentAddIdConstrained
+	}
+
+	resp, err := c.call(req)
+	if err != nil {
+		return err
+	}
+	if _, ok := resp.(*successAgentMsg); ok {
+		return nil
+	}
+	return errors.New("agent: failure")
+}
+
+type rsaCertMsg struct {
+	Type        string `sshtype:"17|25"`
+	CertBytes   []byte
+	D           *big.Int
+	Iqmp        *big.Int // IQMP = Inverse Q Mod P
+	P           *big.Int
+	Q           *big.Int
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+type dsaCertMsg struct {
+	Type        string `sshtype:"17|25"`
+	CertBytes   []byte
+	X           *big.Int
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+type ecdsaCertMsg struct {
+	Type        string `sshtype:"17|25"`
+	CertBytes   []byte
+	D           *big.Int
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+type ed25519CertMsg struct {
+	Type        string `sshtype:"17|25"`
+	CertBytes   []byte
+	Pub         []byte
+	Priv        []byte
+	Comments    string
+	Constraints []byte `ssh:"rest"`
+}
+
+// Add adds a private key to the agent. If a certificate is given,
+// that certificate is added instead as public key.
+func (c *client) Add(key AddedKey) error {
+	var constraints []byte
+
+	if secs := key.LifetimeSecs; secs != 0 {
+		constraints = append(constraints, agentConstrainLifetime)
+
+		var secsBytes [4]byte
+		binary.BigEndian.PutUint32(secsBytes[:], secs)
+		constraints = append(constraints, secsBytes[:]...)
+	}
+
+	if key.ConfirmBeforeUse {
+		constraints = append(constraints, agentConstrainConfirm)
+	}
+
+	if cert := key.Certificate; cert == nil {
+		return c.insertKey(key.PrivateKey, key.Comment, constraints)
+	} else {
+		return c.insertCert(key.PrivateKey, cert, key.Comment, constraints)
+	}
+}
+
+func (c *client) insertCert(s interface{}, cert *ssh.Certificate, comment string, constraints []byte) error {
+	var req []byte
+	switch k := s.(type) {
+	case *rsa.PrivateKey:
+		if len(k.Primes) != 2 {
+			return fmt.Errorf("agent: unsupported RSA key with %d primes", len(k.Primes))
+		}
+		k.Precompute()
+		req = ssh.Marshal(rsaCertMsg{
+			Type:        cert.Type(),
+			CertBytes:   cert.Marshal(),
+			D:           k.D,
+			Iqmp:        k.Precomputed.Qinv,
+			P:           k.Primes[0],
+			Q:           k.Primes[1],
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	case *dsa.PrivateKey:
+		req = ssh.Marshal(dsaCertMsg{
+			Type:        cert.Type(),
+			CertBytes:   cert.Marshal(),
+			X:           k.X,
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	case *ecdsa.PrivateKey:
+		req = ssh.Marshal(ecdsaCertMsg{
+			Type:        cert.Type(),
+			CertBytes:   cert.Marshal(),
+			D:           k.D,
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	case *ed25519.PrivateKey:
+		req = ssh.Marshal(ed25519CertMsg{
+			Type:        cert.Type(),
+			CertBytes:   cert.Marshal(),
+			Pub:         []byte(*k)[32:],
+			Priv:        []byte(*k),
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	default:
+		return fmt.Errorf("agent: unsupported key type %T", s)
+	}
+
+	// if constraints are present then the message type needs to be changed.
+	if len(constraints) != 0 {
+		req[0] = agentAddIdConstrained
+	}
+
+	signer, err := ssh.NewSignerFromKey(s)
+	if err != nil {
+		return err
+	}
+	if bytes.Compare(cert.Key.Marshal(), signer.PublicKey().Marshal()) != 0 {
+		return errors.New("agent: signer and cert have different public key")
+	}
+
+	resp, err := c.call(req)
+	if err != nil {
+		return err
+	}
+	if _, ok := resp.(*successAgentMsg); ok {
+		return nil
+	}
+	return errors.New("agent: failure")
+}
+
+// Signers provides a callback for client authentication.
+func (c *client) Signers() ([]ssh.Signer, error) {
+	keys, err := c.List()
+	if err != nil {
+		return nil, err
+	}
+
+	var result []ssh.Signer
+	for _, k := range keys {
+		result = append(result, &agentKeyringSigner{c, k})
+	}
+	return result, nil
+}
+
+type agentKeyringSigner struct {
+	agent *client
+	pub   ssh.PublicKey
+}
+
+func (s *agentKeyringSigner) PublicKey() ssh.PublicKey {
+	return s.pub
+}
+
+func (s *agentKeyringSigner) Sign(rand io.Reader, data []byte) (*ssh.Signature, error) {
+	// The agent has its own entropy source, so the rand argument is ignored.
+	return s.agent.Sign(s.pub, data)
+}

vendor/golang.org/x/crypto/ssh/agent/forward.go

@@ -0,0 +1,103 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package agent
+
+import (
+	"errors"
+	"io"
+	"net"
+	"sync"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// RequestAgentForwarding sets up agent forwarding for the session.
+// ForwardToAgent or ForwardToRemote should be called to route
+// the authentication requests.
+func RequestAgentForwarding(session *ssh.Session) error {
+	ok, err := session.SendRequest("auth-agent-req@openssh.com", true, nil)
+	if err != nil {
+		return err
+	}
+	if !ok {
+		return errors.New("forwarding request denied")
+	}
+	return nil
+}
+
+// ForwardToAgent routes authentication requests to the given keyring.
+func ForwardToAgent(client *ssh.Client, keyring Agent) error {
+	channels := client.HandleChannelOpen(channelType)
+	if channels == nil {
+		return errors.New("agent: already have handler for " + channelType)
+	}
+
+	go func() {
+		for ch := range channels {
+			channel, reqs, err := ch.Accept()
+			if err != nil {
+				continue
+			}
+			go ssh.DiscardRequests(reqs)
+			go func() {
+				ServeAgent(keyring, channel)
+				channel.Close()
+			}()
+		}
+	}()
+	return nil
+}
+
+const channelType = "auth-agent@openssh.com"
+
+// ForwardToRemote routes authentication requests to the ssh-agent
+// process serving on the given unix socket.
+func ForwardToRemote(client *ssh.Client, addr string) error {
+	channels := client.HandleChannelOpen(channelType)
+	if channels == nil {
+		return errors.New("agent: already have handler for " + channelType)
+	}
+	conn, err := net.Dial("unix", addr)
+	if err != nil {
+		return err
+	}
+	conn.Close()
+
+	go func() {
+		for ch := range channels {
+			channel, reqs, err := ch.Accept()
+			if err != nil {
+				continue
+			}
+			go ssh.DiscardRequests(reqs)
+			go forwardUnixSocket(channel, addr)
+		}
+	}()
+	return nil
+}
+
+func forwardUnixSocket(channel ssh.Channel, addr string) {
+	conn, err := net.Dial("unix", addr)
+	if err != nil {
+		return
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		io.Copy(conn, channel)
+		conn.(*net.UnixConn).CloseWrite()
+		wg.Done()
+	}()
+	go func() {
+		io.Copy(channel, conn)
+		channel.CloseWrite()
+		wg.Done()
+	}()
+
+	wg.Wait()
+	conn.Close()
+	channel.Close()
+}

vendor/golang.org/x/crypto/ssh/agent/keyring.go

@@ -0,0 +1,215 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package agent
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/subtle"
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+
+	"golang.org/x/crypto/ssh"
+)
+
+type privKey struct {
+	signer  ssh.Signer
+	comment string
+	expire  *time.Time
+}
+
+type keyring struct {
+	mu   sync.Mutex
+	keys []privKey
+
+	locked     bool
+	passphrase []byte
+}
+
+var errLocked = errors.New("agent: locked")
+
+// NewKeyring returns an Agent that holds keys in memory.  It is safe
+// for concurrent use by multiple goroutines.
+func NewKeyring() Agent {
+	return &keyring{}
+}
+
+// RemoveAll removes all identities.
+func (r *keyring) RemoveAll() error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.locked {
+		return errLocked
+	}
+
+	r.keys = nil
+	return nil
+}
+
+// removeLocked does the actual key removal. The caller must already be holding the
+// keyring mutex.
+func (r *keyring) removeLocked(want []byte) error {
+	found := false
+	for i := 0; i < len(r.keys); {
+		if bytes.Equal(r.keys[i].signer.PublicKey().Marshal(), want) {
+			found = true
+			r.keys[i] = r.keys[len(r.keys)-1]
+			r.keys = r.keys[:len(r.keys)-1]
+			continue
+		} else {
+			i++
+		}
+	}
+
+	if !found {
+		return errors.New("agent: key not found")
+	}
+	return nil
+}
+
+// Remove removes all identities with the given public key.
+func (r *keyring) Remove(key ssh.PublicKey) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.locked {
+		return errLocked
+	}
+
+	return r.removeLocked(key.Marshal())
+}
+
+// Lock locks the agent. Sign and Remove will fail, and List will return an empty list.
+func (r *keyring) Lock(passphrase []byte) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.locked {
+		return errLocked
+	}
+
+	r.locked = true
+	r.passphrase = passphrase
+	return nil
+}
+
+// Unlock undoes the effect of Lock
+func (r *keyring) Unlock(passphrase []byte) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if !r.locked {
+		return errors.New("agent: not locked")
+	}
+	if len(passphrase) != len(r.passphrase) || 1 != subtle.ConstantTimeCompare(passphrase, r.passphrase) {
+		return fmt.Errorf("agent: incorrect passphrase")
+	}
+
+	r.locked = false
+	r.passphrase = nil
+	return nil
+}
+
+// expireKeysLocked removes expired keys from the keyring. If a key was added
+// with a lifetimesecs contraint and seconds >= lifetimesecs seconds have
+// ellapsed, it is removed. The caller *must* be holding the keyring mutex.
+func (r *keyring) expireKeysLocked() {
+	for _, k := range r.keys {
+		if k.expire != nil && time.Now().After(*k.expire) {
+			r.removeLocked(k.signer.PublicKey().Marshal())
+		}
+	}
+}
+
+// List returns the identities known to the agent.
+func (r *keyring) List() ([]*Key, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.locked {
+		// section 2.7: locked agents return empty.
+		return nil, nil
+	}
+
+	r.expireKeysLocked()
+	var ids []*Key
+	for _, k := range r.keys {
+		pub := k.signer.PublicKey()
+		ids = append(ids, &Key{
+			Format:  pub.Type(),
+			Blob:    pub.Marshal(),
+			Comment: k.comment})
+	}
+	return ids, nil
+}
+
+// Insert adds a private key to the keyring. If a certificate
+// is given, that certificate is added as public key. Note that
+// any constraints given are ignored.
+func (r *keyring) Add(key AddedKey) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.locked {
+		return errLocked
+	}
+	signer, err := ssh.NewSignerFromKey(key.PrivateKey)
+
+	if err != nil {
+		return err
+	}
+
+	if cert := key.Certificate; cert != nil {
+		signer, err = ssh.NewCertSigner(cert, signer)
+		if err != nil {
+			return err
+		}
+	}
+
+	p := privKey{
+		signer:  signer,
+		comment: key.Comment,
+	}
+
+	if key.LifetimeSecs > 0 {
+		t := time.Now().Add(time.Duration(key.LifetimeSecs) * time.Second)
+		p.expire = &t
+	}
+
+	r.keys = append(r.keys, p)
+
+	return nil
+}
+
+// Sign returns a signature for the data.
+func (r *keyring) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.locked {
+		return nil, errLocked
+	}
+
+	r.expireKeysLocked()
+	wanted := key.Marshal()
+	for _, k := range r.keys {
+		if bytes.Equal(k.signer.PublicKey().Marshal(), wanted) {
+			return k.signer.Sign(rand.Reader, data)
+		}
+	}
+	return nil, errors.New("not found")
+}
+
+// Signers returns signers for all the known keys.
+func (r *keyring) Signers() ([]ssh.Signer, error) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.locked {
+		return nil, errLocked
+	}
+
+	r.expireKeysLocked()
+	s := make([]ssh.Signer, 0, len(r.keys))
+	for _, k := range r.keys {
+		s = append(s, k.signer)
+	}
+	return s, nil
+}

vendor/golang.org/x/crypto/ssh/agent/server.go

@@ -0,0 +1,451 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package agent
+
+import (
+	"crypto/dsa"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"math/big"
+
+	"golang.org/x/crypto/ed25519"
+	"golang.org/x/crypto/ssh"
+)
+
+// Server wraps an Agent and uses it to implement the agent side of
+// the SSH-agent, wire protocol.
+type server struct {
+	agent Agent
+}
+
+func (s *server) processRequestBytes(reqData []byte) []byte {
+	rep, err := s.processRequest(reqData)
+	if err != nil {
+		if err != errLocked {
+			// TODO(hanwen): provide better logging interface?
+			log.Printf("agent %d: %v", reqData[0], err)
+		}
+		return []byte{agentFailure}
+	}
+
+	if err == nil && rep == nil {
+		return []byte{agentSuccess}
+	}
+
+	return ssh.Marshal(rep)
+}
+
+func marshalKey(k *Key) []byte {
+	var record struct {
+		Blob    []byte
+		Comment string
+	}
+	record.Blob = k.Marshal()
+	record.Comment = k.Comment
+
+	return ssh.Marshal(&record)
+}
+
+// See [PROTOCOL.agent], section 2.5.1.
+const agentV1IdentitiesAnswer = 2
+
+type agentV1IdentityMsg struct {
+	Numkeys uint32 `sshtype:"2"`
+}
+
+type agentRemoveIdentityMsg struct {
+	KeyBlob []byte `sshtype:"18"`
+}
+
+type agentLockMsg struct {
+	Passphrase []byte `sshtype:"22"`
+}
+
+type agentUnlockMsg struct {
+	Passphrase []byte `sshtype:"23"`
+}
+
+func (s *server) processRequest(data []byte) (interface{}, error) {
+	switch data[0] {
+	case agentRequestV1Identities:
+		return &agentV1IdentityMsg{0}, nil
+
+	case agentRemoveAllV1Identities:
+		return nil, nil
+
+	case agentRemoveIdentity:
+		var req agentRemoveIdentityMsg
+		if err := ssh.Unmarshal(data, &req); err != nil {
+			return nil, err
+		}
+
+		var wk wireKey
+		if err := ssh.Unmarshal(req.KeyBlob, &wk); err != nil {
+			return nil, err
+		}
+
+		return nil, s.agent.Remove(&Key{Format: wk.Format, Blob: req.KeyBlob})
+
+	case agentRemoveAllIdentities:
+		return nil, s.agent.RemoveAll()
+
+	case agentLock:
+		var req agentLockMsg
+		if err := ssh.Unmarshal(data, &req); err != nil {
+			return nil, err
+		}
+
+		return nil, s.agent.Lock(req.Passphrase)
+
+	case agentUnlock:
+		var req agentLockMsg
+		if err := ssh.Unmarshal(data, &req); err != nil {
+			return nil, err
+		}
+		return nil, s.agent.Unlock(req.Passphrase)
+
+	case agentSignRequest:
+		var req signRequestAgentMsg
+		if err := ssh.Unmarshal(data, &req); err != nil {
+			return nil, err
+		}
+
+		var wk wireKey
+		if err := ssh.Unmarshal(req.KeyBlob, &wk); err != nil {
+			return nil, err
+		}
+
+		k := &Key{
+			Format: wk.Format,
+			Blob:   req.KeyBlob,
+		}
+
+		sig, err := s.agent.Sign(k, req.Data) //  TODO(hanwen): flags.
+		if err != nil {
+			return nil, err
+		}
+		return &signResponseAgentMsg{SigBlob: ssh.Marshal(sig)}, nil
+
+	case agentRequestIdentities:
+		keys, err := s.agent.List()
+		if err != nil {
+			return nil, err
+		}
+
+		rep := identitiesAnswerAgentMsg{
+			NumKeys: uint32(len(keys)),
+		}
+		for _, k := range keys {
+			rep.Keys = append(rep.Keys, marshalKey(k)...)
+		}
+		return rep, nil
+
+	case agentAddIdConstrained, agentAddIdentity:
+		return nil, s.insertIdentity(data)
+	}
+
+	return nil, fmt.Errorf("unknown opcode %d", data[0])
+}
+
+func parseRSAKey(req []byte) (*AddedKey, error) {
+	var k rsaKeyMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+	if k.E.BitLen() > 30 {
+		return nil, errors.New("agent: RSA public exponent too large")
+	}
+	priv := &rsa.PrivateKey{
+		PublicKey: rsa.PublicKey{
+			E: int(k.E.Int64()),
+			N: k.N,
+		},
+		D:      k.D,
+		Primes: []*big.Int{k.P, k.Q},
+	}
+	priv.Precompute()
+
+	return &AddedKey{PrivateKey: priv, Comment: k.Comments}, nil
+}
+
+func parseEd25519Key(req []byte) (*AddedKey, error) {
+	var k ed25519KeyMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+	priv := ed25519.PrivateKey(k.Priv)
+	return &AddedKey{PrivateKey: &priv, Comment: k.Comments}, nil
+}
+
+func parseDSAKey(req []byte) (*AddedKey, error) {
+	var k dsaKeyMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+	priv := &dsa.PrivateKey{
+		PublicKey: dsa.PublicKey{
+			Parameters: dsa.Parameters{
+				P: k.P,
+				Q: k.Q,
+				G: k.G,
+			},
+			Y: k.Y,
+		},
+		X: k.X,
+	}
+
+	return &AddedKey{PrivateKey: priv, Comment: k.Comments}, nil
+}
+
+func unmarshalECDSA(curveName string, keyBytes []byte, privScalar *big.Int) (priv *ecdsa.PrivateKey, err error) {
+	priv = &ecdsa.PrivateKey{
+		D: privScalar,
+	}
+
+	switch curveName {
+	case "nistp256":
+		priv.Curve = elliptic.P256()
+	case "nistp384":
+		priv.Curve = elliptic.P384()
+	case "nistp521":
+		priv.Curve = elliptic.P521()
+	default:
+		return nil, fmt.Errorf("agent: unknown curve %q", curveName)
+	}
+
+	priv.X, priv.Y = elliptic.Unmarshal(priv.Curve, keyBytes)
+	if priv.X == nil || priv.Y == nil {
+		return nil, errors.New("agent: point not on curve")
+	}
+
+	return priv, nil
+}
+
+func parseEd25519Cert(req []byte) (*AddedKey, error) {
+	var k ed25519CertMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
+	if err != nil {
+		return nil, err
+	}
+	priv := ed25519.PrivateKey(k.Priv)
+	cert, ok := pubKey.(*ssh.Certificate)
+	if !ok {
+		return nil, errors.New("agent: bad ED25519 certificate")
+	}
+	return &AddedKey{PrivateKey: &priv, Certificate: cert, Comment: k.Comments}, nil
+}
+
+func parseECDSAKey(req []byte) (*AddedKey, error) {
+	var k ecdsaKeyMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+
+	priv, err := unmarshalECDSA(k.Curve, k.KeyBytes, k.D)
+	if err != nil {
+		return nil, err
+	}
+
+	return &AddedKey{PrivateKey: priv, Comment: k.Comments}, nil
+}
+
+func parseRSACert(req []byte) (*AddedKey, error) {
+	var k rsaCertMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+
+	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	cert, ok := pubKey.(*ssh.Certificate)
+	if !ok {
+		return nil, errors.New("agent: bad RSA certificate")
+	}
+
+	// An RSA publickey as marshaled by rsaPublicKey.Marshal() in keys.go
+	var rsaPub struct {
+		Name string
+		E    *big.Int
+		N    *big.Int
+	}
+	if err := ssh.Unmarshal(cert.Key.Marshal(), &rsaPub); err != nil {
+		return nil, fmt.Errorf("agent: Unmarshal failed to parse public key: %v", err)
+	}
+
+	if rsaPub.E.BitLen() > 30 {
+		return nil, errors.New("agent: RSA public exponent too large")
+	}
+
+	priv := rsa.PrivateKey{
+		PublicKey: rsa.PublicKey{
+			E: int(rsaPub.E.Int64()),
+			N: rsaPub.N,
+		},
+		D:      k.D,
+		Primes: []*big.Int{k.Q, k.P},
+	}
+	priv.Precompute()
+
+	return &AddedKey{PrivateKey: &priv, Certificate: cert, Comment: k.Comments}, nil
+}
+
+func parseDSACert(req []byte) (*AddedKey, error) {
+	var k dsaCertMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
+	if err != nil {
+		return nil, err
+	}
+	cert, ok := pubKey.(*ssh.Certificate)
+	if !ok {
+		return nil, errors.New("agent: bad DSA certificate")
+	}
+
+	// A DSA publickey as marshaled by dsaPublicKey.Marshal() in keys.go
+	var w struct {
+		Name       string
+		P, Q, G, Y *big.Int
+	}
+	if err := ssh.Unmarshal(cert.Key.Marshal(), &w); err != nil {
+		return nil, fmt.Errorf("agent: Unmarshal failed to parse public key: %v", err)
+	}
+
+	priv := &dsa.PrivateKey{
+		PublicKey: dsa.PublicKey{
+			Parameters: dsa.Parameters{
+				P: w.P,
+				Q: w.Q,
+				G: w.G,
+			},
+			Y: w.Y,
+		},
+		X: k.X,
+	}
+
+	return &AddedKey{PrivateKey: priv, Certificate: cert, Comment: k.Comments}, nil
+}
+
+func parseECDSACert(req []byte) (*AddedKey, error) {
+	var k ecdsaCertMsg
+	if err := ssh.Unmarshal(req, &k); err != nil {
+		return nil, err
+	}
+
+	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
+	if err != nil {
+		return nil, err
+	}
+	cert, ok := pubKey.(*ssh.Certificate)
+	if !ok {
+		return nil, errors.New("agent: bad ECDSA certificate")
+	}
+
+	// An ECDSA publickey as marshaled by ecdsaPublicKey.Marshal() in keys.go
+	var ecdsaPub struct {
+		Name string
+		ID   string
+		Key  []byte
+	}
+	if err := ssh.Unmarshal(cert.Key.Marshal(), &ecdsaPub); err != nil {
+		return nil, err
+	}
+
+	priv, err := unmarshalECDSA(ecdsaPub.ID, ecdsaPub.Key, k.D)
+	if err != nil {
+		return nil, err
+	}
+
+	return &AddedKey{PrivateKey: priv, Certificate: cert, Comment: k.Comments}, nil
+}
+
+func (s *server) insertIdentity(req []byte) error {
+	var record struct {
+		Type string `sshtype:"17|25"`
+		Rest []byte `ssh:"rest"`
+	}
+
+	if err := ssh.Unmarshal(req, &record); err != nil {
+		return err
+	}
+
+	var addedKey *AddedKey
+	var err error
+
+	switch record.Type {
+	case ssh.KeyAlgoRSA:
+		addedKey, err = parseRSAKey(req)
+	case ssh.KeyAlgoDSA:
+		addedKey, err = parseDSAKey(req)
+	case ssh.KeyAlgoECDSA256, ssh.KeyAlgoECDSA384, ssh.KeyAlgoECDSA521:
+		addedKey, err = parseECDSAKey(req)
+	case ssh.KeyAlgoED25519:
+		addedKey, err = parseEd25519Key(req)
+	case ssh.CertAlgoRSAv01:
+		addedKey, err = parseRSACert(req)
+	case ssh.CertAlgoDSAv01:
+		addedKey, err = parseDSACert(req)
+	case ssh.CertAlgoECDSA256v01, ssh.CertAlgoECDSA384v01, ssh.CertAlgoECDSA521v01:
+		addedKey, err = parseECDSACert(req)
+	case ssh.CertAlgoED25519v01:
+		addedKey, err = parseEd25519Cert(req)
+	default:
+		return fmt.Errorf("agent: not implemented: %q", record.Type)
+	}
+
+	if err != nil {
+		return err
+	}
+	return s.agent.Add(*addedKey)
+}
+
+// ServeAgent serves the agent protocol on the given connection. It
+// returns when an I/O error occurs.
+func ServeAgent(agent Agent, c io.ReadWriter) error {
+	s := &server{agent}
+
+	var length [4]byte
+	for {
+		if _, err := io.ReadFull(c, length[:]); err != nil {
+			return err
+		}
+		l := binary.BigEndian.Uint32(length[:])
+		if l > maxAgentResponseBytes {
+			// We also cap requests.
+			return fmt.Errorf("agent: request too large: %d", l)
+		}
+
+		req := make([]byte, l)
+		if _, err := io.ReadFull(c, req); err != nil {
+			return err
+		}
+
+		repData := s.processRequestBytes(req)
+		if len(repData) > maxAgentResponseBytes {
+			return fmt.Errorf("agent: reply too large: %d bytes", len(repData))
+		}
+
+		binary.BigEndian.PutUint32(length[:], uint32(len(repData)))
+		if _, err := c.Write(length[:]); err != nil {
+			return err
+		}
+		if _, err := c.Write(repData); err != nil {
+			return err
+		}
+	}
+}

vendor/golang.org/x/crypto/ssh/benchmark_test.go

@@ -0,0 +1,122 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"errors"
+	"io"
+	"net"
+	"testing"
+)
+
+type server struct {
+	*ServerConn
+	chans <-chan NewChannel
+}
+
+func newServer(c net.Conn, conf *ServerConfig) (*server, error) {
+	sconn, chans, reqs, err := NewServerConn(c, conf)
+	if err != nil {
+		return nil, err
+	}
+	go DiscardRequests(reqs)
+	return &server{sconn, chans}, nil
+}
+
+func (s *server) Accept() (NewChannel, error) {
+	n, ok := <-s.chans
+	if !ok {
+		return nil, io.EOF
+	}
+	return n, nil
+}
+
+func sshPipe() (Conn, *server, error) {
+	c1, c2, err := netPipe()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	clientConf := ClientConfig{
+		User: "user",
+	}
+	serverConf := ServerConfig{
+		NoClientAuth: true,
+	}
+	serverConf.AddHostKey(testSigners["ecdsa"])
+	done := make(chan *server, 1)
+	go func() {
+		server, err := newServer(c2, &serverConf)
+		if err != nil {
+			done <- nil
+		}
+		done <- server
+	}()
+
+	client, _, reqs, err := NewClientConn(c1, "", &clientConf)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	server := <-done
+	if server == nil {
+		return nil, nil, errors.New("server handshake failed.")
+	}
+	go DiscardRequests(reqs)
+
+	return client, server, nil
+}
+
+func BenchmarkEndToEnd(b *testing.B) {
+	b.StopTimer()
+
+	client, server, err := sshPipe()
+	if err != nil {
+		b.Fatalf("sshPipe: %v", err)
+	}
+
+	defer client.Close()
+	defer server.Close()
+
+	size := (1 << 20)
+	input := make([]byte, size)
+	output := make([]byte, size)
+	b.SetBytes(int64(size))
+	done := make(chan int, 1)
+
+	go func() {
+		newCh, err := server.Accept()
+		if err != nil {
+			b.Fatalf("Client: %v", err)
+		}
+		ch, incoming, err := newCh.Accept()
+		go DiscardRequests(incoming)
+		for i := 0; i < b.N; i++ {
+			if _, err := io.ReadFull(ch, output); err != nil {
+				b.Fatalf("ReadFull: %v", err)
+			}
+		}
+		ch.Close()
+		done <- 1
+	}()
+
+	ch, in, err := client.OpenChannel("speed", nil)
+	if err != nil {
+		b.Fatalf("OpenChannel: %v", err)
+	}
+	go DiscardRequests(in)
+
+	b.ResetTimer()
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		if _, err := ch.Write(input); err != nil {
+			b.Fatalf("WriteFull: %v", err)
+		}
+	}
+	ch.Close()
+	b.StopTimer()
+
+	<-done
+}

vendor/golang.org/x/crypto/ssh/buffer.go

@@ -0,0 +1,98 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"io"
+	"sync"
+)
+
+// buffer provides a linked list buffer for data exchange
+// between producer and consumer. Theoretically the buffer is
+// of unlimited capacity as it does no allocation of its own.
+type buffer struct {
+	// protects concurrent access to head, tail and closed
+	*sync.Cond
+
+	head *element // the buffer that will be read first
+	tail *element // the buffer that will be read last
+
+	closed bool
+}
+
+// An element represents a single link in a linked list.
+type element struct {
+	buf  []byte
+	next *element
+}
+
+// newBuffer returns an empty buffer that is not closed.
+func newBuffer() *buffer {
+	e := new(element)
+	b := &buffer{
+		Cond: newCond(),
+		head: e,
+		tail: e,
+	}
+	return b
+}
+
+// write makes buf available for Read to receive.
+// buf must not be modified after the call to write.
+func (b *buffer) write(buf []byte) {
+	b.Cond.L.Lock()
+	e := &element{buf: buf}
+	b.tail.next = e
+	b.tail = e
+	b.Cond.Signal()
+	b.Cond.L.Unlock()
+}
+
+// eof closes the buffer. Reads from the buffer once all
+// the data has been consumed will receive os.EOF.
+func (b *buffer) eof() error {
+	b.Cond.L.Lock()
+	b.closed = true
+	b.Cond.Signal()
+	b.Cond.L.Unlock()
+	return nil
+}
+
+// Read reads data from the internal buffer in buf.  Reads will block
+// if no data is available, or until the buffer is closed.
+func (b *buffer) Read(buf []byte) (n int, err error) {
+	b.Cond.L.Lock()
+	defer b.Cond.L.Unlock()
+
+	for len(buf) > 0 {
+		// if there is data in b.head, copy it
+		if len(b.head.buf) > 0 {
+			r := copy(buf, b.head.buf)
+			buf, b.head.buf = buf[r:], b.head.buf[r:]
+			n += r
+			continue
+		}
+		// if there is a next buffer, make it the head
+		if len(b.head.buf) == 0 && b.head != b.tail {
+			b.head = b.head.next
+			continue
+		}
+
+		// if at least one byte has been copied, return
+		if n > 0 {
+			break
+		}
+
+		// if nothing was read, and there is nothing outstanding
+		// check to see if the buffer is closed.
+		if b.closed {
+			err = io.EOF
+			break
+		}
+		// out of buffers, wait for producer
+		b.Cond.Wait()
+	}
+	return
+}

vendor/golang.org/x/crypto/ssh/buffer_test.go

@@ -0,0 +1,87 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"io"
+	"testing"
+)
+
+var alphabet = []byte("abcdefghijklmnopqrstuvwxyz")
+
+func TestBufferReadwrite(t *testing.T) {
+	b := newBuffer()
+	b.write(alphabet[:10])
+	r, _ := b.Read(make([]byte, 10))
+	if r != 10 {
+		t.Fatalf("Expected written == read == 10, written: 10, read %d", r)
+	}
+
+	b = newBuffer()
+	b.write(alphabet[:5])
+	r, _ = b.Read(make([]byte, 10))
+	if r != 5 {
+		t.Fatalf("Expected written == read == 5, written: 5, read %d", r)
+	}
+
+	b = newBuffer()
+	b.write(alphabet[:10])
+	r, _ = b.Read(make([]byte, 5))
+	if r != 5 {
+		t.Fatalf("Expected written == 10, read == 5, written: 10, read %d", r)
+	}
+
+	b = newBuffer()
+	b.write(alphabet[:5])
+	b.write(alphabet[5:15])
+	r, _ = b.Read(make([]byte, 10))
+	r2, _ := b.Read(make([]byte, 10))
+	if r != 10 || r2 != 5 || 15 != r+r2 {
+		t.Fatal("Expected written == read == 15")
+	}
+}
+
+func TestBufferClose(t *testing.T) {
+	b := newBuffer()
+	b.write(alphabet[:10])
+	b.eof()
+	_, err := b.Read(make([]byte, 5))
+	if err != nil {
+		t.Fatal("expected read of 5 to not return EOF")
+	}
+	b = newBuffer()
+	b.write(alphabet[:10])
+	b.eof()
+	r, err := b.Read(make([]byte, 5))
+	r2, err2 := b.Read(make([]byte, 10))
+	if r != 5 || r2 != 5 || err != nil || err2 != nil {
+		t.Fatal("expected reads of 5 and 5")
+	}
+
+	b = newBuffer()
+	b.write(alphabet[:10])
+	b.eof()
+	r, err = b.Read(make([]byte, 5))
+	r2, err2 = b.Read(make([]byte, 10))
+	r3, err3 := b.Read(make([]byte, 10))
+	if r != 5 || r2 != 5 || r3 != 0 || err != nil || err2 != nil || err3 != io.EOF {
+		t.Fatal("expected reads of 5 and 5 and 0, with EOF")
+	}
+
+	b = newBuffer()
+	b.write(make([]byte, 5))
+	b.write(make([]byte, 10))
+	b.eof()
+	r, err = b.Read(make([]byte, 9))
+	r2, err2 = b.Read(make([]byte, 3))
+	r3, err3 = b.Read(make([]byte, 3))
+	r4, err4 := b.Read(make([]byte, 10))
+	if err != nil || err2 != nil || err3 != nil || err4 != io.EOF {
+		t.Fatalf("Expected EOF on forth read only, err=%v, err2=%v, err3=%v, err4=%v", err, err2, err3, err4)
+	}
+	if r != 9 || r2 != 3 || r3 != 3 || r4 != 0 {
+		t.Fatal("Expected written == read == 15", r, r2, r3, r4)
+	}
+}

vendor/golang.org/x/crypto/ssh/certs.go

@@ -0,0 +1,503 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"sort"
+	"time"
+)
+
+// These constants from [PROTOCOL.certkeys] represent the algorithm names
+// for certificate types supported by this package.
+const (
+	CertAlgoRSAv01      = "ssh-rsa-cert-v01@openssh.com"
+	CertAlgoDSAv01      = "ssh-dss-cert-v01@openssh.com"
+	CertAlgoECDSA256v01 = "ecdsa-sha2-nistp256-cert-v01@openssh.com"
+	CertAlgoECDSA384v01 = "ecdsa-sha2-nistp384-cert-v01@openssh.com"
+	CertAlgoECDSA521v01 = "ecdsa-sha2-nistp521-cert-v01@openssh.com"
+	CertAlgoED25519v01  = "ssh-ed25519-cert-v01@openssh.com"
+)
+
+// Certificate types distinguish between host and user
+// certificates. The values can be set in the CertType field of
+// Certificate.
+const (
+	UserCert = 1
+	HostCert = 2
+)
+
+// Signature represents a cryptographic signature.
+type Signature struct {
+	Format string
+	Blob   []byte
+}
+
+// CertTimeInfinity can be used for OpenSSHCertV01.ValidBefore to indicate that
+// a certificate does not expire.
+const CertTimeInfinity = 1<<64 - 1
+
+// An Certificate represents an OpenSSH certificate as defined in
+// [PROTOCOL.certkeys]?rev=1.8.
+type Certificate struct {
+	Nonce           []byte
+	Key             PublicKey
+	Serial          uint64
+	CertType        uint32
+	KeyId           string
+	ValidPrincipals []string
+	ValidAfter      uint64
+	ValidBefore     uint64
+	Permissions
+	Reserved     []byte
+	SignatureKey PublicKey
+	Signature    *Signature
+}
+
+// genericCertData holds the key-independent part of the certificate data.
+// Overall, certificates contain an nonce, public key fields and
+// key-independent fields.
+type genericCertData struct {
+	Serial          uint64
+	CertType        uint32
+	KeyId           string
+	ValidPrincipals []byte
+	ValidAfter      uint64
+	ValidBefore     uint64
+	CriticalOptions []byte
+	Extensions      []byte
+	Reserved        []byte
+	SignatureKey    []byte
+	Signature       []byte
+}
+
+func marshalStringList(namelist []string) []byte {
+	var to []byte
+	for _, name := range namelist {
+		s := struct{ N string }{name}
+		to = append(to, Marshal(&s)...)
+	}
+	return to
+}
+
+type optionsTuple struct {
+	Key   string
+	Value []byte
+}
+
+type optionsTupleValue struct {
+	Value string
+}
+
+// serialize a map of critical options or extensions
+// issue #10569 - per [PROTOCOL.certkeys] and SSH implementation,
+// we need two length prefixes for a non-empty string value
+func marshalTuples(tups map[string]string) []byte {
+	keys := make([]string, 0, len(tups))
+	for key := range tups {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+
+	var ret []byte
+	for _, key := range keys {
+		s := optionsTuple{Key: key}
+		if value := tups[key]; len(value) > 0 {
+			s.Value = Marshal(&optionsTupleValue{value})
+		}
+		ret = append(ret, Marshal(&s)...)
+	}
+	return ret
+}
+
+// issue #10569 - per [PROTOCOL.certkeys] and SSH implementation,
+// we need two length prefixes for a non-empty option value
+func parseTuples(in []byte) (map[string]string, error) {
+	tups := map[string]string{}
+	var lastKey string
+	var haveLastKey bool
+
+	for len(in) > 0 {
+		var key, val, extra []byte
+		var ok bool
+
+		if key, in, ok = parseString(in); !ok {
+			return nil, errShortRead
+		}
+		keyStr := string(key)
+		// according to [PROTOCOL.certkeys], the names must be in
+		// lexical order.
+		if haveLastKey && keyStr <= lastKey {
+			return nil, fmt.Errorf("ssh: certificate options are not in lexical order")
+		}
+		lastKey, haveLastKey = keyStr, true
+		// the next field is a data field, which if non-empty has a string embedded
+		if val, in, ok = parseString(in); !ok {
+			return nil, errShortRead
+		}
+		if len(val) > 0 {
+			val, extra, ok = parseString(val)
+			if !ok {
+				return nil, errShortRead
+			}
+			if len(extra) > 0 {
+				return nil, fmt.Errorf("ssh: unexpected trailing data after certificate option value")
+			}
+			tups[keyStr] = string(val)
+		} else {
+			tups[keyStr] = ""
+		}
+	}
+	return tups, nil
+}
+
+func parseCert(in []byte, privAlgo string) (*Certificate, error) {
+	nonce, rest, ok := parseString(in)
+	if !ok {
+		return nil, errShortRead
+	}
+
+	key, rest, err := parsePubKey(rest, privAlgo)
+	if err != nil {
+		return nil, err
+	}
+
+	var g genericCertData
+	if err := Unmarshal(rest, &g); err != nil {
+		return nil, err
+	}
+
+	c := &Certificate{
+		Nonce:       nonce,
+		Key:         key,
+		Serial:      g.Serial,
+		CertType:    g.CertType,
+		KeyId:       g.KeyId,
+		ValidAfter:  g.ValidAfter,
+		ValidBefore: g.ValidBefore,
+	}
+
+	for principals := g.ValidPrincipals; len(principals) > 0; {
+		principal, rest, ok := parseString(principals)
+		if !ok {
+			return nil, errShortRead
+		}
+		c.ValidPrincipals = append(c.ValidPrincipals, string(principal))
+		principals = rest
+	}
+
+	c.CriticalOptions, err = parseTuples(g.CriticalOptions)
+	if err != nil {
+		return nil, err
+	}
+	c.Extensions, err = parseTuples(g.Extensions)
+	if err != nil {
+		return nil, err
+	}
+	c.Reserved = g.Reserved
+	k, err := ParsePublicKey(g.SignatureKey)
+	if err != nil {
+		return nil, err
+	}
+
+	c.SignatureKey = k
+	c.Signature, rest, ok = parseSignatureBody(g.Signature)
+	if !ok || len(rest) > 0 {
+		return nil, errors.New("ssh: signature parse error")
+	}
+
+	return c, nil
+}
+
+type openSSHCertSigner struct {
+	pub    *Certificate
+	signer Signer
+}
+
+// NewCertSigner returns a Signer that signs with the given Certificate, whose
+// private key is held by signer. It returns an error if the public key in cert
+// doesn't match the key used by signer.
+func NewCertSigner(cert *Certificate, signer Signer) (Signer, error) {
+	if bytes.Compare(cert.Key.Marshal(), signer.PublicKey().Marshal()) != 0 {
+		return nil, errors.New("ssh: signer and cert have different public key")
+	}
+
+	return &openSSHCertSigner{cert, signer}, nil
+}
+
+func (s *openSSHCertSigner) Sign(rand io.Reader, data []byte) (*Signature, error) {
+	return s.signer.Sign(rand, data)
+}
+
+func (s *openSSHCertSigner) PublicKey() PublicKey {
+	return s.pub
+}
+
+const sourceAddressCriticalOption = "source-address"
+
+// CertChecker does the work of verifying a certificate. Its methods
+// can be plugged into ClientConfig.HostKeyCallback and
+// ServerConfig.PublicKeyCallback. For the CertChecker to work,
+// minimally, the IsAuthority callback should be set.
+type CertChecker struct {
+	// SupportedCriticalOptions lists the CriticalOptions that the
+	// server application layer understands. These are only used
+	// for user certificates.
+	SupportedCriticalOptions []string
+
+	// IsAuthority should return true if the key is recognized as
+	// an authority. This allows for certificates to be signed by other
+	// certificates.
+	IsAuthority func(auth PublicKey) bool
+
+	// Clock is used for verifying time stamps. If nil, time.Now
+	// is used.
+	Clock func() time.Time
+
+	// UserKeyFallback is called when CertChecker.Authenticate encounters a
+	// public key that is not a certificate. It must implement validation
+	// of user keys or else, if nil, all such keys are rejected.
+	UserKeyFallback func(conn ConnMetadata, key PublicKey) (*Permissions, error)
+
+	// HostKeyFallback is called when CertChecker.CheckHostKey encounters a
+	// public key that is not a certificate. It must implement host key
+	// validation or else, if nil, all such keys are rejected.
+	HostKeyFallback func(addr string, remote net.Addr, key PublicKey) error
+
+	// IsRevoked is called for each certificate so that revocation checking
+	// can be implemented. It should return true if the given certificate
+	// is revoked and false otherwise. If nil, no certificates are
+	// considered to have been revoked.
+	IsRevoked func(cert *Certificate) bool
+}
+
+// CheckHostKey checks a host key certificate. This method can be
+// plugged into ClientConfig.HostKeyCallback.
+func (c *CertChecker) CheckHostKey(addr string, remote net.Addr, key PublicKey) error {
+	cert, ok := key.(*Certificate)
+	if !ok {
+		if c.HostKeyFallback != nil {
+			return c.HostKeyFallback(addr, remote, key)
+		}
+		return errors.New("ssh: non-certificate host key")
+	}
+	if cert.CertType != HostCert {
+		return fmt.Errorf("ssh: certificate presented as a host key has type %d", cert.CertType)
+	}
+
+	return c.CheckCert(addr, cert)
+}
+
+// Authenticate checks a user certificate. Authenticate can be used as
+// a value for ServerConfig.PublicKeyCallback.
+func (c *CertChecker) Authenticate(conn ConnMetadata, pubKey PublicKey) (*Permissions, error) {
+	cert, ok := pubKey.(*Certificate)
+	if !ok {
+		if c.UserKeyFallback != nil {
+			return c.UserKeyFallback(conn, pubKey)
+		}
+		return nil, errors.New("ssh: normal key pairs not accepted")
+	}
+
+	if cert.CertType != UserCert {
+		return nil, fmt.Errorf("ssh: cert has type %d", cert.CertType)
+	}
+
+	if err := c.CheckCert(conn.User(), cert); err != nil {
+		return nil, err
+	}
+
+	return &cert.Permissions, nil
+}
+
+// CheckCert checks CriticalOptions, ValidPrincipals, revocation, timestamp and
+// the signature of the certificate.
+func (c *CertChecker) CheckCert(principal string, cert *Certificate) error {
+	if c.IsRevoked != nil && c.IsRevoked(cert) {
+		return fmt.Errorf("ssh: certicate serial %d revoked", cert.Serial)
+	}
+
+	for opt, _ := range cert.CriticalOptions {
+		// sourceAddressCriticalOption will be enforced by
+		// serverAuthenticate
+		if opt == sourceAddressCriticalOption {
+			continue
+		}
+
+		found := false
+		for _, supp := range c.SupportedCriticalOptions {
+			if supp == opt {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return fmt.Errorf("ssh: unsupported critical option %q in certificate", opt)
+		}
+	}
+
+	if len(cert.ValidPrincipals) > 0 {
+		// By default, certs are valid for all users/hosts.
+		found := false
+		for _, p := range cert.ValidPrincipals {
+			if p == principal {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return fmt.Errorf("ssh: principal %q not in the set of valid principals for given certificate: %q", principal, cert.ValidPrincipals)
+		}
+	}
+
+	if !c.IsAuthority(cert.SignatureKey) {
+		return fmt.Errorf("ssh: certificate signed by unrecognized authority")
+	}
+
+	clock := c.Clock
+	if clock == nil {
+		clock = time.Now
+	}
+
+	unixNow := clock().Unix()
+	if after := int64(cert.ValidAfter); after < 0 || unixNow < int64(cert.ValidAfter) {
+		return fmt.Errorf("ssh: cert is not yet valid")
+	}
+	if before := int64(cert.ValidBefore); cert.ValidBefore != uint64(CertTimeInfinity) && (unixNow >= before || before < 0) {
+		return fmt.Errorf("ssh: cert has expired")
+	}
+	if err := cert.SignatureKey.Verify(cert.bytesForSigning(), cert.Signature); err != nil {
+		return fmt.Errorf("ssh: certificate signature does not verify")
+	}
+
+	return nil
+}
+
+// SignCert sets c.SignatureKey to the authority's public key and stores a
+// Signature, by authority, in the certificate.
+func (c *Certificate) SignCert(rand io.Reader, authority Signer) error {
+	c.Nonce = make([]byte, 32)
+	if _, err := io.ReadFull(rand, c.Nonce); err != nil {
+		return err
+	}
+	c.SignatureKey = authority.PublicKey()
+
+	sig, err := authority.Sign(rand, c.bytesForSigning())
+	if err != nil {
+		return err
+	}
+	c.Signature = sig
+	return nil
+}
+
+var certAlgoNames = map[string]string{
+	KeyAlgoRSA:      CertAlgoRSAv01,
+	KeyAlgoDSA:      CertAlgoDSAv01,
+	KeyAlgoECDSA256: CertAlgoECDSA256v01,
+	KeyAlgoECDSA384: CertAlgoECDSA384v01,
+	KeyAlgoECDSA521: CertAlgoECDSA521v01,
+	KeyAlgoED25519:  CertAlgoED25519v01,
+}
+
+// certToPrivAlgo returns the underlying algorithm for a certificate algorithm.
+// Panics if a non-certificate algorithm is passed.
+func certToPrivAlgo(algo string) string {
+	for privAlgo, pubAlgo := range certAlgoNames {
+		if pubAlgo == algo {
+			return privAlgo
+		}
+	}
+	panic("unknown cert algorithm")
+}
+
+func (cert *Certificate) bytesForSigning() []byte {
+	c2 := *cert
+	c2.Signature = nil
+	out := c2.Marshal()
+	// Drop trailing signature length.
+	return out[:len(out)-4]
+}
+
+// Marshal serializes c into OpenSSH's wire format. It is part of the
+// PublicKey interface.
+func (c *Certificate) Marshal() []byte {
+	generic := genericCertData{
+		Serial:          c.Serial,
+		CertType:        c.CertType,
+		KeyId:           c.KeyId,
+		ValidPrincipals: marshalStringList(c.ValidPrincipals),
+		ValidAfter:      uint64(c.ValidAfter),
+		ValidBefore:     uint64(c.ValidBefore),
+		CriticalOptions: marshalTuples(c.CriticalOptions),
+		Extensions:      marshalTuples(c.Extensions),
+		Reserved:        c.Reserved,
+		SignatureKey:    c.SignatureKey.Marshal(),
+	}
+	if c.Signature != nil {
+		generic.Signature = Marshal(c.Signature)
+	}
+	genericBytes := Marshal(&generic)
+	keyBytes := c.Key.Marshal()
+	_, keyBytes, _ = parseString(keyBytes)
+	prefix := Marshal(&struct {
+		Name  string
+		Nonce []byte
+		Key   []byte `ssh:"rest"`
+	}{c.Type(), c.Nonce, keyBytes})
+
+	result := make([]byte, 0, len(prefix)+len(genericBytes))
+	result = append(result, prefix...)
+	result = append(result, genericBytes...)
+	return result
+}
+
+// Type returns the key name. It is part of the PublicKey interface.
+func (c *Certificate) Type() string {
+	algo, ok := certAlgoNames[c.Key.Type()]
+	if !ok {
+		panic("unknown cert key type " + c.Key.Type())
+	}
+	return algo
+}
+
+// Verify verifies a signature against the certificate's public
+// key. It is part of the PublicKey interface.
+func (c *Certificate) Verify(data []byte, sig *Signature) error {
+	return c.Key.Verify(data, sig)
+}
+
+func parseSignatureBody(in []byte) (out *Signature, rest []byte, ok bool) {
+	format, in, ok := parseString(in)
+	if !ok {
+		return
+	}
+
+	out = &Signature{
+		Format: string(format),
+	}
+
+	if out.Blob, in, ok = parseString(in); !ok {
+		return
+	}
+
+	return out, in, ok
+}
+
+func parseSignature(in []byte) (out *Signature, rest []byte, ok bool) {
+	sigBytes, rest, ok := parseString(in)
+	if !ok {
+		return
+	}
+
+	out, trailing, ok := parseSignatureBody(sigBytes)
+	if !ok || len(trailing) > 0 {
+		return nil, nil, false
+	}
+	return
+}

vendor/golang.org/x/crypto/ssh/certs_test.go

@@ -0,0 +1,216 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"crypto/rand"
+	"reflect"
+	"testing"
+	"time"
+)
+
+// Cert generated by ssh-keygen 6.0p1 Debian-4.
+// % ssh-keygen -s ca-key -I test user-key
+const exampleSSHCert = `ssh-rsa-cert-v01@openssh.com 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`
+
+func TestParseCert(t *testing.T) {
+	authKeyBytes := []byte(exampleSSHCert)
+
+	key, _, _, rest, err := ParseAuthorizedKey(authKeyBytes)
+	if err != nil {
+		t.Fatalf("ParseAuthorizedKey: %v", err)
+	}
+	if len(rest) > 0 {
+		t.Errorf("rest: got %q, want empty", rest)
+	}
+
+	if _, ok := key.(*Certificate); !ok {
+		t.Fatalf("got %v (%T), want *Certificate", key, key)
+	}
+
+	marshaled := MarshalAuthorizedKey(key)
+	// Before comparison, remove the trailing newline that
+	// MarshalAuthorizedKey adds.
+	marshaled = marshaled[:len(marshaled)-1]
+	if !bytes.Equal(authKeyBytes, marshaled) {
+		t.Errorf("marshaled certificate does not match original: got %q, want %q", marshaled, authKeyBytes)
+	}
+}
+
+// Cert generated by ssh-keygen OpenSSH_6.8p1 OS X 10.10.3
+// % ssh-keygen -s ca -I testcert -O source-address=192.168.1.0/24 -O force-command=/bin/sleep user.pub
+// user.pub key: ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDACh1rt2DXfV3hk6fszSQcQ/rueMId0kVD9U7nl8cfEnFxqOCrNT92g4laQIGl2mn8lsGZfTLg8ksHq3gkvgO3oo/0wHy4v32JeBOHTsN5AL4gfHNEhWeWb50ev47hnTsRIt9P4dxogeUo/hTu7j9+s9lLpEQXCvq6xocXQt0j8MV9qZBBXFLXVT3cWIkSqOdwt/5ZBg+1GSrc7WfCXVWgTk4a20uPMuJPxU4RQwZW6X3+O8Pqo8C3cW0OzZRFP6gUYUKUsTI5WntlS+LAxgw1mZNsozFGdbiOPRnEryE3SRldh9vjDR3tin1fGpA5P7+CEB/bqaXtG3V+F2OkqaMN
+// Critical Options:
+//         force-command /bin/sleep
+//         source-address 192.168.1.0/24
+// Extensions:
+//         permit-X11-forwarding
+//         permit-agent-forwarding
+//         permit-port-forwarding
+//         permit-pty
+//         permit-user-rc
+const exampleSSHCertWithOptions = `ssh-rsa-cert-v01@openssh.com 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`
+
+func TestParseCertWithOptions(t *testing.T) {
+	opts := map[string]string{
+		"source-address": "192.168.1.0/24",
+		"force-command":  "/bin/sleep",
+	}
+	exts := map[string]string{
+		"permit-X11-forwarding":   "",
+		"permit-agent-forwarding": "",
+		"permit-port-forwarding":  "",
+		"permit-pty":              "",
+		"permit-user-rc":          "",
+	}
+	authKeyBytes := []byte(exampleSSHCertWithOptions)
+
+	key, _, _, rest, err := ParseAuthorizedKey(authKeyBytes)
+	if err != nil {
+		t.Fatalf("ParseAuthorizedKey: %v", err)
+	}
+	if len(rest) > 0 {
+		t.Errorf("rest: got %q, want empty", rest)
+	}
+	cert, ok := key.(*Certificate)
+	if !ok {
+		t.Fatalf("got %v (%T), want *Certificate", key, key)
+	}
+	if !reflect.DeepEqual(cert.CriticalOptions, opts) {
+		t.Errorf("unexpected critical options - got %v, want %v", cert.CriticalOptions, opts)
+	}
+	if !reflect.DeepEqual(cert.Extensions, exts) {
+		t.Errorf("unexpected Extensions - got %v, want %v", cert.Extensions, exts)
+	}
+	marshaled := MarshalAuthorizedKey(key)
+	// Before comparison, remove the trailing newline that
+	// MarshalAuthorizedKey adds.
+	marshaled = marshaled[:len(marshaled)-1]
+	if !bytes.Equal(authKeyBytes, marshaled) {
+		t.Errorf("marshaled certificate does not match original: got %q, want %q", marshaled, authKeyBytes)
+	}
+}
+
+func TestValidateCert(t *testing.T) {
+	key, _, _, _, err := ParseAuthorizedKey([]byte(exampleSSHCert))
+	if err != nil {
+		t.Fatalf("ParseAuthorizedKey: %v", err)
+	}
+	validCert, ok := key.(*Certificate)
+	if !ok {
+		t.Fatalf("got %v (%T), want *Certificate", key, key)
+	}
+	checker := CertChecker{}
+	checker.IsAuthority = func(k PublicKey) bool {
+		return bytes.Equal(k.Marshal(), validCert.SignatureKey.Marshal())
+	}
+
+	if err := checker.CheckCert("user", validCert); err != nil {
+		t.Errorf("Unable to validate certificate: %v", err)
+	}
+	invalidCert := &Certificate{
+		Key:          testPublicKeys["rsa"],
+		SignatureKey: testPublicKeys["ecdsa"],
+		ValidBefore:  CertTimeInfinity,
+		Signature:    &Signature{},
+	}
+	if err := checker.CheckCert("user", invalidCert); err == nil {
+		t.Error("Invalid cert signature passed validation")
+	}
+}
+
+func TestValidateCertTime(t *testing.T) {
+	cert := Certificate{
+		ValidPrincipals: []string{"user"},
+		Key:             testPublicKeys["rsa"],
+		ValidAfter:      50,
+		ValidBefore:     100,
+	}
+
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+
+	for ts, ok := range map[int64]bool{
+		25:  false,
+		50:  true,
+		99:  true,
+		100: false,
+		125: false,
+	} {
+		checker := CertChecker{
+			Clock: func() time.Time { return time.Unix(ts, 0) },
+		}
+		checker.IsAuthority = func(k PublicKey) bool {
+			return bytes.Equal(k.Marshal(),
+				testPublicKeys["ecdsa"].Marshal())
+		}
+
+		if v := checker.CheckCert("user", &cert); (v == nil) != ok {
+			t.Errorf("Authenticate(%d): %v", ts, v)
+		}
+	}
+}
+
+// TODO(hanwen): tests for
+//
+// host keys:
+// * fallbacks
+
+func TestHostKeyCert(t *testing.T) {
+	cert := &Certificate{
+		ValidPrincipals: []string{"hostname", "hostname.domain"},
+		Key:             testPublicKeys["rsa"],
+		ValidBefore:     CertTimeInfinity,
+		CertType:        HostCert,
+	}
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+
+	checker := &CertChecker{
+		IsAuthority: func(p PublicKey) bool {
+			return bytes.Equal(testPublicKeys["ecdsa"].Marshal(), p.Marshal())
+		},
+	}
+
+	certSigner, err := NewCertSigner(cert, testSigners["rsa"])
+	if err != nil {
+		t.Errorf("NewCertSigner: %v", err)
+	}
+
+	for _, name := range []string{"hostname", "otherhost"} {
+		c1, c2, err := netPipe()
+		if err != nil {
+			t.Fatalf("netPipe: %v", err)
+		}
+		defer c1.Close()
+		defer c2.Close()
+
+		errc := make(chan error)
+
+		go func() {
+			conf := ServerConfig{
+				NoClientAuth: true,
+			}
+			conf.AddHostKey(certSigner)
+			_, _, _, err := NewServerConn(c1, &conf)
+			errc <- err
+		}()
+
+		config := &ClientConfig{
+			User:            "user",
+			HostKeyCallback: checker.CheckHostKey,
+		}
+		_, _, _, err = NewClientConn(c2, name, config)
+
+		succeed := name == "hostname"
+		if (err == nil) != succeed {
+			t.Fatalf("NewClientConn(%q): %v", name, err)
+		}
+
+		err = <-errc
+		if (err == nil) != succeed {
+			t.Fatalf("NewServerConn(%q): %v", name, err)
+		}
+	}
+}

vendor/golang.org/x/crypto/ssh/channel.go

@@ -0,0 +1,633 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"sync"
+)
+
+const (
+	minPacketLength = 9
+	// channelMaxPacket contains the maximum number of bytes that will be
+	// sent in a single packet. As per RFC 4253, section 6.1, 32k is also
+	// the minimum.
+	channelMaxPacket = 1 << 15
+	// We follow OpenSSH here.
+	channelWindowSize = 64 * channelMaxPacket
+)
+
+// NewChannel represents an incoming request to a channel. It must either be
+// accepted for use by calling Accept, or rejected by calling Reject.
+type NewChannel interface {
+	// Accept accepts the channel creation request. It returns the Channel
+	// and a Go channel containing SSH requests. The Go channel must be
+	// serviced otherwise the Channel will hang.
+	Accept() (Channel, <-chan *Request, error)
+
+	// Reject rejects the channel creation request. After calling
+	// this, no other methods on the Channel may be called.
+	Reject(reason RejectionReason, message string) error
+
+	// ChannelType returns the type of the channel, as supplied by the
+	// client.
+	ChannelType() string
+
+	// ExtraData returns the arbitrary payload for this channel, as supplied
+	// by the client. This data is specific to the channel type.
+	ExtraData() []byte
+}
+
+// A Channel is an ordered, reliable, flow-controlled, duplex stream
+// that is multiplexed over an SSH connection.
+type Channel interface {
+	// Read reads up to len(data) bytes from the channel.
+	Read(data []byte) (int, error)
+
+	// Write writes len(data) bytes to the channel.
+	Write(data []byte) (int, error)
+
+	// Close signals end of channel use. No data may be sent after this
+	// call.
+	Close() error
+
+	// CloseWrite signals the end of sending in-band
+	// data. Requests may still be sent, and the other side may
+	// still send data
+	CloseWrite() error
+
+	// SendRequest sends a channel request.  If wantReply is true,
+	// it will wait for a reply and return the result as a
+	// boolean, otherwise the return value will be false. Channel
+	// requests are out-of-band messages so they may be sent even
+	// if the data stream is closed or blocked by flow control.
+	// If the channel is closed before a reply is returned, io.EOF
+	// is returned.
+	SendRequest(name string, wantReply bool, payload []byte) (bool, error)
+
+	// Stderr returns an io.ReadWriter that writes to this channel
+	// with the extended data type set to stderr. Stderr may
+	// safely be read and written from a different goroutine than
+	// Read and Write respectively.
+	Stderr() io.ReadWriter
+}
+
+// Request is a request sent outside of the normal stream of
+// data. Requests can either be specific to an SSH channel, or they
+// can be global.
+type Request struct {
+	Type      string
+	WantReply bool
+	Payload   []byte
+
+	ch  *channel
+	mux *mux
+}
+
+// Reply sends a response to a request. It must be called for all requests
+// where WantReply is true and is a no-op otherwise. The payload argument is
+// ignored for replies to channel-specific requests.
+func (r *Request) Reply(ok bool, payload []byte) error {
+	if !r.WantReply {
+		return nil
+	}
+
+	if r.ch == nil {
+		return r.mux.ackRequest(ok, payload)
+	}
+
+	return r.ch.ackRequest(ok)
+}
+
+// RejectionReason is an enumeration used when rejecting channel creation
+// requests. See RFC 4254, section 5.1.
+type RejectionReason uint32
+
+const (
+	Prohibited RejectionReason = iota + 1
+	ConnectionFailed
+	UnknownChannelType
+	ResourceShortage
+)
+
+// String converts the rejection reason to human readable form.
+func (r RejectionReason) String() string {
+	switch r {
+	case Prohibited:
+		return "administratively prohibited"
+	case ConnectionFailed:
+		return "connect failed"
+	case UnknownChannelType:
+		return "unknown channel type"
+	case ResourceShortage:
+		return "resource shortage"
+	}
+	return fmt.Sprintf("unknown reason %d", int(r))
+}
+
+func min(a uint32, b int) uint32 {
+	if a < uint32(b) {
+		return a
+	}
+	return uint32(b)
+}
+
+type channelDirection uint8
+
+const (
+	channelInbound channelDirection = iota
+	channelOutbound
+)
+
+// channel is an implementation of the Channel interface that works
+// with the mux class.
+type channel struct {
+	// R/O after creation
+	chanType          string
+	extraData         []byte
+	localId, remoteId uint32
+
+	// maxIncomingPayload and maxRemotePayload are the maximum
+	// payload sizes of normal and extended data packets for
+	// receiving and sending, respectively. The wire packet will
+	// be 9 or 13 bytes larger (excluding encryption overhead).
+	maxIncomingPayload uint32
+	maxRemotePayload   uint32
+
+	mux *mux
+
+	// decided is set to true if an accept or reject message has been sent
+	// (for outbound channels) or received (for inbound channels).
+	decided bool
+
+	// direction contains either channelOutbound, for channels created
+	// locally, or channelInbound, for channels created by the peer.
+	direction channelDirection
+
+	// Pending internal channel messages.
+	msg chan interface{}
+
+	// Since requests have no ID, there can be only one request
+	// with WantReply=true outstanding.  This lock is held by a
+	// goroutine that has such an outgoing request pending.
+	sentRequestMu sync.Mutex
+
+	incomingRequests chan *Request
+
+	sentEOF bool
+
+	// thread-safe data
+	remoteWin  window
+	pending    *buffer
+	extPending *buffer
+
+	// windowMu protects myWindow, the flow-control window.
+	windowMu sync.Mutex
+	myWindow uint32
+
+	// writeMu serializes calls to mux.conn.writePacket() and
+	// protects sentClose and packetPool. This mutex must be
+	// different from windowMu, as writePacket can block if there
+	// is a key exchange pending.
+	writeMu   sync.Mutex
+	sentClose bool
+
+	// packetPool has a buffer for each extended channel ID to
+	// save allocations during writes.
+	packetPool map[uint32][]byte
+}
+
+// writePacket sends a packet. If the packet is a channel close, it updates
+// sentClose. This method takes the lock c.writeMu.
+func (c *channel) writePacket(packet []byte) error {
+	c.writeMu.Lock()
+	if c.sentClose {
+		c.writeMu.Unlock()
+		return io.EOF
+	}
+	c.sentClose = (packet[0] == msgChannelClose)
+	err := c.mux.conn.writePacket(packet)
+	c.writeMu.Unlock()
+	return err
+}
+
+func (c *channel) sendMessage(msg interface{}) error {
+	if debugMux {
+		log.Printf("send(%d): %#v", c.mux.chanList.offset, msg)
+	}
+
+	p := Marshal(msg)
+	binary.BigEndian.PutUint32(p[1:], c.remoteId)
+	return c.writePacket(p)
+}
+
+// WriteExtended writes data to a specific extended stream. These streams are
+// used, for example, for stderr.
+func (c *channel) WriteExtended(data []byte, extendedCode uint32) (n int, err error) {
+	if c.sentEOF {
+		return 0, io.EOF
+	}
+	// 1 byte message type, 4 bytes remoteId, 4 bytes data length
+	opCode := byte(msgChannelData)
+	headerLength := uint32(9)
+	if extendedCode > 0 {
+		headerLength += 4
+		opCode = msgChannelExtendedData
+	}
+
+	c.writeMu.Lock()
+	packet := c.packetPool[extendedCode]
+	// We don't remove the buffer from packetPool, so
+	// WriteExtended calls from different goroutines will be
+	// flagged as errors by the race detector.
+	c.writeMu.Unlock()
+
+	for len(data) > 0 {
+		space := min(c.maxRemotePayload, len(data))
+		if space, err = c.remoteWin.reserve(space); err != nil {
+			return n, err
+		}
+		if want := headerLength + space; uint32(cap(packet)) < want {
+			packet = make([]byte, want)
+		} else {
+			packet = packet[:want]
+		}
+
+		todo := data[:space]
+
+		packet[0] = opCode
+		binary.BigEndian.PutUint32(packet[1:], c.remoteId)
+		if extendedCode > 0 {
+			binary.BigEndian.PutUint32(packet[5:], uint32(extendedCode))
+		}
+		binary.BigEndian.PutUint32(packet[headerLength-4:], uint32(len(todo)))
+		copy(packet[headerLength:], todo)
+		if err = c.writePacket(packet); err != nil {
+			return n, err
+		}
+
+		n += len(todo)
+		data = data[len(todo):]
+	}
+
+	c.writeMu.Lock()
+	c.packetPool[extendedCode] = packet
+	c.writeMu.Unlock()
+
+	return n, err
+}
+
+func (c *channel) handleData(packet []byte) error {
+	headerLen := 9
+	isExtendedData := packet[0] == msgChannelExtendedData
+	if isExtendedData {
+		headerLen = 13
+	}
+	if len(packet) < headerLen {
+		// malformed data packet
+		return parseError(packet[0])
+	}
+
+	var extended uint32
+	if isExtendedData {
+		extended = binary.BigEndian.Uint32(packet[5:])
+	}
+
+	length := binary.BigEndian.Uint32(packet[headerLen-4 : headerLen])
+	if length == 0 {
+		return nil
+	}
+	if length > c.maxIncomingPayload {
+		// TODO(hanwen): should send Disconnect?
+		return errors.New("ssh: incoming packet exceeds maximum payload size")
+	}
+
+	data := packet[headerLen:]
+	if length != uint32(len(data)) {
+		return errors.New("ssh: wrong packet length")
+	}
+
+	c.windowMu.Lock()
+	if c.myWindow < length {
+		c.windowMu.Unlock()
+		// TODO(hanwen): should send Disconnect with reason?
+		return errors.New("ssh: remote side wrote too much")
+	}
+	c.myWindow -= length
+	c.windowMu.Unlock()
+
+	if extended == 1 {
+		c.extPending.write(data)
+	} else if extended > 0 {
+		// discard other extended data.
+	} else {
+		c.pending.write(data)
+	}
+	return nil
+}
+
+func (c *channel) adjustWindow(n uint32) error {
+	c.windowMu.Lock()
+	// Since myWindow is managed on our side, and can never exceed
+	// the initial window setting, we don't worry about overflow.
+	c.myWindow += uint32(n)
+	c.windowMu.Unlock()
+	return c.sendMessage(windowAdjustMsg{
+		AdditionalBytes: uint32(n),
+	})
+}
+
+func (c *channel) ReadExtended(data []byte, extended uint32) (n int, err error) {
+	switch extended {
+	case 1:
+		n, err = c.extPending.Read(data)
+	case 0:
+		n, err = c.pending.Read(data)
+	default:
+		return 0, fmt.Errorf("ssh: extended code %d unimplemented", extended)
+	}
+
+	if n > 0 {
+		err = c.adjustWindow(uint32(n))
+		// sendWindowAdjust can return io.EOF if the remote
+		// peer has closed the connection, however we want to
+		// defer forwarding io.EOF to the caller of Read until
+		// the buffer has been drained.
+		if n > 0 && err == io.EOF {
+			err = nil
+		}
+	}
+
+	return n, err
+}
+
+func (c *channel) close() {
+	c.pending.eof()
+	c.extPending.eof()
+	close(c.msg)
+	close(c.incomingRequests)
+	c.writeMu.Lock()
+	// This is not necessary for a normal channel teardown, but if
+	// there was another error, it is.
+	c.sentClose = true
+	c.writeMu.Unlock()
+	// Unblock writers.
+	c.remoteWin.close()
+}
+
+// responseMessageReceived is called when a success or failure message is
+// received on a channel to check that such a message is reasonable for the
+// given channel.
+func (c *channel) responseMessageReceived() error {
+	if c.direction == channelInbound {
+		return errors.New("ssh: channel response message received on inbound channel")
+	}
+	if c.decided {
+		return errors.New("ssh: duplicate response received for channel")
+	}
+	c.decided = true
+	return nil
+}
+
+func (c *channel) handlePacket(packet []byte) error {
+	switch packet[0] {
+	case msgChannelData, msgChannelExtendedData:
+		return c.handleData(packet)
+	case msgChannelClose:
+		c.sendMessage(channelCloseMsg{PeersId: c.remoteId})
+		c.mux.chanList.remove(c.localId)
+		c.close()
+		return nil
+	case msgChannelEOF:
+		// RFC 4254 is mute on how EOF affects dataExt messages but
+		// it is logical to signal EOF at the same time.
+		c.extPending.eof()
+		c.pending.eof()
+		return nil
+	}
+
+	decoded, err := decode(packet)
+	if err != nil {
+		return err
+	}
+
+	switch msg := decoded.(type) {
+	case *channelOpenFailureMsg:
+		if err := c.responseMessageReceived(); err != nil {
+			return err
+		}
+		c.mux.chanList.remove(msg.PeersId)
+		c.msg <- msg
+	case *channelOpenConfirmMsg:
+		if err := c.responseMessageReceived(); err != nil {
+			return err
+		}
+		if msg.MaxPacketSize < minPacketLength || msg.MaxPacketSize > 1<<31 {
+			return fmt.Errorf("ssh: invalid MaxPacketSize %d from peer", msg.MaxPacketSize)
+		}
+		c.remoteId = msg.MyId
+		c.maxRemotePayload = msg.MaxPacketSize
+		c.remoteWin.add(msg.MyWindow)
+		c.msg <- msg
+	case *windowAdjustMsg:
+		if !c.remoteWin.add(msg.AdditionalBytes) {
+			return fmt.Errorf("ssh: invalid window update for %d bytes", msg.AdditionalBytes)
+		}
+	case *channelRequestMsg:
+		req := Request{
+			Type:      msg.Request,
+			WantReply: msg.WantReply,
+			Payload:   msg.RequestSpecificData,
+			ch:        c,
+		}
+
+		c.incomingRequests <- &req
+	default:
+		c.msg <- msg
+	}
+	return nil
+}
+
+func (m *mux) newChannel(chanType string, direction channelDirection, extraData []byte) *channel {
+	ch := &channel{
+		remoteWin:        window{Cond: newCond()},
+		myWindow:         channelWindowSize,
+		pending:          newBuffer(),
+		extPending:       newBuffer(),
+		direction:        direction,
+		incomingRequests: make(chan *Request, 16),
+		msg:              make(chan interface{}, 16),
+		chanType:         chanType,
+		extraData:        extraData,
+		mux:              m,
+		packetPool:       make(map[uint32][]byte),
+	}
+	ch.localId = m.chanList.add(ch)
+	return ch
+}
+
+var errUndecided = errors.New("ssh: must Accept or Reject channel")
+var errDecidedAlready = errors.New("ssh: can call Accept or Reject only once")
+
+type extChannel struct {
+	code uint32
+	ch   *channel
+}
+
+func (e *extChannel) Write(data []byte) (n int, err error) {
+	return e.ch.WriteExtended(data, e.code)
+}
+
+func (e *extChannel) Read(data []byte) (n int, err error) {
+	return e.ch.ReadExtended(data, e.code)
+}
+
+func (c *channel) Accept() (Channel, <-chan *Request, error) {
+	if c.decided {
+		return nil, nil, errDecidedAlready
+	}
+	c.maxIncomingPayload = channelMaxPacket
+	confirm := channelOpenConfirmMsg{
+		PeersId:       c.remoteId,
+		MyId:          c.localId,
+		MyWindow:      c.myWindow,
+		MaxPacketSize: c.maxIncomingPayload,
+	}
+	c.decided = true
+	if err := c.sendMessage(confirm); err != nil {
+		return nil, nil, err
+	}
+
+	return c, c.incomingRequests, nil
+}
+
+func (ch *channel) Reject(reason RejectionReason, message string) error {
+	if ch.decided {
+		return errDecidedAlready
+	}
+	reject := channelOpenFailureMsg{
+		PeersId:  ch.remoteId,
+		Reason:   reason,
+		Message:  message,
+		Language: "en",
+	}
+	ch.decided = true
+	return ch.sendMessage(reject)
+}
+
+func (ch *channel) Read(data []byte) (int, error) {
+	if !ch.decided {
+		return 0, errUndecided
+	}
+	return ch.ReadExtended(data, 0)
+}
+
+func (ch *channel) Write(data []byte) (int, error) {
+	if !ch.decided {
+		return 0, errUndecided
+	}
+	return ch.WriteExtended(data, 0)
+}
+
+func (ch *channel) CloseWrite() error {
+	if !ch.decided {
+		return errUndecided
+	}
+	ch.sentEOF = true
+	return ch.sendMessage(channelEOFMsg{
+		PeersId: ch.remoteId})
+}
+
+func (ch *channel) Close() error {
+	if !ch.decided {
+		return errUndecided
+	}
+
+	return ch.sendMessage(channelCloseMsg{
+		PeersId: ch.remoteId})
+}
+
+// Extended returns an io.ReadWriter that sends and receives data on the given,
+// SSH extended stream. Such streams are used, for example, for stderr.
+func (ch *channel) Extended(code uint32) io.ReadWriter {
+	if !ch.decided {
+		return nil
+	}
+	return &extChannel{code, ch}
+}
+
+func (ch *channel) Stderr() io.ReadWriter {
+	return ch.Extended(1)
+}
+
+func (ch *channel) SendRequest(name string, wantReply bool, payload []byte) (bool, error) {
+	if !ch.decided {
+		return false, errUndecided
+	}
+
+	if wantReply {
+		ch.sentRequestMu.Lock()
+		defer ch.sentRequestMu.Unlock()
+	}
+
+	msg := channelRequestMsg{
+		PeersId:             ch.remoteId,
+		Request:             name,
+		WantReply:           wantReply,
+		RequestSpecificData: payload,
+	}
+
+	if err := ch.sendMessage(msg); err != nil {
+		return false, err
+	}
+
+	if wantReply {
+		m, ok := (<-ch.msg)
+		if !ok {
+			return false, io.EOF
+		}
+		switch m.(type) {
+		case *channelRequestFailureMsg:
+			return false, nil
+		case *channelRequestSuccessMsg:
+			return true, nil
+		default:
+			return false, fmt.Errorf("ssh: unexpected response to channel request: %#v", m)
+		}
+	}
+
+	return false, nil
+}
+
+// ackRequest either sends an ack or nack to the channel request.
+func (ch *channel) ackRequest(ok bool) error {
+	if !ch.decided {
+		return errUndecided
+	}
+
+	var msg interface{}
+	if !ok {
+		msg = channelRequestFailureMsg{
+			PeersId: ch.remoteId,
+		}
+	} else {
+		msg = channelRequestSuccessMsg{
+			PeersId: ch.remoteId,
+		}
+	}
+	return ch.sendMessage(msg)
+}
+
+func (ch *channel) ChannelType() string {
+	return ch.chanType
+}
+
+func (ch *channel) ExtraData() []byte {
+	return ch.extraData
+}

vendor/golang.org/x/crypto/ssh/cipher.go

@@ -0,0 +1,579 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/rc4"
+	"crypto/subtle"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"hash"
+	"io"
+	"io/ioutil"
+)
+
+const (
+	packetSizeMultiple = 16 // TODO(huin) this should be determined by the cipher.
+
+	// RFC 4253 section 6.1 defines a minimum packet size of 32768 that implementations
+	// MUST be able to process (plus a few more kilobytes for padding and mac). The RFC
+	// indicates implementations SHOULD be able to handle larger packet sizes, but then
+	// waffles on about reasonable limits.
+	//
+	// OpenSSH caps their maxPacket at 256kB so we choose to do
+	// the same. maxPacket is also used to ensure that uint32
+	// length fields do not overflow, so it should remain well
+	// below 4G.
+	maxPacket = 256 * 1024
+)
+
+// noneCipher implements cipher.Stream and provides no encryption. It is used
+// by the transport before the first key-exchange.
+type noneCipher struct{}
+
+func (c noneCipher) XORKeyStream(dst, src []byte) {
+	copy(dst, src)
+}
+
+func newAESCTR(key, iv []byte) (cipher.Stream, error) {
+	c, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	return cipher.NewCTR(c, iv), nil
+}
+
+func newRC4(key, iv []byte) (cipher.Stream, error) {
+	return rc4.NewCipher(key)
+}
+
+type streamCipherMode struct {
+	keySize    int
+	ivSize     int
+	skip       int
+	createFunc func(key, iv []byte) (cipher.Stream, error)
+}
+
+func (c *streamCipherMode) createStream(key, iv []byte) (cipher.Stream, error) {
+	if len(key) < c.keySize {
+		panic("ssh: key length too small for cipher")
+	}
+	if len(iv) < c.ivSize {
+		panic("ssh: iv too small for cipher")
+	}
+
+	stream, err := c.createFunc(key[:c.keySize], iv[:c.ivSize])
+	if err != nil {
+		return nil, err
+	}
+
+	var streamDump []byte
+	if c.skip > 0 {
+		streamDump = make([]byte, 512)
+	}
+
+	for remainingToDump := c.skip; remainingToDump > 0; {
+		dumpThisTime := remainingToDump
+		if dumpThisTime > len(streamDump) {
+			dumpThisTime = len(streamDump)
+		}
+		stream.XORKeyStream(streamDump[:dumpThisTime], streamDump[:dumpThisTime])
+		remainingToDump -= dumpThisTime
+	}
+
+	return stream, nil
+}
+
+// cipherModes documents properties of supported ciphers. Ciphers not included
+// are not supported and will not be negotiated, even if explicitly requested in
+// ClientConfig.Crypto.Ciphers.
+var cipherModes = map[string]*streamCipherMode{
+	// Ciphers from RFC4344, which introduced many CTR-based ciphers. Algorithms
+	// are defined in the order specified in the RFC.
+	"aes128-ctr": {16, aes.BlockSize, 0, newAESCTR},
+	"aes192-ctr": {24, aes.BlockSize, 0, newAESCTR},
+	"aes256-ctr": {32, aes.BlockSize, 0, newAESCTR},
+
+	// Ciphers from RFC4345, which introduces security-improved arcfour ciphers.
+	// They are defined in the order specified in the RFC.
+	"arcfour128": {16, 0, 1536, newRC4},
+	"arcfour256": {32, 0, 1536, newRC4},
+
+	// Cipher defined in RFC 4253, which describes SSH Transport Layer Protocol.
+	// Note that this cipher is not safe, as stated in RFC 4253: "Arcfour (and
+	// RC4) has problems with weak keys, and should be used with caution."
+	// RFC4345 introduces improved versions of Arcfour.
+	"arcfour": {16, 0, 0, newRC4},
+
+	// AES-GCM is not a stream cipher, so it is constructed with a
+	// special case. If we add any more non-stream ciphers, we
+	// should invest a cleaner way to do this.
+	gcmCipherID: {16, 12, 0, nil},
+
+	// CBC mode is insecure and so is not included in the default config.
+	// (See http://www.isg.rhul.ac.uk/~kp/SandPfinal.pdf). If absolutely
+	// needed, it's possible to specify a custom Config to enable it.
+	// You should expect that an active attacker can recover plaintext if
+	// you do.
+	aes128cbcID: {16, aes.BlockSize, 0, nil},
+
+	// 3des-cbc is insecure and is disabled by default.
+	tripledescbcID: {24, des.BlockSize, 0, nil},
+}
+
+// prefixLen is the length of the packet prefix that contains the packet length
+// and number of padding bytes.
+const prefixLen = 5
+
+// streamPacketCipher is a packetCipher using a stream cipher.
+type streamPacketCipher struct {
+	mac    hash.Hash
+	cipher cipher.Stream
+
+	// The following members are to avoid per-packet allocations.
+	prefix      [prefixLen]byte
+	seqNumBytes [4]byte
+	padding     [2 * packetSizeMultiple]byte
+	packetData  []byte
+	macResult   []byte
+}
+
+// readPacket reads and decrypt a single packet from the reader argument.
+func (s *streamPacketCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) {
+	if _, err := io.ReadFull(r, s.prefix[:]); err != nil {
+		return nil, err
+	}
+
+	s.cipher.XORKeyStream(s.prefix[:], s.prefix[:])
+	length := binary.BigEndian.Uint32(s.prefix[0:4])
+	paddingLength := uint32(s.prefix[4])
+
+	var macSize uint32
+	if s.mac != nil {
+		s.mac.Reset()
+		binary.BigEndian.PutUint32(s.seqNumBytes[:], seqNum)
+		s.mac.Write(s.seqNumBytes[:])
+		s.mac.Write(s.prefix[:])
+		macSize = uint32(s.mac.Size())
+	}
+
+	if length <= paddingLength+1 {
+		return nil, errors.New("ssh: invalid packet length, packet too small")
+	}
+
+	if length > maxPacket {
+		return nil, errors.New("ssh: invalid packet length, packet too large")
+	}
+
+	// the maxPacket check above ensures that length-1+macSize
+	// does not overflow.
+	if uint32(cap(s.packetData)) < length-1+macSize {
+		s.packetData = make([]byte, length-1+macSize)
+	} else {
+		s.packetData = s.packetData[:length-1+macSize]
+	}
+
+	if _, err := io.ReadFull(r, s.packetData); err != nil {
+		return nil, err
+	}
+	mac := s.packetData[length-1:]
+	data := s.packetData[:length-1]
+	s.cipher.XORKeyStream(data, data)
+
+	if s.mac != nil {
+		s.mac.Write(data)
+		s.macResult = s.mac.Sum(s.macResult[:0])
+		if subtle.ConstantTimeCompare(s.macResult, mac) != 1 {
+			return nil, errors.New("ssh: MAC failure")
+		}
+	}
+
+	return s.packetData[:length-paddingLength-1], nil
+}
+
+// writePacket encrypts and sends a packet of data to the writer argument
+func (s *streamPacketCipher) writePacket(seqNum uint32, w io.Writer, rand io.Reader, packet []byte) error {
+	if len(packet) > maxPacket {
+		return errors.New("ssh: packet too large")
+	}
+
+	paddingLength := packetSizeMultiple - (prefixLen+len(packet))%packetSizeMultiple
+	if paddingLength < 4 {
+		paddingLength += packetSizeMultiple
+	}
+
+	length := len(packet) + 1 + paddingLength
+	binary.BigEndian.PutUint32(s.prefix[:], uint32(length))
+	s.prefix[4] = byte(paddingLength)
+	padding := s.padding[:paddingLength]
+	if _, err := io.ReadFull(rand, padding); err != nil {
+		return err
+	}
+
+	if s.mac != nil {
+		s.mac.Reset()
+		binary.BigEndian.PutUint32(s.seqNumBytes[:], seqNum)
+		s.mac.Write(s.seqNumBytes[:])
+		s.mac.Write(s.prefix[:])
+		s.mac.Write(packet)
+		s.mac.Write(padding)
+	}
+
+	s.cipher.XORKeyStream(s.prefix[:], s.prefix[:])
+	s.cipher.XORKeyStream(packet, packet)
+	s.cipher.XORKeyStream(padding, padding)
+
+	if _, err := w.Write(s.prefix[:]); err != nil {
+		return err
+	}
+	if _, err := w.Write(packet); err != nil {
+		return err
+	}
+	if _, err := w.Write(padding); err != nil {
+		return err
+	}
+
+	if s.mac != nil {
+		s.macResult = s.mac.Sum(s.macResult[:0])
+		if _, err := w.Write(s.macResult); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+type gcmCipher struct {
+	aead   cipher.AEAD
+	prefix [4]byte
+	iv     []byte
+	buf    []byte
+}
+
+func newGCMCipher(iv, key, macKey []byte) (packetCipher, error) {
+	c, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	aead, err := cipher.NewGCM(c)
+	if err != nil {
+		return nil, err
+	}
+
+	return &gcmCipher{
+		aead: aead,
+		iv:   iv,
+	}, nil
+}
+
+const gcmTagSize = 16
+
+func (c *gcmCipher) writePacket(seqNum uint32, w io.Writer, rand io.Reader, packet []byte) error {
+	// Pad out to multiple of 16 bytes. This is different from the
+	// stream cipher because that encrypts the length too.
+	padding := byte(packetSizeMultiple - (1+len(packet))%packetSizeMultiple)
+	if padding < 4 {
+		padding += packetSizeMultiple
+	}
+
+	length := uint32(len(packet) + int(padding) + 1)
+	binary.BigEndian.PutUint32(c.prefix[:], length)
+	if _, err := w.Write(c.prefix[:]); err != nil {
+		return err
+	}
+
+	if cap(c.buf) < int(length) {
+		c.buf = make([]byte, length)
+	} else {
+		c.buf = c.buf[:length]
+	}
+
+	c.buf[0] = padding
+	copy(c.buf[1:], packet)
+	if _, err := io.ReadFull(rand, c.buf[1+len(packet):]); err != nil {
+		return err
+	}
+	c.buf = c.aead.Seal(c.buf[:0], c.iv, c.buf, c.prefix[:])
+	if _, err := w.Write(c.buf); err != nil {
+		return err
+	}
+	c.incIV()
+
+	return nil
+}
+
+func (c *gcmCipher) incIV() {
+	for i := 4 + 7; i >= 4; i-- {
+		c.iv[i]++
+		if c.iv[i] != 0 {
+			break
+		}
+	}
+}
+
+func (c *gcmCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) {
+	if _, err := io.ReadFull(r, c.prefix[:]); err != nil {
+		return nil, err
+	}
+	length := binary.BigEndian.Uint32(c.prefix[:])
+	if length > maxPacket {
+		return nil, errors.New("ssh: max packet length exceeded.")
+	}
+
+	if cap(c.buf) < int(length+gcmTagSize) {
+		c.buf = make([]byte, length+gcmTagSize)
+	} else {
+		c.buf = c.buf[:length+gcmTagSize]
+	}
+
+	if _, err := io.ReadFull(r, c.buf); err != nil {
+		return nil, err
+	}
+
+	plain, err := c.aead.Open(c.buf[:0], c.iv, c.buf, c.prefix[:])
+	if err != nil {
+		return nil, err
+	}
+	c.incIV()
+
+	padding := plain[0]
+	if padding < 4 || padding >= 20 {
+		return nil, fmt.Errorf("ssh: illegal padding %d", padding)
+	}
+
+	if int(padding+1) >= len(plain) {
+		return nil, fmt.Errorf("ssh: padding %d too large", padding)
+	}
+	plain = plain[1 : length-uint32(padding)]
+	return plain, nil
+}
+
+// cbcCipher implements aes128-cbc cipher defined in RFC 4253 section 6.1
+type cbcCipher struct {
+	mac       hash.Hash
+	macSize   uint32
+	decrypter cipher.BlockMode
+	encrypter cipher.BlockMode
+
+	// The following members are to avoid per-packet allocations.
+	seqNumBytes [4]byte
+	packetData  []byte
+	macResult   []byte
+
+	// Amount of data we should still read to hide which
+	// verification error triggered.
+	oracleCamouflage uint32
+}
+
+func newCBCCipher(c cipher.Block, iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+	cbc := &cbcCipher{
+		mac:        macModes[algs.MAC].new(macKey),
+		decrypter:  cipher.NewCBCDecrypter(c, iv),
+		encrypter:  cipher.NewCBCEncrypter(c, iv),
+		packetData: make([]byte, 1024),
+	}
+	if cbc.mac != nil {
+		cbc.macSize = uint32(cbc.mac.Size())
+	}
+
+	return cbc, nil
+}
+
+func newAESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+	c, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	cbc, err := newCBCCipher(c, iv, key, macKey, algs)
+	if err != nil {
+		return nil, err
+	}
+
+	return cbc, nil
+}
+
+func newTripleDESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+	c, err := des.NewTripleDESCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	cbc, err := newCBCCipher(c, iv, key, macKey, algs)
+	if err != nil {
+		return nil, err
+	}
+
+	return cbc, nil
+}
+
+func maxUInt32(a, b int) uint32 {
+	if a > b {
+		return uint32(a)
+	}
+	return uint32(b)
+}
+
+const (
+	cbcMinPacketSizeMultiple = 8
+	cbcMinPacketSize         = 16
+	cbcMinPaddingSize        = 4
+)
+
+// cbcError represents a verification error that may leak information.
+type cbcError string
+
+func (e cbcError) Error() string { return string(e) }
+
+func (c *cbcCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) {
+	p, err := c.readPacketLeaky(seqNum, r)
+	if err != nil {
+		if _, ok := err.(cbcError); ok {
+			// Verification error: read a fixed amount of
+			// data, to make distinguishing between
+			// failing MAC and failing length check more
+			// difficult.
+			io.CopyN(ioutil.Discard, r, int64(c.oracleCamouflage))
+		}
+	}
+	return p, err
+}
+
+func (c *cbcCipher) readPacketLeaky(seqNum uint32, r io.Reader) ([]byte, error) {
+	blockSize := c.decrypter.BlockSize()
+
+	// Read the header, which will include some of the subsequent data in the
+	// case of block ciphers - this is copied back to the payload later.
+	// How many bytes of payload/padding will be read with this first read.
+	firstBlockLength := uint32((prefixLen + blockSize - 1) / blockSize * blockSize)
+	firstBlock := c.packetData[:firstBlockLength]
+	if _, err := io.ReadFull(r, firstBlock); err != nil {
+		return nil, err
+	}
+
+	c.oracleCamouflage = maxPacket + 4 + c.macSize - firstBlockLength
+
+	c.decrypter.CryptBlocks(firstBlock, firstBlock)
+	length := binary.BigEndian.Uint32(firstBlock[:4])
+	if length > maxPacket {
+		return nil, cbcError("ssh: packet too large")
+	}
+	if length+4 < maxUInt32(cbcMinPacketSize, blockSize) {
+		// The minimum size of a packet is 16 (or the cipher block size, whichever
+		// is larger) bytes.
+		return nil, cbcError("ssh: packet too small")
+	}
+	// The length of the packet (including the length field but not the MAC) must
+	// be a multiple of the block size or 8, whichever is larger.
+	if (length+4)%maxUInt32(cbcMinPacketSizeMultiple, blockSize) != 0 {
+		return nil, cbcError("ssh: invalid packet length multiple")
+	}
+
+	paddingLength := uint32(firstBlock[4])
+	if paddingLength < cbcMinPaddingSize || length <= paddingLength+1 {
+		return nil, cbcError("ssh: invalid packet length")
+	}
+
+	// Positions within the c.packetData buffer:
+	macStart := 4 + length
+	paddingStart := macStart - paddingLength
+
+	// Entire packet size, starting before length, ending at end of mac.
+	entirePacketSize := macStart + c.macSize
+
+	// Ensure c.packetData is large enough for the entire packet data.
+	if uint32(cap(c.packetData)) < entirePacketSize {
+		// Still need to upsize and copy, but this should be rare at runtime, only
+		// on upsizing the packetData buffer.
+		c.packetData = make([]byte, entirePacketSize)
+		copy(c.packetData, firstBlock)
+	} else {
+		c.packetData = c.packetData[:entirePacketSize]
+	}
+
+	if n, err := io.ReadFull(r, c.packetData[firstBlockLength:]); err != nil {
+		return nil, err
+	} else {
+		c.oracleCamouflage -= uint32(n)
+	}
+
+	remainingCrypted := c.packetData[firstBlockLength:macStart]
+	c.decrypter.CryptBlocks(remainingCrypted, remainingCrypted)
+
+	mac := c.packetData[macStart:]
+	if c.mac != nil {
+		c.mac.Reset()
+		binary.BigEndian.PutUint32(c.seqNumBytes[:], seqNum)
+		c.mac.Write(c.seqNumBytes[:])
+		c.mac.Write(c.packetData[:macStart])
+		c.macResult = c.mac.Sum(c.macResult[:0])
+		if subtle.ConstantTimeCompare(c.macResult, mac) != 1 {
+			return nil, cbcError("ssh: MAC failure")
+		}
+	}
+
+	return c.packetData[prefixLen:paddingStart], nil
+}
+
+func (c *cbcCipher) writePacket(seqNum uint32, w io.Writer, rand io.Reader, packet []byte) error {
+	effectiveBlockSize := maxUInt32(cbcMinPacketSizeMultiple, c.encrypter.BlockSize())
+
+	// Length of encrypted portion of the packet (header, payload, padding).
+	// Enforce minimum padding and packet size.
+	encLength := maxUInt32(prefixLen+len(packet)+cbcMinPaddingSize, cbcMinPaddingSize)
+	// Enforce block size.
+	encLength = (encLength + effectiveBlockSize - 1) / effectiveBlockSize * effectiveBlockSize
+
+	length := encLength - 4
+	paddingLength := int(length) - (1 + len(packet))
+
+	// Overall buffer contains: header, payload, padding, mac.
+	// Space for the MAC is reserved in the capacity but not the slice length.
+	bufferSize := encLength + c.macSize
+	if uint32(cap(c.packetData)) < bufferSize {
+		c.packetData = make([]byte, encLength, bufferSize)
+	} else {
+		c.packetData = c.packetData[:encLength]
+	}
+
+	p := c.packetData
+
+	// Packet header.
+	binary.BigEndian.PutUint32(p, length)
+	p = p[4:]
+	p[0] = byte(paddingLength)
+
+	// Payload.
+	p = p[1:]
+	copy(p, packet)
+
+	// Padding.
+	p = p[len(packet):]
+	if _, err := io.ReadFull(rand, p); err != nil {
+		return err
+	}
+
+	if c.mac != nil {
+		c.mac.Reset()
+		binary.BigEndian.PutUint32(c.seqNumBytes[:], seqNum)
+		c.mac.Write(c.seqNumBytes[:])
+		c.mac.Write(c.packetData)
+		// The MAC is now appended into the capacity reserved for it earlier.
+		c.packetData = c.mac.Sum(c.packetData)
+	}
+
+	c.encrypter.CryptBlocks(c.packetData[:encLength], c.packetData[:encLength])
+
+	if _, err := w.Write(c.packetData); err != nil {
+		return err
+	}
+
+	return nil
+}

vendor/golang.org/x/crypto/ssh/cipher_test.go

@@ -0,0 +1,127 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/aes"
+	"crypto/rand"
+	"testing"
+)
+
+func TestDefaultCiphersExist(t *testing.T) {
+	for _, cipherAlgo := range supportedCiphers {
+		if _, ok := cipherModes[cipherAlgo]; !ok {
+			t.Errorf("default cipher %q is unknown", cipherAlgo)
+		}
+	}
+}
+
+func TestPacketCiphers(t *testing.T) {
+	// Still test aes128cbc cipher although it's commented out.
+	cipherModes[aes128cbcID] = &streamCipherMode{16, aes.BlockSize, 0, nil}
+	defer delete(cipherModes, aes128cbcID)
+
+	for cipher := range cipherModes {
+		kr := &kexResult{Hash: crypto.SHA1}
+		algs := directionAlgorithms{
+			Cipher:      cipher,
+			MAC:         "hmac-sha1",
+			Compression: "none",
+		}
+		client, err := newPacketCipher(clientKeys, algs, kr)
+		if err != nil {
+			t.Errorf("newPacketCipher(client, %q): %v", cipher, err)
+			continue
+		}
+		server, err := newPacketCipher(clientKeys, algs, kr)
+		if err != nil {
+			t.Errorf("newPacketCipher(client, %q): %v", cipher, err)
+			continue
+		}
+
+		want := "bla bla"
+		input := []byte(want)
+		buf := &bytes.Buffer{}
+		if err := client.writePacket(0, buf, rand.Reader, input); err != nil {
+			t.Errorf("writePacket(%q): %v", cipher, err)
+			continue
+		}
+
+		packet, err := server.readPacket(0, buf)
+		if err != nil {
+			t.Errorf("readPacket(%q): %v", cipher, err)
+			continue
+		}
+
+		if string(packet) != want {
+			t.Errorf("roundtrip(%q): got %q, want %q", cipher, packet, want)
+		}
+	}
+}
+
+func TestCBCOracleCounterMeasure(t *testing.T) {
+	cipherModes[aes128cbcID] = &streamCipherMode{16, aes.BlockSize, 0, nil}
+	defer delete(cipherModes, aes128cbcID)
+
+	kr := &kexResult{Hash: crypto.SHA1}
+	algs := directionAlgorithms{
+		Cipher:      aes128cbcID,
+		MAC:         "hmac-sha1",
+		Compression: "none",
+	}
+	client, err := newPacketCipher(clientKeys, algs, kr)
+	if err != nil {
+		t.Fatalf("newPacketCipher(client): %v", err)
+	}
+
+	want := "bla bla"
+	input := []byte(want)
+	buf := &bytes.Buffer{}
+	if err := client.writePacket(0, buf, rand.Reader, input); err != nil {
+		t.Errorf("writePacket: %v", err)
+	}
+
+	packetSize := buf.Len()
+	buf.Write(make([]byte, 2*maxPacket))
+
+	// We corrupt each byte, but this usually will only test the
+	// 'packet too large' or 'MAC failure' cases.
+	lastRead := -1
+	for i := 0; i < packetSize; i++ {
+		server, err := newPacketCipher(clientKeys, algs, kr)
+		if err != nil {
+			t.Fatalf("newPacketCipher(client): %v", err)
+		}
+
+		fresh := &bytes.Buffer{}
+		fresh.Write(buf.Bytes())
+		fresh.Bytes()[i] ^= 0x01
+
+		before := fresh.Len()
+		_, err = server.readPacket(0, fresh)
+		if err == nil {
+			t.Errorf("corrupt byte %d: readPacket succeeded ", i)
+			continue
+		}
+		if _, ok := err.(cbcError); !ok {
+			t.Errorf("corrupt byte %d: got %v (%T), want cbcError", i, err, err)
+			continue
+		}
+
+		after := fresh.Len()
+		bytesRead := before - after
+		if bytesRead < maxPacket {
+			t.Errorf("corrupt byte %d: read %d bytes, want more than %d", i, bytesRead, maxPacket)
+			continue
+		}
+
+		if i > 0 && bytesRead != lastRead {
+			t.Errorf("corrupt byte %d: read %d bytes, want %d bytes read", i, bytesRead, lastRead)
+		}
+		lastRead = bytesRead
+	}
+}

vendor/golang.org/x/crypto/ssh/client.go

@@ -0,0 +1,213 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"sync"
+	"time"
+)
+
+// Client implements a traditional SSH client that supports shells,
+// subprocesses, port forwarding and tunneled dialing.
+type Client struct {
+	Conn
+
+	forwards        forwardList // forwarded tcpip connections from the remote side
+	mu              sync.Mutex
+	channelHandlers map[string]chan NewChannel
+}
+
+// HandleChannelOpen returns a channel on which NewChannel requests
+// for the given type are sent. If the type already is being handled,
+// nil is returned. The channel is closed when the connection is closed.
+func (c *Client) HandleChannelOpen(channelType string) <-chan NewChannel {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.channelHandlers == nil {
+		// The SSH channel has been closed.
+		c := make(chan NewChannel)
+		close(c)
+		return c
+	}
+
+	ch := c.channelHandlers[channelType]
+	if ch != nil {
+		return nil
+	}
+
+	ch = make(chan NewChannel, 16)
+	c.channelHandlers[channelType] = ch
+	return ch
+}
+
+// NewClient creates a Client on top of the given connection.
+func NewClient(c Conn, chans <-chan NewChannel, reqs <-chan *Request) *Client {
+	conn := &Client{
+		Conn:            c,
+		channelHandlers: make(map[string]chan NewChannel, 1),
+	}
+
+	go conn.handleGlobalRequests(reqs)
+	go conn.handleChannelOpens(chans)
+	go func() {
+		conn.Wait()
+		conn.forwards.closeAll()
+	}()
+	go conn.forwards.handleChannels(conn.HandleChannelOpen("forwarded-tcpip"))
+	return conn
+}
+
+// NewClientConn establishes an authenticated SSH connection using c
+// as the underlying transport.  The Request and NewChannel channels
+// must be serviced or the connection will hang.
+func NewClientConn(c net.Conn, addr string, config *ClientConfig) (Conn, <-chan NewChannel, <-chan *Request, error) {
+	fullConf := *config
+	fullConf.SetDefaults()
+	conn := &connection{
+		sshConn: sshConn{conn: c},
+	}
+
+	if err := conn.clientHandshake(addr, &fullConf); err != nil {
+		c.Close()
+		return nil, nil, nil, fmt.Errorf("ssh: handshake failed: %v", err)
+	}
+	conn.mux = newMux(conn.transport)
+	return conn, conn.mux.incomingChannels, conn.mux.incomingRequests, nil
+}
+
+// clientHandshake performs the client side key exchange. See RFC 4253 Section
+// 7.
+func (c *connection) clientHandshake(dialAddress string, config *ClientConfig) error {
+	if config.ClientVersion != "" {
+		c.clientVersion = []byte(config.ClientVersion)
+	} else {
+		c.clientVersion = []byte(packageVersion)
+	}
+	var err error
+	c.serverVersion, err = exchangeVersions(c.sshConn.conn, c.clientVersion)
+	if err != nil {
+		return err
+	}
+
+	c.transport = newClientTransport(
+		newTransport(c.sshConn.conn, config.Rand, true /* is client */),
+		c.clientVersion, c.serverVersion, config, dialAddress, c.sshConn.RemoteAddr())
+	if err := c.transport.requestInitialKeyChange(); err != nil {
+		return err
+	}
+
+	// We just did the key change, so the session ID is established.
+	c.sessionID = c.transport.getSessionID()
+
+	return c.clientAuthenticate(config)
+}
+
+// verifyHostKeySignature verifies the host key obtained in the key
+// exchange.
+func verifyHostKeySignature(hostKey PublicKey, result *kexResult) error {
+	sig, rest, ok := parseSignatureBody(result.Signature)
+	if len(rest) > 0 || !ok {
+		return errors.New("ssh: signature parse error")
+	}
+
+	return hostKey.Verify(result.H, sig)
+}
+
+// NewSession opens a new Session for this client. (A session is a remote
+// execution of a program.)
+func (c *Client) NewSession() (*Session, error) {
+	ch, in, err := c.OpenChannel("session", nil)
+	if err != nil {
+		return nil, err
+	}
+	return newSession(ch, in)
+}
+
+func (c *Client) handleGlobalRequests(incoming <-chan *Request) {
+	for r := range incoming {
+		// This handles keepalive messages and matches
+		// the behaviour of OpenSSH.
+		r.Reply(false, nil)
+	}
+}
+
+// handleChannelOpens channel open messages from the remote side.
+func (c *Client) handleChannelOpens(in <-chan NewChannel) {
+	for ch := range in {
+		c.mu.Lock()
+		handler := c.channelHandlers[ch.ChannelType()]
+		c.mu.Unlock()
+
+		if handler != nil {
+			handler <- ch
+		} else {
+			ch.Reject(UnknownChannelType, fmt.Sprintf("unknown channel type: %v", ch.ChannelType()))
+		}
+	}
+
+	c.mu.Lock()
+	for _, ch := range c.channelHandlers {
+		close(ch)
+	}
+	c.channelHandlers = nil
+	c.mu.Unlock()
+}
+
+// Dial starts a client connection to the given SSH server. It is a
+// convenience function that connects to the given network address,
+// initiates the SSH handshake, and then sets up a Client.  For access
+// to incoming channels and requests, use net.Dial with NewClientConn
+// instead.
+func Dial(network, addr string, config *ClientConfig) (*Client, error) {
+	conn, err := net.DialTimeout(network, addr, config.Timeout)
+	if err != nil {
+		return nil, err
+	}
+	c, chans, reqs, err := NewClientConn(conn, addr, config)
+	if err != nil {
+		return nil, err
+	}
+	return NewClient(c, chans, reqs), nil
+}
+
+// A ClientConfig structure is used to configure a Client. It must not be
+// modified after having been passed to an SSH function.
+type ClientConfig struct {
+	// Config contains configuration that is shared between clients and
+	// servers.
+	Config
+
+	// User contains the username to authenticate as.
+	User string
+
+	// Auth contains possible authentication methods to use with the
+	// server. Only the first instance of a particular RFC 4252 method will
+	// be used during authentication.
+	Auth []AuthMethod
+
+	// HostKeyCallback, if not nil, is called during the cryptographic
+	// handshake to validate the server's host key. A nil HostKeyCallback
+	// implies that all host keys are accepted.
+	HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
+
+	// ClientVersion contains the version identification string that will
+	// be used for the connection. If empty, a reasonable default is used.
+	ClientVersion string
+
+	// HostKeyAlgorithms lists the key types that the client will
+	// accept from the server as host key, in order of
+	// preference. If empty, a reasonable default is used. Any
+	// string returned from PublicKey.Type method may be used, or
+	// any of the CertAlgoXxxx and KeyAlgoXxxx constants.
+	HostKeyAlgorithms []string
+
+	// Timeout is the maximum amount of time for the TCP connection to establish.
+	//
+	// A Timeout of zero means no timeout.
+	Timeout time.Duration
+}

vendor/golang.org/x/crypto/ssh/client_auth.go

@@ -0,0 +1,473 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+)
+
+// clientAuthenticate authenticates with the remote server. See RFC 4252.
+func (c *connection) clientAuthenticate(config *ClientConfig) error {
+	// initiate user auth session
+	if err := c.transport.writePacket(Marshal(&serviceRequestMsg{serviceUserAuth})); err != nil {
+		return err
+	}
+	packet, err := c.transport.readPacket()
+	if err != nil {
+		return err
+	}
+	var serviceAccept serviceAcceptMsg
+	if err := Unmarshal(packet, &serviceAccept); err != nil {
+		return err
+	}
+
+	// during the authentication phase the client first attempts the "none" method
+	// then any untried methods suggested by the server.
+	tried := make(map[string]bool)
+	var lastMethods []string
+	for auth := AuthMethod(new(noneAuth)); auth != nil; {
+		ok, methods, err := auth.auth(c.transport.getSessionID(), config.User, c.transport, config.Rand)
+		if err != nil {
+			return err
+		}
+		if ok {
+			// success
+			return nil
+		}
+		tried[auth.method()] = true
+		if methods == nil {
+			methods = lastMethods
+		}
+		lastMethods = methods
+
+		auth = nil
+
+	findNext:
+		for _, a := range config.Auth {
+			candidateMethod := a.method()
+			if tried[candidateMethod] {
+				continue
+			}
+			for _, meth := range methods {
+				if meth == candidateMethod {
+					auth = a
+					break findNext
+				}
+			}
+		}
+	}
+	return fmt.Errorf("ssh: unable to authenticate, attempted methods %v, no supported methods remain", keys(tried))
+}
+
+func keys(m map[string]bool) []string {
+	s := make([]string, 0, len(m))
+
+	for key := range m {
+		s = append(s, key)
+	}
+	return s
+}
+
+// An AuthMethod represents an instance of an RFC 4252 authentication method.
+type AuthMethod interface {
+	// auth authenticates user over transport t.
+	// Returns true if authentication is successful.
+	// If authentication is not successful, a []string of alternative
+	// method names is returned. If the slice is nil, it will be ignored
+	// and the previous set of possible methods will be reused.
+	auth(session []byte, user string, p packetConn, rand io.Reader) (bool, []string, error)
+
+	// method returns the RFC 4252 method name.
+	method() string
+}
+
+// "none" authentication, RFC 4252 section 5.2.
+type noneAuth int
+
+func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+	if err := c.writePacket(Marshal(&userAuthRequestMsg{
+		User:    user,
+		Service: serviceSSH,
+		Method:  "none",
+	})); err != nil {
+		return false, nil, err
+	}
+
+	return handleAuthResponse(c)
+}
+
+func (n *noneAuth) method() string {
+	return "none"
+}
+
+// passwordCallback is an AuthMethod that fetches the password through
+// a function call, e.g. by prompting the user.
+type passwordCallback func() (password string, err error)
+
+func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+	type passwordAuthMsg struct {
+		User     string `sshtype:"50"`
+		Service  string
+		Method   string
+		Reply    bool
+		Password string
+	}
+
+	pw, err := cb()
+	// REVIEW NOTE: is there a need to support skipping a password attempt?
+	// The program may only find out that the user doesn't have a password
+	// when prompting.
+	if err != nil {
+		return false, nil, err
+	}
+
+	if err := c.writePacket(Marshal(&passwordAuthMsg{
+		User:     user,
+		Service:  serviceSSH,
+		Method:   cb.method(),
+		Reply:    false,
+		Password: pw,
+	})); err != nil {
+		return false, nil, err
+	}
+
+	return handleAuthResponse(c)
+}
+
+func (cb passwordCallback) method() string {
+	return "password"
+}
+
+// Password returns an AuthMethod using the given password.
+func Password(secret string) AuthMethod {
+	return passwordCallback(func() (string, error) { return secret, nil })
+}
+
+// PasswordCallback returns an AuthMethod that uses a callback for
+// fetching a password.
+func PasswordCallback(prompt func() (secret string, err error)) AuthMethod {
+	return passwordCallback(prompt)
+}
+
+type publickeyAuthMsg struct {
+	User    string `sshtype:"50"`
+	Service string
+	Method  string
+	// HasSig indicates to the receiver packet that the auth request is signed and
+	// should be used for authentication of the request.
+	HasSig   bool
+	Algoname string
+	PubKey   []byte
+	// Sig is tagged with "rest" so Marshal will exclude it during
+	// validateKey
+	Sig []byte `ssh:"rest"`
+}
+
+// publicKeyCallback is an AuthMethod that uses a set of key
+// pairs for authentication.
+type publicKeyCallback func() ([]Signer, error)
+
+func (cb publicKeyCallback) method() string {
+	return "publickey"
+}
+
+func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+	// Authentication is performed in two stages. The first stage sends an
+	// enquiry to test if each key is acceptable to the remote. The second
+	// stage attempts to authenticate with the valid keys obtained in the
+	// first stage.
+
+	signers, err := cb()
+	if err != nil {
+		return false, nil, err
+	}
+	var validKeys []Signer
+	for _, signer := range signers {
+		if ok, err := validateKey(signer.PublicKey(), user, c); ok {
+			validKeys = append(validKeys, signer)
+		} else {
+			if err != nil {
+				return false, nil, err
+			}
+		}
+	}
+
+	// methods that may continue if this auth is not successful.
+	var methods []string
+	for _, signer := range validKeys {
+		pub := signer.PublicKey()
+
+		pubKey := pub.Marshal()
+		sign, err := signer.Sign(rand, buildDataSignedForAuth(session, userAuthRequestMsg{
+			User:    user,
+			Service: serviceSSH,
+			Method:  cb.method(),
+		}, []byte(pub.Type()), pubKey))
+		if err != nil {
+			return false, nil, err
+		}
+
+		// manually wrap the serialized signature in a string
+		s := Marshal(sign)
+		sig := make([]byte, stringLength(len(s)))
+		marshalString(sig, s)
+		msg := publickeyAuthMsg{
+			User:     user,
+			Service:  serviceSSH,
+			Method:   cb.method(),
+			HasSig:   true,
+			Algoname: pub.Type(),
+			PubKey:   pubKey,
+			Sig:      sig,
+		}
+		p := Marshal(&msg)
+		if err := c.writePacket(p); err != nil {
+			return false, nil, err
+		}
+		var success bool
+		success, methods, err = handleAuthResponse(c)
+		if err != nil {
+			return false, nil, err
+		}
+		if success {
+			return success, methods, err
+		}
+	}
+	return false, methods, nil
+}
+
+// validateKey validates the key provided is acceptable to the server.
+func validateKey(key PublicKey, user string, c packetConn) (bool, error) {
+	pubKey := key.Marshal()
+	msg := publickeyAuthMsg{
+		User:     user,
+		Service:  serviceSSH,
+		Method:   "publickey",
+		HasSig:   false,
+		Algoname: key.Type(),
+		PubKey:   pubKey,
+	}
+	if err := c.writePacket(Marshal(&msg)); err != nil {
+		return false, err
+	}
+
+	return confirmKeyAck(key, c)
+}
+
+func confirmKeyAck(key PublicKey, c packetConn) (bool, error) {
+	pubKey := key.Marshal()
+	algoname := key.Type()
+
+	for {
+		packet, err := c.readPacket()
+		if err != nil {
+			return false, err
+		}
+		switch packet[0] {
+		case msgUserAuthBanner:
+			// TODO(gpaul): add callback to present the banner to the user
+		case msgUserAuthPubKeyOk:
+			var msg userAuthPubKeyOkMsg
+			if err := Unmarshal(packet, &msg); err != nil {
+				return false, err
+			}
+			if msg.Algo != algoname || !bytes.Equal(msg.PubKey, pubKey) {
+				return false, nil
+			}
+			return true, nil
+		case msgUserAuthFailure:
+			return false, nil
+		default:
+			return false, unexpectedMessageError(msgUserAuthSuccess, packet[0])
+		}
+	}
+}
+
+// PublicKeys returns an AuthMethod that uses the given key
+// pairs.
+func PublicKeys(signers ...Signer) AuthMethod {
+	return publicKeyCallback(func() ([]Signer, error) { return signers, nil })
+}
+
+// PublicKeysCallback returns an AuthMethod that runs the given
+// function to obtain a list of key pairs.
+func PublicKeysCallback(getSigners func() (signers []Signer, err error)) AuthMethod {
+	return publicKeyCallback(getSigners)
+}
+
+// handleAuthResponse returns whether the preceding authentication request succeeded
+// along with a list of remaining authentication methods to try next and
+// an error if an unexpected response was received.
+func handleAuthResponse(c packetConn) (bool, []string, error) {
+	for {
+		packet, err := c.readPacket()
+		if err != nil {
+			return false, nil, err
+		}
+
+		switch packet[0] {
+		case msgUserAuthBanner:
+			// TODO: add callback to present the banner to the user
+		case msgUserAuthFailure:
+			var msg userAuthFailureMsg
+			if err := Unmarshal(packet, &msg); err != nil {
+				return false, nil, err
+			}
+			return false, msg.Methods, nil
+		case msgUserAuthSuccess:
+			return true, nil, nil
+		default:
+			return false, nil, unexpectedMessageError(msgUserAuthSuccess, packet[0])
+		}
+	}
+}
+
+// KeyboardInteractiveChallenge should print questions, optionally
+// disabling echoing (e.g. for passwords), and return all the answers.
+// Challenge may be called multiple times in a single session. After
+// successful authentication, the server may send a challenge with no
+// questions, for which the user and instruction messages should be
+// printed.  RFC 4256 section 3.3 details how the UI should behave for
+// both CLI and GUI environments.
+type KeyboardInteractiveChallenge func(user, instruction string, questions []string, echos []bool) (answers []string, err error)
+
+// KeyboardInteractive returns a AuthMethod using a prompt/response
+// sequence controlled by the server.
+func KeyboardInteractive(challenge KeyboardInteractiveChallenge) AuthMethod {
+	return challenge
+}
+
+func (cb KeyboardInteractiveChallenge) method() string {
+	return "keyboard-interactive"
+}
+
+func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+	type initiateMsg struct {
+		User       string `sshtype:"50"`
+		Service    string
+		Method     string
+		Language   string
+		Submethods string
+	}
+
+	if err := c.writePacket(Marshal(&initiateMsg{
+		User:    user,
+		Service: serviceSSH,
+		Method:  "keyboard-interactive",
+	})); err != nil {
+		return false, nil, err
+	}
+
+	for {
+		packet, err := c.readPacket()
+		if err != nil {
+			return false, nil, err
+		}
+
+		// like handleAuthResponse, but with less options.
+		switch packet[0] {
+		case msgUserAuthBanner:
+			// TODO: Print banners during userauth.
+			continue
+		case msgUserAuthInfoRequest:
+			// OK
+		case msgUserAuthFailure:
+			var msg userAuthFailureMsg
+			if err := Unmarshal(packet, &msg); err != nil {
+				return false, nil, err
+			}
+			return false, msg.Methods, nil
+		case msgUserAuthSuccess:
+			return true, nil, nil
+		default:
+			return false, nil, unexpectedMessageError(msgUserAuthInfoRequest, packet[0])
+		}
+
+		var msg userAuthInfoRequestMsg
+		if err := Unmarshal(packet, &msg); err != nil {
+			return false, nil, err
+		}
+
+		// Manually unpack the prompt/echo pairs.
+		rest := msg.Prompts
+		var prompts []string
+		var echos []bool
+		for i := 0; i < int(msg.NumPrompts); i++ {
+			prompt, r, ok := parseString(rest)
+			if !ok || len(r) == 0 {
+				return false, nil, errors.New("ssh: prompt format error")
+			}
+			prompts = append(prompts, string(prompt))
+			echos = append(echos, r[0] != 0)
+			rest = r[1:]
+		}
+
+		if len(rest) != 0 {
+			return false, nil, errors.New("ssh: extra data following keyboard-interactive pairs")
+		}
+
+		answers, err := cb(msg.User, msg.Instruction, prompts, echos)
+		if err != nil {
+			return false, nil, err
+		}
+
+		if len(answers) != len(prompts) {
+			return false, nil, errors.New("ssh: not enough answers from keyboard-interactive callback")
+		}
+		responseLength := 1 + 4
+		for _, a := range answers {
+			responseLength += stringLength(len(a))
+		}
+		serialized := make([]byte, responseLength)
+		p := serialized
+		p[0] = msgUserAuthInfoResponse
+		p = p[1:]
+		p = marshalUint32(p, uint32(len(answers)))
+		for _, a := range answers {
+			p = marshalString(p, []byte(a))
+		}
+
+		if err := c.writePacket(serialized); err != nil {
+			return false, nil, err
+		}
+	}
+}
+
+type retryableAuthMethod struct {
+	authMethod AuthMethod
+	maxTries   int
+}
+
+func (r *retryableAuthMethod) auth(session []byte, user string, c packetConn, rand io.Reader) (ok bool, methods []string, err error) {
+	for i := 0; r.maxTries <= 0 || i < r.maxTries; i++ {
+		ok, methods, err = r.authMethod.auth(session, user, c, rand)
+		if ok || err != nil { // either success or error terminate
+			return ok, methods, err
+		}
+	}
+	return ok, methods, err
+}
+
+func (r *retryableAuthMethod) method() string {
+	return r.authMethod.method()
+}
+
+// RetryableAuthMethod is a decorator for other auth methods enabling them to
+// be retried up to maxTries before considering that AuthMethod itself failed.
+// If maxTries is <= 0, will retry indefinitely
+//
+// This is useful for interactive clients using challenge/response type
+// authentication (e.g. Keyboard-Interactive, Password, etc) where the user
+// could mistype their response resulting in the server issuing a
+// SSH_MSG_USERAUTH_FAILURE (rfc4252 #8 [password] and rfc4256 #3.4
+// [keyboard-interactive]); Without this decorator, the non-retryable
+// AuthMethod would be removed from future consideration, and never tried again
+// (and so the user would never be able to retry their entry).
+func RetryableAuthMethod(auth AuthMethod, maxTries int) AuthMethod {
+	return &retryableAuthMethod{authMethod: auth, maxTries: maxTries}
+}

vendor/golang.org/x/crypto/ssh/client_auth_test.go

@@ -0,0 +1,472 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+	"testing"
+)
+
+type keyboardInteractive map[string]string
+
+func (cr keyboardInteractive) Challenge(user string, instruction string, questions []string, echos []bool) ([]string, error) {
+	var answers []string
+	for _, q := range questions {
+		answers = append(answers, cr[q])
+	}
+	return answers, nil
+}
+
+// reused internally by tests
+var clientPassword = "tiger"
+
+// tryAuth runs a handshake with a given config against an SSH server
+// with config serverConfig
+func tryAuth(t *testing.T, config *ClientConfig) error {
+	c1, c2, err := netPipe()
+	if err != nil {
+		t.Fatalf("netPipe: %v", err)
+	}
+	defer c1.Close()
+	defer c2.Close()
+
+	certChecker := CertChecker{
+		IsAuthority: func(k PublicKey) bool {
+			return bytes.Equal(k.Marshal(), testPublicKeys["ecdsa"].Marshal())
+		},
+		UserKeyFallback: func(conn ConnMetadata, key PublicKey) (*Permissions, error) {
+			if conn.User() == "testuser" && bytes.Equal(key.Marshal(), testPublicKeys["rsa"].Marshal()) {
+				return nil, nil
+			}
+
+			return nil, fmt.Errorf("pubkey for %q not acceptable", conn.User())
+		},
+		IsRevoked: func(c *Certificate) bool {
+			return c.Serial == 666
+		},
+	}
+
+	serverConfig := &ServerConfig{
+		PasswordCallback: func(conn ConnMetadata, pass []byte) (*Permissions, error) {
+			if conn.User() == "testuser" && string(pass) == clientPassword {
+				return nil, nil
+			}
+			return nil, errors.New("password auth failed")
+		},
+		PublicKeyCallback: certChecker.Authenticate,
+		KeyboardInteractiveCallback: func(conn ConnMetadata, challenge KeyboardInteractiveChallenge) (*Permissions, error) {
+			ans, err := challenge("user",
+				"instruction",
+				[]string{"question1", "question2"},
+				[]bool{true, true})
+			if err != nil {
+				return nil, err
+			}
+			ok := conn.User() == "testuser" && ans[0] == "answer1" && ans[1] == "answer2"
+			if ok {
+				challenge("user", "motd", nil, nil)
+				return nil, nil
+			}
+			return nil, errors.New("keyboard-interactive failed")
+		},
+		AuthLogCallback: func(conn ConnMetadata, method string, err error) {
+			t.Logf("user %q, method %q: %v", conn.User(), method, err)
+		},
+	}
+	serverConfig.AddHostKey(testSigners["rsa"])
+
+	go newServer(c1, serverConfig)
+	_, _, _, err = NewClientConn(c2, "", config)
+	return err
+}
+
+func TestClientAuthPublicKey(t *testing.T) {
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			PublicKeys(testSigners["rsa"]),
+		},
+	}
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("unable to dial remote side: %s", err)
+	}
+}
+
+func TestAuthMethodPassword(t *testing.T) {
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			Password(clientPassword),
+		},
+	}
+
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("unable to dial remote side: %s", err)
+	}
+}
+
+func TestAuthMethodFallback(t *testing.T) {
+	var passwordCalled bool
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			PublicKeys(testSigners["rsa"]),
+			PasswordCallback(
+				func() (string, error) {
+					passwordCalled = true
+					return "WRONG", nil
+				}),
+		},
+	}
+
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("unable to dial remote side: %s", err)
+	}
+
+	if passwordCalled {
+		t.Errorf("password auth tried before public-key auth.")
+	}
+}
+
+func TestAuthMethodWrongPassword(t *testing.T) {
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			Password("wrong"),
+			PublicKeys(testSigners["rsa"]),
+		},
+	}
+
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("unable to dial remote side: %s", err)
+	}
+}
+
+func TestAuthMethodKeyboardInteractive(t *testing.T) {
+	answers := keyboardInteractive(map[string]string{
+		"question1": "answer1",
+		"question2": "answer2",
+	})
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			KeyboardInteractive(answers.Challenge),
+		},
+	}
+
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("unable to dial remote side: %s", err)
+	}
+}
+
+func TestAuthMethodWrongKeyboardInteractive(t *testing.T) {
+	answers := keyboardInteractive(map[string]string{
+		"question1": "answer1",
+		"question2": "WRONG",
+	})
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			KeyboardInteractive(answers.Challenge),
+		},
+	}
+
+	if err := tryAuth(t, config); err == nil {
+		t.Fatalf("wrong answers should not have authenticated with KeyboardInteractive")
+	}
+}
+
+// the mock server will only authenticate ssh-rsa keys
+func TestAuthMethodInvalidPublicKey(t *testing.T) {
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			PublicKeys(testSigners["dsa"]),
+		},
+	}
+
+	if err := tryAuth(t, config); err == nil {
+		t.Fatalf("dsa private key should not have authenticated with rsa public key")
+	}
+}
+
+// the client should authenticate with the second key
+func TestAuthMethodRSAandDSA(t *testing.T) {
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			PublicKeys(testSigners["dsa"], testSigners["rsa"]),
+		},
+	}
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("client could not authenticate with rsa key: %v", err)
+	}
+}
+
+func TestClientHMAC(t *testing.T) {
+	for _, mac := range supportedMACs {
+		config := &ClientConfig{
+			User: "testuser",
+			Auth: []AuthMethod{
+				PublicKeys(testSigners["rsa"]),
+			},
+			Config: Config{
+				MACs: []string{mac},
+			},
+		}
+		if err := tryAuth(t, config); err != nil {
+			t.Fatalf("client could not authenticate with mac algo %s: %v", mac, err)
+		}
+	}
+}
+
+// issue 4285.
+func TestClientUnsupportedCipher(t *testing.T) {
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			PublicKeys(),
+		},
+		Config: Config{
+			Ciphers: []string{"aes128-cbc"}, // not currently supported
+		},
+	}
+	if err := tryAuth(t, config); err == nil {
+		t.Errorf("expected no ciphers in common")
+	}
+}
+
+func TestClientUnsupportedKex(t *testing.T) {
+	if os.Getenv("GO_BUILDER_NAME") != "" {
+		t.Skip("skipping known-flaky test on the Go build dashboard; see golang.org/issue/15198")
+	}
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			PublicKeys(),
+		},
+		Config: Config{
+			KeyExchanges: []string{"diffie-hellman-group-exchange-sha256"}, // not currently supported
+		},
+	}
+	if err := tryAuth(t, config); err == nil || !strings.Contains(err.Error(), "common algorithm") {
+		t.Errorf("got %v, expected 'common algorithm'", err)
+	}
+}
+
+func TestClientLoginCert(t *testing.T) {
+	cert := &Certificate{
+		Key:         testPublicKeys["rsa"],
+		ValidBefore: CertTimeInfinity,
+		CertType:    UserCert,
+	}
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	certSigner, err := NewCertSigner(cert, testSigners["rsa"])
+	if err != nil {
+		t.Fatalf("NewCertSigner: %v", err)
+	}
+
+	clientConfig := &ClientConfig{
+		User: "user",
+	}
+	clientConfig.Auth = append(clientConfig.Auth, PublicKeys(certSigner))
+
+	t.Log("should succeed")
+	if err := tryAuth(t, clientConfig); err != nil {
+		t.Errorf("cert login failed: %v", err)
+	}
+
+	t.Log("corrupted signature")
+	cert.Signature.Blob[0]++
+	if err := tryAuth(t, clientConfig); err == nil {
+		t.Errorf("cert login passed with corrupted sig")
+	}
+
+	t.Log("revoked")
+	cert.Serial = 666
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	if err := tryAuth(t, clientConfig); err == nil {
+		t.Errorf("revoked cert login succeeded")
+	}
+	cert.Serial = 1
+
+	t.Log("sign with wrong key")
+	cert.SignCert(rand.Reader, testSigners["dsa"])
+	if err := tryAuth(t, clientConfig); err == nil {
+		t.Errorf("cert login passed with non-authoritative key")
+	}
+
+	t.Log("host cert")
+	cert.CertType = HostCert
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	if err := tryAuth(t, clientConfig); err == nil {
+		t.Errorf("cert login passed with wrong type")
+	}
+	cert.CertType = UserCert
+
+	t.Log("principal specified")
+	cert.ValidPrincipals = []string{"user"}
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	if err := tryAuth(t, clientConfig); err != nil {
+		t.Errorf("cert login failed: %v", err)
+	}
+
+	t.Log("wrong principal specified")
+	cert.ValidPrincipals = []string{"fred"}
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	if err := tryAuth(t, clientConfig); err == nil {
+		t.Errorf("cert login passed with wrong principal")
+	}
+	cert.ValidPrincipals = nil
+
+	t.Log("added critical option")
+	cert.CriticalOptions = map[string]string{"root-access": "yes"}
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	if err := tryAuth(t, clientConfig); err == nil {
+		t.Errorf("cert login passed with unrecognized critical option")
+	}
+
+	t.Log("allowed source address")
+	cert.CriticalOptions = map[string]string{"source-address": "127.0.0.42/24"}
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	if err := tryAuth(t, clientConfig); err != nil {
+		t.Errorf("cert login with source-address failed: %v", err)
+	}
+
+	t.Log("disallowed source address")
+	cert.CriticalOptions = map[string]string{"source-address": "127.0.0.42"}
+	cert.SignCert(rand.Reader, testSigners["ecdsa"])
+	if err := tryAuth(t, clientConfig); err == nil {
+		t.Errorf("cert login with source-address succeeded")
+	}
+}
+
+func testPermissionsPassing(withPermissions bool, t *testing.T) {
+	serverConfig := &ServerConfig{
+		PublicKeyCallback: func(conn ConnMetadata, key PublicKey) (*Permissions, error) {
+			if conn.User() == "nopermissions" {
+				return nil, nil
+			} else {
+				return &Permissions{}, nil
+			}
+		},
+	}
+	serverConfig.AddHostKey(testSigners["rsa"])
+
+	clientConfig := &ClientConfig{
+		Auth: []AuthMethod{
+			PublicKeys(testSigners["rsa"]),
+		},
+	}
+	if withPermissions {
+		clientConfig.User = "permissions"
+	} else {
+		clientConfig.User = "nopermissions"
+	}
+
+	c1, c2, err := netPipe()
+	if err != nil {
+		t.Fatalf("netPipe: %v", err)
+	}
+	defer c1.Close()
+	defer c2.Close()
+
+	go NewClientConn(c2, "", clientConfig)
+	serverConn, err := newServer(c1, serverConfig)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if p := serverConn.Permissions; (p != nil) != withPermissions {
+		t.Fatalf("withPermissions is %t, but Permissions object is %#v", withPermissions, p)
+	}
+}
+
+func TestPermissionsPassing(t *testing.T) {
+	testPermissionsPassing(true, t)
+}
+
+func TestNoPermissionsPassing(t *testing.T) {
+	testPermissionsPassing(false, t)
+}
+
+func TestRetryableAuth(t *testing.T) {
+	n := 0
+	passwords := []string{"WRONG1", "WRONG2"}
+
+	config := &ClientConfig{
+		User: "testuser",
+		Auth: []AuthMethod{
+			RetryableAuthMethod(PasswordCallback(func() (string, error) {
+				p := passwords[n]
+				n++
+				return p, nil
+			}), 2),
+			PublicKeys(testSigners["rsa"]),
+		},
+	}
+
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("unable to dial remote side: %s", err)
+	}
+	if n != 2 {
+		t.Fatalf("Did not try all passwords")
+	}
+}
+
+func ExampleRetryableAuthMethod(t *testing.T) {
+	user := "testuser"
+	NumberOfPrompts := 3
+
+	// Normally this would be a callback that prompts the user to answer the
+	// provided questions
+	Cb := func(user, instruction string, questions []string, echos []bool) (answers []string, err error) {
+		return []string{"answer1", "answer2"}, nil
+	}
+
+	config := &ClientConfig{
+		User: user,
+		Auth: []AuthMethod{
+			RetryableAuthMethod(KeyboardInteractiveChallenge(Cb), NumberOfPrompts),
+		},
+	}
+
+	if err := tryAuth(t, config); err != nil {
+		t.Fatalf("unable to dial remote side: %s", err)
+	}
+}
+
+// Test if username is received on server side when NoClientAuth is used
+func TestClientAuthNone(t *testing.T) {
+	user := "testuser"
+	serverConfig := &ServerConfig{
+		NoClientAuth: true,
+	}
+	serverConfig.AddHostKey(testSigners["rsa"])
+
+	clientConfig := &ClientConfig{
+		User: user,
+	}
+
+	c1, c2, err := netPipe()
+	if err != nil {
+		t.Fatalf("netPipe: %v", err)
+	}
+	defer c1.Close()
+	defer c2.Close()
+
+	go NewClientConn(c2, "", clientConfig)
+	serverConn, err := newServer(c1, serverConfig)
+	if err != nil {
+		t.Fatalf("newServer: %v", err)
+	}
+	if serverConn.User() != user {
+		t.Fatalf("server: got %q, want %q", serverConn.User(), user)
+	}
+}

vendor/golang.org/x/crypto/ssh/client_test.go

@@ -0,0 +1,39 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"net"
+	"testing"
+)
+
+func testClientVersion(t *testing.T, config *ClientConfig, expected string) {
+	clientConn, serverConn := net.Pipe()
+	defer clientConn.Close()
+	receivedVersion := make(chan string, 1)
+	go func() {
+		version, err := readVersion(serverConn)
+		if err != nil {
+			receivedVersion <- ""
+		} else {
+			receivedVersion <- string(version)
+		}
+		serverConn.Close()
+	}()
+	NewClientConn(clientConn, "", config)
+	actual := <-receivedVersion
+	if actual != expected {
+		t.Fatalf("got %s; want %s", actual, expected)
+	}
+}
+
+func TestCustomClientVersion(t *testing.T) {
+	version := "Test-Client-Version-0.0"
+	testClientVersion(t, &ClientConfig{ClientVersion: version}, version)
+}
+
+func TestDefaultClientVersion(t *testing.T) {
+	testClientVersion(t, &ClientConfig{}, packageVersion)
+}

vendor/golang.org/x/crypto/ssh/common.go

@@ -0,0 +1,356 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"crypto"
+	"crypto/rand"
+	"fmt"
+	"io"
+	"sync"
+
+	_ "crypto/sha1"
+	_ "crypto/sha256"
+	_ "crypto/sha512"
+)
+
+// These are string constants in the SSH protocol.
+const (
+	compressionNone = "none"
+	serviceUserAuth = "ssh-userauth"
+	serviceSSH      = "ssh-connection"
+)
+
+// supportedCiphers specifies the supported ciphers in preference order.
+var supportedCiphers = []string{
+	"aes128-ctr", "aes192-ctr", "aes256-ctr",
+	"aes128-gcm@openssh.com",
+	"arcfour256", "arcfour128",
+}
+
+// supportedKexAlgos specifies the supported key-exchange algorithms in
+// preference order.
+var supportedKexAlgos = []string{
+	kexAlgoCurve25519SHA256,
+	// P384 and P521 are not constant-time yet, but since we don't
+	// reuse ephemeral keys, using them for ECDH should be OK.
+	kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521,
+	kexAlgoDH14SHA1, kexAlgoDH1SHA1,
+}
+
+// supportedKexAlgos specifies the supported host-key algorithms (i.e. methods
+// of authenticating servers) in preference order.
+var supportedHostKeyAlgos = []string{
+	CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01,
+	CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoED25519v01,
+
+	KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521,
+	KeyAlgoRSA, KeyAlgoDSA,
+
+	KeyAlgoED25519,
+}
+
+// supportedMACs specifies a default set of MAC algorithms in preference order.
+// This is based on RFC 4253, section 6.4, but with hmac-md5 variants removed
+// because they have reached the end of their useful life.
+var supportedMACs = []string{
+	"hmac-sha2-256", "hmac-sha1", "hmac-sha1-96",
+}
+
+var supportedCompressions = []string{compressionNone}
+
+// hashFuncs keeps the mapping of supported algorithms to their respective
+// hashes needed for signature verification.
+var hashFuncs = map[string]crypto.Hash{
+	KeyAlgoRSA:          crypto.SHA1,
+	KeyAlgoDSA:          crypto.SHA1,
+	KeyAlgoECDSA256:     crypto.SHA256,
+	KeyAlgoECDSA384:     crypto.SHA384,
+	KeyAlgoECDSA521:     crypto.SHA512,
+	CertAlgoRSAv01:      crypto.SHA1,
+	CertAlgoDSAv01:      crypto.SHA1,
+	CertAlgoECDSA256v01: crypto.SHA256,
+	CertAlgoECDSA384v01: crypto.SHA384,
+	CertAlgoECDSA521v01: crypto.SHA512,
+}
+
+// unexpectedMessageError results when the SSH message that we received didn't
+// match what we wanted.
+func unexpectedMessageError(expected, got uint8) error {
+	return fmt.Errorf("ssh: unexpected message type %d (expected %d)", got, expected)
+}
+
+// parseError results from a malformed SSH message.
+func parseError(tag uint8) error {
+	return fmt.Errorf("ssh: parse error in message type %d", tag)
+}
+
+func findCommon(what string, client []string, server []string) (common string, err error) {
+	for _, c := range client {
+		for _, s := range server {
+			if c == s {
+				return c, nil
+			}
+		}
+	}
+	return "", fmt.Errorf("ssh: no common algorithm for %s; client offered: %v, server offered: %v", what, client, server)
+}
+
+type directionAlgorithms struct {
+	Cipher      string
+	MAC         string
+	Compression string
+}
+
+type algorithms struct {
+	kex     string
+	hostKey string
+	w       directionAlgorithms
+	r       directionAlgorithms
+}
+
+func findAgreedAlgorithms(clientKexInit, serverKexInit *kexInitMsg) (algs *algorithms, err error) {
+	result := &algorithms{}
+
+	result.kex, err = findCommon("key exchange", clientKexInit.KexAlgos, serverKexInit.KexAlgos)
+	if err != nil {
+		return
+	}
+
+	result.hostKey, err = findCommon("host key", clientKexInit.ServerHostKeyAlgos, serverKexInit.ServerHostKeyAlgos)
+	if err != nil {
+		return
+	}
+
+	result.w.Cipher, err = findCommon("client to server cipher", clientKexInit.CiphersClientServer, serverKexInit.CiphersClientServer)
+	if err != nil {
+		return
+	}
+
+	result.r.Cipher, err = findCommon("server to client cipher", clientKexInit.CiphersServerClient, serverKexInit.CiphersServerClient)
+	if err != nil {
+		return
+	}
+
+	result.w.MAC, err = findCommon("client to server MAC", clientKexInit.MACsClientServer, serverKexInit.MACsClientServer)
+	if err != nil {
+		return
+	}
+
+	result.r.MAC, err = findCommon("server to client MAC", clientKexInit.MACsServerClient, serverKexInit.MACsServerClient)
+	if err != nil {
+		return
+	}
+
+	result.w.Compression, err = findCommon("client to server compression", clientKexInit.CompressionClientServer, serverKexInit.CompressionClientServer)
+	if err != nil {
+		return
+	}
+
+	result.r.Compression, err = findCommon("server to client compression", clientKexInit.CompressionServerClient, serverKexInit.CompressionServerClient)
+	if err != nil {
+		return
+	}
+
+	return result, nil
+}
+
+// If rekeythreshold is too small, we can't make any progress sending
+// stuff.
+const minRekeyThreshold uint64 = 256
+
+// Config contains configuration data common to both ServerConfig and
+// ClientConfig.
+type Config struct {
+	// Rand provides the source of entropy for cryptographic
+	// primitives. If Rand is nil, the cryptographic random reader
+	// in package crypto/rand will be used.
+	Rand io.Reader
+
+	// The maximum number of bytes sent or received after which a
+	// new key is negotiated. It must be at least 256. If
+	// unspecified, 1 gigabyte is used.
+	RekeyThreshold uint64
+
+	// The allowed key exchanges algorithms. If unspecified then a
+	// default set of algorithms is used.
+	KeyExchanges []string
+
+	// The allowed cipher algorithms. If unspecified then a sensible
+	// default is used.
+	Ciphers []string
+
+	// The allowed MAC algorithms. If unspecified then a sensible default
+	// is used.
+	MACs []string
+}
+
+// SetDefaults sets sensible values for unset fields in config. This is
+// exported for testing: Configs passed to SSH functions are copied and have
+// default values set automatically.
+func (c *Config) SetDefaults() {
+	if c.Rand == nil {
+		c.Rand = rand.Reader
+	}
+	if c.Ciphers == nil {
+		c.Ciphers = supportedCiphers
+	}
+	var ciphers []string
+	for _, c := range c.Ciphers {
+		if cipherModes[c] != nil {
+			// reject the cipher if we have no cipherModes definition
+			ciphers = append(ciphers, c)
+		}
+	}
+	c.Ciphers = ciphers
+
+	if c.KeyExchanges == nil {
+		c.KeyExchanges = supportedKexAlgos
+	}
+
+	if c.MACs == nil {
+		c.MACs = supportedMACs
+	}
+
+	if c.RekeyThreshold == 0 {
+		// RFC 4253, section 9 suggests rekeying after 1G.
+		c.RekeyThreshold = 1 << 30
+	}
+	if c.RekeyThreshold < minRekeyThreshold {
+		c.RekeyThreshold = minRekeyThreshold
+	}
+}
+
+// buildDataSignedForAuth returns the data that is signed in order to prove
+// possession of a private key. See RFC 4252, section 7.
+func buildDataSignedForAuth(sessionId []byte, req userAuthRequestMsg, algo, pubKey []byte) []byte {
+	data := struct {
+		Session []byte
+		Type    byte
+		User    string
+		Service string
+		Method  string
+		Sign    bool
+		Algo    []byte
+		PubKey  []byte
+	}{
+		sessionId,
+		msgUserAuthRequest,
+		req.User,
+		req.Service,
+		req.Method,
+		true,
+		algo,
+		pubKey,
+	}
+	return Marshal(data)
+}
+
+func appendU16(buf []byte, n uint16) []byte {
+	return append(buf, byte(n>>8), byte(n))
+}
+
+func appendU32(buf []byte, n uint32) []byte {
+	return append(buf, byte(n>>24), byte(n>>16), byte(n>>8), byte(n))
+}
+
+func appendU64(buf []byte, n uint64) []byte {
+	return append(buf,
+		byte(n>>56), byte(n>>48), byte(n>>40), byte(n>>32),
+		byte(n>>24), byte(n>>16), byte(n>>8), byte(n))
+}
+
+func appendInt(buf []byte, n int) []byte {
+	return appendU32(buf, uint32(n))
+}
+
+func appendString(buf []byte, s string) []byte {
+	buf = appendU32(buf, uint32(len(s)))
+	buf = append(buf, s...)
+	return buf
+}
+
+func appendBool(buf []byte, b bool) []byte {
+	if b {
+		return append(buf, 1)
+	}
+	return append(buf, 0)
+}
+
+// newCond is a helper to hide the fact that there is no usable zero
+// value for sync.Cond.
+func newCond() *sync.Cond { return sync.NewCond(new(sync.Mutex)) }
+
+// window represents the buffer available to clients
+// wishing to write to a channel.
+type window struct {
+	*sync.Cond
+	win          uint32 // RFC 4254 5.2 says the window size can grow to 2^32-1
+	writeWaiters int
+	closed       bool
+}
+
+// add adds win to the amount of window available
+// for consumers.
+func (w *window) add(win uint32) bool {
+	// a zero sized window adjust is a noop.
+	if win == 0 {
+		return true
+	}
+	w.L.Lock()
+	if w.win+win < win {
+		w.L.Unlock()
+		return false
+	}
+	w.win += win
+	// It is unusual that multiple goroutines would be attempting to reserve
+	// window space, but not guaranteed. Use broadcast to notify all waiters
+	// that additional window is available.
+	w.Broadcast()
+	w.L.Unlock()
+	return true
+}
+
+// close sets the window to closed, so all reservations fail
+// immediately.
+func (w *window) close() {
+	w.L.Lock()
+	w.closed = true
+	w.Broadcast()
+	w.L.Unlock()
+}
+
+// reserve reserves win from the available window capacity.
+// If no capacity remains, reserve will block. reserve may
+// return less than requested.
+func (w *window) reserve(win uint32) (uint32, error) {
+	var err error
+	w.L.Lock()
+	w.writeWaiters++
+	w.Broadcast()
+	for w.win == 0 && !w.closed {
+		w.Wait()
+	}
+	w.writeWaiters--
+	if w.win < win {
+		win = w.win
+	}
+	w.win -= win
+	if w.closed {
+		err = io.EOF
+	}
+	w.L.Unlock()
+	return win, err
+}
+
+// waitWriterBlocked waits until some goroutine is blocked for further
+// writes. It is used in tests only.
+func (w *window) waitWriterBlocked() {
+	w.Cond.L.Lock()
+	for w.writeWaiters == 0 {
+		w.Cond.Wait()
+	}
+	w.Cond.L.Unlock()
+}

vendor/golang.org/x/crypto/ssh/connection.go

@@ -0,0 +1,143 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"fmt"
+	"net"
+)
+
+// OpenChannelError is returned if the other side rejects an
+// OpenChannel request.
+type OpenChannelError struct {
+	Reason  RejectionReason
+	Message string
+}
+
+func (e *OpenChannelError) Error() string {
+	return fmt.Sprintf("ssh: rejected: %s (%s)", e.Reason, e.Message)
+}
+
+// ConnMetadata holds metadata for the connection.
+type ConnMetadata interface {
+	// User returns the user ID for this connection.
+	User() string
+
+	// SessionID returns the sesson hash, also denoted by H.
+	SessionID() []byte
+
+	// ClientVersion returns the client's version string as hashed
+	// into the session ID.
+	ClientVersion() []byte
+
+	// ServerVersion returns the server's version string as hashed
+	// into the session ID.
+	ServerVersion() []byte
+
+	// RemoteAddr returns the remote address for this connection.
+	RemoteAddr() net.Addr
+
+	// LocalAddr returns the local address for this connection.
+	LocalAddr() net.Addr
+}
+
+// Conn represents an SSH connection for both server and client roles.
+// Conn is the basis for implementing an application layer, such
+// as ClientConn, which implements the traditional shell access for
+// clients.
+type Conn interface {
+	ConnMetadata
+
+	// SendRequest sends a global request, and returns the
+	// reply. If wantReply is true, it returns the response status
+	// and payload. See also RFC4254, section 4.
+	SendRequest(name string, wantReply bool, payload []byte) (bool, []byte, error)
+
+	// OpenChannel tries to open an channel. If the request is
+	// rejected, it returns *OpenChannelError. On success it returns
+	// the SSH Channel and a Go channel for incoming, out-of-band
+	// requests. The Go channel must be serviced, or the
+	// connection will hang.
+	OpenChannel(name string, data []byte) (Channel, <-chan *Request, error)
+
+	// Close closes the underlying network connection
+	Close() error
+
+	// Wait blocks until the connection has shut down, and returns the
+	// error causing the shutdown.
+	Wait() error
+
+	// TODO(hanwen): consider exposing:
+	//   RequestKeyChange
+	//   Disconnect
+}
+
+// DiscardRequests consumes and rejects all requests from the
+// passed-in channel.
+func DiscardRequests(in <-chan *Request) {
+	for req := range in {
+		if req.WantReply {
+			req.Reply(false, nil)
+		}
+	}
+}
+
+// A connection represents an incoming connection.
+type connection struct {
+	transport *handshakeTransport
+	sshConn
+
+	// The connection protocol.
+	*mux
+}
+
+func (c *connection) Close() error {
+	return c.sshConn.conn.Close()
+}
+
+// sshconn provides net.Conn metadata, but disallows direct reads and
+// writes.
+type sshConn struct {
+	conn net.Conn
+
+	user          string
+	sessionID     []byte
+	clientVersion []byte
+	serverVersion []byte
+}
+
+func dup(src []byte) []byte {
+	dst := make([]byte, len(src))
+	copy(dst, src)
+	return dst
+}
+
+func (c *sshConn) User() string {
+	return c.user
+}
+
+func (c *sshConn) RemoteAddr() net.Addr {
+	return c.conn.RemoteAddr()
+}
+
+func (c *sshConn) Close() error {
+	return c.conn.Close()
+}
+
+func (c *sshConn) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+func (c *sshConn) SessionID() []byte {
+	return dup(c.sessionID)
+}
+
+func (c *sshConn) ClientVersion() []byte {
+	return dup(c.clientVersion)
+}
+
+func (c *sshConn) ServerVersion() []byte {
+	return dup(c.serverVersion)
+}

vendor/golang.org/x/crypto/ssh/doc.go

@@ -0,0 +1,18 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package ssh implements an SSH client and server.
+
+SSH is a transport security protocol, an authentication protocol and a
+family of application protocols. The most typical application level
+protocol is a remote shell and this is specifically implemented.  However,
+the multiplexed nature of SSH is exposed to users that wish to support
+others.
+
+References:
+  [PROTOCOL.certkeys]: http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL.certkeys?rev=HEAD
+  [SSH-PARAMETERS]:    http://www.iana.org/assignments/ssh-parameters/ssh-parameters.xml#ssh-parameters-1
+*/
+package ssh // import "golang.org/x/crypto/ssh"

vendor/golang.org/x/crypto/ssh/example_test.go

@@ -0,0 +1,262 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh_test
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+	"net/http"
+
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+func ExampleNewServerConn() {
+	// Public key authentication is done by comparing
+	// the public key of a received connection
+	// with the entries in the authorized_keys file.
+	authorizedKeysBytes, err := ioutil.ReadFile("authorized_keys")
+	if err != nil {
+		log.Fatalf("Failed to load authorized_keys, err: %v", err)
+	}
+
+	authorizedKeysMap := map[string]bool{}
+	for len(authorizedKeysBytes) > 0 {
+		pubKey, _, _, rest, err := ssh.ParseAuthorizedKey(authorizedKeysBytes)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		authorizedKeysMap[string(pubKey.Marshal())] = true
+		authorizedKeysBytes = rest
+	}
+
+	// An SSH server is represented by a ServerConfig, which holds
+	// certificate details and handles authentication of ServerConns.
+	config := &ssh.ServerConfig{
+		// Remove to disable password auth.
+		PasswordCallback: func(c ssh.ConnMetadata, pass []byte) (*ssh.Permissions, error) {
+			// Should use constant-time compare (or better, salt+hash) in
+			// a production setting.
+			if c.User() == "testuser" && string(pass) == "tiger" {
+				return nil, nil
+			}
+			return nil, fmt.Errorf("password rejected for %q", c.User())
+		},
+
+		// Remove to disable public key auth.
+		PublicKeyCallback: func(c ssh.ConnMetadata, pubKey ssh.PublicKey) (*ssh.Permissions, error) {
+			if authorizedKeysMap[string(pubKey.Marshal())] {
+				return nil, nil
+			}
+			return nil, fmt.Errorf("unknown public key for %q", c.User())
+		},
+	}
+
+	privateBytes, err := ioutil.ReadFile("id_rsa")
+	if err != nil {
+		log.Fatal("Failed to load private key: ", err)
+	}
+
+	private, err := ssh.ParsePrivateKey(privateBytes)
+	if err != nil {
+		log.Fatal("Failed to parse private key: ", err)
+	}
+
+	config.AddHostKey(private)
+
+	// Once a ServerConfig has been configured, connections can be
+	// accepted.
+	listener, err := net.Listen("tcp", "0.0.0.0:2022")
+	if err != nil {
+		log.Fatal("failed to listen for connection: ", err)
+	}
+	nConn, err := listener.Accept()
+	if err != nil {
+		log.Fatal("failed to accept incoming connection: ", err)
+	}
+
+	// Before use, a handshake must be performed on the incoming
+	// net.Conn.
+	_, chans, reqs, err := ssh.NewServerConn(nConn, config)
+	if err != nil {
+		log.Fatal("failed to handshake: ", err)
+	}
+	// The incoming Request channel must be serviced.
+	go ssh.DiscardRequests(reqs)
+
+	// Service the incoming Channel channel.
+
+	// Service the incoming Channel channel.
+	for newChannel := range chans {
+		// Channels have a type, depending on the application level
+		// protocol intended. In the case of a shell, the type is
+		// "session" and ServerShell may be used to present a simple
+		// terminal interface.
+		if newChannel.ChannelType() != "session" {
+			newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
+			continue
+		}
+		channel, requests, err := newChannel.Accept()
+		if err != nil {
+			log.Fatalf("Could not accept channel: %v", err)
+		}
+
+		// Sessions have out-of-band requests such as "shell",
+		// "pty-req" and "env".  Here we handle only the
+		// "shell" request.
+		go func(in <-chan *ssh.Request) {
+			for req := range in {
+				req.Reply(req.Type == "shell", nil)
+			}
+		}(requests)
+
+		term := terminal.NewTerminal(channel, "> ")
+
+		go func() {
+			defer channel.Close()
+			for {
+				line, err := term.ReadLine()
+				if err != nil {
+					break
+				}
+				fmt.Println(line)
+			}
+		}()
+	}
+}
+
+func ExampleDial() {
+	// An SSH client is represented with a ClientConn.
+	//
+	// To authenticate with the remote server you must pass at least one
+	// implementation of AuthMethod via the Auth field in ClientConfig.
+	config := &ssh.ClientConfig{
+		User: "username",
+		Auth: []ssh.AuthMethod{
+			ssh.Password("yourpassword"),
+		},
+	}
+	client, err := ssh.Dial("tcp", "yourserver.com:22", config)
+	if err != nil {
+		log.Fatal("Failed to dial: ", err)
+	}
+
+	// Each ClientConn can support multiple interactive sessions,
+	// represented by a Session.
+	session, err := client.NewSession()
+	if err != nil {
+		log.Fatal("Failed to create session: ", err)
+	}
+	defer session.Close()
+
+	// Once a Session is created, you can execute a single command on
+	// the remote side using the Run method.
+	var b bytes.Buffer
+	session.Stdout = &b
+	if err := session.Run("/usr/bin/whoami"); err != nil {
+		log.Fatal("Failed to run: " + err.Error())
+	}
+	fmt.Println(b.String())
+}
+
+func ExamplePublicKeys() {
+	// A public key may be used to authenticate against the remote
+	// server by using an unencrypted PEM-encoded private key file.
+	//
+	// If you have an encrypted private key, the crypto/x509 package
+	// can be used to decrypt it.
+	key, err := ioutil.ReadFile("/home/user/.ssh/id_rsa")
+	if err != nil {
+		log.Fatalf("unable to read private key: %v", err)
+	}
+
+	// Create the Signer for this private key.
+	signer, err := ssh.ParsePrivateKey(key)
+	if err != nil {
+		log.Fatalf("unable to parse private key: %v", err)
+	}
+
+	config := &ssh.ClientConfig{
+		User: "user",
+		Auth: []ssh.AuthMethod{
+			// Use the PublicKeys method for remote authentication.
+			ssh.PublicKeys(signer),
+		},
+	}
+
+	// Connect to the remote server and perform the SSH handshake.
+	client, err := ssh.Dial("tcp", "host.com:22", config)
+	if err != nil {
+		log.Fatalf("unable to connect: %v", err)
+	}
+	defer client.Close()
+}
+
+func ExampleClient_Listen() {
+	config := &ssh.ClientConfig{
+		User: "username",
+		Auth: []ssh.AuthMethod{
+			ssh.Password("password"),
+		},
+	}
+	// Dial your ssh server.
+	conn, err := ssh.Dial("tcp", "localhost:22", config)
+	if err != nil {
+		log.Fatal("unable to connect: ", err)
+	}
+	defer conn.Close()
+
+	// Request the remote side to open port 8080 on all interfaces.
+	l, err := conn.Listen("tcp", "0.0.0.0:8080")
+	if err != nil {
+		log.Fatal("unable to register tcp forward: ", err)
+	}
+	defer l.Close()
+
+	// Serve HTTP with your SSH server acting as a reverse proxy.
+	http.Serve(l, http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
+		fmt.Fprintf(resp, "Hello world!\n")
+	}))
+}
+
+func ExampleSession_RequestPty() {
+	// Create client config
+	config := &ssh.ClientConfig{
+		User: "username",
+		Auth: []ssh.AuthMethod{
+			ssh.Password("password"),
+		},
+	}
+	// Connect to ssh server
+	conn, err := ssh.Dial("tcp", "localhost:22", config)
+	if err != nil {
+		log.Fatal("unable to connect: ", err)
+	}
+	defer conn.Close()
+	// Create a session
+	session, err := conn.NewSession()
+	if err != nil {
+		log.Fatal("unable to create session: ", err)
+	}
+	defer session.Close()
+	// Set up terminal modes
+	modes := ssh.TerminalModes{
+		ssh.ECHO:          0,     // disable echoing
+		ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
+		ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
+	}
+	// Request pseudo terminal
+	if err := session.RequestPty("xterm", 40, 80, modes); err != nil {
+		log.Fatal("request for pseudo terminal failed: ", err)
+	}
+	// Start remote shell
+	if err := session.Shell(); err != nil {
+		log.Fatal("failed to start shell: ", err)
+	}
+}

vendor/golang.org/x/crypto/ssh/handshake.go

@@ -0,0 +1,460 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"sync"
+)
+
+// debugHandshake, if set, prints messages sent and received.  Key
+// exchange messages are printed as if DH were used, so the debug
+// messages are wrong when using ECDH.
+const debugHandshake = false
+
+// keyingTransport is a packet based transport that supports key
+// changes. It need not be thread-safe. It should pass through
+// msgNewKeys in both directions.
+type keyingTransport interface {
+	packetConn
+
+	// prepareKeyChange sets up a key change. The key change for a
+	// direction will be effected if a msgNewKeys message is sent
+	// or received.
+	prepareKeyChange(*algorithms, *kexResult) error
+}
+
+// handshakeTransport implements rekeying on top of a keyingTransport
+// and offers a thread-safe writePacket() interface.
+type handshakeTransport struct {
+	conn   keyingTransport
+	config *Config
+
+	serverVersion []byte
+	clientVersion []byte
+
+	// hostKeys is non-empty if we are the server. In that case,
+	// it contains all host keys that can be used to sign the
+	// connection.
+	hostKeys []Signer
+
+	// hostKeyAlgorithms is non-empty if we are the client. In that case,
+	// we accept these key types from the server as host key.
+	hostKeyAlgorithms []string
+
+	// On read error, incoming is closed, and readError is set.
+	incoming  chan []byte
+	readError error
+
+	// data for host key checking
+	hostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
+	dialAddress     string
+	remoteAddr      net.Addr
+
+	readSinceKex uint64
+
+	// Protects the writing side of the connection
+	mu              sync.Mutex
+	cond            *sync.Cond
+	sentInitPacket  []byte
+	sentInitMsg     *kexInitMsg
+	writtenSinceKex uint64
+	writeError      error
+
+	// The session ID or nil if first kex did not complete yet.
+	sessionID []byte
+}
+
+func newHandshakeTransport(conn keyingTransport, config *Config, clientVersion, serverVersion []byte) *handshakeTransport {
+	t := &handshakeTransport{
+		conn:          conn,
+		serverVersion: serverVersion,
+		clientVersion: clientVersion,
+		incoming:      make(chan []byte, 16),
+		config:        config,
+	}
+	t.cond = sync.NewCond(&t.mu)
+	return t
+}
+
+func newClientTransport(conn keyingTransport, clientVersion, serverVersion []byte, config *ClientConfig, dialAddr string, addr net.Addr) *handshakeTransport {
+	t := newHandshakeTransport(conn, &config.Config, clientVersion, serverVersion)
+	t.dialAddress = dialAddr
+	t.remoteAddr = addr
+	t.hostKeyCallback = config.HostKeyCallback
+	if config.HostKeyAlgorithms != nil {
+		t.hostKeyAlgorithms = config.HostKeyAlgorithms
+	} else {
+		t.hostKeyAlgorithms = supportedHostKeyAlgos
+	}
+	go t.readLoop()
+	return t
+}
+
+func newServerTransport(conn keyingTransport, clientVersion, serverVersion []byte, config *ServerConfig) *handshakeTransport {
+	t := newHandshakeTransport(conn, &config.Config, clientVersion, serverVersion)
+	t.hostKeys = config.hostKeys
+	go t.readLoop()
+	return t
+}
+
+func (t *handshakeTransport) getSessionID() []byte {
+	return t.sessionID
+}
+
+func (t *handshakeTransport) id() string {
+	if len(t.hostKeys) > 0 {
+		return "server"
+	}
+	return "client"
+}
+
+func (t *handshakeTransport) readPacket() ([]byte, error) {
+	p, ok := <-t.incoming
+	if !ok {
+		return nil, t.readError
+	}
+	return p, nil
+}
+
+func (t *handshakeTransport) readLoop() {
+	for {
+		p, err := t.readOnePacket()
+		if err != nil {
+			t.readError = err
+			close(t.incoming)
+			break
+		}
+		if p[0] == msgIgnore || p[0] == msgDebug {
+			continue
+		}
+		t.incoming <- p
+	}
+
+	// If we can't read, declare the writing part dead too.
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.writeError == nil {
+		t.writeError = t.readError
+	}
+	t.cond.Broadcast()
+}
+
+func (t *handshakeTransport) readOnePacket() ([]byte, error) {
+	if t.readSinceKex > t.config.RekeyThreshold {
+		if err := t.requestKeyChange(); err != nil {
+			return nil, err
+		}
+	}
+
+	p, err := t.conn.readPacket()
+	if err != nil {
+		return nil, err
+	}
+
+	t.readSinceKex += uint64(len(p))
+	if debugHandshake {
+		if p[0] == msgChannelData || p[0] == msgChannelExtendedData {
+			log.Printf("%s got data (packet %d bytes)", t.id(), len(p))
+		} else {
+			msg, err := decode(p)
+			log.Printf("%s got %T %v (%v)", t.id(), msg, msg, err)
+		}
+	}
+	if p[0] != msgKexInit {
+		return p, nil
+	}
+
+	t.mu.Lock()
+
+	firstKex := t.sessionID == nil
+
+	err = t.enterKeyExchangeLocked(p)
+	if err != nil {
+		// drop connection
+		t.conn.Close()
+		t.writeError = err
+	}
+
+	if debugHandshake {
+		log.Printf("%s exited key exchange (first %v), err %v", t.id(), firstKex, err)
+	}
+
+	// Unblock writers.
+	t.sentInitMsg = nil
+	t.sentInitPacket = nil
+	t.cond.Broadcast()
+	t.writtenSinceKex = 0
+	t.mu.Unlock()
+
+	if err != nil {
+		return nil, err
+	}
+
+	t.readSinceKex = 0
+
+	// By default, a key exchange is hidden from higher layers by
+	// translating it into msgIgnore.
+	successPacket := []byte{msgIgnore}
+	if firstKex {
+		// sendKexInit() for the first kex waits for
+		// msgNewKeys so the authentication process is
+		// guaranteed to happen over an encrypted transport.
+		successPacket = []byte{msgNewKeys}
+	}
+
+	return successPacket, nil
+}
+
+// keyChangeCategory describes whether a key exchange is the first on a
+// connection, or a subsequent one.
+type keyChangeCategory bool
+
+const (
+	firstKeyExchange      keyChangeCategory = true
+	subsequentKeyExchange keyChangeCategory = false
+)
+
+// sendKexInit sends a key change message, and returns the message
+// that was sent. After initiating the key change, all writes will be
+// blocked until the change is done, and a failed key change will
+// close the underlying transport. This function is safe for
+// concurrent use by multiple goroutines.
+func (t *handshakeTransport) sendKexInit(isFirst keyChangeCategory) error {
+	var err error
+
+	t.mu.Lock()
+	// If this is the initial key change, but we already have a sessionID,
+	// then do nothing because the key exchange has already completed
+	// asynchronously.
+	if !isFirst || t.sessionID == nil {
+		_, _, err = t.sendKexInitLocked(isFirst)
+	}
+	t.mu.Unlock()
+	if err != nil {
+		return err
+	}
+	if isFirst {
+		if packet, err := t.readPacket(); err != nil {
+			return err
+		} else if packet[0] != msgNewKeys {
+			return unexpectedMessageError(msgNewKeys, packet[0])
+		}
+	}
+	return nil
+}
+
+func (t *handshakeTransport) requestInitialKeyChange() error {
+	return t.sendKexInit(firstKeyExchange)
+}
+
+func (t *handshakeTransport) requestKeyChange() error {
+	return t.sendKexInit(subsequentKeyExchange)
+}
+
+// sendKexInitLocked sends a key change message. t.mu must be locked
+// while this happens.
+func (t *handshakeTransport) sendKexInitLocked(isFirst keyChangeCategory) (*kexInitMsg, []byte, error) {
+	// kexInits may be sent either in response to the other side,
+	// or because our side wants to initiate a key change, so we
+	// may have already sent a kexInit. In that case, don't send a
+	// second kexInit.
+	if t.sentInitMsg != nil {
+		return t.sentInitMsg, t.sentInitPacket, nil
+	}
+
+	msg := &kexInitMsg{
+		KexAlgos:                t.config.KeyExchanges,
+		CiphersClientServer:     t.config.Ciphers,
+		CiphersServerClient:     t.config.Ciphers,
+		MACsClientServer:        t.config.MACs,
+		MACsServerClient:        t.config.MACs,
+		CompressionClientServer: supportedCompressions,
+		CompressionServerClient: supportedCompressions,
+	}
+	io.ReadFull(rand.Reader, msg.Cookie[:])
+
+	if len(t.hostKeys) > 0 {
+		for _, k := range t.hostKeys {
+			msg.ServerHostKeyAlgos = append(
+				msg.ServerHostKeyAlgos, k.PublicKey().Type())
+		}
+	} else {
+		msg.ServerHostKeyAlgos = t.hostKeyAlgorithms
+	}
+	packet := Marshal(msg)
+
+	// writePacket destroys the contents, so save a copy.
+	packetCopy := make([]byte, len(packet))
+	copy(packetCopy, packet)
+
+	if err := t.conn.writePacket(packetCopy); err != nil {
+		return nil, nil, err
+	}
+
+	t.sentInitMsg = msg
+	t.sentInitPacket = packet
+	return msg, packet, nil
+}
+
+func (t *handshakeTransport) writePacket(p []byte) error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if t.writtenSinceKex > t.config.RekeyThreshold {
+		t.sendKexInitLocked(subsequentKeyExchange)
+	}
+	for t.sentInitMsg != nil && t.writeError == nil {
+		t.cond.Wait()
+	}
+	if t.writeError != nil {
+		return t.writeError
+	}
+	t.writtenSinceKex += uint64(len(p))
+
+	switch p[0] {
+	case msgKexInit:
+		return errors.New("ssh: only handshakeTransport can send kexInit")
+	case msgNewKeys:
+		return errors.New("ssh: only handshakeTransport can send newKeys")
+	default:
+		return t.conn.writePacket(p)
+	}
+}
+
+func (t *handshakeTransport) Close() error {
+	return t.conn.Close()
+}
+
+// enterKeyExchange runs the key exchange. t.mu must be held while running this.
+func (t *handshakeTransport) enterKeyExchangeLocked(otherInitPacket []byte) error {
+	if debugHandshake {
+		log.Printf("%s entered key exchange", t.id())
+	}
+	myInit, myInitPacket, err := t.sendKexInitLocked(subsequentKeyExchange)
+	if err != nil {
+		return err
+	}
+
+	otherInit := &kexInitMsg{}
+	if err := Unmarshal(otherInitPacket, otherInit); err != nil {
+		return err
+	}
+
+	magics := handshakeMagics{
+		clientVersion: t.clientVersion,
+		serverVersion: t.serverVersion,
+		clientKexInit: otherInitPacket,
+		serverKexInit: myInitPacket,
+	}
+
+	clientInit := otherInit
+	serverInit := myInit
+	if len(t.hostKeys) == 0 {
+		clientInit = myInit
+		serverInit = otherInit
+
+		magics.clientKexInit = myInitPacket
+		magics.serverKexInit = otherInitPacket
+	}
+
+	algs, err := findAgreedAlgorithms(clientInit, serverInit)
+	if err != nil {
+		return err
+	}
+
+	// We don't send FirstKexFollows, but we handle receiving it.
+	//
+	// RFC 4253 section 7 defines the kex and the agreement method for
+	// first_kex_packet_follows. It states that the guessed packet
+	// should be ignored if the "kex algorithm and/or the host
+	// key algorithm is guessed wrong (server and client have
+	// different preferred algorithm), or if any of the other
+	// algorithms cannot be agreed upon". The other algorithms have
+	// already been checked above so the kex algorithm and host key
+	// algorithm are checked here.
+	if otherInit.FirstKexFollows && (clientInit.KexAlgos[0] != serverInit.KexAlgos[0] || clientInit.ServerHostKeyAlgos[0] != serverInit.ServerHostKeyAlgos[0]) {
+		// other side sent a kex message for the wrong algorithm,
+		// which we have to ignore.
+		if _, err := t.conn.readPacket(); err != nil {
+			return err
+		}
+	}
+
+	kex, ok := kexAlgoMap[algs.kex]
+	if !ok {
+		return fmt.Errorf("ssh: unexpected key exchange algorithm %v", algs.kex)
+	}
+
+	var result *kexResult
+	if len(t.hostKeys) > 0 {
+		result, err = t.server(kex, algs, &magics)
+	} else {
+		result, err = t.client(kex, algs, &magics)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	if t.sessionID == nil {
+		t.sessionID = result.H
+	}
+	result.SessionID = t.sessionID
+
+	t.conn.prepareKeyChange(algs, result)
+	if err = t.conn.writePacket([]byte{msgNewKeys}); err != nil {
+		return err
+	}
+	if packet, err := t.conn.readPacket(); err != nil {
+		return err
+	} else if packet[0] != msgNewKeys {
+		return unexpectedMessageError(msgNewKeys, packet[0])
+	}
+
+	return nil
+}
+
+func (t *handshakeTransport) server(kex kexAlgorithm, algs *algorithms, magics *handshakeMagics) (*kexResult, error) {
+	var hostKey Signer
+	for _, k := range t.hostKeys {
+		if algs.hostKey == k.PublicKey().Type() {
+			hostKey = k
+		}
+	}
+
+	r, err := kex.Server(t.conn, t.config.Rand, magics, hostKey)
+	return r, err
+}
+
+func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *handshakeMagics) (*kexResult, error) {
+	result, err := kex.Client(t.conn, t.config.Rand, magics)
+	if err != nil {
+		return nil, err
+	}
+
+	hostKey, err := ParsePublicKey(result.HostKey)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := verifyHostKeySignature(hostKey, result); err != nil {
+		return nil, err
+	}
+
+	if t.hostKeyCallback != nil {
+		err = t.hostKeyCallback(t.dialAddress, t.remoteAddr, hostKey)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return result, nil
+}

vendor/golang.org/x/crypto/ssh/handshake_test.go

@@ -0,0 +1,486 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"net"
+	"reflect"
+	"runtime"
+	"strings"
+	"sync"
+	"testing"
+)
+
+type testChecker struct {
+	calls []string
+}
+
+func (t *testChecker) Check(dialAddr string, addr net.Addr, key PublicKey) error {
+	if dialAddr == "bad" {
+		return fmt.Errorf("dialAddr is bad")
+	}
+
+	if tcpAddr, ok := addr.(*net.TCPAddr); !ok || tcpAddr == nil {
+		return fmt.Errorf("testChecker: got %T want *net.TCPAddr", addr)
+	}
+
+	t.calls = append(t.calls, fmt.Sprintf("%s %v %s %x", dialAddr, addr, key.Type(), key.Marshal()))
+
+	return nil
+}
+
+// netPipe is analogous to net.Pipe, but it uses a real net.Conn, and
+// therefore is buffered (net.Pipe deadlocks if both sides start with
+// a write.)
+func netPipe() (net.Conn, net.Conn, error) {
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		return nil, nil, err
+	}
+	defer listener.Close()
+	c1, err := net.Dial("tcp", listener.Addr().String())
+	if err != nil {
+		return nil, nil, err
+	}
+
+	c2, err := listener.Accept()
+	if err != nil {
+		c1.Close()
+		return nil, nil, err
+	}
+
+	return c1, c2, nil
+}
+
+func handshakePair(clientConf *ClientConfig, addr string) (client *handshakeTransport, server *handshakeTransport, err error) {
+	a, b, err := netPipe()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	trC := newTransport(a, rand.Reader, true)
+	trS := newTransport(b, rand.Reader, false)
+	clientConf.SetDefaults()
+
+	v := []byte("version")
+	client = newClientTransport(trC, v, v, clientConf, addr, a.RemoteAddr())
+
+	serverConf := &ServerConfig{}
+	serverConf.AddHostKey(testSigners["ecdsa"])
+	serverConf.AddHostKey(testSigners["rsa"])
+	serverConf.SetDefaults()
+	server = newServerTransport(trS, v, v, serverConf)
+
+	return client, server, nil
+}
+
+func TestHandshakeBasic(t *testing.T) {
+	if runtime.GOOS == "plan9" {
+		t.Skip("see golang.org/issue/7237")
+	}
+	checker := &testChecker{}
+	trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
+	if err != nil {
+		t.Fatalf("handshakePair: %v", err)
+	}
+
+	defer trC.Close()
+	defer trS.Close()
+
+	go func() {
+		// Client writes a bunch of stuff, and does a key
+		// change in the middle. This should not confuse the
+		// handshake in progress
+		for i := 0; i < 10; i++ {
+			p := []byte{msgRequestSuccess, byte(i)}
+			if err := trC.writePacket(p); err != nil {
+				t.Fatalf("sendPacket: %v", err)
+			}
+			if i == 5 {
+				// halfway through, we request a key change.
+				err := trC.sendKexInit(subsequentKeyExchange)
+				if err != nil {
+					t.Fatalf("sendKexInit: %v", err)
+				}
+			}
+		}
+		trC.Close()
+	}()
+
+	// Server checks that client messages come in cleanly
+	i := 0
+	for {
+		p, err := trS.readPacket()
+		if err != nil {
+			break
+		}
+		if p[0] == msgNewKeys {
+			continue
+		}
+		want := []byte{msgRequestSuccess, byte(i)}
+		if bytes.Compare(p, want) != 0 {
+			t.Errorf("message %d: got %q, want %q", i, p, want)
+		}
+		i++
+	}
+	if i != 10 {
+		t.Errorf("received %d messages, want 10.", i)
+	}
+
+	// If all went well, we registered exactly 1 key change.
+	if len(checker.calls) != 1 {
+		t.Fatalf("got %d host key checks, want 1", len(checker.calls))
+	}
+
+	pub := testSigners["ecdsa"].PublicKey()
+	want := fmt.Sprintf("%s %v %s %x", "addr", trC.remoteAddr, pub.Type(), pub.Marshal())
+	if want != checker.calls[0] {
+		t.Errorf("got %q want %q for host key check", checker.calls[0], want)
+	}
+}
+
+func TestHandshakeError(t *testing.T) {
+	checker := &testChecker{}
+	trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "bad")
+	if err != nil {
+		t.Fatalf("handshakePair: %v", err)
+	}
+	defer trC.Close()
+	defer trS.Close()
+
+	// send a packet
+	packet := []byte{msgRequestSuccess, 42}
+	if err := trC.writePacket(packet); err != nil {
+		t.Errorf("writePacket: %v", err)
+	}
+
+	// Now request a key change.
+	err = trC.sendKexInit(subsequentKeyExchange)
+	if err != nil {
+		t.Errorf("sendKexInit: %v", err)
+	}
+
+	// the key change will fail, and afterwards we can't write.
+	if err := trC.writePacket([]byte{msgRequestSuccess, 43}); err == nil {
+		t.Errorf("writePacket after botched rekey succeeded.")
+	}
+
+	readback, err := trS.readPacket()
+	if err != nil {
+		t.Fatalf("server closed too soon: %v", err)
+	}
+	if bytes.Compare(readback, packet) != 0 {
+		t.Errorf("got %q want %q", readback, packet)
+	}
+	readback, err = trS.readPacket()
+	if err == nil {
+		t.Errorf("got a message %q after failed key change", readback)
+	}
+}
+
+func TestForceFirstKex(t *testing.T) {
+	checker := &testChecker{}
+	trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
+	if err != nil {
+		t.Fatalf("handshakePair: %v", err)
+	}
+
+	defer trC.Close()
+	defer trS.Close()
+
+	trC.writePacket(Marshal(&serviceRequestMsg{serviceUserAuth}))
+
+	// We setup the initial key exchange, but the remote side
+	// tries to send serviceRequestMsg in cleartext, which is
+	// disallowed.
+
+	err = trS.sendKexInit(firstKeyExchange)
+	if err == nil {
+		t.Errorf("server first kex init should reject unexpected packet")
+	}
+}
+
+func TestHandshakeTwice(t *testing.T) {
+	checker := &testChecker{}
+	trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
+	if err != nil {
+		t.Fatalf("handshakePair: %v", err)
+	}
+
+	defer trC.Close()
+	defer trS.Close()
+
+	// Both sides should ask for the first key exchange first.
+	err = trS.sendKexInit(firstKeyExchange)
+	if err != nil {
+		t.Errorf("server sendKexInit: %v", err)
+	}
+
+	err = trC.sendKexInit(firstKeyExchange)
+	if err != nil {
+		t.Errorf("client sendKexInit: %v", err)
+	}
+
+	sent := 0
+	// send a packet
+	packet := make([]byte, 5)
+	packet[0] = msgRequestSuccess
+	if err := trC.writePacket(packet); err != nil {
+		t.Errorf("writePacket: %v", err)
+	}
+	sent++
+
+	// Send another packet. Use a fresh one, since writePacket destroys.
+	packet = make([]byte, 5)
+	packet[0] = msgRequestSuccess
+	if err := trC.writePacket(packet); err != nil {
+		t.Errorf("writePacket: %v", err)
+	}
+	sent++
+
+	// 2nd key change.
+	err = trC.sendKexInit(subsequentKeyExchange)
+	if err != nil {
+		t.Errorf("sendKexInit: %v", err)
+	}
+
+	packet = make([]byte, 5)
+	packet[0] = msgRequestSuccess
+	if err := trC.writePacket(packet); err != nil {
+		t.Errorf("writePacket: %v", err)
+	}
+	sent++
+
+	packet = make([]byte, 5)
+	packet[0] = msgRequestSuccess
+	for i := 0; i < sent; i++ {
+		msg, err := trS.readPacket()
+		if err != nil {
+			t.Fatalf("server closed too soon: %v", err)
+		}
+
+		if bytes.Compare(msg, packet) != 0 {
+			t.Errorf("packet %d: got %q want %q", i, msg, packet)
+		}
+	}
+	if len(checker.calls) != 2 {
+		t.Errorf("got %d key changes, want 2", len(checker.calls))
+	}
+}
+
+func TestHandshakeAutoRekeyWrite(t *testing.T) {
+	checker := &testChecker{}
+	clientConf := &ClientConfig{HostKeyCallback: checker.Check}
+	clientConf.RekeyThreshold = 500
+	trC, trS, err := handshakePair(clientConf, "addr")
+	if err != nil {
+		t.Fatalf("handshakePair: %v", err)
+	}
+	defer trC.Close()
+	defer trS.Close()
+
+	for i := 0; i < 5; i++ {
+		packet := make([]byte, 251)
+		packet[0] = msgRequestSuccess
+		if err := trC.writePacket(packet); err != nil {
+			t.Errorf("writePacket: %v", err)
+		}
+	}
+
+	j := 0
+	for ; j < 5; j++ {
+		_, err := trS.readPacket()
+		if err != nil {
+			break
+		}
+	}
+
+	if j != 5 {
+		t.Errorf("got %d, want 5 messages", j)
+	}
+
+	if len(checker.calls) != 2 {
+		t.Errorf("got %d key changes, wanted 2", len(checker.calls))
+	}
+}
+
+type syncChecker struct {
+	called chan int
+}
+
+func (t *syncChecker) Check(dialAddr string, addr net.Addr, key PublicKey) error {
+	t.called <- 1
+	return nil
+}
+
+func TestHandshakeAutoRekeyRead(t *testing.T) {
+	sync := &syncChecker{make(chan int, 2)}
+	clientConf := &ClientConfig{
+		HostKeyCallback: sync.Check,
+	}
+	clientConf.RekeyThreshold = 500
+
+	trC, trS, err := handshakePair(clientConf, "addr")
+	if err != nil {
+		t.Fatalf("handshakePair: %v", err)
+	}
+	defer trC.Close()
+	defer trS.Close()
+
+	packet := make([]byte, 501)
+	packet[0] = msgRequestSuccess
+	if err := trS.writePacket(packet); err != nil {
+		t.Fatalf("writePacket: %v", err)
+	}
+	// While we read out the packet, a key change will be
+	// initiated.
+	if _, err := trC.readPacket(); err != nil {
+		t.Fatalf("readPacket(client): %v", err)
+	}
+
+	<-sync.called
+}
+
+// errorKeyingTransport generates errors after a given number of
+// read/write operations.
+type errorKeyingTransport struct {
+	packetConn
+	readLeft, writeLeft int
+}
+
+func (n *errorKeyingTransport) prepareKeyChange(*algorithms, *kexResult) error {
+	return nil
+}
+func (n *errorKeyingTransport) getSessionID() []byte {
+	return nil
+}
+
+func (n *errorKeyingTransport) writePacket(packet []byte) error {
+	if n.writeLeft == 0 {
+		n.Close()
+		return errors.New("barf")
+	}
+
+	n.writeLeft--
+	return n.packetConn.writePacket(packet)
+}
+
+func (n *errorKeyingTransport) readPacket() ([]byte, error) {
+	if n.readLeft == 0 {
+		n.Close()
+		return nil, errors.New("barf")
+	}
+
+	n.readLeft--
+	return n.packetConn.readPacket()
+}
+
+func TestHandshakeErrorHandlingRead(t *testing.T) {
+	for i := 0; i < 20; i++ {
+		testHandshakeErrorHandlingN(t, i, -1)
+	}
+}
+
+func TestHandshakeErrorHandlingWrite(t *testing.T) {
+	for i := 0; i < 20; i++ {
+		testHandshakeErrorHandlingN(t, -1, i)
+	}
+}
+
+// testHandshakeErrorHandlingN runs handshakes, injecting errors. If
+// handshakeTransport deadlocks, the go runtime will detect it and
+// panic.
+func testHandshakeErrorHandlingN(t *testing.T, readLimit, writeLimit int) {
+	msg := Marshal(&serviceRequestMsg{strings.Repeat("x", int(minRekeyThreshold)/4)})
+
+	a, b := memPipe()
+	defer a.Close()
+	defer b.Close()
+
+	key := testSigners["ecdsa"]
+	serverConf := Config{RekeyThreshold: minRekeyThreshold}
+	serverConf.SetDefaults()
+	serverConn := newHandshakeTransport(&errorKeyingTransport{a, readLimit, writeLimit}, &serverConf, []byte{'a'}, []byte{'b'})
+	serverConn.hostKeys = []Signer{key}
+	go serverConn.readLoop()
+
+	clientConf := Config{RekeyThreshold: 10 * minRekeyThreshold}
+	clientConf.SetDefaults()
+	clientConn := newHandshakeTransport(&errorKeyingTransport{b, -1, -1}, &clientConf, []byte{'a'}, []byte{'b'})
+	clientConn.hostKeyAlgorithms = []string{key.PublicKey().Type()}
+	go clientConn.readLoop()
+
+	var wg sync.WaitGroup
+	wg.Add(4)
+
+	for _, hs := range []packetConn{serverConn, clientConn} {
+		go func(c packetConn) {
+			for {
+				err := c.writePacket(msg)
+				if err != nil {
+					break
+				}
+			}
+			wg.Done()
+		}(hs)
+		go func(c packetConn) {
+			for {
+				_, err := c.readPacket()
+				if err != nil {
+					break
+				}
+			}
+			wg.Done()
+		}(hs)
+	}
+
+	wg.Wait()
+}
+
+func TestDisconnect(t *testing.T) {
+	if runtime.GOOS == "plan9" {
+		t.Skip("see golang.org/issue/7237")
+	}
+	checker := &testChecker{}
+	trC, trS, err := handshakePair(&ClientConfig{HostKeyCallback: checker.Check}, "addr")
+	if err != nil {
+		t.Fatalf("handshakePair: %v", err)
+	}
+
+	defer trC.Close()
+	defer trS.Close()
+
+	trC.writePacket([]byte{msgRequestSuccess, 0, 0})
+	errMsg := &disconnectMsg{
+		Reason:  42,
+		Message: "such is life",
+	}
+	trC.writePacket(Marshal(errMsg))
+	trC.writePacket([]byte{msgRequestSuccess, 0, 0})
+
+	packet, err := trS.readPacket()
+	if err != nil {
+		t.Fatalf("readPacket 1: %v", err)
+	}
+	if packet[0] != msgRequestSuccess {
+		t.Errorf("got packet %v, want packet type %d", packet, msgRequestSuccess)
+	}
+
+	_, err = trS.readPacket()
+	if err == nil {
+		t.Errorf("readPacket 2 succeeded")
+	} else if !reflect.DeepEqual(err, errMsg) {
+		t.Errorf("got error %#v, want %#v", err, errMsg)
+	}
+
+	_, err = trS.readPacket()
+	if err == nil {
+		t.Errorf("readPacket 3 succeeded")
+	}
+}

vendor/golang.org/x/crypto/ssh/kex.go

@@ -0,0 +1,540 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/subtle"
+	"errors"
+	"io"
+	"math/big"
+
+	"golang.org/x/crypto/curve25519"
+)
+
+const (
+	kexAlgoDH1SHA1          = "diffie-hellman-group1-sha1"
+	kexAlgoDH14SHA1         = "diffie-hellman-group14-sha1"
+	kexAlgoECDH256          = "ecdh-sha2-nistp256"
+	kexAlgoECDH384          = "ecdh-sha2-nistp384"
+	kexAlgoECDH521          = "ecdh-sha2-nistp521"
+	kexAlgoCurve25519SHA256 = "curve25519-sha256@libssh.org"
+)
+
+// kexResult captures the outcome of a key exchange.
+type kexResult struct {
+	// Session hash. See also RFC 4253, section 8.
+	H []byte
+
+	// Shared secret. See also RFC 4253, section 8.
+	K []byte
+
+	// Host key as hashed into H.
+	HostKey []byte
+
+	// Signature of H.
+	Signature []byte
+
+	// A cryptographic hash function that matches the security
+	// level of the key exchange algorithm. It is used for
+	// calculating H, and for deriving keys from H and K.
+	Hash crypto.Hash
+
+	// The session ID, which is the first H computed. This is used
+	// to derive key material inside the transport.
+	SessionID []byte
+}
+
+// handshakeMagics contains data that is always included in the
+// session hash.
+type handshakeMagics struct {
+	clientVersion, serverVersion []byte
+	clientKexInit, serverKexInit []byte
+}
+
+func (m *handshakeMagics) write(w io.Writer) {
+	writeString(w, m.clientVersion)
+	writeString(w, m.serverVersion)
+	writeString(w, m.clientKexInit)
+	writeString(w, m.serverKexInit)
+}
+
+// kexAlgorithm abstracts different key exchange algorithms.
+type kexAlgorithm interface {
+	// Server runs server-side key agreement, signing the result
+	// with a hostkey.
+	Server(p packetConn, rand io.Reader, magics *handshakeMagics, s Signer) (*kexResult, error)
+
+	// Client runs the client-side key agreement. Caller is
+	// responsible for verifying the host key signature.
+	Client(p packetConn, rand io.Reader, magics *handshakeMagics) (*kexResult, error)
+}
+
+// dhGroup is a multiplicative group suitable for implementing Diffie-Hellman key agreement.
+type dhGroup struct {
+	g, p, pMinus1 *big.Int
+}
+
+func (group *dhGroup) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int, error) {
+	if theirPublic.Cmp(bigOne) <= 0 || theirPublic.Cmp(group.pMinus1) >= 0 {
+		return nil, errors.New("ssh: DH parameter out of bounds")
+	}
+	return new(big.Int).Exp(theirPublic, myPrivate, group.p), nil
+}
+
+func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
+	hashFunc := crypto.SHA1
+
+	var x *big.Int
+	for {
+		var err error
+		if x, err = rand.Int(randSource, group.pMinus1); err != nil {
+			return nil, err
+		}
+		if x.Sign() > 0 {
+			break
+		}
+	}
+
+	X := new(big.Int).Exp(group.g, x, group.p)
+	kexDHInit := kexDHInitMsg{
+		X: X,
+	}
+	if err := c.writePacket(Marshal(&kexDHInit)); err != nil {
+		return nil, err
+	}
+
+	packet, err := c.readPacket()
+	if err != nil {
+		return nil, err
+	}
+
+	var kexDHReply kexDHReplyMsg
+	if err = Unmarshal(packet, &kexDHReply); err != nil {
+		return nil, err
+	}
+
+	kInt, err := group.diffieHellman(kexDHReply.Y, x)
+	if err != nil {
+		return nil, err
+	}
+
+	h := hashFunc.New()
+	magics.write(h)
+	writeString(h, kexDHReply.HostKey)
+	writeInt(h, X)
+	writeInt(h, kexDHReply.Y)
+	K := make([]byte, intLength(kInt))
+	marshalInt(K, kInt)
+	h.Write(K)
+
+	return &kexResult{
+		H:         h.Sum(nil),
+		K:         K,
+		HostKey:   kexDHReply.HostKey,
+		Signature: kexDHReply.Signature,
+		Hash:      crypto.SHA1,
+	}, nil
+}
+
+func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
+	hashFunc := crypto.SHA1
+	packet, err := c.readPacket()
+	if err != nil {
+		return
+	}
+	var kexDHInit kexDHInitMsg
+	if err = Unmarshal(packet, &kexDHInit); err != nil {
+		return
+	}
+
+	var y *big.Int
+	for {
+		if y, err = rand.Int(randSource, group.pMinus1); err != nil {
+			return
+		}
+		if y.Sign() > 0 {
+			break
+		}
+	}
+
+	Y := new(big.Int).Exp(group.g, y, group.p)
+	kInt, err := group.diffieHellman(kexDHInit.X, y)
+	if err != nil {
+		return nil, err
+	}
+
+	hostKeyBytes := priv.PublicKey().Marshal()
+
+	h := hashFunc.New()
+	magics.write(h)
+	writeString(h, hostKeyBytes)
+	writeInt(h, kexDHInit.X)
+	writeInt(h, Y)
+
+	K := make([]byte, intLength(kInt))
+	marshalInt(K, kInt)
+	h.Write(K)
+
+	H := h.Sum(nil)
+
+	// H is already a hash, but the hostkey signing will apply its
+	// own key-specific hash algorithm.
+	sig, err := signAndMarshal(priv, randSource, H)
+	if err != nil {
+		return nil, err
+	}
+
+	kexDHReply := kexDHReplyMsg{
+		HostKey:   hostKeyBytes,
+		Y:         Y,
+		Signature: sig,
+	}
+	packet = Marshal(&kexDHReply)
+
+	err = c.writePacket(packet)
+	return &kexResult{
+		H:         H,
+		K:         K,
+		HostKey:   hostKeyBytes,
+		Signature: sig,
+		Hash:      crypto.SHA1,
+	}, nil
+}
+
+// ecdh performs Elliptic Curve Diffie-Hellman key exchange as
+// described in RFC 5656, section 4.
+type ecdh struct {
+	curve elliptic.Curve
+}
+
+func (kex *ecdh) Client(c packetConn, rand io.Reader, magics *handshakeMagics) (*kexResult, error) {
+	ephKey, err := ecdsa.GenerateKey(kex.curve, rand)
+	if err != nil {
+		return nil, err
+	}
+
+	kexInit := kexECDHInitMsg{
+		ClientPubKey: elliptic.Marshal(kex.curve, ephKey.PublicKey.X, ephKey.PublicKey.Y),
+	}
+
+	serialized := Marshal(&kexInit)
+	if err := c.writePacket(serialized); err != nil {
+		return nil, err
+	}
+
+	packet, err := c.readPacket()
+	if err != nil {
+		return nil, err
+	}
+
+	var reply kexECDHReplyMsg
+	if err = Unmarshal(packet, &reply); err != nil {
+		return nil, err
+	}
+
+	x, y, err := unmarshalECKey(kex.curve, reply.EphemeralPubKey)
+	if err != nil {
+		return nil, err
+	}
+
+	// generate shared secret
+	secret, _ := kex.curve.ScalarMult(x, y, ephKey.D.Bytes())
+
+	h := ecHash(kex.curve).New()
+	magics.write(h)
+	writeString(h, reply.HostKey)
+	writeString(h, kexInit.ClientPubKey)
+	writeString(h, reply.EphemeralPubKey)
+	K := make([]byte, intLength(secret))
+	marshalInt(K, secret)
+	h.Write(K)
+
+	return &kexResult{
+		H:         h.Sum(nil),
+		K:         K,
+		HostKey:   reply.HostKey,
+		Signature: reply.Signature,
+		Hash:      ecHash(kex.curve),
+	}, nil
+}
+
+// unmarshalECKey parses and checks an EC key.
+func unmarshalECKey(curve elliptic.Curve, pubkey []byte) (x, y *big.Int, err error) {
+	x, y = elliptic.Unmarshal(curve, pubkey)
+	if x == nil {
+		return nil, nil, errors.New("ssh: elliptic.Unmarshal failure")
+	}
+	if !validateECPublicKey(curve, x, y) {
+		return nil, nil, errors.New("ssh: public key not on curve")
+	}
+	return x, y, nil
+}
+
+// validateECPublicKey checks that the point is a valid public key for
+// the given curve. See [SEC1], 3.2.2
+func validateECPublicKey(curve elliptic.Curve, x, y *big.Int) bool {
+	if x.Sign() == 0 && y.Sign() == 0 {
+		return false
+	}
+
+	if x.Cmp(curve.Params().P) >= 0 {
+		return false
+	}
+
+	if y.Cmp(curve.Params().P) >= 0 {
+		return false
+	}
+
+	if !curve.IsOnCurve(x, y) {
+		return false
+	}
+
+	// We don't check if N * PubKey == 0, since
+	//
+	// - the NIST curves have cofactor = 1, so this is implicit.
+	// (We don't foresee an implementation that supports non NIST
+	// curves)
+	//
+	// - for ephemeral keys, we don't need to worry about small
+	// subgroup attacks.
+	return true
+}
+
+func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
+	packet, err := c.readPacket()
+	if err != nil {
+		return nil, err
+	}
+
+	var kexECDHInit kexECDHInitMsg
+	if err = Unmarshal(packet, &kexECDHInit); err != nil {
+		return nil, err
+	}
+
+	clientX, clientY, err := unmarshalECKey(kex.curve, kexECDHInit.ClientPubKey)
+	if err != nil {
+		return nil, err
+	}
+
+	// We could cache this key across multiple users/multiple
+	// connection attempts, but the benefit is small. OpenSSH
+	// generates a new key for each incoming connection.
+	ephKey, err := ecdsa.GenerateKey(kex.curve, rand)
+	if err != nil {
+		return nil, err
+	}
+
+	hostKeyBytes := priv.PublicKey().Marshal()
+
+	serializedEphKey := elliptic.Marshal(kex.curve, ephKey.PublicKey.X, ephKey.PublicKey.Y)
+
+	// generate shared secret
+	secret, _ := kex.curve.ScalarMult(clientX, clientY, ephKey.D.Bytes())
+
+	h := ecHash(kex.curve).New()
+	magics.write(h)
+	writeString(h, hostKeyBytes)
+	writeString(h, kexECDHInit.ClientPubKey)
+	writeString(h, serializedEphKey)
+
+	K := make([]byte, intLength(secret))
+	marshalInt(K, secret)
+	h.Write(K)
+
+	H := h.Sum(nil)
+
+	// H is already a hash, but the hostkey signing will apply its
+	// own key-specific hash algorithm.
+	sig, err := signAndMarshal(priv, rand, H)
+	if err != nil {
+		return nil, err
+	}
+
+	reply := kexECDHReplyMsg{
+		EphemeralPubKey: serializedEphKey,
+		HostKey:         hostKeyBytes,
+		Signature:       sig,
+	}
+
+	serialized := Marshal(&reply)
+	if err := c.writePacket(serialized); err != nil {
+		return nil, err
+	}
+
+	return &kexResult{
+		H:         H,
+		K:         K,
+		HostKey:   reply.HostKey,
+		Signature: sig,
+		Hash:      ecHash(kex.curve),
+	}, nil
+}
+
+var kexAlgoMap = map[string]kexAlgorithm{}
+
+func init() {
+	// This is the group called diffie-hellman-group1-sha1 in RFC
+	// 4253 and Oakley Group 2 in RFC 2409.
+	p, _ := new(big.Int).SetString("FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF", 16)
+	kexAlgoMap[kexAlgoDH1SHA1] = &dhGroup{
+		g: new(big.Int).SetInt64(2),
+		p: p,
+		pMinus1: new(big.Int).Sub(p, bigOne),
+	}
+
+	// This is the group called diffie-hellman-group14-sha1 in RFC
+	// 4253 and Oakley Group 14 in RFC 3526.
+	p, _ = new(big.Int).SetString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
+
+	kexAlgoMap[kexAlgoDH14SHA1] = &dhGroup{
+		g: new(big.Int).SetInt64(2),
+		p: p,
+		pMinus1: new(big.Int).Sub(p, bigOne),
+	}
+
+	kexAlgoMap[kexAlgoECDH521] = &ecdh{elliptic.P521()}
+	kexAlgoMap[kexAlgoECDH384] = &ecdh{elliptic.P384()}
+	kexAlgoMap[kexAlgoECDH256] = &ecdh{elliptic.P256()}
+	kexAlgoMap[kexAlgoCurve25519SHA256] = &curve25519sha256{}
+}
+
+// curve25519sha256 implements the curve25519-sha256@libssh.org key
+// agreement protocol, as described in
+// https://git.libssh.org/projects/libssh.git/tree/doc/curve25519-sha256@libssh.org.txt
+type curve25519sha256 struct{}
+
+type curve25519KeyPair struct {
+	priv [32]byte
+	pub  [32]byte
+}
+
+func (kp *curve25519KeyPair) generate(rand io.Reader) error {
+	if _, err := io.ReadFull(rand, kp.priv[:]); err != nil {
+		return err
+	}
+	curve25519.ScalarBaseMult(&kp.pub, &kp.priv)
+	return nil
+}
+
+// curve25519Zeros is just an array of 32 zero bytes so that we have something
+// convenient to compare against in order to reject curve25519 points with the
+// wrong order.
+var curve25519Zeros [32]byte
+
+func (kex *curve25519sha256) Client(c packetConn, rand io.Reader, magics *handshakeMagics) (*kexResult, error) {
+	var kp curve25519KeyPair
+	if err := kp.generate(rand); err != nil {
+		return nil, err
+	}
+	if err := c.writePacket(Marshal(&kexECDHInitMsg{kp.pub[:]})); err != nil {
+		return nil, err
+	}
+
+	packet, err := c.readPacket()
+	if err != nil {
+		return nil, err
+	}
+
+	var reply kexECDHReplyMsg
+	if err = Unmarshal(packet, &reply); err != nil {
+		return nil, err
+	}
+	if len(reply.EphemeralPubKey) != 32 {
+		return nil, errors.New("ssh: peer's curve25519 public value has wrong length")
+	}
+
+	var servPub, secret [32]byte
+	copy(servPub[:], reply.EphemeralPubKey)
+	curve25519.ScalarMult(&secret, &kp.priv, &servPub)
+	if subtle.ConstantTimeCompare(secret[:], curve25519Zeros[:]) == 1 {
+		return nil, errors.New("ssh: peer's curve25519 public value has wrong order")
+	}
+
+	h := crypto.SHA256.New()
+	magics.write(h)
+	writeString(h, reply.HostKey)
+	writeString(h, kp.pub[:])
+	writeString(h, reply.EphemeralPubKey)
+
+	kInt := new(big.Int).SetBytes(secret[:])
+	K := make([]byte, intLength(kInt))
+	marshalInt(K, kInt)
+	h.Write(K)
+
+	return &kexResult{
+		H:         h.Sum(nil),
+		K:         K,
+		HostKey:   reply.HostKey,
+		Signature: reply.Signature,
+		Hash:      crypto.SHA256,
+	}, nil
+}
+
+func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
+	packet, err := c.readPacket()
+	if err != nil {
+		return
+	}
+	var kexInit kexECDHInitMsg
+	if err = Unmarshal(packet, &kexInit); err != nil {
+		return
+	}
+
+	if len(kexInit.ClientPubKey) != 32 {
+		return nil, errors.New("ssh: peer's curve25519 public value has wrong length")
+	}
+
+	var kp curve25519KeyPair
+	if err := kp.generate(rand); err != nil {
+		return nil, err
+	}
+
+	var clientPub, secret [32]byte
+	copy(clientPub[:], kexInit.ClientPubKey)
+	curve25519.ScalarMult(&secret, &kp.priv, &clientPub)
+	if subtle.ConstantTimeCompare(secret[:], curve25519Zeros[:]) == 1 {
+		return nil, errors.New("ssh: peer's curve25519 public value has wrong order")
+	}
+
+	hostKeyBytes := priv.PublicKey().Marshal()
+
+	h := crypto.SHA256.New()
+	magics.write(h)
+	writeString(h, hostKeyBytes)
+	writeString(h, kexInit.ClientPubKey)
+	writeString(h, kp.pub[:])
+
+	kInt := new(big.Int).SetBytes(secret[:])
+	K := make([]byte, intLength(kInt))
+	marshalInt(K, kInt)
+	h.Write(K)
+
+	H := h.Sum(nil)
+
+	sig, err := signAndMarshal(priv, rand, H)
+	if err != nil {
+		return nil, err
+	}
+
+	reply := kexECDHReplyMsg{
+		EphemeralPubKey: kp.pub[:],
+		HostKey:         hostKeyBytes,
+		Signature:       sig,
+	}
+	if err := c.writePacket(Marshal(&reply)); err != nil {
+		return nil, err
+	}
+	return &kexResult{
+		H:         H,
+		K:         K,
+		HostKey:   hostKeyBytes,
+		Signature: sig,
+		Hash:      crypto.SHA256,
+	}, nil
+}

vendor/golang.org/x/crypto/ssh/kex_test.go

@@ -0,0 +1,50 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+// Key exchange tests.
+
+import (
+	"crypto/rand"
+	"reflect"
+	"testing"
+)
+
+func TestKexes(t *testing.T) {
+	type kexResultErr struct {
+		result *kexResult
+		err    error
+	}
+
+	for name, kex := range kexAlgoMap {
+		a, b := memPipe()
+
+		s := make(chan kexResultErr, 1)
+		c := make(chan kexResultErr, 1)
+		var magics handshakeMagics
+		go func() {
+			r, e := kex.Client(a, rand.Reader, &magics)
+			a.Close()
+			c <- kexResultErr{r, e}
+		}()
+		go func() {
+			r, e := kex.Server(b, rand.Reader, &magics, testSigners["ecdsa"])
+			b.Close()
+			s <- kexResultErr{r, e}
+		}()
+
+		clientRes := <-c
+		serverRes := <-s
+		if clientRes.err != nil {
+			t.Errorf("client: %v", clientRes.err)
+		}
+		if serverRes.err != nil {
+			t.Errorf("server: %v", serverRes.err)
+		}
+		if !reflect.DeepEqual(clientRes.result, serverRes.result) {
+			t.Errorf("kex %q: mismatch %#v, %#v", name, clientRes.result, serverRes.result)
+		}
+	}
+}

vendor/golang.org/x/crypto/ssh/keys.go

@@ -0,0 +1,880 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/dsa"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/asn1"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"strings"
+
+	"golang.org/x/crypto/ed25519"
+)
+
+// These constants represent the algorithm names for key types supported by this
+// package.
+const (
+	KeyAlgoRSA      = "ssh-rsa"
+	KeyAlgoDSA      = "ssh-dss"
+	KeyAlgoECDSA256 = "ecdsa-sha2-nistp256"
+	KeyAlgoECDSA384 = "ecdsa-sha2-nistp384"
+	KeyAlgoECDSA521 = "ecdsa-sha2-nistp521"
+	KeyAlgoED25519  = "ssh-ed25519"
+)
+
+// parsePubKey parses a public key of the given algorithm.
+// Use ParsePublicKey for keys with prepended algorithm.
+func parsePubKey(in []byte, algo string) (pubKey PublicKey, rest []byte, err error) {
+	switch algo {
+	case KeyAlgoRSA:
+		return parseRSA(in)
+	case KeyAlgoDSA:
+		return parseDSA(in)
+	case KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521:
+		return parseECDSA(in)
+	case KeyAlgoED25519:
+		return parseED25519(in)
+	case CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoED25519v01:
+		cert, err := parseCert(in, certToPrivAlgo(algo))
+		if err != nil {
+			return nil, nil, err
+		}
+		return cert, nil, nil
+	}
+	return nil, nil, fmt.Errorf("ssh: unknown key algorithm: %v", algo)
+}
+
+// parseAuthorizedKey parses a public key in OpenSSH authorized_keys format
+// (see sshd(8) manual page) once the options and key type fields have been
+// removed.
+func parseAuthorizedKey(in []byte) (out PublicKey, comment string, err error) {
+	in = bytes.TrimSpace(in)
+
+	i := bytes.IndexAny(in, " \t")
+	if i == -1 {
+		i = len(in)
+	}
+	base64Key := in[:i]
+
+	key := make([]byte, base64.StdEncoding.DecodedLen(len(base64Key)))
+	n, err := base64.StdEncoding.Decode(key, base64Key)
+	if err != nil {
+		return nil, "", err
+	}
+	key = key[:n]
+	out, err = ParsePublicKey(key)
+	if err != nil {
+		return nil, "", err
+	}
+	comment = string(bytes.TrimSpace(in[i:]))
+	return out, comment, nil
+}
+
+// ParseKnownHosts parses an entry in the format of the known_hosts file.
+//
+// The known_hosts format is documented in the sshd(8) manual page. This
+// function will parse a single entry from in. On successful return, marker
+// will contain the optional marker value (i.e. "cert-authority" or "revoked")
+// or else be empty, hosts will contain the hosts that this entry matches,
+// pubKey will contain the public key and comment will contain any trailing
+// comment at the end of the line. See the sshd(8) manual page for the various
+// forms that a host string can take.
+//
+// The unparsed remainder of the input will be returned in rest. This function
+// can be called repeatedly to parse multiple entries.
+//
+// If no entries were found in the input then err will be io.EOF. Otherwise a
+// non-nil err value indicates a parse error.
+func ParseKnownHosts(in []byte) (marker string, hosts []string, pubKey PublicKey, comment string, rest []byte, err error) {
+	for len(in) > 0 {
+		end := bytes.IndexByte(in, '\n')
+		if end != -1 {
+			rest = in[end+1:]
+			in = in[:end]
+		} else {
+			rest = nil
+		}
+
+		end = bytes.IndexByte(in, '\r')
+		if end != -1 {
+			in = in[:end]
+		}
+
+		in = bytes.TrimSpace(in)
+		if len(in) == 0 || in[0] == '#' {
+			in = rest
+			continue
+		}
+
+		i := bytes.IndexAny(in, " \t")
+		if i == -1 {
+			in = rest
+			continue
+		}
+
+		// Strip out the beginning of the known_host key.
+		// This is either an optional marker or a (set of) hostname(s).
+		keyFields := bytes.Fields(in)
+		if len(keyFields) < 3 || len(keyFields) > 5 {
+			return "", nil, nil, "", nil, errors.New("ssh: invalid entry in known_hosts data")
+		}
+
+		// keyFields[0] is either "@cert-authority", "@revoked" or a comma separated
+		// list of hosts
+		marker := ""
+		if keyFields[0][0] == '@' {
+			marker = string(keyFields[0][1:])
+			keyFields = keyFields[1:]
+		}
+
+		hosts := string(keyFields[0])
+		// keyFields[1] contains the key type (e.g. “ssh-rsa”).
+		// However, that information is duplicated inside the
+		// base64-encoded key and so is ignored here.
+
+		key := bytes.Join(keyFields[2:], []byte(" "))
+		if pubKey, comment, err = parseAuthorizedKey(key); err != nil {
+			return "", nil, nil, "", nil, err
+		}
+
+		return marker, strings.Split(hosts, ","), pubKey, comment, rest, nil
+	}
+
+	return "", nil, nil, "", nil, io.EOF
+}
+
+// ParseAuthorizedKeys parses a public key from an authorized_keys
+// file used in OpenSSH according to the sshd(8) manual page.
+func ParseAuthorizedKey(in []byte) (out PublicKey, comment string, options []string, rest []byte, err error) {
+	for len(in) > 0 {
+		end := bytes.IndexByte(in, '\n')
+		if end != -1 {
+			rest = in[end+1:]
+			in = in[:end]
+		} else {
+			rest = nil
+		}
+
+		end = bytes.IndexByte(in, '\r')
+		if end != -1 {
+			in = in[:end]
+		}
+
+		in = bytes.TrimSpace(in)
+		if len(in) == 0 || in[0] == '#' {
+			in = rest
+			continue
+		}
+
+		i := bytes.IndexAny(in, " \t")
+		if i == -1 {
+			in = rest
+			continue
+		}
+
+		if out, comment, err = parseAuthorizedKey(in[i:]); err == nil {
+			return out, comment, options, rest, nil
+		}
+
+		// No key type recognised. Maybe there's an options field at
+		// the beginning.
+		var b byte
+		inQuote := false
+		var candidateOptions []string
+		optionStart := 0
+		for i, b = range in {
+			isEnd := !inQuote && (b == ' ' || b == '\t')
+			if (b == ',' && !inQuote) || isEnd {
+				if i-optionStart > 0 {
+					candidateOptions = append(candidateOptions, string(in[optionStart:i]))
+				}
+				optionStart = i + 1
+			}
+			if isEnd {
+				break
+			}
+			if b == '"' && (i == 0 || (i > 0 && in[i-1] != '\\')) {
+				inQuote = !inQuote
+			}
+		}
+		for i < len(in) && (in[i] == ' ' || in[i] == '\t') {
+			i++
+		}
+		if i == len(in) {
+			// Invalid line: unmatched quote
+			in = rest
+			continue
+		}
+
+		in = in[i:]
+		i = bytes.IndexAny(in, " \t")
+		if i == -1 {
+			in = rest
+			continue
+		}
+
+		if out, comment, err = parseAuthorizedKey(in[i:]); err == nil {
+			options = candidateOptions
+			return out, comment, options, rest, nil
+		}
+
+		in = rest
+		continue
+	}
+
+	return nil, "", nil, nil, errors.New("ssh: no key found")
+}
+
+// ParsePublicKey parses an SSH public key formatted for use in
+// the SSH wire protocol according to RFC 4253, section 6.6.
+func ParsePublicKey(in []byte) (out PublicKey, err error) {
+	algo, in, ok := parseString(in)
+	if !ok {
+		return nil, errShortRead
+	}
+	var rest []byte
+	out, rest, err = parsePubKey(in, string(algo))
+	if len(rest) > 0 {
+		return nil, errors.New("ssh: trailing junk in public key")
+	}
+
+	return out, err
+}
+
+// MarshalAuthorizedKey serializes key for inclusion in an OpenSSH
+// authorized_keys file. The return value ends with newline.
+func MarshalAuthorizedKey(key PublicKey) []byte {
+	b := &bytes.Buffer{}
+	b.WriteString(key.Type())
+	b.WriteByte(' ')
+	e := base64.NewEncoder(base64.StdEncoding, b)
+	e.Write(key.Marshal())
+	e.Close()
+	b.WriteByte('\n')
+	return b.Bytes()
+}
+
+// PublicKey is an abstraction of different types of public keys.
+type PublicKey interface {
+	// Type returns the key's type, e.g. "ssh-rsa".
+	Type() string
+
+	// Marshal returns the serialized key data in SSH wire format,
+	// with the name prefix.
+	Marshal() []byte
+
+	// Verify that sig is a signature on the given data using this
+	// key. This function will hash the data appropriately first.
+	Verify(data []byte, sig *Signature) error
+}
+
+// CryptoPublicKey, if implemented by a PublicKey,
+// returns the underlying crypto.PublicKey form of the key.
+type CryptoPublicKey interface {
+	CryptoPublicKey() crypto.PublicKey
+}
+
+// A Signer can create signatures that verify against a public key.
+type Signer interface {
+	// PublicKey returns an associated PublicKey instance.
+	PublicKey() PublicKey
+
+	// Sign returns raw signature for the given data. This method
+	// will apply the hash specified for the keytype to the data.
+	Sign(rand io.Reader, data []byte) (*Signature, error)
+}
+
+type rsaPublicKey rsa.PublicKey
+
+func (r *rsaPublicKey) Type() string {
+	return "ssh-rsa"
+}
+
+// parseRSA parses an RSA key according to RFC 4253, section 6.6.
+func parseRSA(in []byte) (out PublicKey, rest []byte, err error) {
+	var w struct {
+		E    *big.Int
+		N    *big.Int
+		Rest []byte `ssh:"rest"`
+	}
+	if err := Unmarshal(in, &w); err != nil {
+		return nil, nil, err
+	}
+
+	if w.E.BitLen() > 24 {
+		return nil, nil, errors.New("ssh: exponent too large")
+	}
+	e := w.E.Int64()
+	if e < 3 || e&1 == 0 {
+		return nil, nil, errors.New("ssh: incorrect exponent")
+	}
+
+	var key rsa.PublicKey
+	key.E = int(e)
+	key.N = w.N
+	return (*rsaPublicKey)(&key), w.Rest, nil
+}
+
+func (r *rsaPublicKey) Marshal() []byte {
+	e := new(big.Int).SetInt64(int64(r.E))
+	// RSA publickey struct layout should match the struct used by
+	// parseRSACert in the x/crypto/ssh/agent package.
+	wirekey := struct {
+		Name string
+		E    *big.Int
+		N    *big.Int
+	}{
+		KeyAlgoRSA,
+		e,
+		r.N,
+	}
+	return Marshal(&wirekey)
+}
+
+func (r *rsaPublicKey) Verify(data []byte, sig *Signature) error {
+	if sig.Format != r.Type() {
+		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, r.Type())
+	}
+	h := crypto.SHA1.New()
+	h.Write(data)
+	digest := h.Sum(nil)
+	return rsa.VerifyPKCS1v15((*rsa.PublicKey)(r), crypto.SHA1, digest, sig.Blob)
+}
+
+func (r *rsaPublicKey) CryptoPublicKey() crypto.PublicKey {
+	return (*rsa.PublicKey)(r)
+}
+
+type dsaPublicKey dsa.PublicKey
+
+func (r *dsaPublicKey) Type() string {
+	return "ssh-dss"
+}
+
+// parseDSA parses an DSA key according to RFC 4253, section 6.6.
+func parseDSA(in []byte) (out PublicKey, rest []byte, err error) {
+	var w struct {
+		P, Q, G, Y *big.Int
+		Rest       []byte `ssh:"rest"`
+	}
+	if err := Unmarshal(in, &w); err != nil {
+		return nil, nil, err
+	}
+
+	key := &dsaPublicKey{
+		Parameters: dsa.Parameters{
+			P: w.P,
+			Q: w.Q,
+			G: w.G,
+		},
+		Y: w.Y,
+	}
+	return key, w.Rest, nil
+}
+
+func (k *dsaPublicKey) Marshal() []byte {
+	// DSA publickey struct layout should match the struct used by
+	// parseDSACert in the x/crypto/ssh/agent package.
+	w := struct {
+		Name       string
+		P, Q, G, Y *big.Int
+	}{
+		k.Type(),
+		k.P,
+		k.Q,
+		k.G,
+		k.Y,
+	}
+
+	return Marshal(&w)
+}
+
+func (k *dsaPublicKey) Verify(data []byte, sig *Signature) error {
+	if sig.Format != k.Type() {
+		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type())
+	}
+	h := crypto.SHA1.New()
+	h.Write(data)
+	digest := h.Sum(nil)
+
+	// Per RFC 4253, section 6.6,
+	// The value for 'dss_signature_blob' is encoded as a string containing
+	// r, followed by s (which are 160-bit integers, without lengths or
+	// padding, unsigned, and in network byte order).
+	// For DSS purposes, sig.Blob should be exactly 40 bytes in length.
+	if len(sig.Blob) != 40 {
+		return errors.New("ssh: DSA signature parse error")
+	}
+	r := new(big.Int).SetBytes(sig.Blob[:20])
+	s := new(big.Int).SetBytes(sig.Blob[20:])
+	if dsa.Verify((*dsa.PublicKey)(k), digest, r, s) {
+		return nil
+	}
+	return errors.New("ssh: signature did not verify")
+}
+
+func (k *dsaPublicKey) CryptoPublicKey() crypto.PublicKey {
+	return (*dsa.PublicKey)(k)
+}
+
+type dsaPrivateKey struct {
+	*dsa.PrivateKey
+}
+
+func (k *dsaPrivateKey) PublicKey() PublicKey {
+	return (*dsaPublicKey)(&k.PrivateKey.PublicKey)
+}
+
+func (k *dsaPrivateKey) Sign(rand io.Reader, data []byte) (*Signature, error) {
+	h := crypto.SHA1.New()
+	h.Write(data)
+	digest := h.Sum(nil)
+	r, s, err := dsa.Sign(rand, k.PrivateKey, digest)
+	if err != nil {
+		return nil, err
+	}
+
+	sig := make([]byte, 40)
+	rb := r.Bytes()
+	sb := s.Bytes()
+
+	copy(sig[20-len(rb):20], rb)
+	copy(sig[40-len(sb):], sb)
+
+	return &Signature{
+		Format: k.PublicKey().Type(),
+		Blob:   sig,
+	}, nil
+}
+
+type ecdsaPublicKey ecdsa.PublicKey
+
+func (key *ecdsaPublicKey) Type() string {
+	return "ecdsa-sha2-" + key.nistID()
+}
+
+func (key *ecdsaPublicKey) nistID() string {
+	switch key.Params().BitSize {
+	case 256:
+		return "nistp256"
+	case 384:
+		return "nistp384"
+	case 521:
+		return "nistp521"
+	}
+	panic("ssh: unsupported ecdsa key size")
+}
+
+type ed25519PublicKey ed25519.PublicKey
+
+func (key ed25519PublicKey) Type() string {
+	return KeyAlgoED25519
+}
+
+func parseED25519(in []byte) (out PublicKey, rest []byte, err error) {
+	var w struct {
+		KeyBytes []byte
+		Rest     []byte `ssh:"rest"`
+	}
+
+	if err := Unmarshal(in, &w); err != nil {
+		return nil, nil, err
+	}
+
+	key := ed25519.PublicKey(w.KeyBytes)
+
+	return (ed25519PublicKey)(key), w.Rest, nil
+}
+
+func (key ed25519PublicKey) Marshal() []byte {
+	w := struct {
+		Name     string
+		KeyBytes []byte
+	}{
+		KeyAlgoED25519,
+		[]byte(key),
+	}
+	return Marshal(&w)
+}
+
+func (key ed25519PublicKey) Verify(b []byte, sig *Signature) error {
+	if sig.Format != key.Type() {
+		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, key.Type())
+	}
+
+	edKey := (ed25519.PublicKey)(key)
+	if ok := ed25519.Verify(edKey, b, sig.Blob); !ok {
+		return errors.New("ssh: signature did not verify")
+	}
+
+	return nil
+}
+
+func (k ed25519PublicKey) CryptoPublicKey() crypto.PublicKey {
+	return ed25519.PublicKey(k)
+}
+
+func supportedEllipticCurve(curve elliptic.Curve) bool {
+	return curve == elliptic.P256() || curve == elliptic.P384() || curve == elliptic.P521()
+}
+
+// ecHash returns the hash to match the given elliptic curve, see RFC
+// 5656, section 6.2.1
+func ecHash(curve elliptic.Curve) crypto.Hash {
+	bitSize := curve.Params().BitSize
+	switch {
+	case bitSize <= 256:
+		return crypto.SHA256
+	case bitSize <= 384:
+		return crypto.SHA384
+	}
+	return crypto.SHA512
+}
+
+// parseECDSA parses an ECDSA key according to RFC 5656, section 3.1.
+func parseECDSA(in []byte) (out PublicKey, rest []byte, err error) {
+	var w struct {
+		Curve    string
+		KeyBytes []byte
+		Rest     []byte `ssh:"rest"`
+	}
+
+	if err := Unmarshal(in, &w); err != nil {
+		return nil, nil, err
+	}
+
+	key := new(ecdsa.PublicKey)
+
+	switch w.Curve {
+	case "nistp256":
+		key.Curve = elliptic.P256()
+	case "nistp384":
+		key.Curve = elliptic.P384()
+	case "nistp521":
+		key.Curve = elliptic.P521()
+	default:
+		return nil, nil, errors.New("ssh: unsupported curve")
+	}
+
+	key.X, key.Y = elliptic.Unmarshal(key.Curve, w.KeyBytes)
+	if key.X == nil || key.Y == nil {
+		return nil, nil, errors.New("ssh: invalid curve point")
+	}
+	return (*ecdsaPublicKey)(key), w.Rest, nil
+}
+
+func (key *ecdsaPublicKey) Marshal() []byte {
+	// See RFC 5656, section 3.1.
+	keyBytes := elliptic.Marshal(key.Curve, key.X, key.Y)
+	// ECDSA publickey struct layout should match the struct used by
+	// parseECDSACert in the x/crypto/ssh/agent package.
+	w := struct {
+		Name string
+		ID   string
+		Key  []byte
+	}{
+		key.Type(),
+		key.nistID(),
+		keyBytes,
+	}
+
+	return Marshal(&w)
+}
+
+func (key *ecdsaPublicKey) Verify(data []byte, sig *Signature) error {
+	if sig.Format != key.Type() {
+		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, key.Type())
+	}
+
+	h := ecHash(key.Curve).New()
+	h.Write(data)
+	digest := h.Sum(nil)
+
+	// Per RFC 5656, section 3.1.2,
+	// The ecdsa_signature_blob value has the following specific encoding:
+	//    mpint    r
+	//    mpint    s
+	var ecSig struct {
+		R *big.Int
+		S *big.Int
+	}
+
+	if err := Unmarshal(sig.Blob, &ecSig); err != nil {
+		return err
+	}
+
+	if ecdsa.Verify((*ecdsa.PublicKey)(key), digest, ecSig.R, ecSig.S) {
+		return nil
+	}
+	return errors.New("ssh: signature did not verify")
+}
+
+func (k *ecdsaPublicKey) CryptoPublicKey() crypto.PublicKey {
+	return (*ecdsa.PublicKey)(k)
+}
+
+// NewSignerFromKey takes an *rsa.PrivateKey, *dsa.PrivateKey,
+// *ecdsa.PrivateKey or any other crypto.Signer and returns a corresponding
+// Signer instance. ECDSA keys must use P-256, P-384 or P-521.
+func NewSignerFromKey(key interface{}) (Signer, error) {
+	switch key := key.(type) {
+	case crypto.Signer:
+		return NewSignerFromSigner(key)
+	case *dsa.PrivateKey:
+		return &dsaPrivateKey{key}, nil
+	default:
+		return nil, fmt.Errorf("ssh: unsupported key type %T", key)
+	}
+}
+
+type wrappedSigner struct {
+	signer crypto.Signer
+	pubKey PublicKey
+}
+
+// NewSignerFromSigner takes any crypto.Signer implementation and
+// returns a corresponding Signer interface. This can be used, for
+// example, with keys kept in hardware modules.
+func NewSignerFromSigner(signer crypto.Signer) (Signer, error) {
+	pubKey, err := NewPublicKey(signer.Public())
+	if err != nil {
+		return nil, err
+	}
+
+	return &wrappedSigner{signer, pubKey}, nil
+}
+
+func (s *wrappedSigner) PublicKey() PublicKey {
+	return s.pubKey
+}
+
+func (s *wrappedSigner) Sign(rand io.Reader, data []byte) (*Signature, error) {
+	var hashFunc crypto.Hash
+
+	switch key := s.pubKey.(type) {
+	case *rsaPublicKey, *dsaPublicKey:
+		hashFunc = crypto.SHA1
+	case *ecdsaPublicKey:
+		hashFunc = ecHash(key.Curve)
+	case ed25519PublicKey:
+	default:
+		return nil, fmt.Errorf("ssh: unsupported key type %T", key)
+	}
+
+	var digest []byte
+	if hashFunc != 0 {
+		h := hashFunc.New()
+		h.Write(data)
+		digest = h.Sum(nil)
+	} else {
+		digest = data
+	}
+
+	signature, err := s.signer.Sign(rand, digest, hashFunc)
+	if err != nil {
+		return nil, err
+	}
+
+	// crypto.Signer.Sign is expected to return an ASN.1-encoded signature
+	// for ECDSA and DSA, but that's not the encoding expected by SSH, so
+	// re-encode.
+	switch s.pubKey.(type) {
+	case *ecdsaPublicKey, *dsaPublicKey:
+		type asn1Signature struct {
+			R, S *big.Int
+		}
+		asn1Sig := new(asn1Signature)
+		_, err := asn1.Unmarshal(signature, asn1Sig)
+		if err != nil {
+			return nil, err
+		}
+
+		switch s.pubKey.(type) {
+		case *ecdsaPublicKey:
+			signature = Marshal(asn1Sig)
+
+		case *dsaPublicKey:
+			signature = make([]byte, 40)
+			r := asn1Sig.R.Bytes()
+			s := asn1Sig.S.Bytes()
+			copy(signature[20-len(r):20], r)
+			copy(signature[40-len(s):40], s)
+		}
+	}
+
+	return &Signature{
+		Format: s.pubKey.Type(),
+		Blob:   signature,
+	}, nil
+}
+
+// NewPublicKey takes an *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey,
+// or ed25519.PublicKey returns a corresponding PublicKey instance.
+// ECDSA keys must use P-256, P-384 or P-521.
+func NewPublicKey(key interface{}) (PublicKey, error) {
+	switch key := key.(type) {
+	case *rsa.PublicKey:
+		return (*rsaPublicKey)(key), nil
+	case *ecdsa.PublicKey:
+		if !supportedEllipticCurve(key.Curve) {
+			return nil, errors.New("ssh: only P-256, P-384 and P-521 EC keys are supported.")
+		}
+		return (*ecdsaPublicKey)(key), nil
+	case *dsa.PublicKey:
+		return (*dsaPublicKey)(key), nil
+	case ed25519.PublicKey:
+		return (ed25519PublicKey)(key), nil
+	default:
+		return nil, fmt.Errorf("ssh: unsupported key type %T", key)
+	}
+}
+
+// ParsePrivateKey returns a Signer from a PEM encoded private key. It supports
+// the same keys as ParseRawPrivateKey.
+func ParsePrivateKey(pemBytes []byte) (Signer, error) {
+	key, err := ParseRawPrivateKey(pemBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewSignerFromKey(key)
+}
+
+// encryptedBlock tells whether a private key is
+// encrypted by examining its Proc-Type header
+// for a mention of ENCRYPTED
+// according to RFC 1421 Section 4.6.1.1.
+func encryptedBlock(block *pem.Block) bool {
+	return strings.Contains(block.Headers["Proc-Type"], "ENCRYPTED")
+}
+
+// ParseRawPrivateKey returns a private key from a PEM encoded private key. It
+// supports RSA (PKCS#1), DSA (OpenSSL), and ECDSA private keys.
+func ParseRawPrivateKey(pemBytes []byte) (interface{}, error) {
+	block, _ := pem.Decode(pemBytes)
+	if block == nil {
+		return nil, errors.New("ssh: no key found")
+	}
+
+	if encryptedBlock(block) {
+		return nil, errors.New("ssh: cannot decode encrypted private keys")
+	}
+
+	switch block.Type {
+	case "RSA PRIVATE KEY":
+		return x509.ParsePKCS1PrivateKey(block.Bytes)
+	case "EC PRIVATE KEY":
+		return x509.ParseECPrivateKey(block.Bytes)
+	case "DSA PRIVATE KEY":
+		return ParseDSAPrivateKey(block.Bytes)
+	case "OPENSSH PRIVATE KEY":
+		return parseOpenSSHPrivateKey(block.Bytes)
+	default:
+		return nil, fmt.Errorf("ssh: unsupported key type %q", block.Type)
+	}
+}
+
+// ParseDSAPrivateKey returns a DSA private key from its ASN.1 DER encoding, as
+// specified by the OpenSSL DSA man page.
+func ParseDSAPrivateKey(der []byte) (*dsa.PrivateKey, error) {
+	var k struct {
+		Version int
+		P       *big.Int
+		Q       *big.Int
+		G       *big.Int
+		Priv    *big.Int
+		Pub     *big.Int
+	}
+	rest, err := asn1.Unmarshal(der, &k)
+	if err != nil {
+		return nil, errors.New("ssh: failed to parse DSA key: " + err.Error())
+	}
+	if len(rest) > 0 {
+		return nil, errors.New("ssh: garbage after DSA key")
+	}
+
+	return &dsa.PrivateKey{
+		PublicKey: dsa.PublicKey{
+			Parameters: dsa.Parameters{
+				P: k.P,
+				Q: k.Q,
+				G: k.G,
+			},
+			Y: k.Priv,
+		},
+		X: k.Pub,
+	}, nil
+}
+
+// Implemented based on the documentation at
+// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key
+func parseOpenSSHPrivateKey(key []byte) (*ed25519.PrivateKey, error) {
+	magic := append([]byte("openssh-key-v1"), 0)
+	if !bytes.Equal(magic, key[0:len(magic)]) {
+		return nil, errors.New("ssh: invalid openssh private key format")
+	}
+	remaining := key[len(magic):]
+
+	var w struct {
+		CipherName   string
+		KdfName      string
+		KdfOpts      string
+		NumKeys      uint32
+		PubKey       []byte
+		PrivKeyBlock []byte
+	}
+
+	if err := Unmarshal(remaining, &w); err != nil {
+		return nil, err
+	}
+
+	pk1 := struct {
+		Check1  uint32
+		Check2  uint32
+		Keytype string
+		Pub     []byte
+		Priv    []byte
+		Comment string
+		Pad     []byte `ssh:"rest"`
+	}{}
+
+	if err := Unmarshal(w.PrivKeyBlock, &pk1); err != nil {
+		return nil, err
+	}
+
+	if pk1.Check1 != pk1.Check2 {
+		return nil, errors.New("ssh: checkint mismatch")
+	}
+
+	// we only handle ed25519 keys currently
+	if pk1.Keytype != KeyAlgoED25519 {
+		return nil, errors.New("ssh: unhandled key type")
+	}
+
+	for i, b := range pk1.Pad {
+		if int(b) != i+1 {
+			return nil, errors.New("ssh: padding not as expected")
+		}
+	}
+
+	if len(pk1.Priv) != ed25519.PrivateKeySize {
+		return nil, errors.New("ssh: private key unexpected length")
+	}
+
+	pk := ed25519.PrivateKey(make([]byte, ed25519.PrivateKeySize))
+	copy(pk, pk1.Priv)
+	return &pk, nil
+}

vendor/golang.org/x/crypto/ssh/keys_test.go

@@ -0,0 +1,456 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"crypto/dsa"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"encoding/base64"
+	"fmt"
+	"reflect"
+	"strings"
+	"testing"
+
+	"golang.org/x/crypto/ed25519"
+	"golang.org/x/crypto/ssh/testdata"
+)
+
+func rawKey(pub PublicKey) interface{} {
+	switch k := pub.(type) {
+	case *rsaPublicKey:
+		return (*rsa.PublicKey)(k)
+	case *dsaPublicKey:
+		return (*dsa.PublicKey)(k)
+	case *ecdsaPublicKey:
+		return (*ecdsa.PublicKey)(k)
+	case ed25519PublicKey:
+		return (ed25519.PublicKey)(k)
+	case *Certificate:
+		return k
+	}
+	panic("unknown key type")
+}
+
+func TestKeyMarshalParse(t *testing.T) {
+	for _, priv := range testSigners {
+		pub := priv.PublicKey()
+		roundtrip, err := ParsePublicKey(pub.Marshal())
+		if err != nil {
+			t.Errorf("ParsePublicKey(%T): %v", pub, err)
+		}
+
+		k1 := rawKey(pub)
+		k2 := rawKey(roundtrip)
+
+		if !reflect.DeepEqual(k1, k2) {
+			t.Errorf("got %#v in roundtrip, want %#v", k2, k1)
+		}
+	}
+}
+
+func TestUnsupportedCurves(t *testing.T) {
+	raw, err := ecdsa.GenerateKey(elliptic.P224(), rand.Reader)
+	if err != nil {
+		t.Fatalf("GenerateKey: %v", err)
+	}
+
+	if _, err = NewSignerFromKey(raw); err == nil || !strings.Contains(err.Error(), "only P-256") {
+		t.Fatalf("NewPrivateKey should not succeed with P-224, got: %v", err)
+	}
+
+	if _, err = NewPublicKey(&raw.PublicKey); err == nil || !strings.Contains(err.Error(), "only P-256") {
+		t.Fatalf("NewPublicKey should not succeed with P-224, got: %v", err)
+	}
+}
+
+func TestNewPublicKey(t *testing.T) {
+	for _, k := range testSigners {
+		raw := rawKey(k.PublicKey())
+		// Skip certificates, as NewPublicKey does not support them.
+		if _, ok := raw.(*Certificate); ok {
+			continue
+		}
+		pub, err := NewPublicKey(raw)
+		if err != nil {
+			t.Errorf("NewPublicKey(%#v): %v", raw, err)
+		}
+		if !reflect.DeepEqual(k.PublicKey(), pub) {
+			t.Errorf("NewPublicKey(%#v) = %#v, want %#v", raw, pub, k.PublicKey())
+		}
+	}
+}
+
+func TestKeySignVerify(t *testing.T) {
+	for _, priv := range testSigners {
+		pub := priv.PublicKey()
+
+		data := []byte("sign me")
+		sig, err := priv.Sign(rand.Reader, data)
+		if err != nil {
+			t.Fatalf("Sign(%T): %v", priv, err)
+		}
+
+		if err := pub.Verify(data, sig); err != nil {
+			t.Errorf("publicKey.Verify(%T): %v", priv, err)
+		}
+		sig.Blob[5]++
+		if err := pub.Verify(data, sig); err == nil {
+			t.Errorf("publicKey.Verify on broken sig did not fail")
+		}
+	}
+}
+
+func TestParseRSAPrivateKey(t *testing.T) {
+	key := testPrivateKeys["rsa"]
+
+	rsa, ok := key.(*rsa.PrivateKey)
+	if !ok {
+		t.Fatalf("got %T, want *rsa.PrivateKey", rsa)
+	}
+
+	if err := rsa.Validate(); err != nil {
+		t.Errorf("Validate: %v", err)
+	}
+}
+
+func TestParseECPrivateKey(t *testing.T) {
+	key := testPrivateKeys["ecdsa"]
+
+	ecKey, ok := key.(*ecdsa.PrivateKey)
+	if !ok {
+		t.Fatalf("got %T, want *ecdsa.PrivateKey", ecKey)
+	}
+
+	if !validateECPublicKey(ecKey.Curve, ecKey.X, ecKey.Y) {
+		t.Fatalf("public key does not validate.")
+	}
+}
+
+// See Issue https://github.com/golang/go/issues/6650.
+func TestParseEncryptedPrivateKeysFails(t *testing.T) {
+	const wantSubstring = "encrypted"
+	for i, tt := range testdata.PEMEncryptedKeys {
+		_, err := ParsePrivateKey(tt.PEMBytes)
+		if err == nil {
+			t.Errorf("#%d key %s: ParsePrivateKey successfully parsed, expected an error", i, tt.Name)
+			continue
+		}
+
+		if !strings.Contains(err.Error(), wantSubstring) {
+			t.Errorf("#%d key %s: got error %q, want substring %q", i, tt.Name, err, wantSubstring)
+		}
+	}
+}
+
+func TestParseDSA(t *testing.T) {
+	// We actually exercise the ParsePrivateKey codepath here, as opposed to
+	// using the ParseRawPrivateKey+NewSignerFromKey path that testdata_test.go
+	// uses.
+	s, err := ParsePrivateKey(testdata.PEMBytes["dsa"])
+	if err != nil {
+		t.Fatalf("ParsePrivateKey returned error: %s", err)
+	}
+
+	data := []byte("sign me")
+	sig, err := s.Sign(rand.Reader, data)
+	if err != nil {
+		t.Fatalf("dsa.Sign: %v", err)
+	}
+
+	if err := s.PublicKey().Verify(data, sig); err != nil {
+		t.Errorf("Verify failed: %v", err)
+	}
+}
+
+// Tests for authorized_keys parsing.
+
+// getTestKey returns a public key, and its base64 encoding.
+func getTestKey() (PublicKey, string) {
+	k := testPublicKeys["rsa"]
+
+	b := &bytes.Buffer{}
+	e := base64.NewEncoder(base64.StdEncoding, b)
+	e.Write(k.Marshal())
+	e.Close()
+
+	return k, b.String()
+}
+
+func TestMarshalParsePublicKey(t *testing.T) {
+	pub, pubSerialized := getTestKey()
+	line := fmt.Sprintf("%s %s user@host", pub.Type(), pubSerialized)
+
+	authKeys := MarshalAuthorizedKey(pub)
+	actualFields := strings.Fields(string(authKeys))
+	if len(actualFields) == 0 {
+		t.Fatalf("failed authKeys: %v", authKeys)
+	}
+
+	// drop the comment
+	expectedFields := strings.Fields(line)[0:2]
+
+	if !reflect.DeepEqual(actualFields, expectedFields) {
+		t.Errorf("got %v, expected %v", actualFields, expectedFields)
+	}
+
+	actPub, _, _, _, err := ParseAuthorizedKey([]byte(line))
+	if err != nil {
+		t.Fatalf("cannot parse %v: %v", line, err)
+	}
+	if !reflect.DeepEqual(actPub, pub) {
+		t.Errorf("got %v, expected %v", actPub, pub)
+	}
+}
+
+type authResult struct {
+	pubKey   PublicKey
+	options  []string
+	comments string
+	rest     string
+	ok       bool
+}
+
+func testAuthorizedKeys(t *testing.T, authKeys []byte, expected []authResult) {
+	rest := authKeys
+	var values []authResult
+	for len(rest) > 0 {
+		var r authResult
+		var err error
+		r.pubKey, r.comments, r.options, rest, err = ParseAuthorizedKey(rest)
+		r.ok = (err == nil)
+		t.Log(err)
+		r.rest = string(rest)
+		values = append(values, r)
+	}
+
+	if !reflect.DeepEqual(values, expected) {
+		t.Errorf("got %#v, expected %#v", values, expected)
+	}
+}
+
+func TestAuthorizedKeyBasic(t *testing.T) {
+	pub, pubSerialized := getTestKey()
+	line := "ssh-rsa " + pubSerialized + " user@host"
+	testAuthorizedKeys(t, []byte(line),
+		[]authResult{
+			{pub, nil, "user@host", "", true},
+		})
+}
+
+func TestAuth(t *testing.T) {
+	pub, pubSerialized := getTestKey()
+	authWithOptions := []string{
+		`# comments to ignore before any keys...`,
+		``,
+		`env="HOME=/home/root",no-port-forwarding ssh-rsa ` + pubSerialized + ` user@host`,
+		`# comments to ignore, along with a blank line`,
+		``,
+		`env="HOME=/home/root2" ssh-rsa ` + pubSerialized + ` user2@host2`,
+		``,
+		`# more comments, plus a invalid entry`,
+		`ssh-rsa data-that-will-not-parse user@host3`,
+	}
+	for _, eol := range []string{"\n", "\r\n"} {
+		authOptions := strings.Join(authWithOptions, eol)
+		rest2 := strings.Join(authWithOptions[3:], eol)
+		rest3 := strings.Join(authWithOptions[6:], eol)
+		testAuthorizedKeys(t, []byte(authOptions), []authResult{
+			{pub, []string{`env="HOME=/home/root"`, "no-port-forwarding"}, "user@host", rest2, true},
+			{pub, []string{`env="HOME=/home/root2"`}, "user2@host2", rest3, true},
+			{nil, nil, "", "", false},
+		})
+	}
+}
+
+func TestAuthWithQuotedSpaceInEnv(t *testing.T) {
+	pub, pubSerialized := getTestKey()
+	authWithQuotedSpaceInEnv := []byte(`env="HOME=/home/root dir",no-port-forwarding ssh-rsa ` + pubSerialized + ` user@host`)
+	testAuthorizedKeys(t, []byte(authWithQuotedSpaceInEnv), []authResult{
+		{pub, []string{`env="HOME=/home/root dir"`, "no-port-forwarding"}, "user@host", "", true},
+	})
+}
+
+func TestAuthWithQuotedCommaInEnv(t *testing.T) {
+	pub, pubSerialized := getTestKey()
+	authWithQuotedCommaInEnv := []byte(`env="HOME=/home/root,dir",no-port-forwarding ssh-rsa ` + pubSerialized + `   user@host`)
+	testAuthorizedKeys(t, []byte(authWithQuotedCommaInEnv), []authResult{
+		{pub, []string{`env="HOME=/home/root,dir"`, "no-port-forwarding"}, "user@host", "", true},
+	})
+}
+
+func TestAuthWithQuotedQuoteInEnv(t *testing.T) {
+	pub, pubSerialized := getTestKey()
+	authWithQuotedQuoteInEnv := []byte(`env="HOME=/home/\"root dir",no-port-forwarding` + "\t" + `ssh-rsa` + "\t" + pubSerialized + `   user@host`)
+	authWithDoubleQuotedQuote := []byte(`no-port-forwarding,env="HOME=/home/ \"root dir\"" ssh-rsa ` + pubSerialized + "\t" + `user@host`)
+	testAuthorizedKeys(t, []byte(authWithQuotedQuoteInEnv), []authResult{
+		{pub, []string{`env="HOME=/home/\"root dir"`, "no-port-forwarding"}, "user@host", "", true},
+	})
+
+	testAuthorizedKeys(t, []byte(authWithDoubleQuotedQuote), []authResult{
+		{pub, []string{"no-port-forwarding", `env="HOME=/home/ \"root dir\""`}, "user@host", "", true},
+	})
+}
+
+func TestAuthWithInvalidSpace(t *testing.T) {
+	_, pubSerialized := getTestKey()
+	authWithInvalidSpace := []byte(`env="HOME=/home/root dir", no-port-forwarding ssh-rsa ` + pubSerialized + ` user@host
+#more to follow but still no valid keys`)
+	testAuthorizedKeys(t, []byte(authWithInvalidSpace), []authResult{
+		{nil, nil, "", "", false},
+	})
+}
+
+func TestAuthWithMissingQuote(t *testing.T) {
+	pub, pubSerialized := getTestKey()
+	authWithMissingQuote := []byte(`env="HOME=/home/root,no-port-forwarding ssh-rsa ` + pubSerialized + ` user@host
+env="HOME=/home/root",shared-control ssh-rsa ` + pubSerialized + ` user@host`)
+
+	testAuthorizedKeys(t, []byte(authWithMissingQuote), []authResult{
+		{pub, []string{`env="HOME=/home/root"`, `shared-control`}, "user@host", "", true},
+	})
+}
+
+func TestInvalidEntry(t *testing.T) {
+	authInvalid := []byte(`ssh-rsa`)
+	_, _, _, _, err := ParseAuthorizedKey(authInvalid)
+	if err == nil {
+		t.Errorf("got valid entry for %q", authInvalid)
+	}
+}
+
+var knownHostsParseTests = []struct {
+	input string
+	err   string
+
+	marker  string
+	comment string
+	hosts   []string
+	rest    string
+}{
+	{
+		"",
+		"EOF",
+
+		"", "", nil, "",
+	},
+	{
+		"# Just a comment",
+		"EOF",
+
+		"", "", nil, "",
+	},
+	{
+		"   \t   ",
+		"EOF",
+
+		"", "", nil, "",
+	},
+	{
+		"localhost ssh-rsa {RSAPUB}",
+		"",
+
+		"", "", []string{"localhost"}, "",
+	},
+	{
+		"localhost\tssh-rsa {RSAPUB}",
+		"",
+
+		"", "", []string{"localhost"}, "",
+	},
+	{
+		"localhost\tssh-rsa {RSAPUB}\tcomment comment",
+		"",
+
+		"", "comment comment", []string{"localhost"}, "",
+	},
+	{
+		"localhost\tssh-rsa {RSAPUB}\tcomment comment\n",
+		"",
+
+		"", "comment comment", []string{"localhost"}, "",
+	},
+	{
+		"localhost\tssh-rsa {RSAPUB}\tcomment comment\r\n",
+		"",
+
+		"", "comment comment", []string{"localhost"}, "",
+	},
+	{
+		"localhost\tssh-rsa {RSAPUB}\tcomment comment\r\nnext line",
+		"",
+
+		"", "comment comment", []string{"localhost"}, "next line",
+	},
+	{
+		"localhost,[host2:123]\tssh-rsa {RSAPUB}\tcomment comment",
+		"",
+
+		"", "comment comment", []string{"localhost", "[host2:123]"}, "",
+	},
+	{
+		"@marker \tlocalhost,[host2:123]\tssh-rsa {RSAPUB}",
+		"",
+
+		"marker", "", []string{"localhost", "[host2:123]"}, "",
+	},
+	{
+		"@marker \tlocalhost,[host2:123]\tssh-rsa aabbccdd",
+		"short read",
+
+		"", "", nil, "",
+	},
+}
+
+func TestKnownHostsParsing(t *testing.T) {
+	rsaPub, rsaPubSerialized := getTestKey()
+
+	for i, test := range knownHostsParseTests {
+		var expectedKey PublicKey
+		const rsaKeyToken = "{RSAPUB}"
+
+		input := test.input
+		if strings.Contains(input, rsaKeyToken) {
+			expectedKey = rsaPub
+			input = strings.Replace(test.input, rsaKeyToken, rsaPubSerialized, -1)
+		}
+
+		marker, hosts, pubKey, comment, rest, err := ParseKnownHosts([]byte(input))
+		if err != nil {
+			if len(test.err) == 0 {
+				t.Errorf("#%d: unexpectedly failed with %q", i, err)
+			} else if !strings.Contains(err.Error(), test.err) {
+				t.Errorf("#%d: expected error containing %q, but got %q", i, test.err, err)
+			}
+			continue
+		} else if len(test.err) != 0 {
+			t.Errorf("#%d: succeeded but expected error including %q", i, test.err)
+			continue
+		}
+
+		if !reflect.DeepEqual(expectedKey, pubKey) {
+			t.Errorf("#%d: expected key %#v, but got %#v", i, expectedKey, pubKey)
+		}
+
+		if marker != test.marker {
+			t.Errorf("#%d: expected marker %q, but got %q", i, test.marker, marker)
+		}
+
+		if comment != test.comment {
+			t.Errorf("#%d: expected comment %q, but got %q", i, test.comment, comment)
+		}
+
+		if !reflect.DeepEqual(test.hosts, hosts) {
+			t.Errorf("#%d: expected hosts %#v, but got %#v", i, test.hosts, hosts)
+		}
+
+		if rest := string(rest); rest != test.rest {
+			t.Errorf("#%d: expected remaining input to be %q, but got %q", i, test.rest, rest)
+		}
+	}
+}

vendor/golang.org/x/crypto/ssh/mac.go

@@ -0,0 +1,57 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+// Message authentication support
+
+import (
+	"crypto/hmac"
+	"crypto/sha1"
+	"crypto/sha256"
+	"hash"
+)
+
+type macMode struct {
+	keySize int
+	new     func(key []byte) hash.Hash
+}
+
+// truncatingMAC wraps around a hash.Hash and truncates the output digest to
+// a given size.
+type truncatingMAC struct {
+	length int
+	hmac   hash.Hash
+}
+
+func (t truncatingMAC) Write(data []byte) (int, error) {
+	return t.hmac.Write(data)
+}
+
+func (t truncatingMAC) Sum(in []byte) []byte {
+	out := t.hmac.Sum(in)
+	return out[:len(in)+t.length]
+}
+
+func (t truncatingMAC) Reset() {
+	t.hmac.Reset()
+}
+
+func (t truncatingMAC) Size() int {
+	return t.length
+}
+
+func (t truncatingMAC) BlockSize() int { return t.hmac.BlockSize() }
+
+var macModes = map[string]*macMode{
+	"hmac-sha2-256": {32, func(key []byte) hash.Hash {
+		return hmac.New(sha256.New, key)
+	}},
+	"hmac-sha1": {20, func(key []byte) hash.Hash {
+		return hmac.New(sha1.New, key)
+	}},
+	"hmac-sha1-96": {20, func(key []byte) hash.Hash {
+		return truncatingMAC{12, hmac.New(sha1.New, key)}
+	}},
+}

vendor/golang.org/x/crypto/ssh/mempipe_test.go

@@ -0,0 +1,110 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"io"
+	"sync"
+	"testing"
+)
+
+// An in-memory packetConn. It is safe to call Close and writePacket
+// from different goroutines.
+type memTransport struct {
+	eof     bool
+	pending [][]byte
+	write   *memTransport
+	sync.Mutex
+	*sync.Cond
+}
+
+func (t *memTransport) readPacket() ([]byte, error) {
+	t.Lock()
+	defer t.Unlock()
+	for {
+		if len(t.pending) > 0 {
+			r := t.pending[0]
+			t.pending = t.pending[1:]
+			return r, nil
+		}
+		if t.eof {
+			return nil, io.EOF
+		}
+		t.Cond.Wait()
+	}
+}
+
+func (t *memTransport) closeSelf() error {
+	t.Lock()
+	defer t.Unlock()
+	if t.eof {
+		return io.EOF
+	}
+	t.eof = true
+	t.Cond.Broadcast()
+	return nil
+}
+
+func (t *memTransport) Close() error {
+	err := t.write.closeSelf()
+	t.closeSelf()
+	return err
+}
+
+func (t *memTransport) writePacket(p []byte) error {
+	t.write.Lock()
+	defer t.write.Unlock()
+	if t.write.eof {
+		return io.EOF
+	}
+	c := make([]byte, len(p))
+	copy(c, p)
+	t.write.pending = append(t.write.pending, c)
+	t.write.Cond.Signal()
+	return nil
+}
+
+func memPipe() (a, b packetConn) {
+	t1 := memTransport{}
+	t2 := memTransport{}
+	t1.write = &t2
+	t2.write = &t1
+	t1.Cond = sync.NewCond(&t1.Mutex)
+	t2.Cond = sync.NewCond(&t2.Mutex)
+	return &t1, &t2
+}
+
+func TestMemPipe(t *testing.T) {
+	a, b := memPipe()
+	if err := a.writePacket([]byte{42}); err != nil {
+		t.Fatalf("writePacket: %v", err)
+	}
+	if err := a.Close(); err != nil {
+		t.Fatal("Close: ", err)
+	}
+	p, err := b.readPacket()
+	if err != nil {
+		t.Fatal("readPacket: ", err)
+	}
+	if len(p) != 1 || p[0] != 42 {
+		t.Fatalf("got %v, want {42}", p)
+	}
+	p, err = b.readPacket()
+	if err != io.EOF {
+		t.Fatalf("got %v, %v, want EOF", p, err)
+	}
+}
+
+func TestDoubleClose(t *testing.T) {
+	a, _ := memPipe()
+	err := a.Close()
+	if err != nil {
+		t.Errorf("Close: %v", err)
+	}
+	err = a.Close()
+	if err != io.EOF {
+		t.Errorf("expect EOF on double close.")
+	}
+}

vendor/golang.org/x/crypto/ssh/messages.go

@@ -0,0 +1,758 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+// These are SSH message type numbers. They are scattered around several
+// documents but many were taken from [SSH-PARAMETERS].
+const (
+	msgIgnore        = 2
+	msgUnimplemented = 3
+	msgDebug         = 4
+	msgNewKeys       = 21
+
+	// Standard authentication messages
+	msgUserAuthSuccess = 52
+	msgUserAuthBanner  = 53
+)
+
+// SSH messages:
+//
+// These structures mirror the wire format of the corresponding SSH messages.
+// They are marshaled using reflection with the marshal and unmarshal functions
+// in this file. The only wrinkle is that a final member of type []byte with a
+// ssh tag of "rest" receives the remainder of a packet when unmarshaling.
+
+// See RFC 4253, section 11.1.
+const msgDisconnect = 1
+
+// disconnectMsg is the message that signals a disconnect. It is also
+// the error type returned from mux.Wait()
+type disconnectMsg struct {
+	Reason   uint32 `sshtype:"1"`
+	Message  string
+	Language string
+}
+
+func (d *disconnectMsg) Error() string {
+	return fmt.Sprintf("ssh: disconnect, reason %d: %s", d.Reason, d.Message)
+}
+
+// See RFC 4253, section 7.1.
+const msgKexInit = 20
+
+type kexInitMsg struct {
+	Cookie                  [16]byte `sshtype:"20"`
+	KexAlgos                []string
+	ServerHostKeyAlgos      []string
+	CiphersClientServer     []string
+	CiphersServerClient     []string
+	MACsClientServer        []string
+	MACsServerClient        []string
+	CompressionClientServer []string
+	CompressionServerClient []string
+	LanguagesClientServer   []string
+	LanguagesServerClient   []string
+	FirstKexFollows         bool
+	Reserved                uint32
+}
+
+// See RFC 4253, section 8.
+
+// Diffie-Helman
+const msgKexDHInit = 30
+
+type kexDHInitMsg struct {
+	X *big.Int `sshtype:"30"`
+}
+
+const msgKexECDHInit = 30
+
+type kexECDHInitMsg struct {
+	ClientPubKey []byte `sshtype:"30"`
+}
+
+const msgKexECDHReply = 31
+
+type kexECDHReplyMsg struct {
+	HostKey         []byte `sshtype:"31"`
+	EphemeralPubKey []byte
+	Signature       []byte
+}
+
+const msgKexDHReply = 31
+
+type kexDHReplyMsg struct {
+	HostKey   []byte `sshtype:"31"`
+	Y         *big.Int
+	Signature []byte
+}
+
+// See RFC 4253, section 10.
+const msgServiceRequest = 5
+
+type serviceRequestMsg struct {
+	Service string `sshtype:"5"`
+}
+
+// See RFC 4253, section 10.
+const msgServiceAccept = 6
+
+type serviceAcceptMsg struct {
+	Service string `sshtype:"6"`
+}
+
+// See RFC 4252, section 5.
+const msgUserAuthRequest = 50
+
+type userAuthRequestMsg struct {
+	User    string `sshtype:"50"`
+	Service string
+	Method  string
+	Payload []byte `ssh:"rest"`
+}
+
+// Used for debug printouts of packets.
+type userAuthSuccessMsg struct {
+}
+
+// See RFC 4252, section 5.1
+const msgUserAuthFailure = 51
+
+type userAuthFailureMsg struct {
+	Methods        []string `sshtype:"51"`
+	PartialSuccess bool
+}
+
+// See RFC 4256, section 3.2
+const msgUserAuthInfoRequest = 60
+const msgUserAuthInfoResponse = 61
+
+type userAuthInfoRequestMsg struct {
+	User               string `sshtype:"60"`
+	Instruction        string
+	DeprecatedLanguage string
+	NumPrompts         uint32
+	Prompts            []byte `ssh:"rest"`
+}
+
+// See RFC 4254, section 5.1.
+const msgChannelOpen = 90
+
+type channelOpenMsg struct {
+	ChanType         string `sshtype:"90"`
+	PeersId          uint32
+	PeersWindow      uint32
+	MaxPacketSize    uint32
+	TypeSpecificData []byte `ssh:"rest"`
+}
+
+const msgChannelExtendedData = 95
+const msgChannelData = 94
+
+// Used for debug print outs of packets.
+type channelDataMsg struct {
+	PeersId uint32 `sshtype:"94"`
+	Length  uint32
+	Rest    []byte `ssh:"rest"`
+}
+
+// See RFC 4254, section 5.1.
+const msgChannelOpenConfirm = 91
+
+type channelOpenConfirmMsg struct {
+	PeersId          uint32 `sshtype:"91"`
+	MyId             uint32
+	MyWindow         uint32
+	MaxPacketSize    uint32
+	TypeSpecificData []byte `ssh:"rest"`
+}
+
+// See RFC 4254, section 5.1.
+const msgChannelOpenFailure = 92
+
+type channelOpenFailureMsg struct {
+	PeersId  uint32 `sshtype:"92"`
+	Reason   RejectionReason
+	Message  string
+	Language string
+}
+
+const msgChannelRequest = 98
+
+type channelRequestMsg struct {
+	PeersId             uint32 `sshtype:"98"`
+	Request             string
+	WantReply           bool
+	RequestSpecificData []byte `ssh:"rest"`
+}
+
+// See RFC 4254, section 5.4.
+const msgChannelSuccess = 99
+
+type channelRequestSuccessMsg struct {
+	PeersId uint32 `sshtype:"99"`
+}
+
+// See RFC 4254, section 5.4.
+const msgChannelFailure = 100
+
+type channelRequestFailureMsg struct {
+	PeersId uint32 `sshtype:"100"`
+}
+
+// See RFC 4254, section 5.3
+const msgChannelClose = 97
+
+type channelCloseMsg struct {
+	PeersId uint32 `sshtype:"97"`
+}
+
+// See RFC 4254, section 5.3
+const msgChannelEOF = 96
+
+type channelEOFMsg struct {
+	PeersId uint32 `sshtype:"96"`
+}
+
+// See RFC 4254, section 4
+const msgGlobalRequest = 80
+
+type globalRequestMsg struct {
+	Type      string `sshtype:"80"`
+	WantReply bool
+	Data      []byte `ssh:"rest"`
+}
+
+// See RFC 4254, section 4
+const msgRequestSuccess = 81
+
+type globalRequestSuccessMsg struct {
+	Data []byte `ssh:"rest" sshtype:"81"`
+}
+
+// See RFC 4254, section 4
+const msgRequestFailure = 82
+
+type globalRequestFailureMsg struct {
+	Data []byte `ssh:"rest" sshtype:"82"`
+}
+
+// See RFC 4254, section 5.2
+const msgChannelWindowAdjust = 93
+
+type windowAdjustMsg struct {
+	PeersId         uint32 `sshtype:"93"`
+	AdditionalBytes uint32
+}
+
+// See RFC 4252, section 7
+const msgUserAuthPubKeyOk = 60
+
+type userAuthPubKeyOkMsg struct {
+	Algo   string `sshtype:"60"`
+	PubKey []byte
+}
+
+// typeTags returns the possible type bytes for the given reflect.Type, which
+// should be a struct. The possible values are separated by a '|' character.
+func typeTags(structType reflect.Type) (tags []byte) {
+	tagStr := structType.Field(0).Tag.Get("sshtype")
+
+	for _, tag := range strings.Split(tagStr, "|") {
+		i, err := strconv.Atoi(tag)
+		if err == nil {
+			tags = append(tags, byte(i))
+		}
+	}
+
+	return tags
+}
+
+func fieldError(t reflect.Type, field int, problem string) error {
+	if problem != "" {
+		problem = ": " + problem
+	}
+	return fmt.Errorf("ssh: unmarshal error for field %s of type %s%s", t.Field(field).Name, t.Name(), problem)
+}
+
+var errShortRead = errors.New("ssh: short read")
+
+// Unmarshal parses data in SSH wire format into a structure. The out
+// argument should be a pointer to struct. If the first member of the
+// struct has the "sshtype" tag set to a '|'-separated set of numbers
+// in decimal, the packet must start with one of those numbers. In
+// case of error, Unmarshal returns a ParseError or
+// UnexpectedMessageError.
+func Unmarshal(data []byte, out interface{}) error {
+	v := reflect.ValueOf(out).Elem()
+	structType := v.Type()
+	expectedTypes := typeTags(structType)
+
+	var expectedType byte
+	if len(expectedTypes) > 0 {
+		expectedType = expectedTypes[0]
+	}
+
+	if len(data) == 0 {
+		return parseError(expectedType)
+	}
+
+	if len(expectedTypes) > 0 {
+		goodType := false
+		for _, e := range expectedTypes {
+			if e > 0 && data[0] == e {
+				goodType = true
+				break
+			}
+		}
+		if !goodType {
+			return fmt.Errorf("ssh: unexpected message type %d (expected one of %v)", data[0], expectedTypes)
+		}
+		data = data[1:]
+	}
+
+	var ok bool
+	for i := 0; i < v.NumField(); i++ {
+		field := v.Field(i)
+		t := field.Type()
+		switch t.Kind() {
+		case reflect.Bool:
+			if len(data) < 1 {
+				return errShortRead
+			}
+			field.SetBool(data[0] != 0)
+			data = data[1:]
+		case reflect.Array:
+			if t.Elem().Kind() != reflect.Uint8 {
+				return fieldError(structType, i, "array of unsupported type")
+			}
+			if len(data) < t.Len() {
+				return errShortRead
+			}
+			for j, n := 0, t.Len(); j < n; j++ {
+				field.Index(j).Set(reflect.ValueOf(data[j]))
+			}
+			data = data[t.Len():]
+		case reflect.Uint64:
+			var u64 uint64
+			if u64, data, ok = parseUint64(data); !ok {
+				return errShortRead
+			}
+			field.SetUint(u64)
+		case reflect.Uint32:
+			var u32 uint32
+			if u32, data, ok = parseUint32(data); !ok {
+				return errShortRead
+			}
+			field.SetUint(uint64(u32))
+		case reflect.Uint8:
+			if len(data) < 1 {
+				return errShortRead
+			}
+			field.SetUint(uint64(data[0]))
+			data = data[1:]
+		case reflect.String:
+			var s []byte
+			if s, data, ok = parseString(data); !ok {
+				return fieldError(structType, i, "")
+			}
+			field.SetString(string(s))
+		case reflect.Slice:
+			switch t.Elem().Kind() {
+			case reflect.Uint8:
+				if structType.Field(i).Tag.Get("ssh") == "rest" {
+					field.Set(reflect.ValueOf(data))
+					data = nil
+				} else {
+					var s []byte
+					if s, data, ok = parseString(data); !ok {
+						return errShortRead
+					}
+					field.Set(reflect.ValueOf(s))
+				}
+			case reflect.String:
+				var nl []string
+				if nl, data, ok = parseNameList(data); !ok {
+					return errShortRead
+				}
+				field.Set(reflect.ValueOf(nl))
+			default:
+				return fieldError(structType, i, "slice of unsupported type")
+			}
+		case reflect.Ptr:
+			if t == bigIntType {
+				var n *big.Int
+				if n, data, ok = parseInt(data); !ok {
+					return errShortRead
+				}
+				field.Set(reflect.ValueOf(n))
+			} else {
+				return fieldError(structType, i, "pointer to unsupported type")
+			}
+		default:
+			return fieldError(structType, i, fmt.Sprintf("unsupported type: %v", t))
+		}
+	}
+
+	if len(data) != 0 {
+		return parseError(expectedType)
+	}
+
+	return nil
+}
+
+// Marshal serializes the message in msg to SSH wire format.  The msg
+// argument should be a struct or pointer to struct. If the first
+// member has the "sshtype" tag set to a number in decimal, that
+// number is prepended to the result. If the last of member has the
+// "ssh" tag set to "rest", its contents are appended to the output.
+func Marshal(msg interface{}) []byte {
+	out := make([]byte, 0, 64)
+	return marshalStruct(out, msg)
+}
+
+func marshalStruct(out []byte, msg interface{}) []byte {
+	v := reflect.Indirect(reflect.ValueOf(msg))
+	msgTypes := typeTags(v.Type())
+	if len(msgTypes) > 0 {
+		out = append(out, msgTypes[0])
+	}
+
+	for i, n := 0, v.NumField(); i < n; i++ {
+		field := v.Field(i)
+		switch t := field.Type(); t.Kind() {
+		case reflect.Bool:
+			var v uint8
+			if field.Bool() {
+				v = 1
+			}
+			out = append(out, v)
+		case reflect.Array:
+			if t.Elem().Kind() != reflect.Uint8 {
+				panic(fmt.Sprintf("array of non-uint8 in field %d: %T", i, field.Interface()))
+			}
+			for j, l := 0, t.Len(); j < l; j++ {
+				out = append(out, uint8(field.Index(j).Uint()))
+			}
+		case reflect.Uint32:
+			out = appendU32(out, uint32(field.Uint()))
+		case reflect.Uint64:
+			out = appendU64(out, uint64(field.Uint()))
+		case reflect.Uint8:
+			out = append(out, uint8(field.Uint()))
+		case reflect.String:
+			s := field.String()
+			out = appendInt(out, len(s))
+			out = append(out, s...)
+		case reflect.Slice:
+			switch t.Elem().Kind() {
+			case reflect.Uint8:
+				if v.Type().Field(i).Tag.Get("ssh") != "rest" {
+					out = appendInt(out, field.Len())
+				}
+				out = append(out, field.Bytes()...)
+			case reflect.String:
+				offset := len(out)
+				out = appendU32(out, 0)
+				if n := field.Len(); n > 0 {
+					for j := 0; j < n; j++ {
+						f := field.Index(j)
+						if j != 0 {
+							out = append(out, ',')
+						}
+						out = append(out, f.String()...)
+					}
+					// overwrite length value
+					binary.BigEndian.PutUint32(out[offset:], uint32(len(out)-offset-4))
+				}
+			default:
+				panic(fmt.Sprintf("slice of unknown type in field %d: %T", i, field.Interface()))
+			}
+		case reflect.Ptr:
+			if t == bigIntType {
+				var n *big.Int
+				nValue := reflect.ValueOf(&n)
+				nValue.Elem().Set(field)
+				needed := intLength(n)
+				oldLength := len(out)
+
+				if cap(out)-len(out) < needed {
+					newOut := make([]byte, len(out), 2*(len(out)+needed))
+					copy(newOut, out)
+					out = newOut
+				}
+				out = out[:oldLength+needed]
+				marshalInt(out[oldLength:], n)
+			} else {
+				panic(fmt.Sprintf("pointer to unknown type in field %d: %T", i, field.Interface()))
+			}
+		}
+	}
+
+	return out
+}
+
+var bigOne = big.NewInt(1)
+
+func parseString(in []byte) (out, rest []byte, ok bool) {
+	if len(in) < 4 {
+		return
+	}
+	length := binary.BigEndian.Uint32(in)
+	in = in[4:]
+	if uint32(len(in)) < length {
+		return
+	}
+	out = in[:length]
+	rest = in[length:]
+	ok = true
+	return
+}
+
+var (
+	comma         = []byte{','}
+	emptyNameList = []string{}
+)
+
+func parseNameList(in []byte) (out []string, rest []byte, ok bool) {
+	contents, rest, ok := parseString(in)
+	if !ok {
+		return
+	}
+	if len(contents) == 0 {
+		out = emptyNameList
+		return
+	}
+	parts := bytes.Split(contents, comma)
+	out = make([]string, len(parts))
+	for i, part := range parts {
+		out[i] = string(part)
+	}
+	return
+}
+
+func parseInt(in []byte) (out *big.Int, rest []byte, ok bool) {
+	contents, rest, ok := parseString(in)
+	if !ok {
+		return
+	}
+	out = new(big.Int)
+
+	if len(contents) > 0 && contents[0]&0x80 == 0x80 {
+		// This is a negative number
+		notBytes := make([]byte, len(contents))
+		for i := range notBytes {
+			notBytes[i] = ^contents[i]
+		}
+		out.SetBytes(notBytes)
+		out.Add(out, bigOne)
+		out.Neg(out)
+	} else {
+		// Positive number
+		out.SetBytes(contents)
+	}
+	ok = true
+	return
+}
+
+func parseUint32(in []byte) (uint32, []byte, bool) {
+	if len(in) < 4 {
+		return 0, nil, false
+	}
+	return binary.BigEndian.Uint32(in), in[4:], true
+}
+
+func parseUint64(in []byte) (uint64, []byte, bool) {
+	if len(in) < 8 {
+		return 0, nil, false
+	}
+	return binary.BigEndian.Uint64(in), in[8:], true
+}
+
+func intLength(n *big.Int) int {
+	length := 4 /* length bytes */
+	if n.Sign() < 0 {
+		nMinus1 := new(big.Int).Neg(n)
+		nMinus1.Sub(nMinus1, bigOne)
+		bitLen := nMinus1.BitLen()
+		if bitLen%8 == 0 {
+			// The number will need 0xff padding
+			length++
+		}
+		length += (bitLen + 7) / 8
+	} else if n.Sign() == 0 {
+		// A zero is the zero length string
+	} else {
+		bitLen := n.BitLen()
+		if bitLen%8 == 0 {
+			// The number will need 0x00 padding
+			length++
+		}
+		length += (bitLen + 7) / 8
+	}
+
+	return length
+}
+
+func marshalUint32(to []byte, n uint32) []byte {
+	binary.BigEndian.PutUint32(to, n)
+	return to[4:]
+}
+
+func marshalUint64(to []byte, n uint64) []byte {
+	binary.BigEndian.PutUint64(to, n)
+	return to[8:]
+}
+
+func marshalInt(to []byte, n *big.Int) []byte {
+	lengthBytes := to
+	to = to[4:]
+	length := 0
+
+	if n.Sign() < 0 {
+		// A negative number has to be converted to two's-complement
+		// form. So we'll subtract 1 and invert. If the
+		// most-significant-bit isn't set then we'll need to pad the
+		// beginning with 0xff in order to keep the number negative.
+		nMinus1 := new(big.Int).Neg(n)
+		nMinus1.Sub(nMinus1, bigOne)
+		bytes := nMinus1.Bytes()
+		for i := range bytes {
+			bytes[i] ^= 0xff
+		}
+		if len(bytes) == 0 || bytes[0]&0x80 == 0 {
+			to[0] = 0xff
+			to = to[1:]
+			length++
+		}
+		nBytes := copy(to, bytes)
+		to = to[nBytes:]
+		length += nBytes
+	} else if n.Sign() == 0 {
+		// A zero is the zero length string
+	} else {
+		bytes := n.Bytes()
+		if len(bytes) > 0 && bytes[0]&0x80 != 0 {
+			// We'll have to pad this with a 0x00 in order to
+			// stop it looking like a negative number.
+			to[0] = 0
+			to = to[1:]
+			length++
+		}
+		nBytes := copy(to, bytes)
+		to = to[nBytes:]
+		length += nBytes
+	}
+
+	lengthBytes[0] = byte(length >> 24)
+	lengthBytes[1] = byte(length >> 16)
+	lengthBytes[2] = byte(length >> 8)
+	lengthBytes[3] = byte(length)
+	return to
+}
+
+func writeInt(w io.Writer, n *big.Int) {
+	length := intLength(n)
+	buf := make([]byte, length)
+	marshalInt(buf, n)
+	w.Write(buf)
+}
+
+func writeString(w io.Writer, s []byte) {
+	var lengthBytes [4]byte
+	lengthBytes[0] = byte(len(s) >> 24)
+	lengthBytes[1] = byte(len(s) >> 16)
+	lengthBytes[2] = byte(len(s) >> 8)
+	lengthBytes[3] = byte(len(s))
+	w.Write(lengthBytes[:])
+	w.Write(s)
+}
+
+func stringLength(n int) int {
+	return 4 + n
+}
+
+func marshalString(to []byte, s []byte) []byte {
+	to[0] = byte(len(s) >> 24)
+	to[1] = byte(len(s) >> 16)
+	to[2] = byte(len(s) >> 8)
+	to[3] = byte(len(s))
+	to = to[4:]
+	copy(to, s)
+	return to[len(s):]
+}
+
+var bigIntType = reflect.TypeOf((*big.Int)(nil))
+
+// Decode a packet into its corresponding message.
+func decode(packet []byte) (interface{}, error) {
+	var msg interface{}
+	switch packet[0] {
+	case msgDisconnect:
+		msg = new(disconnectMsg)
+	case msgServiceRequest:
+		msg = new(serviceRequestMsg)
+	case msgServiceAccept:
+		msg = new(serviceAcceptMsg)
+	case msgKexInit:
+		msg = new(kexInitMsg)
+	case msgKexDHInit:
+		msg = new(kexDHInitMsg)
+	case msgKexDHReply:
+		msg = new(kexDHReplyMsg)
+	case msgUserAuthRequest:
+		msg = new(userAuthRequestMsg)
+	case msgUserAuthSuccess:
+		return new(userAuthSuccessMsg), nil
+	case msgUserAuthFailure:
+		msg = new(userAuthFailureMsg)
+	case msgUserAuthPubKeyOk:
+		msg = new(userAuthPubKeyOkMsg)
+	case msgGlobalRequest:
+		msg = new(globalRequestMsg)
+	case msgRequestSuccess:
+		msg = new(globalRequestSuccessMsg)
+	case msgRequestFailure:
+		msg = new(globalRequestFailureMsg)
+	case msgChannelOpen:
+		msg = new(channelOpenMsg)
+	case msgChannelData:
+		msg = new(channelDataMsg)
+	case msgChannelOpenConfirm:
+		msg = new(channelOpenConfirmMsg)
+	case msgChannelOpenFailure:
+		msg = new(channelOpenFailureMsg)
+	case msgChannelWindowAdjust:
+		msg = new(windowAdjustMsg)
+	case msgChannelEOF:
+		msg = new(channelEOFMsg)
+	case msgChannelClose:
+		msg = new(channelCloseMsg)
+	case msgChannelRequest:
+		msg = new(channelRequestMsg)
+	case msgChannelSuccess:
+		msg = new(channelRequestSuccessMsg)
+	case msgChannelFailure:
+		msg = new(channelRequestFailureMsg)
+	default:
+		return nil, unexpectedMessageError(0, packet[0])
+	}
+	if err := Unmarshal(packet, msg); err != nil {
+		return nil, err
+	}
+	return msg, nil
+}

vendor/golang.org/x/crypto/ssh/messages_test.go

@@ -0,0 +1,288 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"math/big"
+	"math/rand"
+	"reflect"
+	"testing"
+	"testing/quick"
+)
+
+var intLengthTests = []struct {
+	val, length int
+}{
+	{0, 4 + 0},
+	{1, 4 + 1},
+	{127, 4 + 1},
+	{128, 4 + 2},
+	{-1, 4 + 1},
+}
+
+func TestIntLength(t *testing.T) {
+	for _, test := range intLengthTests {
+		v := new(big.Int).SetInt64(int64(test.val))
+		length := intLength(v)
+		if length != test.length {
+			t.Errorf("For %d, got length %d but expected %d", test.val, length, test.length)
+		}
+	}
+}
+
+type msgAllTypes struct {
+	Bool    bool `sshtype:"21"`
+	Array   [16]byte
+	Uint64  uint64
+	Uint32  uint32
+	Uint8   uint8
+	String  string
+	Strings []string
+	Bytes   []byte
+	Int     *big.Int
+	Rest    []byte `ssh:"rest"`
+}
+
+func (t *msgAllTypes) Generate(rand *rand.Rand, size int) reflect.Value {
+	m := &msgAllTypes{}
+	m.Bool = rand.Intn(2) == 1
+	randomBytes(m.Array[:], rand)
+	m.Uint64 = uint64(rand.Int63n(1<<63 - 1))
+	m.Uint32 = uint32(rand.Intn((1 << 31) - 1))
+	m.Uint8 = uint8(rand.Intn(1 << 8))
+	m.String = string(m.Array[:])
+	m.Strings = randomNameList(rand)
+	m.Bytes = m.Array[:]
+	m.Int = randomInt(rand)
+	m.Rest = m.Array[:]
+	return reflect.ValueOf(m)
+}
+
+func TestMarshalUnmarshal(t *testing.T) {
+	rand := rand.New(rand.NewSource(0))
+	iface := &msgAllTypes{}
+	ty := reflect.ValueOf(iface).Type()
+
+	n := 100
+	if testing.Short() {
+		n = 5
+	}
+	for j := 0; j < n; j++ {
+		v, ok := quick.Value(ty, rand)
+		if !ok {
+			t.Errorf("failed to create value")
+			break
+		}
+
+		m1 := v.Elem().Interface()
+		m2 := iface
+
+		marshaled := Marshal(m1)
+		if err := Unmarshal(marshaled, m2); err != nil {
+			t.Errorf("Unmarshal %#v: %s", m1, err)
+			break
+		}
+
+		if !reflect.DeepEqual(v.Interface(), m2) {
+			t.Errorf("got: %#v\nwant:%#v\n%x", m2, m1, marshaled)
+			break
+		}
+	}
+}
+
+func TestUnmarshalEmptyPacket(t *testing.T) {
+	var b []byte
+	var m channelRequestSuccessMsg
+	if err := Unmarshal(b, &m); err == nil {
+		t.Fatalf("unmarshal of empty slice succeeded")
+	}
+}
+
+func TestUnmarshalUnexpectedPacket(t *testing.T) {
+	type S struct {
+		I uint32 `sshtype:"43"`
+		S string
+		B bool
+	}
+
+	s := S{11, "hello", true}
+	packet := Marshal(s)
+	packet[0] = 42
+	roundtrip := S{}
+	err := Unmarshal(packet, &roundtrip)
+	if err == nil {
+		t.Fatal("expected error, not nil")
+	}
+}
+
+func TestMarshalPtr(t *testing.T) {
+	s := struct {
+		S string
+	}{"hello"}
+
+	m1 := Marshal(s)
+	m2 := Marshal(&s)
+	if !bytes.Equal(m1, m2) {
+		t.Errorf("got %q, want %q for marshaled pointer", m2, m1)
+	}
+}
+
+func TestBareMarshalUnmarshal(t *testing.T) {
+	type S struct {
+		I uint32
+		S string
+		B bool
+	}
+
+	s := S{42, "hello", true}
+	packet := Marshal(s)
+	roundtrip := S{}
+	Unmarshal(packet, &roundtrip)
+
+	if !reflect.DeepEqual(s, roundtrip) {
+		t.Errorf("got %#v, want %#v", roundtrip, s)
+	}
+}
+
+func TestBareMarshal(t *testing.T) {
+	type S2 struct {
+		I uint32
+	}
+	s := S2{42}
+	packet := Marshal(s)
+	i, rest, ok := parseUint32(packet)
+	if len(rest) > 0 || !ok {
+		t.Errorf("parseInt(%q): parse error", packet)
+	}
+	if i != s.I {
+		t.Errorf("got %d, want %d", i, s.I)
+	}
+}
+
+func TestUnmarshalShortKexInitPacket(t *testing.T) {
+	// This used to panic.
+	// Issue 11348
+	packet := []byte{0x14, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0xff, 0xff, 0xff, 0xff}
+	kim := &kexInitMsg{}
+	if err := Unmarshal(packet, kim); err == nil {
+		t.Error("truncated packet unmarshaled without error")
+	}
+}
+
+func TestMarshalMultiTag(t *testing.T) {
+	var res struct {
+		A uint32 `sshtype:"1|2"`
+	}
+
+	good1 := struct {
+		A uint32 `sshtype:"1"`
+	}{
+		1,
+	}
+	good2 := struct {
+		A uint32 `sshtype:"2"`
+	}{
+		1,
+	}
+
+	if e := Unmarshal(Marshal(good1), &res); e != nil {
+		t.Errorf("error unmarshaling multipart tag: %v", e)
+	}
+
+	if e := Unmarshal(Marshal(good2), &res); e != nil {
+		t.Errorf("error unmarshaling multipart tag: %v", e)
+	}
+
+	bad1 := struct {
+		A uint32 `sshtype:"3"`
+	}{
+		1,
+	}
+	if e := Unmarshal(Marshal(bad1), &res); e == nil {
+		t.Errorf("bad struct unmarshaled without error")
+	}
+}
+
+func randomBytes(out []byte, rand *rand.Rand) {
+	for i := 0; i < len(out); i++ {
+		out[i] = byte(rand.Int31())
+	}
+}
+
+func randomNameList(rand *rand.Rand) []string {
+	ret := make([]string, rand.Int31()&15)
+	for i := range ret {
+		s := make([]byte, 1+(rand.Int31()&15))
+		for j := range s {
+			s[j] = 'a' + uint8(rand.Int31()&15)
+		}
+		ret[i] = string(s)
+	}
+	return ret
+}
+
+func randomInt(rand *rand.Rand) *big.Int {
+	return new(big.Int).SetInt64(int64(int32(rand.Uint32())))
+}
+
+func (*kexInitMsg) Generate(rand *rand.Rand, size int) reflect.Value {
+	ki := &kexInitMsg{}
+	randomBytes(ki.Cookie[:], rand)
+	ki.KexAlgos = randomNameList(rand)
+	ki.ServerHostKeyAlgos = randomNameList(rand)
+	ki.CiphersClientServer = randomNameList(rand)
+	ki.CiphersServerClient = randomNameList(rand)
+	ki.MACsClientServer = randomNameList(rand)
+	ki.MACsServerClient = randomNameList(rand)
+	ki.CompressionClientServer = randomNameList(rand)
+	ki.CompressionServerClient = randomNameList(rand)
+	ki.LanguagesClientServer = randomNameList(rand)
+	ki.LanguagesServerClient = randomNameList(rand)
+	if rand.Int31()&1 == 1 {
+		ki.FirstKexFollows = true
+	}
+	return reflect.ValueOf(ki)
+}
+
+func (*kexDHInitMsg) Generate(rand *rand.Rand, size int) reflect.Value {
+	dhi := &kexDHInitMsg{}
+	dhi.X = randomInt(rand)
+	return reflect.ValueOf(dhi)
+}
+
+var (
+	_kexInitMsg   = new(kexInitMsg).Generate(rand.New(rand.NewSource(0)), 10).Elem().Interface()
+	_kexDHInitMsg = new(kexDHInitMsg).Generate(rand.New(rand.NewSource(0)), 10).Elem().Interface()
+
+	_kexInit   = Marshal(_kexInitMsg)
+	_kexDHInit = Marshal(_kexDHInitMsg)
+)
+
+func BenchmarkMarshalKexInitMsg(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Marshal(_kexInitMsg)
+	}
+}
+
+func BenchmarkUnmarshalKexInitMsg(b *testing.B) {
+	m := new(kexInitMsg)
+	for i := 0; i < b.N; i++ {
+		Unmarshal(_kexInit, m)
+	}
+}
+
+func BenchmarkMarshalKexDHInitMsg(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Marshal(_kexDHInitMsg)
+	}
+}
+
+func BenchmarkUnmarshalKexDHInitMsg(b *testing.B) {
+	m := new(kexDHInitMsg)
+	for i := 0; i < b.N; i++ {
+		Unmarshal(_kexDHInit, m)
+	}
+}

vendor/golang.org/x/crypto/ssh/mux.go

@@ -0,0 +1,330 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"log"
+	"sync"
+	"sync/atomic"
+)
+
+// debugMux, if set, causes messages in the connection protocol to be
+// logged.
+const debugMux = false
+
+// chanList is a thread safe channel list.
+type chanList struct {
+	// protects concurrent access to chans
+	sync.Mutex
+
+	// chans are indexed by the local id of the channel, which the
+	// other side should send in the PeersId field.
+	chans []*channel
+
+	// This is a debugging aid: it offsets all IDs by this
+	// amount. This helps distinguish otherwise identical
+	// server/client muxes
+	offset uint32
+}
+
+// Assigns a channel ID to the given channel.
+func (c *chanList) add(ch *channel) uint32 {
+	c.Lock()
+	defer c.Unlock()
+	for i := range c.chans {
+		if c.chans[i] == nil {
+			c.chans[i] = ch
+			return uint32(i) + c.offset
+		}
+	}
+	c.chans = append(c.chans, ch)
+	return uint32(len(c.chans)-1) + c.offset
+}
+
+// getChan returns the channel for the given ID.
+func (c *chanList) getChan(id uint32) *channel {
+	id -= c.offset
+
+	c.Lock()
+	defer c.Unlock()
+	if id < uint32(len(c.chans)) {
+		return c.chans[id]
+	}
+	return nil
+}
+
+func (c *chanList) remove(id uint32) {
+	id -= c.offset
+	c.Lock()
+	if id < uint32(len(c.chans)) {
+		c.chans[id] = nil
+	}
+	c.Unlock()
+}
+
+// dropAll forgets all channels it knows, returning them in a slice.
+func (c *chanList) dropAll() []*channel {
+	c.Lock()
+	defer c.Unlock()
+	var r []*channel
+
+	for _, ch := range c.chans {
+		if ch == nil {
+			continue
+		}
+		r = append(r, ch)
+	}
+	c.chans = nil
+	return r
+}
+
+// mux represents the state for the SSH connection protocol, which
+// multiplexes many channels onto a single packet transport.
+type mux struct {
+	conn     packetConn
+	chanList chanList
+
+	incomingChannels chan NewChannel
+
+	globalSentMu     sync.Mutex
+	globalResponses  chan interface{}
+	incomingRequests chan *Request
+
+	errCond *sync.Cond
+	err     error
+}
+
+// When debugging, each new chanList instantiation has a different
+// offset.
+var globalOff uint32
+
+func (m *mux) Wait() error {
+	m.errCond.L.Lock()
+	defer m.errCond.L.Unlock()
+	for m.err == nil {
+		m.errCond.Wait()
+	}
+	return m.err
+}
+
+// newMux returns a mux that runs over the given connection.
+func newMux(p packetConn) *mux {
+	m := &mux{
+		conn:             p,
+		incomingChannels: make(chan NewChannel, 16),
+		globalResponses:  make(chan interface{}, 1),
+		incomingRequests: make(chan *Request, 16),
+		errCond:          newCond(),
+	}
+	if debugMux {
+		m.chanList.offset = atomic.AddUint32(&globalOff, 1)
+	}
+
+	go m.loop()
+	return m
+}
+
+func (m *mux) sendMessage(msg interface{}) error {
+	p := Marshal(msg)
+	if debugMux {
+		log.Printf("send global(%d): %#v", m.chanList.offset, msg)
+	}
+	return m.conn.writePacket(p)
+}
+
+func (m *mux) SendRequest(name string, wantReply bool, payload []byte) (bool, []byte, error) {
+	if wantReply {
+		m.globalSentMu.Lock()
+		defer m.globalSentMu.Unlock()
+	}
+
+	if err := m.sendMessage(globalRequestMsg{
+		Type:      name,
+		WantReply: wantReply,
+		Data:      payload,
+	}); err != nil {
+		return false, nil, err
+	}
+
+	if !wantReply {
+		return false, nil, nil
+	}
+
+	msg, ok := <-m.globalResponses
+	if !ok {
+		return false, nil, io.EOF
+	}
+	switch msg := msg.(type) {
+	case *globalRequestFailureMsg:
+		return false, msg.Data, nil
+	case *globalRequestSuccessMsg:
+		return true, msg.Data, nil
+	default:
+		return false, nil, fmt.Errorf("ssh: unexpected response to request: %#v", msg)
+	}
+}
+
+// ackRequest must be called after processing a global request that
+// has WantReply set.
+func (m *mux) ackRequest(ok bool, data []byte) error {
+	if ok {
+		return m.sendMessage(globalRequestSuccessMsg{Data: data})
+	}
+	return m.sendMessage(globalRequestFailureMsg{Data: data})
+}
+
+func (m *mux) Close() error {
+	return m.conn.Close()
+}
+
+// loop runs the connection machine. It will process packets until an
+// error is encountered. To synchronize on loop exit, use mux.Wait.
+func (m *mux) loop() {
+	var err error
+	for err == nil {
+		err = m.onePacket()
+	}
+
+	for _, ch := range m.chanList.dropAll() {
+		ch.close()
+	}
+
+	close(m.incomingChannels)
+	close(m.incomingRequests)
+	close(m.globalResponses)
+
+	m.conn.Close()
+
+	m.errCond.L.Lock()
+	m.err = err
+	m.errCond.Broadcast()
+	m.errCond.L.Unlock()
+
+	if debugMux {
+		log.Println("loop exit", err)
+	}
+}
+
+// onePacket reads and processes one packet.
+func (m *mux) onePacket() error {
+	packet, err := m.conn.readPacket()
+	if err != nil {
+		return err
+	}
+
+	if debugMux {
+		if packet[0] == msgChannelData || packet[0] == msgChannelExtendedData {
+			log.Printf("decoding(%d): data packet - %d bytes", m.chanList.offset, len(packet))
+		} else {
+			p, _ := decode(packet)
+			log.Printf("decoding(%d): %d %#v - %d bytes", m.chanList.offset, packet[0], p, len(packet))
+		}
+	}
+
+	switch packet[0] {
+	case msgChannelOpen:
+		return m.handleChannelOpen(packet)
+	case msgGlobalRequest, msgRequestSuccess, msgRequestFailure:
+		return m.handleGlobalPacket(packet)
+	}
+
+	// assume a channel packet.
+	if len(packet) < 5 {
+		return parseError(packet[0])
+	}
+	id := binary.BigEndian.Uint32(packet[1:])
+	ch := m.chanList.getChan(id)
+	if ch == nil {
+		return fmt.Errorf("ssh: invalid channel %d", id)
+	}
+
+	return ch.handlePacket(packet)
+}
+
+func (m *mux) handleGlobalPacket(packet []byte) error {
+	msg, err := decode(packet)
+	if err != nil {
+		return err
+	}
+
+	switch msg := msg.(type) {
+	case *globalRequestMsg:
+		m.incomingRequests <- &Request{
+			Type:      msg.Type,
+			WantReply: msg.WantReply,
+			Payload:   msg.Data,
+			mux:       m,
+		}
+	case *globalRequestSuccessMsg, *globalRequestFailureMsg:
+		m.globalResponses <- msg
+	default:
+		panic(fmt.Sprintf("not a global message %#v", msg))
+	}
+
+	return nil
+}
+
+// handleChannelOpen schedules a channel to be Accept()ed.
+func (m *mux) handleChannelOpen(packet []byte) error {
+	var msg channelOpenMsg
+	if err := Unmarshal(packet, &msg); err != nil {
+		return err
+	}
+
+	if msg.MaxPacketSize < minPacketLength || msg.MaxPacketSize > 1<<31 {
+		failMsg := channelOpenFailureMsg{
+			PeersId:  msg.PeersId,
+			Reason:   ConnectionFailed,
+			Message:  "invalid request",
+			Language: "en_US.UTF-8",
+		}
+		return m.sendMessage(failMsg)
+	}
+
+	c := m.newChannel(msg.ChanType, channelInbound, msg.TypeSpecificData)
+	c.remoteId = msg.PeersId
+	c.maxRemotePayload = msg.MaxPacketSize
+	c.remoteWin.add(msg.PeersWindow)
+	m.incomingChannels <- c
+	return nil
+}
+
+func (m *mux) OpenChannel(chanType string, extra []byte) (Channel, <-chan *Request, error) {
+	ch, err := m.openChannel(chanType, extra)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return ch, ch.incomingRequests, nil
+}
+
+func (m *mux) openChannel(chanType string, extra []byte) (*channel, error) {
+	ch := m.newChannel(chanType, channelOutbound, extra)
+
+	ch.maxIncomingPayload = channelMaxPacket
+
+	open := channelOpenMsg{
+		ChanType:         chanType,
+		PeersWindow:      ch.myWindow,
+		MaxPacketSize:    ch.maxIncomingPayload,
+		TypeSpecificData: extra,
+		PeersId:          ch.localId,
+	}
+	if err := m.sendMessage(open); err != nil {
+		return nil, err
+	}
+
+	switch msg := (<-ch.msg).(type) {
+	case *channelOpenConfirmMsg:
+		return ch, nil
+	case *channelOpenFailureMsg:
+		return nil, &OpenChannelError{msg.Reason, msg.Message}
+	default:
+		return nil, fmt.Errorf("ssh: unexpected packet in response to channel open: %T", msg)
+	}
+}

vendor/golang.org/x/crypto/ssh/mux_test.go

@@ -0,0 +1,502 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"io"
+	"io/ioutil"
+	"sync"
+	"testing"
+)
+
+func muxPair() (*mux, *mux) {
+	a, b := memPipe()
+
+	s := newMux(a)
+	c := newMux(b)
+
+	return s, c
+}
+
+// Returns both ends of a channel, and the mux for the the 2nd
+// channel.
+func channelPair(t *testing.T) (*channel, *channel, *mux) {
+	c, s := muxPair()
+
+	res := make(chan *channel, 1)
+	go func() {
+		newCh, ok := <-s.incomingChannels
+		if !ok {
+			t.Fatalf("No incoming channel")
+		}
+		if newCh.ChannelType() != "chan" {
+			t.Fatalf("got type %q want chan", newCh.ChannelType())
+		}
+		ch, _, err := newCh.Accept()
+		if err != nil {
+			t.Fatalf("Accept %v", err)
+		}
+		res <- ch.(*channel)
+	}()
+
+	ch, err := c.openChannel("chan", nil)
+	if err != nil {
+		t.Fatalf("OpenChannel: %v", err)
+	}
+
+	return <-res, ch, c
+}
+
+// Test that stderr and stdout can be addressed from different
+// goroutines. This is intended for use with the race detector.
+func TestMuxChannelExtendedThreadSafety(t *testing.T) {
+	writer, reader, mux := channelPair(t)
+	defer writer.Close()
+	defer reader.Close()
+	defer mux.Close()
+
+	var wr, rd sync.WaitGroup
+	magic := "hello world"
+
+	wr.Add(2)
+	go func() {
+		io.WriteString(writer, magic)
+		wr.Done()
+	}()
+	go func() {
+		io.WriteString(writer.Stderr(), magic)
+		wr.Done()
+	}()
+
+	rd.Add(2)
+	go func() {
+		c, err := ioutil.ReadAll(reader)
+		if string(c) != magic {
+			t.Fatalf("stdout read got %q, want %q (error %s)", c, magic, err)
+		}
+		rd.Done()
+	}()
+	go func() {
+		c, err := ioutil.ReadAll(reader.Stderr())
+		if string(c) != magic {
+			t.Fatalf("stderr read got %q, want %q (error %s)", c, magic, err)
+		}
+		rd.Done()
+	}()
+
+	wr.Wait()
+	writer.CloseWrite()
+	rd.Wait()
+}
+
+func TestMuxReadWrite(t *testing.T) {
+	s, c, mux := channelPair(t)
+	defer s.Close()
+	defer c.Close()
+	defer mux.Close()
+
+	magic := "hello world"
+	magicExt := "hello stderr"
+	go func() {
+		_, err := s.Write([]byte(magic))
+		if err != nil {
+			t.Fatalf("Write: %v", err)
+		}
+		_, err = s.Extended(1).Write([]byte(magicExt))
+		if err != nil {
+			t.Fatalf("Write: %v", err)
+		}
+		err = s.Close()
+		if err != nil {
+			t.Fatalf("Close: %v", err)
+		}
+	}()
+
+	var buf [1024]byte
+	n, err := c.Read(buf[:])
+	if err != nil {
+		t.Fatalf("server Read: %v", err)
+	}
+	got := string(buf[:n])
+	if got != magic {
+		t.Fatalf("server: got %q want %q", got, magic)
+	}
+
+	n, err = c.Extended(1).Read(buf[:])
+	if err != nil {
+		t.Fatalf("server Read: %v", err)
+	}
+
+	got = string(buf[:n])
+	if got != magicExt {
+		t.Fatalf("server: got %q want %q", got, magic)
+	}
+}
+
+func TestMuxChannelOverflow(t *testing.T) {
+	reader, writer, mux := channelPair(t)
+	defer reader.Close()
+	defer writer.Close()
+	defer mux.Close()
+
+	wDone := make(chan int, 1)
+	go func() {
+		if _, err := writer.Write(make([]byte, channelWindowSize)); err != nil {
+			t.Errorf("could not fill window: %v", err)
+		}
+		writer.Write(make([]byte, 1))
+		wDone <- 1
+	}()
+	writer.remoteWin.waitWriterBlocked()
+
+	// Send 1 byte.
+	packet := make([]byte, 1+4+4+1)
+	packet[0] = msgChannelData
+	marshalUint32(packet[1:], writer.remoteId)
+	marshalUint32(packet[5:], uint32(1))
+	packet[9] = 42
+
+	if err := writer.mux.conn.writePacket(packet); err != nil {
+		t.Errorf("could not send packet")
+	}
+	if _, err := reader.SendRequest("hello", true, nil); err == nil {
+		t.Errorf("SendRequest succeeded.")
+	}
+	<-wDone
+}
+
+func TestMuxChannelCloseWriteUnblock(t *testing.T) {
+	reader, writer, mux := channelPair(t)
+	defer reader.Close()
+	defer writer.Close()
+	defer mux.Close()
+
+	wDone := make(chan int, 1)
+	go func() {
+		if _, err := writer.Write(make([]byte, channelWindowSize)); err != nil {
+			t.Errorf("could not fill window: %v", err)
+		}
+		if _, err := writer.Write(make([]byte, 1)); err != io.EOF {
+			t.Errorf("got %v, want EOF for unblock write", err)
+		}
+		wDone <- 1
+	}()
+
+	writer.remoteWin.waitWriterBlocked()
+	reader.Close()
+	<-wDone
+}
+
+func TestMuxConnectionCloseWriteUnblock(t *testing.T) {
+	reader, writer, mux := channelPair(t)
+	defer reader.Close()
+	defer writer.Close()
+	defer mux.Close()
+
+	wDone := make(chan int, 1)
+	go func() {
+		if _, err := writer.Write(make([]byte, channelWindowSize)); err != nil {
+			t.Errorf("could not fill window: %v", err)
+		}
+		if _, err := writer.Write(make([]byte, 1)); err != io.EOF {
+			t.Errorf("got %v, want EOF for unblock write", err)
+		}
+		wDone <- 1
+	}()
+
+	writer.remoteWin.waitWriterBlocked()
+	mux.Close()
+	<-wDone
+}
+
+func TestMuxReject(t *testing.T) {
+	client, server := muxPair()
+	defer server.Close()
+	defer client.Close()
+
+	go func() {
+		ch, ok := <-server.incomingChannels
+		if !ok {
+			t.Fatalf("Accept")
+		}
+		if ch.ChannelType() != "ch" || string(ch.ExtraData()) != "extra" {
+			t.Fatalf("unexpected channel: %q, %q", ch.ChannelType(), ch.ExtraData())
+		}
+		ch.Reject(RejectionReason(42), "message")
+	}()
+
+	ch, err := client.openChannel("ch", []byte("extra"))
+	if ch != nil {
+		t.Fatal("openChannel not rejected")
+	}
+
+	ocf, ok := err.(*OpenChannelError)
+	if !ok {
+		t.Errorf("got %#v want *OpenChannelError", err)
+	} else if ocf.Reason != 42 || ocf.Message != "message" {
+		t.Errorf("got %#v, want {Reason: 42, Message: %q}", ocf, "message")
+	}
+
+	want := "ssh: rejected: unknown reason 42 (message)"
+	if err.Error() != want {
+		t.Errorf("got %q, want %q", err.Error(), want)
+	}
+}
+
+func TestMuxChannelRequest(t *testing.T) {
+	client, server, mux := channelPair(t)
+	defer server.Close()
+	defer client.Close()
+	defer mux.Close()
+
+	var received int
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		for r := range server.incomingRequests {
+			received++
+			r.Reply(r.Type == "yes", nil)
+		}
+		wg.Done()
+	}()
+	_, err := client.SendRequest("yes", false, nil)
+	if err != nil {
+		t.Fatalf("SendRequest: %v", err)
+	}
+	ok, err := client.SendRequest("yes", true, nil)
+	if err != nil {
+		t.Fatalf("SendRequest: %v", err)
+	}
+
+	if !ok {
+		t.Errorf("SendRequest(yes): %v", ok)
+
+	}
+
+	ok, err = client.SendRequest("no", true, nil)
+	if err != nil {
+		t.Fatalf("SendRequest: %v", err)
+	}
+	if ok {
+		t.Errorf("SendRequest(no): %v", ok)
+
+	}
+
+	client.Close()
+	wg.Wait()
+
+	if received != 3 {
+		t.Errorf("got %d requests, want %d", received, 3)
+	}
+}
+
+func TestMuxGlobalRequest(t *testing.T) {
+	clientMux, serverMux := muxPair()
+	defer serverMux.Close()
+	defer clientMux.Close()
+
+	var seen bool
+	go func() {
+		for r := range serverMux.incomingRequests {
+			seen = seen || r.Type == "peek"
+			if r.WantReply {
+				err := r.Reply(r.Type == "yes",
+					append([]byte(r.Type), r.Payload...))
+				if err != nil {
+					t.Errorf("AckRequest: %v", err)
+				}
+			}
+		}
+	}()
+
+	_, _, err := clientMux.SendRequest("peek", false, nil)
+	if err != nil {
+		t.Errorf("SendRequest: %v", err)
+	}
+
+	ok, data, err := clientMux.SendRequest("yes", true, []byte("a"))
+	if !ok || string(data) != "yesa" || err != nil {
+		t.Errorf("SendRequest(\"yes\", true, \"a\"): %v %v %v",
+			ok, data, err)
+	}
+	if ok, data, err := clientMux.SendRequest("yes", true, []byte("a")); !ok || string(data) != "yesa" || err != nil {
+		t.Errorf("SendRequest(\"yes\", true, \"a\"): %v %v %v",
+			ok, data, err)
+	}
+
+	if ok, data, err := clientMux.SendRequest("no", true, []byte("a")); ok || string(data) != "noa" || err != nil {
+		t.Errorf("SendRequest(\"no\", true, \"a\"): %v %v %v",
+			ok, data, err)
+	}
+
+	if !seen {
+		t.Errorf("never saw 'peek' request")
+	}
+}
+
+func TestMuxGlobalRequestUnblock(t *testing.T) {
+	clientMux, serverMux := muxPair()
+	defer serverMux.Close()
+	defer clientMux.Close()
+
+	result := make(chan error, 1)
+	go func() {
+		_, _, err := clientMux.SendRequest("hello", true, nil)
+		result <- err
+	}()
+
+	<-serverMux.incomingRequests
+	serverMux.conn.Close()
+	err := <-result
+
+	if err != io.EOF {
+		t.Errorf("want EOF, got %v", io.EOF)
+	}
+}
+
+func TestMuxChannelRequestUnblock(t *testing.T) {
+	a, b, connB := channelPair(t)
+	defer a.Close()
+	defer b.Close()
+	defer connB.Close()
+
+	result := make(chan error, 1)
+	go func() {
+		_, err := a.SendRequest("hello", true, nil)
+		result <- err
+	}()
+
+	<-b.incomingRequests
+	connB.conn.Close()
+	err := <-result
+
+	if err != io.EOF {
+		t.Errorf("want EOF, got %v", err)
+	}
+}
+
+func TestMuxCloseChannel(t *testing.T) {
+	r, w, mux := channelPair(t)
+	defer mux.Close()
+	defer r.Close()
+	defer w.Close()
+
+	result := make(chan error, 1)
+	go func() {
+		var b [1024]byte
+		_, err := r.Read(b[:])
+		result <- err
+	}()
+	if err := w.Close(); err != nil {
+		t.Errorf("w.Close: %v", err)
+	}
+
+	if _, err := w.Write([]byte("hello")); err != io.EOF {
+		t.Errorf("got err %v, want io.EOF after Close", err)
+	}
+
+	if err := <-result; err != io.EOF {
+		t.Errorf("got %v (%T), want io.EOF", err, err)
+	}
+}
+
+func TestMuxCloseWriteChannel(t *testing.T) {
+	r, w, mux := channelPair(t)
+	defer mux.Close()
+
+	result := make(chan error, 1)
+	go func() {
+		var b [1024]byte
+		_, err := r.Read(b[:])
+		result <- err
+	}()
+	if err := w.CloseWrite(); err != nil {
+		t.Errorf("w.CloseWrite: %v", err)
+	}
+
+	if _, err := w.Write([]byte("hello")); err != io.EOF {
+		t.Errorf("got err %v, want io.EOF after CloseWrite", err)
+	}
+
+	if err := <-result; err != io.EOF {
+		t.Errorf("got %v (%T), want io.EOF", err, err)
+	}
+}
+
+func TestMuxInvalidRecord(t *testing.T) {
+	a, b := muxPair()
+	defer a.Close()
+	defer b.Close()
+
+	packet := make([]byte, 1+4+4+1)
+	packet[0] = msgChannelData
+	marshalUint32(packet[1:], 29348723 /* invalid channel id */)
+	marshalUint32(packet[5:], 1)
+	packet[9] = 42
+
+	a.conn.writePacket(packet)
+	go a.SendRequest("hello", false, nil)
+	// 'a' wrote an invalid packet, so 'b' has exited.
+	req, ok := <-b.incomingRequests
+	if ok {
+		t.Errorf("got request %#v after receiving invalid packet", req)
+	}
+}
+
+func TestZeroWindowAdjust(t *testing.T) {
+	a, b, mux := channelPair(t)
+	defer a.Close()
+	defer b.Close()
+	defer mux.Close()
+
+	go func() {
+		io.WriteString(a, "hello")
+		// bogus adjust.
+		a.sendMessage(windowAdjustMsg{})
+		io.WriteString(a, "world")
+		a.Close()
+	}()
+
+	want := "helloworld"
+	c, _ := ioutil.ReadAll(b)
+	if string(c) != want {
+		t.Errorf("got %q want %q", c, want)
+	}
+}
+
+func TestMuxMaxPacketSize(t *testing.T) {
+	a, b, mux := channelPair(t)
+	defer a.Close()
+	defer b.Close()
+	defer mux.Close()
+
+	large := make([]byte, a.maxRemotePayload+1)
+	packet := make([]byte, 1+4+4+1+len(large))
+	packet[0] = msgChannelData
+	marshalUint32(packet[1:], a.remoteId)
+	marshalUint32(packet[5:], uint32(len(large)))
+	packet[9] = 42
+
+	if err := a.mux.conn.writePacket(packet); err != nil {
+		t.Errorf("could not send packet")
+	}
+
+	go a.SendRequest("hello", false, nil)
+
+	_, ok := <-b.incomingRequests
+	if ok {
+		t.Errorf("connection still alive after receiving large packet.")
+	}
+}
+
+// Don't ship code with debug=true.
+func TestDebug(t *testing.T) {
+	if debugMux {
+		t.Error("mux debug switched on")
+	}
+	if debugHandshake {
+		t.Error("handshake debug switched on")
+	}
+}

vendor/golang.org/x/crypto/ssh/server.go

@@ -0,0 +1,488 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+)
+
+// The Permissions type holds fine-grained permissions that are
+// specific to a user or a specific authentication method for a
+// user. Permissions, except for "source-address", must be enforced in
+// the server application layer, after successful authentication. The
+// Permissions are passed on in ServerConn so a server implementation
+// can honor them.
+type Permissions struct {
+	// Critical options restrict default permissions. Common
+	// restrictions are "source-address" and "force-command". If
+	// the server cannot enforce the restriction, or does not
+	// recognize it, the user should not authenticate.
+	CriticalOptions map[string]string
+
+	// Extensions are extra functionality that the server may
+	// offer on authenticated connections. Common extensions are
+	// "permit-agent-forwarding", "permit-X11-forwarding". Lack of
+	// support for an extension does not preclude authenticating a
+	// user.
+	Extensions map[string]string
+}
+
+// ServerConfig holds server specific configuration data.
+type ServerConfig struct {
+	// Config contains configuration shared between client and server.
+	Config
+
+	hostKeys []Signer
+
+	// NoClientAuth is true if clients are allowed to connect without
+	// authenticating.
+	NoClientAuth bool
+
+	// PasswordCallback, if non-nil, is called when a user
+	// attempts to authenticate using a password.
+	PasswordCallback func(conn ConnMetadata, password []byte) (*Permissions, error)
+
+	// PublicKeyCallback, if non-nil, is called when a client attempts public
+	// key authentication. It must return true if the given public key is
+	// valid for the given user. For example, see CertChecker.Authenticate.
+	PublicKeyCallback func(conn ConnMetadata, key PublicKey) (*Permissions, error)
+
+	// KeyboardInteractiveCallback, if non-nil, is called when
+	// keyboard-interactive authentication is selected (RFC
+	// 4256). The client object's Challenge function should be
+	// used to query the user. The callback may offer multiple
+	// Challenge rounds. To avoid information leaks, the client
+	// should be presented a challenge even if the user is
+	// unknown.
+	KeyboardInteractiveCallback func(conn ConnMetadata, client KeyboardInteractiveChallenge) (*Permissions, error)
+
+	// AuthLogCallback, if non-nil, is called to log all authentication
+	// attempts.
+	AuthLogCallback func(conn ConnMetadata, method string, err error)
+
+	// ServerVersion is the version identification string to announce in
+	// the public handshake.
+	// If empty, a reasonable default is used.
+	// Note that RFC 4253 section 4.2 requires that this string start with
+	// "SSH-2.0-".
+	ServerVersion string
+}
+
+// AddHostKey adds a private key as a host key. If an existing host
+// key exists with the same algorithm, it is overwritten. Each server
+// config must have at least one host key.
+func (s *ServerConfig) AddHostKey(key Signer) {
+	for i, k := range s.hostKeys {
+		if k.PublicKey().Type() == key.PublicKey().Type() {
+			s.hostKeys[i] = key
+			return
+		}
+	}
+
+	s.hostKeys = append(s.hostKeys, key)
+}
+
+// cachedPubKey contains the results of querying whether a public key is
+// acceptable for a user.
+type cachedPubKey struct {
+	user       string
+	pubKeyData []byte
+	result     error
+	perms      *Permissions
+}
+
+const maxCachedPubKeys = 16
+
+// pubKeyCache caches tests for public keys.  Since SSH clients
+// will query whether a public key is acceptable before attempting to
+// authenticate with it, we end up with duplicate queries for public
+// key validity.  The cache only applies to a single ServerConn.
+type pubKeyCache struct {
+	keys []cachedPubKey
+}
+
+// get returns the result for a given user/algo/key tuple.
+func (c *pubKeyCache) get(user string, pubKeyData []byte) (cachedPubKey, bool) {
+	for _, k := range c.keys {
+		if k.user == user && bytes.Equal(k.pubKeyData, pubKeyData) {
+			return k, true
+		}
+	}
+	return cachedPubKey{}, false
+}
+
+// add adds the given tuple to the cache.
+func (c *pubKeyCache) add(candidate cachedPubKey) {
+	if len(c.keys) < maxCachedPubKeys {
+		c.keys = append(c.keys, candidate)
+	}
+}
+
+// ServerConn is an authenticated SSH connection, as seen from the
+// server
+type ServerConn struct {
+	Conn
+
+	// If the succeeding authentication callback returned a
+	// non-nil Permissions pointer, it is stored here.
+	Permissions *Permissions
+}
+
+// NewServerConn starts a new SSH server with c as the underlying
+// transport.  It starts with a handshake and, if the handshake is
+// unsuccessful, it closes the connection and returns an error.  The
+// Request and NewChannel channels must be serviced, or the connection
+// will hang.
+func NewServerConn(c net.Conn, config *ServerConfig) (*ServerConn, <-chan NewChannel, <-chan *Request, error) {
+	fullConf := *config
+	fullConf.SetDefaults()
+	s := &connection{
+		sshConn: sshConn{conn: c},
+	}
+	perms, err := s.serverHandshake(&fullConf)
+	if err != nil {
+		c.Close()
+		return nil, nil, nil, err
+	}
+	return &ServerConn{s, perms}, s.mux.incomingChannels, s.mux.incomingRequests, nil
+}
+
+// signAndMarshal signs the data with the appropriate algorithm,
+// and serializes the result in SSH wire format.
+func signAndMarshal(k Signer, rand io.Reader, data []byte) ([]byte, error) {
+	sig, err := k.Sign(rand, data)
+	if err != nil {
+		return nil, err
+	}
+
+	return Marshal(sig), nil
+}
+
+// handshake performs key exchange and user authentication.
+func (s *connection) serverHandshake(config *ServerConfig) (*Permissions, error) {
+	if len(config.hostKeys) == 0 {
+		return nil, errors.New("ssh: server has no host keys")
+	}
+
+	if !config.NoClientAuth && config.PasswordCallback == nil && config.PublicKeyCallback == nil && config.KeyboardInteractiveCallback == nil {
+		return nil, errors.New("ssh: no authentication methods configured but NoClientAuth is also false")
+	}
+
+	if config.ServerVersion != "" {
+		s.serverVersion = []byte(config.ServerVersion)
+	} else {
+		s.serverVersion = []byte(packageVersion)
+	}
+	var err error
+	s.clientVersion, err = exchangeVersions(s.sshConn.conn, s.serverVersion)
+	if err != nil {
+		return nil, err
+	}
+
+	tr := newTransport(s.sshConn.conn, config.Rand, false /* not client */)
+	s.transport = newServerTransport(tr, s.clientVersion, s.serverVersion, config)
+
+	if err := s.transport.requestInitialKeyChange(); err != nil {
+		return nil, err
+	}
+
+	// We just did the key change, so the session ID is established.
+	s.sessionID = s.transport.getSessionID()
+
+	var packet []byte
+	if packet, err = s.transport.readPacket(); err != nil {
+		return nil, err
+	}
+
+	var serviceRequest serviceRequestMsg
+	if err = Unmarshal(packet, &serviceRequest); err != nil {
+		return nil, err
+	}
+	if serviceRequest.Service != serviceUserAuth {
+		return nil, errors.New("ssh: requested service '" + serviceRequest.Service + "' before authenticating")
+	}
+	serviceAccept := serviceAcceptMsg{
+		Service: serviceUserAuth,
+	}
+	if err := s.transport.writePacket(Marshal(&serviceAccept)); err != nil {
+		return nil, err
+	}
+
+	perms, err := s.serverAuthenticate(config)
+	if err != nil {
+		return nil, err
+	}
+	s.mux = newMux(s.transport)
+	return perms, err
+}
+
+func isAcceptableAlgo(algo string) bool {
+	switch algo {
+	case KeyAlgoRSA, KeyAlgoDSA, KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521, KeyAlgoED25519,
+		CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01:
+		return true
+	}
+	return false
+}
+
+func checkSourceAddress(addr net.Addr, sourceAddr string) error {
+	if addr == nil {
+		return errors.New("ssh: no address known for client, but source-address match required")
+	}
+
+	tcpAddr, ok := addr.(*net.TCPAddr)
+	if !ok {
+		return fmt.Errorf("ssh: remote address %v is not an TCP address when checking source-address match", addr)
+	}
+
+	if allowedIP := net.ParseIP(sourceAddr); allowedIP != nil {
+		if bytes.Equal(allowedIP, tcpAddr.IP) {
+			return nil
+		}
+	} else {
+		_, ipNet, err := net.ParseCIDR(sourceAddr)
+		if err != nil {
+			return fmt.Errorf("ssh: error parsing source-address restriction %q: %v", sourceAddr, err)
+		}
+
+		if ipNet.Contains(tcpAddr.IP) {
+			return nil
+		}
+	}
+
+	return fmt.Errorf("ssh: remote address %v is not allowed because of source-address restriction", addr)
+}
+
+func (s *connection) serverAuthenticate(config *ServerConfig) (*Permissions, error) {
+	var err error
+	var cache pubKeyCache
+	var perms *Permissions
+
+userAuthLoop:
+	for {
+		var userAuthReq userAuthRequestMsg
+		if packet, err := s.transport.readPacket(); err != nil {
+			return nil, err
+		} else if err = Unmarshal(packet, &userAuthReq); err != nil {
+			return nil, err
+		}
+
+		if userAuthReq.Service != serviceSSH {
+			return nil, errors.New("ssh: client attempted to negotiate for unknown service: " + userAuthReq.Service)
+		}
+
+		s.user = userAuthReq.User
+		perms = nil
+		authErr := errors.New("no auth passed yet")
+
+		switch userAuthReq.Method {
+		case "none":
+			if config.NoClientAuth {
+				authErr = nil
+			}
+		case "password":
+			if config.PasswordCallback == nil {
+				authErr = errors.New("ssh: password auth not configured")
+				break
+			}
+			payload := userAuthReq.Payload
+			if len(payload) < 1 || payload[0] != 0 {
+				return nil, parseError(msgUserAuthRequest)
+			}
+			payload = payload[1:]
+			password, payload, ok := parseString(payload)
+			if !ok || len(payload) > 0 {
+				return nil, parseError(msgUserAuthRequest)
+			}
+
+			perms, authErr = config.PasswordCallback(s, password)
+		case "keyboard-interactive":
+			if config.KeyboardInteractiveCallback == nil {
+				authErr = errors.New("ssh: keyboard-interactive auth not configubred")
+				break
+			}
+
+			prompter := &sshClientKeyboardInteractive{s}
+			perms, authErr = config.KeyboardInteractiveCallback(s, prompter.Challenge)
+		case "publickey":
+			if config.PublicKeyCallback == nil {
+				authErr = errors.New("ssh: publickey auth not configured")
+				break
+			}
+			payload := userAuthReq.Payload
+			if len(payload) < 1 {
+				return nil, parseError(msgUserAuthRequest)
+			}
+			isQuery := payload[0] == 0
+			payload = payload[1:]
+			algoBytes, payload, ok := parseString(payload)
+			if !ok {
+				return nil, parseError(msgUserAuthRequest)
+			}
+			algo := string(algoBytes)
+			if !isAcceptableAlgo(algo) {
+				authErr = fmt.Errorf("ssh: algorithm %q not accepted", algo)
+				break
+			}
+
+			pubKeyData, payload, ok := parseString(payload)
+			if !ok {
+				return nil, parseError(msgUserAuthRequest)
+			}
+
+			pubKey, err := ParsePublicKey(pubKeyData)
+			if err != nil {
+				return nil, err
+			}
+
+			candidate, ok := cache.get(s.user, pubKeyData)
+			if !ok {
+				candidate.user = s.user
+				candidate.pubKeyData = pubKeyData
+				candidate.perms, candidate.result = config.PublicKeyCallback(s, pubKey)
+				if candidate.result == nil && candidate.perms != nil && candidate.perms.CriticalOptions != nil && candidate.perms.CriticalOptions[sourceAddressCriticalOption] != "" {
+					candidate.result = checkSourceAddress(
+						s.RemoteAddr(),
+						candidate.perms.CriticalOptions[sourceAddressCriticalOption])
+				}
+				cache.add(candidate)
+			}
+
+			if isQuery {
+				// The client can query if the given public key
+				// would be okay.
+				if len(payload) > 0 {
+					return nil, parseError(msgUserAuthRequest)
+				}
+
+				if candidate.result == nil {
+					okMsg := userAuthPubKeyOkMsg{
+						Algo:   algo,
+						PubKey: pubKeyData,
+					}
+					if err = s.transport.writePacket(Marshal(&okMsg)); err != nil {
+						return nil, err
+					}
+					continue userAuthLoop
+				}
+				authErr = candidate.result
+			} else {
+				sig, payload, ok := parseSignature(payload)
+				if !ok || len(payload) > 0 {
+					return nil, parseError(msgUserAuthRequest)
+				}
+				// Ensure the public key algo and signature algo
+				// are supported.  Compare the private key
+				// algorithm name that corresponds to algo with
+				// sig.Format.  This is usually the same, but
+				// for certs, the names differ.
+				if !isAcceptableAlgo(sig.Format) {
+					break
+				}
+				signedData := buildDataSignedForAuth(s.transport.getSessionID(), userAuthReq, algoBytes, pubKeyData)
+
+				if err := pubKey.Verify(signedData, sig); err != nil {
+					return nil, err
+				}
+
+				authErr = candidate.result
+				perms = candidate.perms
+			}
+		default:
+			authErr = fmt.Errorf("ssh: unknown method %q", userAuthReq.Method)
+		}
+
+		if config.AuthLogCallback != nil {
+			config.AuthLogCallback(s, userAuthReq.Method, authErr)
+		}
+
+		if authErr == nil {
+			break userAuthLoop
+		}
+
+		var failureMsg userAuthFailureMsg
+		if config.PasswordCallback != nil {
+			failureMsg.Methods = append(failureMsg.Methods, "password")
+		}
+		if config.PublicKeyCallback != nil {
+			failureMsg.Methods = append(failureMsg.Methods, "publickey")
+		}
+		if config.KeyboardInteractiveCallback != nil {
+			failureMsg.Methods = append(failureMsg.Methods, "keyboard-interactive")
+		}
+
+		if len(failureMsg.Methods) == 0 {
+			return nil, errors.New("ssh: no authentication methods configured but NoClientAuth is also false")
+		}
+
+		if err = s.transport.writePacket(Marshal(&failureMsg)); err != nil {
+			return nil, err
+		}
+	}
+
+	if err = s.transport.writePacket([]byte{msgUserAuthSuccess}); err != nil {
+		return nil, err
+	}
+	return perms, nil
+}
+
+// sshClientKeyboardInteractive implements a ClientKeyboardInteractive by
+// asking the client on the other side of a ServerConn.
+type sshClientKeyboardInteractive struct {
+	*connection
+}
+
+func (c *sshClientKeyboardInteractive) Challenge(user, instruction string, questions []string, echos []bool) (answers []string, err error) {
+	if len(questions) != len(echos) {
+		return nil, errors.New("ssh: echos and questions must have equal length")
+	}
+
+	var prompts []byte
+	for i := range questions {
+		prompts = appendString(prompts, questions[i])
+		prompts = appendBool(prompts, echos[i])
+	}
+
+	if err := c.transport.writePacket(Marshal(&userAuthInfoRequestMsg{
+		Instruction: instruction,
+		NumPrompts:  uint32(len(questions)),
+		Prompts:     prompts,
+	})); err != nil {
+		return nil, err
+	}
+
+	packet, err := c.transport.readPacket()
+	if err != nil {
+		return nil, err
+	}
+	if packet[0] != msgUserAuthInfoResponse {
+		return nil, unexpectedMessageError(msgUserAuthInfoResponse, packet[0])
+	}
+	packet = packet[1:]
+
+	n, packet, ok := parseUint32(packet)
+	if !ok || int(n) != len(questions) {
+		return nil, parseError(msgUserAuthInfoResponse)
+	}
+
+	for i := uint32(0); i < n; i++ {
+		ans, rest, ok := parseString(packet)
+		if !ok {
+			return nil, parseError(msgUserAuthInfoResponse)
+		}
+
+		answers = append(answers, string(ans))
+		packet = rest
+	}
+	if len(packet) != 0 {
+		return nil, errors.New("ssh: junk at end of message")
+	}
+
+	return answers, nil
+}

vendor/golang.org/x/crypto/ssh/session.go

@@ -0,0 +1,627 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+// Session implements an interactive session described in
+// "RFC 4254, section 6".
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"sync"
+)
+
+type Signal string
+
+// POSIX signals as listed in RFC 4254 Section 6.10.
+const (
+	SIGABRT Signal = "ABRT"
+	SIGALRM Signal = "ALRM"
+	SIGFPE  Signal = "FPE"
+	SIGHUP  Signal = "HUP"
+	SIGILL  Signal = "ILL"
+	SIGINT  Signal = "INT"
+	SIGKILL Signal = "KILL"
+	SIGPIPE Signal = "PIPE"
+	SIGQUIT Signal = "QUIT"
+	SIGSEGV Signal = "SEGV"
+	SIGTERM Signal = "TERM"
+	SIGUSR1 Signal = "USR1"
+	SIGUSR2 Signal = "USR2"
+)
+
+var signals = map[Signal]int{
+	SIGABRT: 6,
+	SIGALRM: 14,
+	SIGFPE:  8,
+	SIGHUP:  1,
+	SIGILL:  4,
+	SIGINT:  2,
+	SIGKILL: 9,
+	SIGPIPE: 13,
+	SIGQUIT: 3,
+	SIGSEGV: 11,
+	SIGTERM: 15,
+}
+
+type TerminalModes map[uint8]uint32
+
+// POSIX terminal mode flags as listed in RFC 4254 Section 8.
+const (
+	tty_OP_END    = 0
+	VINTR         = 1
+	VQUIT         = 2
+	VERASE        = 3
+	VKILL         = 4
+	VEOF          = 5
+	VEOL          = 6
+	VEOL2         = 7
+	VSTART        = 8
+	VSTOP         = 9
+	VSUSP         = 10
+	VDSUSP        = 11
+	VREPRINT      = 12
+	VWERASE       = 13
+	VLNEXT        = 14
+	VFLUSH        = 15
+	VSWTCH        = 16
+	VSTATUS       = 17
+	VDISCARD      = 18
+	IGNPAR        = 30
+	PARMRK        = 31
+	INPCK         = 32
+	ISTRIP        = 33
+	INLCR         = 34
+	IGNCR         = 35
+	ICRNL         = 36
+	IUCLC         = 37
+	IXON          = 38
+	IXANY         = 39
+	IXOFF         = 40
+	IMAXBEL       = 41
+	ISIG          = 50
+	ICANON        = 51
+	XCASE         = 52
+	ECHO          = 53
+	ECHOE         = 54
+	ECHOK         = 55
+	ECHONL        = 56
+	NOFLSH        = 57
+	TOSTOP        = 58
+	IEXTEN        = 59
+	ECHOCTL       = 60
+	ECHOKE        = 61
+	PENDIN        = 62
+	OPOST         = 70
+	OLCUC         = 71
+	ONLCR         = 72
+	OCRNL         = 73
+	ONOCR         = 74
+	ONLRET        = 75
+	CS7           = 90
+	CS8           = 91
+	PARENB        = 92
+	PARODD        = 93
+	TTY_OP_ISPEED = 128
+	TTY_OP_OSPEED = 129
+)
+
+// A Session represents a connection to a remote command or shell.
+type Session struct {
+	// Stdin specifies the remote process's standard input.
+	// If Stdin is nil, the remote process reads from an empty
+	// bytes.Buffer.
+	Stdin io.Reader
+
+	// Stdout and Stderr specify the remote process's standard
+	// output and error.
+	//
+	// If either is nil, Run connects the corresponding file
+	// descriptor to an instance of ioutil.Discard. There is a
+	// fixed amount of buffering that is shared for the two streams.
+	// If either blocks it may eventually cause the remote
+	// command to block.
+	Stdout io.Writer
+	Stderr io.Writer
+
+	ch        Channel // the channel backing this session
+	started   bool    // true once Start, Run or Shell is invoked.
+	copyFuncs []func() error
+	errors    chan error // one send per copyFunc
+
+	// true if pipe method is active
+	stdinpipe, stdoutpipe, stderrpipe bool
+
+	// stdinPipeWriter is non-nil if StdinPipe has not been called
+	// and Stdin was specified by the user; it is the write end of
+	// a pipe connecting Session.Stdin to the stdin channel.
+	stdinPipeWriter io.WriteCloser
+
+	exitStatus chan error
+}
+
+// SendRequest sends an out-of-band channel request on the SSH channel
+// underlying the session.
+func (s *Session) SendRequest(name string, wantReply bool, payload []byte) (bool, error) {
+	return s.ch.SendRequest(name, wantReply, payload)
+}
+
+func (s *Session) Close() error {
+	return s.ch.Close()
+}
+
+// RFC 4254 Section 6.4.
+type setenvRequest struct {
+	Name  string
+	Value string
+}
+
+// Setenv sets an environment variable that will be applied to any
+// command executed by Shell or Run.
+func (s *Session) Setenv(name, value string) error {
+	msg := setenvRequest{
+		Name:  name,
+		Value: value,
+	}
+	ok, err := s.ch.SendRequest("env", true, Marshal(&msg))
+	if err == nil && !ok {
+		err = errors.New("ssh: setenv failed")
+	}
+	return err
+}
+
+// RFC 4254 Section 6.2.
+type ptyRequestMsg struct {
+	Term     string
+	Columns  uint32
+	Rows     uint32
+	Width    uint32
+	Height   uint32
+	Modelist string
+}
+
+// RequestPty requests the association of a pty with the session on the remote host.
+func (s *Session) RequestPty(term string, h, w int, termmodes TerminalModes) error {
+	var tm []byte
+	for k, v := range termmodes {
+		kv := struct {
+			Key byte
+			Val uint32
+		}{k, v}
+
+		tm = append(tm, Marshal(&kv)...)
+	}
+	tm = append(tm, tty_OP_END)
+	req := ptyRequestMsg{
+		Term:     term,
+		Columns:  uint32(w),
+		Rows:     uint32(h),
+		Width:    uint32(w * 8),
+		Height:   uint32(h * 8),
+		Modelist: string(tm),
+	}
+	ok, err := s.ch.SendRequest("pty-req", true, Marshal(&req))
+	if err == nil && !ok {
+		err = errors.New("ssh: pty-req failed")
+	}
+	return err
+}
+
+// RFC 4254 Section 6.5.
+type subsystemRequestMsg struct {
+	Subsystem string
+}
+
+// RequestSubsystem requests the association of a subsystem with the session on the remote host.
+// A subsystem is a predefined command that runs in the background when the ssh session is initiated
+func (s *Session) RequestSubsystem(subsystem string) error {
+	msg := subsystemRequestMsg{
+		Subsystem: subsystem,
+	}
+	ok, err := s.ch.SendRequest("subsystem", true, Marshal(&msg))
+	if err == nil && !ok {
+		err = errors.New("ssh: subsystem request failed")
+	}
+	return err
+}
+
+// RFC 4254 Section 6.9.
+type signalMsg struct {
+	Signal string
+}
+
+// Signal sends the given signal to the remote process.
+// sig is one of the SIG* constants.
+func (s *Session) Signal(sig Signal) error {
+	msg := signalMsg{
+		Signal: string(sig),
+	}
+
+	_, err := s.ch.SendRequest("signal", false, Marshal(&msg))
+	return err
+}
+
+// RFC 4254 Section 6.5.
+type execMsg struct {
+	Command string
+}
+
+// Start runs cmd on the remote host. Typically, the remote
+// server passes cmd to the shell for interpretation.
+// A Session only accepts one call to Run, Start or Shell.
+func (s *Session) Start(cmd string) error {
+	if s.started {
+		return errors.New("ssh: session already started")
+	}
+	req := execMsg{
+		Command: cmd,
+	}
+
+	ok, err := s.ch.SendRequest("exec", true, Marshal(&req))
+	if err == nil && !ok {
+		err = fmt.Errorf("ssh: command %v failed", cmd)
+	}
+	if err != nil {
+		return err
+	}
+	return s.start()
+}
+
+// Run runs cmd on the remote host. Typically, the remote
+// server passes cmd to the shell for interpretation.
+// A Session only accepts one call to Run, Start, Shell, Output,
+// or CombinedOutput.
+//
+// The returned error is nil if the command runs, has no problems
+// copying stdin, stdout, and stderr, and exits with a zero exit
+// status.
+//
+// If the remote server does not send an exit status, an error of type
+// *ExitMissingError is returned. If the command completes
+// unsuccessfully or is interrupted by a signal, the error is of type
+// *ExitError. Other error types may be returned for I/O problems.
+func (s *Session) Run(cmd string) error {
+	err := s.Start(cmd)
+	if err != nil {
+		return err
+	}
+	return s.Wait()
+}
+
+// Output runs cmd on the remote host and returns its standard output.
+func (s *Session) Output(cmd string) ([]byte, error) {
+	if s.Stdout != nil {
+		return nil, errors.New("ssh: Stdout already set")
+	}
+	var b bytes.Buffer
+	s.Stdout = &b
+	err := s.Run(cmd)
+	return b.Bytes(), err
+}
+
+type singleWriter struct {
+	b  bytes.Buffer
+	mu sync.Mutex
+}
+
+func (w *singleWriter) Write(p []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	return w.b.Write(p)
+}
+
+// CombinedOutput runs cmd on the remote host and returns its combined
+// standard output and standard error.
+func (s *Session) CombinedOutput(cmd string) ([]byte, error) {
+	if s.Stdout != nil {
+		return nil, errors.New("ssh: Stdout already set")
+	}
+	if s.Stderr != nil {
+		return nil, errors.New("ssh: Stderr already set")
+	}
+	var b singleWriter
+	s.Stdout = &b
+	s.Stderr = &b
+	err := s.Run(cmd)
+	return b.b.Bytes(), err
+}
+
+// Shell starts a login shell on the remote host. A Session only
+// accepts one call to Run, Start, Shell, Output, or CombinedOutput.
+func (s *Session) Shell() error {
+	if s.started {
+		return errors.New("ssh: session already started")
+	}
+
+	ok, err := s.ch.SendRequest("shell", true, nil)
+	if err == nil && !ok {
+		return errors.New("ssh: could not start shell")
+	}
+	if err != nil {
+		return err
+	}
+	return s.start()
+}
+
+func (s *Session) start() error {
+	s.started = true
+
+	type F func(*Session)
+	for _, setupFd := range []F{(*Session).stdin, (*Session).stdout, (*Session).stderr} {
+		setupFd(s)
+	}
+
+	s.errors = make(chan error, len(s.copyFuncs))
+	for _, fn := range s.copyFuncs {
+		go func(fn func() error) {
+			s.errors <- fn()
+		}(fn)
+	}
+	return nil
+}
+
+// Wait waits for the remote command to exit.
+//
+// The returned error is nil if the command runs, has no problems
+// copying stdin, stdout, and stderr, and exits with a zero exit
+// status.
+//
+// If the remote server does not send an exit status, an error of type
+// *ExitMissingError is returned. If the command completes
+// unsuccessfully or is interrupted by a signal, the error is of type
+// *ExitError. Other error types may be returned for I/O problems.
+func (s *Session) Wait() error {
+	if !s.started {
+		return errors.New("ssh: session not started")
+	}
+	waitErr := <-s.exitStatus
+
+	if s.stdinPipeWriter != nil {
+		s.stdinPipeWriter.Close()
+	}
+	var copyError error
+	for _ = range s.copyFuncs {
+		if err := <-s.errors; err != nil && copyError == nil {
+			copyError = err
+		}
+	}
+	if waitErr != nil {
+		return waitErr
+	}
+	return copyError
+}
+
+func (s *Session) wait(reqs <-chan *Request) error {
+	wm := Waitmsg{status: -1}
+	// Wait for msg channel to be closed before returning.
+	for msg := range reqs {
+		switch msg.Type {
+		case "exit-status":
+			wm.status = int(binary.BigEndian.Uint32(msg.Payload))
+		case "exit-signal":
+			var sigval struct {
+				Signal     string
+				CoreDumped bool
+				Error      string
+				Lang       string
+			}
+			if err := Unmarshal(msg.Payload, &sigval); err != nil {
+				return err
+			}
+
+			// Must sanitize strings?
+			wm.signal = sigval.Signal
+			wm.msg = sigval.Error
+			wm.lang = sigval.Lang
+		default:
+			// This handles keepalives and matches
+			// OpenSSH's behaviour.
+			if msg.WantReply {
+				msg.Reply(false, nil)
+			}
+		}
+	}
+	if wm.status == 0 {
+		return nil
+	}
+	if wm.status == -1 {
+		// exit-status was never sent from server
+		if wm.signal == "" {
+			// signal was not sent either.  RFC 4254
+			// section 6.10 recommends against this
+			// behavior, but it is allowed, so we let
+			// clients handle it.
+			return &ExitMissingError{}
+		}
+		wm.status = 128
+		if _, ok := signals[Signal(wm.signal)]; ok {
+			wm.status += signals[Signal(wm.signal)]
+		}
+	}
+
+	return &ExitError{wm}
+}
+
+// ExitMissingError is returned if a session is torn down cleanly, but
+// the server sends no confirmation of the exit status.
+type ExitMissingError struct{}
+
+func (e *ExitMissingError) Error() string {
+	return "wait: remote command exited without exit status or exit signal"
+}
+
+func (s *Session) stdin() {
+	if s.stdinpipe {
+		return
+	}
+	var stdin io.Reader
+	if s.Stdin == nil {
+		stdin = new(bytes.Buffer)
+	} else {
+		r, w := io.Pipe()
+		go func() {
+			_, err := io.Copy(w, s.Stdin)
+			w.CloseWithError(err)
+		}()
+		stdin, s.stdinPipeWriter = r, w
+	}
+	s.copyFuncs = append(s.copyFuncs, func() error {
+		_, err := io.Copy(s.ch, stdin)
+		if err1 := s.ch.CloseWrite(); err == nil && err1 != io.EOF {
+			err = err1
+		}
+		return err
+	})
+}
+
+func (s *Session) stdout() {
+	if s.stdoutpipe {
+		return
+	}
+	if s.Stdout == nil {
+		s.Stdout = ioutil.Discard
+	}
+	s.copyFuncs = append(s.copyFuncs, func() error {
+		_, err := io.Copy(s.Stdout, s.ch)
+		return err
+	})
+}
+
+func (s *Session) stderr() {
+	if s.stderrpipe {
+		return
+	}
+	if s.Stderr == nil {
+		s.Stderr = ioutil.Discard
+	}
+	s.copyFuncs = append(s.copyFuncs, func() error {
+		_, err := io.Copy(s.Stderr, s.ch.Stderr())
+		return err
+	})
+}
+
+// sessionStdin reroutes Close to CloseWrite.
+type sessionStdin struct {
+	io.Writer
+	ch Channel
+}
+
+func (s *sessionStdin) Close() error {
+	return s.ch.CloseWrite()
+}
+
+// StdinPipe returns a pipe that will be connected to the
+// remote command's standard input when the command starts.
+func (s *Session) StdinPipe() (io.WriteCloser, error) {
+	if s.Stdin != nil {
+		return nil, errors.New("ssh: Stdin already set")
+	}
+	if s.started {
+		return nil, errors.New("ssh: StdinPipe after process started")
+	}
+	s.stdinpipe = true
+	return &sessionStdin{s.ch, s.ch}, nil
+}
+
+// StdoutPipe returns a pipe that will be connected to the
+// remote command's standard output when the command starts.
+// There is a fixed amount of buffering that is shared between
+// stdout and stderr streams. If the StdoutPipe reader is
+// not serviced fast enough it may eventually cause the
+// remote command to block.
+func (s *Session) StdoutPipe() (io.Reader, error) {
+	if s.Stdout != nil {
+		return nil, errors.New("ssh: Stdout already set")
+	}
+	if s.started {
+		return nil, errors.New("ssh: StdoutPipe after process started")
+	}
+	s.stdoutpipe = true
+	return s.ch, nil
+}
+
+// StderrPipe returns a pipe that will be connected to the
+// remote command's standard error when the command starts.
+// There is a fixed amount of buffering that is shared between
+// stdout and stderr streams. If the StderrPipe reader is
+// not serviced fast enough it may eventually cause the
+// remote command to block.
+func (s *Session) StderrPipe() (io.Reader, error) {
+	if s.Stderr != nil {
+		return nil, errors.New("ssh: Stderr already set")
+	}
+	if s.started {
+		return nil, errors.New("ssh: StderrPipe after process started")
+	}
+	s.stderrpipe = true
+	return s.ch.Stderr(), nil
+}
+
+// newSession returns a new interactive session on the remote host.
+func newSession(ch Channel, reqs <-chan *Request) (*Session, error) {
+	s := &Session{
+		ch: ch,
+	}
+	s.exitStatus = make(chan error, 1)
+	go func() {
+		s.exitStatus <- s.wait(reqs)
+	}()
+
+	return s, nil
+}
+
+// An ExitError reports unsuccessful completion of a remote command.
+type ExitError struct {
+	Waitmsg
+}
+
+func (e *ExitError) Error() string {
+	return e.Waitmsg.String()
+}
+
+// Waitmsg stores the information about an exited remote command
+// as reported by Wait.
+type Waitmsg struct {
+	status int
+	signal string
+	msg    string
+	lang   string
+}
+
+// ExitStatus returns the exit status of the remote command.
+func (w Waitmsg) ExitStatus() int {
+	return w.status
+}
+
+// Signal returns the exit signal of the remote command if
+// it was terminated violently.
+func (w Waitmsg) Signal() string {
+	return w.signal
+}
+
+// Msg returns the exit message given by the remote command
+func (w Waitmsg) Msg() string {
+	return w.msg
+}
+
+// Lang returns the language tag. See RFC 3066
+func (w Waitmsg) Lang() string {
+	return w.lang
+}
+
+func (w Waitmsg) String() string {
+	str := fmt.Sprintf("Process exited with status %v", w.status)
+	if w.signal != "" {
+		str += fmt.Sprintf(" from signal %v", w.signal)
+	}
+	if w.msg != "" {
+		str += fmt.Sprintf(". Reason was: %v", w.msg)
+	}
+	return str
+}

vendor/golang.org/x/crypto/ssh/session_test.go

@@ -0,0 +1,770 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+// Session tests.
+
+import (
+	"bytes"
+	crypto_rand "crypto/rand"
+	"errors"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"net"
+	"testing"
+
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+type serverType func(Channel, <-chan *Request, *testing.T)
+
+// dial constructs a new test server and returns a *ClientConn.
+func dial(handler serverType, t *testing.T) *Client {
+	c1, c2, err := netPipe()
+	if err != nil {
+		t.Fatalf("netPipe: %v", err)
+	}
+
+	go func() {
+		defer c1.Close()
+		conf := ServerConfig{
+			NoClientAuth: true,
+		}
+		conf.AddHostKey(testSigners["rsa"])
+
+		_, chans, reqs, err := NewServerConn(c1, &conf)
+		if err != nil {
+			t.Fatalf("Unable to handshake: %v", err)
+		}
+		go DiscardRequests(reqs)
+
+		for newCh := range chans {
+			if newCh.ChannelType() != "session" {
+				newCh.Reject(UnknownChannelType, "unknown channel type")
+				continue
+			}
+
+			ch, inReqs, err := newCh.Accept()
+			if err != nil {
+				t.Errorf("Accept: %v", err)
+				continue
+			}
+			go func() {
+				handler(ch, inReqs, t)
+			}()
+		}
+	}()
+
+	config := &ClientConfig{
+		User: "testuser",
+	}
+
+	conn, chans, reqs, err := NewClientConn(c2, "", config)
+	if err != nil {
+		t.Fatalf("unable to dial remote side: %v", err)
+	}
+
+	return NewClient(conn, chans, reqs)
+}
+
+// Test a simple string is returned to session.Stdout.
+func TestSessionShell(t *testing.T) {
+	conn := dial(shellHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+	stdout := new(bytes.Buffer)
+	session.Stdout = stdout
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %s", err)
+	}
+	if err := session.Wait(); err != nil {
+		t.Fatalf("Remote command did not exit cleanly: %v", err)
+	}
+	actual := stdout.String()
+	if actual != "golang" {
+		t.Fatalf("Remote shell did not return expected string: expected=golang, actual=%s", actual)
+	}
+}
+
+// TODO(dfc) add support for Std{in,err}Pipe when the Server supports it.
+
+// Test a simple string is returned via StdoutPipe.
+func TestSessionStdoutPipe(t *testing.T) {
+	conn := dial(shellHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+	stdout, err := session.StdoutPipe()
+	if err != nil {
+		t.Fatalf("Unable to request StdoutPipe(): %v", err)
+	}
+	var buf bytes.Buffer
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	done := make(chan bool, 1)
+	go func() {
+		if _, err := io.Copy(&buf, stdout); err != nil {
+			t.Errorf("Copy of stdout failed: %v", err)
+		}
+		done <- true
+	}()
+	if err := session.Wait(); err != nil {
+		t.Fatalf("Remote command did not exit cleanly: %v", err)
+	}
+	<-done
+	actual := buf.String()
+	if actual != "golang" {
+		t.Fatalf("Remote shell did not return expected string: expected=golang, actual=%s", actual)
+	}
+}
+
+// Test that a simple string is returned via the Output helper,
+// and that stderr is discarded.
+func TestSessionOutput(t *testing.T) {
+	conn := dial(fixedOutputHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+
+	buf, err := session.Output("") // cmd is ignored by fixedOutputHandler
+	if err != nil {
+		t.Error("Remote command did not exit cleanly:", err)
+	}
+	w := "this-is-stdout."
+	g := string(buf)
+	if g != w {
+		t.Error("Remote command did not return expected string:")
+		t.Logf("want %q", w)
+		t.Logf("got  %q", g)
+	}
+}
+
+// Test that both stdout and stderr are returned
+// via the CombinedOutput helper.
+func TestSessionCombinedOutput(t *testing.T) {
+	conn := dial(fixedOutputHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+
+	buf, err := session.CombinedOutput("") // cmd is ignored by fixedOutputHandler
+	if err != nil {
+		t.Error("Remote command did not exit cleanly:", err)
+	}
+	const stdout = "this-is-stdout."
+	const stderr = "this-is-stderr."
+	g := string(buf)
+	if g != stdout+stderr && g != stderr+stdout {
+		t.Error("Remote command did not return expected string:")
+		t.Logf("want %q, or %q", stdout+stderr, stderr+stdout)
+		t.Logf("got  %q", g)
+	}
+}
+
+// Test non-0 exit status is returned correctly.
+func TestExitStatusNonZero(t *testing.T) {
+	conn := dial(exitStatusNonZeroHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	err = session.Wait()
+	if err == nil {
+		t.Fatalf("expected command to fail but it didn't")
+	}
+	e, ok := err.(*ExitError)
+	if !ok {
+		t.Fatalf("expected *ExitError but got %T", err)
+	}
+	if e.ExitStatus() != 15 {
+		t.Fatalf("expected command to exit with 15 but got %v", e.ExitStatus())
+	}
+}
+
+// Test 0 exit status is returned correctly.
+func TestExitStatusZero(t *testing.T) {
+	conn := dial(exitStatusZeroHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	err = session.Wait()
+	if err != nil {
+		t.Fatalf("expected nil but got %v", err)
+	}
+}
+
+// Test exit signal and status are both returned correctly.
+func TestExitSignalAndStatus(t *testing.T) {
+	conn := dial(exitSignalAndStatusHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	err = session.Wait()
+	if err == nil {
+		t.Fatalf("expected command to fail but it didn't")
+	}
+	e, ok := err.(*ExitError)
+	if !ok {
+		t.Fatalf("expected *ExitError but got %T", err)
+	}
+	if e.Signal() != "TERM" || e.ExitStatus() != 15 {
+		t.Fatalf("expected command to exit with signal TERM and status 15 but got signal %s and status %v", e.Signal(), e.ExitStatus())
+	}
+}
+
+// Test exit signal and status are both returned correctly.
+func TestKnownExitSignalOnly(t *testing.T) {
+	conn := dial(exitSignalHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	err = session.Wait()
+	if err == nil {
+		t.Fatalf("expected command to fail but it didn't")
+	}
+	e, ok := err.(*ExitError)
+	if !ok {
+		t.Fatalf("expected *ExitError but got %T", err)
+	}
+	if e.Signal() != "TERM" || e.ExitStatus() != 143 {
+		t.Fatalf("expected command to exit with signal TERM and status 143 but got signal %s and status %v", e.Signal(), e.ExitStatus())
+	}
+}
+
+// Test exit signal and status are both returned correctly.
+func TestUnknownExitSignal(t *testing.T) {
+	conn := dial(exitSignalUnknownHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	err = session.Wait()
+	if err == nil {
+		t.Fatalf("expected command to fail but it didn't")
+	}
+	e, ok := err.(*ExitError)
+	if !ok {
+		t.Fatalf("expected *ExitError but got %T", err)
+	}
+	if e.Signal() != "SYS" || e.ExitStatus() != 128 {
+		t.Fatalf("expected command to exit with signal SYS and status 128 but got signal %s and status %v", e.Signal(), e.ExitStatus())
+	}
+}
+
+func TestExitWithoutStatusOrSignal(t *testing.T) {
+	conn := dial(exitWithoutSignalOrStatus, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("Unable to request new session: %v", err)
+	}
+	defer session.Close()
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	err = session.Wait()
+	if err == nil {
+		t.Fatalf("expected command to fail but it didn't")
+	}
+	if _, ok := err.(*ExitMissingError); !ok {
+		t.Fatalf("got %T want *ExitMissingError", err)
+	}
+}
+
+// windowTestBytes is the number of bytes that we'll send to the SSH server.
+const windowTestBytes = 16000 * 200
+
+// TestServerWindow writes random data to the server. The server is expected to echo
+// the same data back, which is compared against the original.
+func TestServerWindow(t *testing.T) {
+	origBuf := bytes.NewBuffer(make([]byte, 0, windowTestBytes))
+	io.CopyN(origBuf, crypto_rand.Reader, windowTestBytes)
+	origBytes := origBuf.Bytes()
+
+	conn := dial(echoHandler, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer session.Close()
+	result := make(chan []byte)
+
+	go func() {
+		defer close(result)
+		echoedBuf := bytes.NewBuffer(make([]byte, 0, windowTestBytes))
+		serverStdout, err := session.StdoutPipe()
+		if err != nil {
+			t.Errorf("StdoutPipe failed: %v", err)
+			return
+		}
+		n, err := copyNRandomly("stdout", echoedBuf, serverStdout, windowTestBytes)
+		if err != nil && err != io.EOF {
+			t.Errorf("Read only %d bytes from server, expected %d: %v", n, windowTestBytes, err)
+		}
+		result <- echoedBuf.Bytes()
+	}()
+
+	serverStdin, err := session.StdinPipe()
+	if err != nil {
+		t.Fatalf("StdinPipe failed: %v", err)
+	}
+	written, err := copyNRandomly("stdin", serverStdin, origBuf, windowTestBytes)
+	if err != nil {
+		t.Fatalf("failed to copy origBuf to serverStdin: %v", err)
+	}
+	if written != windowTestBytes {
+		t.Fatalf("Wrote only %d of %d bytes to server", written, windowTestBytes)
+	}
+
+	echoedBytes := <-result
+
+	if !bytes.Equal(origBytes, echoedBytes) {
+		t.Fatalf("Echoed buffer differed from original, orig %d, echoed %d", len(origBytes), len(echoedBytes))
+	}
+}
+
+// Verify the client can handle a keepalive packet from the server.
+func TestClientHandlesKeepalives(t *testing.T) {
+	conn := dial(channelKeepaliveSender, t)
+	defer conn.Close()
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer session.Close()
+	if err := session.Shell(); err != nil {
+		t.Fatalf("Unable to execute command: %v", err)
+	}
+	err = session.Wait()
+	if err != nil {
+		t.Fatalf("expected nil but got: %v", err)
+	}
+}
+
+type exitStatusMsg struct {
+	Status uint32
+}
+
+type exitSignalMsg struct {
+	Signal     string
+	CoreDumped bool
+	Errmsg     string
+	Lang       string
+}
+
+func handleTerminalRequests(in <-chan *Request) {
+	for req := range in {
+		ok := false
+		switch req.Type {
+		case "shell":
+			ok = true
+			if len(req.Payload) > 0 {
+				// We don't accept any commands, only the default shell.
+				ok = false
+			}
+		case "env":
+			ok = true
+		}
+		req.Reply(ok, nil)
+	}
+}
+
+func newServerShell(ch Channel, in <-chan *Request, prompt string) *terminal.Terminal {
+	term := terminal.NewTerminal(ch, prompt)
+	go handleTerminalRequests(in)
+	return term
+}
+
+func exitStatusZeroHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	// this string is returned to stdout
+	shell := newServerShell(ch, in, "> ")
+	readLine(shell, t)
+	sendStatus(0, ch, t)
+}
+
+func exitStatusNonZeroHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	shell := newServerShell(ch, in, "> ")
+	readLine(shell, t)
+	sendStatus(15, ch, t)
+}
+
+func exitSignalAndStatusHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	shell := newServerShell(ch, in, "> ")
+	readLine(shell, t)
+	sendStatus(15, ch, t)
+	sendSignal("TERM", ch, t)
+}
+
+func exitSignalHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	shell := newServerShell(ch, in, "> ")
+	readLine(shell, t)
+	sendSignal("TERM", ch, t)
+}
+
+func exitSignalUnknownHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	shell := newServerShell(ch, in, "> ")
+	readLine(shell, t)
+	sendSignal("SYS", ch, t)
+}
+
+func exitWithoutSignalOrStatus(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	shell := newServerShell(ch, in, "> ")
+	readLine(shell, t)
+}
+
+func shellHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	// this string is returned to stdout
+	shell := newServerShell(ch, in, "golang")
+	readLine(shell, t)
+	sendStatus(0, ch, t)
+}
+
+// Ignores the command, writes fixed strings to stderr and stdout.
+// Strings are "this-is-stdout." and "this-is-stderr.".
+func fixedOutputHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	_, err := ch.Read(nil)
+
+	req, ok := <-in
+	if !ok {
+		t.Fatalf("error: expected channel request, got: %#v", err)
+		return
+	}
+
+	// ignore request, always send some text
+	req.Reply(true, nil)
+
+	_, err = io.WriteString(ch, "this-is-stdout.")
+	if err != nil {
+		t.Fatalf("error writing on server: %v", err)
+	}
+	_, err = io.WriteString(ch.Stderr(), "this-is-stderr.")
+	if err != nil {
+		t.Fatalf("error writing on server: %v", err)
+	}
+	sendStatus(0, ch, t)
+}
+
+func readLine(shell *terminal.Terminal, t *testing.T) {
+	if _, err := shell.ReadLine(); err != nil && err != io.EOF {
+		t.Errorf("unable to read line: %v", err)
+	}
+}
+
+func sendStatus(status uint32, ch Channel, t *testing.T) {
+	msg := exitStatusMsg{
+		Status: status,
+	}
+	if _, err := ch.SendRequest("exit-status", false, Marshal(&msg)); err != nil {
+		t.Errorf("unable to send status: %v", err)
+	}
+}
+
+func sendSignal(signal string, ch Channel, t *testing.T) {
+	sig := exitSignalMsg{
+		Signal:     signal,
+		CoreDumped: false,
+		Errmsg:     "Process terminated",
+		Lang:       "en-GB-oed",
+	}
+	if _, err := ch.SendRequest("exit-signal", false, Marshal(&sig)); err != nil {
+		t.Errorf("unable to send signal: %v", err)
+	}
+}
+
+func discardHandler(ch Channel, t *testing.T) {
+	defer ch.Close()
+	io.Copy(ioutil.Discard, ch)
+}
+
+func echoHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	if n, err := copyNRandomly("echohandler", ch, ch, windowTestBytes); err != nil {
+		t.Errorf("short write, wrote %d, expected %d: %v ", n, windowTestBytes, err)
+	}
+}
+
+// copyNRandomly copies n bytes from src to dst. It uses a variable, and random,
+// buffer size to exercise more code paths.
+func copyNRandomly(title string, dst io.Writer, src io.Reader, n int) (int, error) {
+	var (
+		buf       = make([]byte, 32*1024)
+		written   int
+		remaining = n
+	)
+	for remaining > 0 {
+		l := rand.Intn(1 << 15)
+		if remaining < l {
+			l = remaining
+		}
+		nr, er := src.Read(buf[:l])
+		nw, ew := dst.Write(buf[:nr])
+		remaining -= nw
+		written += nw
+		if ew != nil {
+			return written, ew
+		}
+		if nr != nw {
+			return written, io.ErrShortWrite
+		}
+		if er != nil && er != io.EOF {
+			return written, er
+		}
+	}
+	return written, nil
+}
+
+func channelKeepaliveSender(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	shell := newServerShell(ch, in, "> ")
+	readLine(shell, t)
+	if _, err := ch.SendRequest("keepalive@openssh.com", true, nil); err != nil {
+		t.Errorf("unable to send channel keepalive request: %v", err)
+	}
+	sendStatus(0, ch, t)
+}
+
+func TestClientWriteEOF(t *testing.T) {
+	conn := dial(simpleEchoHandler, t)
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer session.Close()
+	stdin, err := session.StdinPipe()
+	if err != nil {
+		t.Fatalf("StdinPipe failed: %v", err)
+	}
+	stdout, err := session.StdoutPipe()
+	if err != nil {
+		t.Fatalf("StdoutPipe failed: %v", err)
+	}
+
+	data := []byte(`0000`)
+	_, err = stdin.Write(data)
+	if err != nil {
+		t.Fatalf("Write failed: %v", err)
+	}
+	stdin.Close()
+
+	res, err := ioutil.ReadAll(stdout)
+	if err != nil {
+		t.Fatalf("Read failed: %v", err)
+	}
+
+	if !bytes.Equal(data, res) {
+		t.Fatalf("Read differed from write, wrote: %v, read: %v", data, res)
+	}
+}
+
+func simpleEchoHandler(ch Channel, in <-chan *Request, t *testing.T) {
+	defer ch.Close()
+	data, err := ioutil.ReadAll(ch)
+	if err != nil {
+		t.Errorf("handler read error: %v", err)
+	}
+	_, err = ch.Write(data)
+	if err != nil {
+		t.Errorf("handler write error: %v", err)
+	}
+}
+
+func TestSessionID(t *testing.T) {
+	c1, c2, err := netPipe()
+	if err != nil {
+		t.Fatalf("netPipe: %v", err)
+	}
+	defer c1.Close()
+	defer c2.Close()
+
+	serverID := make(chan []byte, 1)
+	clientID := make(chan []byte, 1)
+
+	serverConf := &ServerConfig{
+		NoClientAuth: true,
+	}
+	serverConf.AddHostKey(testSigners["ecdsa"])
+	clientConf := &ClientConfig{
+		User: "user",
+	}
+
+	go func() {
+		conn, chans, reqs, err := NewServerConn(c1, serverConf)
+		if err != nil {
+			t.Fatalf("server handshake: %v", err)
+		}
+		serverID <- conn.SessionID()
+		go DiscardRequests(reqs)
+		for ch := range chans {
+			ch.Reject(Prohibited, "")
+		}
+	}()
+
+	go func() {
+		conn, chans, reqs, err := NewClientConn(c2, "", clientConf)
+		if err != nil {
+			t.Fatalf("client handshake: %v", err)
+		}
+		clientID <- conn.SessionID()
+		go DiscardRequests(reqs)
+		for ch := range chans {
+			ch.Reject(Prohibited, "")
+		}
+	}()
+
+	s := <-serverID
+	c := <-clientID
+	if bytes.Compare(s, c) != 0 {
+		t.Errorf("server session ID (%x) != client session ID (%x)", s, c)
+	} else if len(s) == 0 {
+		t.Errorf("client and server SessionID were empty.")
+	}
+}
+
+type noReadConn struct {
+	readSeen bool
+	net.Conn
+}
+
+func (c *noReadConn) Close() error {
+	return nil
+}
+
+func (c *noReadConn) Read(b []byte) (int, error) {
+	c.readSeen = true
+	return 0, errors.New("noReadConn error")
+}
+
+func TestInvalidServerConfiguration(t *testing.T) {
+	c1, c2, err := netPipe()
+	if err != nil {
+		t.Fatalf("netPipe: %v", err)
+	}
+	defer c1.Close()
+	defer c2.Close()
+
+	serveConn := noReadConn{Conn: c1}
+	serverConf := &ServerConfig{}
+
+	NewServerConn(&serveConn, serverConf)
+	if serveConn.readSeen {
+		t.Fatalf("NewServerConn attempted to Read() from Conn while configuration is missing host key")
+	}
+
+	serverConf.AddHostKey(testSigners["ecdsa"])
+
+	NewServerConn(&serveConn, serverConf)
+	if serveConn.readSeen {
+		t.Fatalf("NewServerConn attempted to Read() from Conn while configuration is missing authentication method")
+	}
+}
+
+func TestHostKeyAlgorithms(t *testing.T) {
+	serverConf := &ServerConfig{
+		NoClientAuth: true,
+	}
+	serverConf.AddHostKey(testSigners["rsa"])
+	serverConf.AddHostKey(testSigners["ecdsa"])
+
+	connect := func(clientConf *ClientConfig, want string) {
+		var alg string
+		clientConf.HostKeyCallback = func(h string, a net.Addr, key PublicKey) error {
+			alg = key.Type()
+			return nil
+		}
+		c1, c2, err := netPipe()
+		if err != nil {
+			t.Fatalf("netPipe: %v", err)
+		}
+		defer c1.Close()
+		defer c2.Close()
+
+		go NewServerConn(c1, serverConf)
+		_, _, _, err = NewClientConn(c2, "", clientConf)
+		if err != nil {
+			t.Fatalf("NewClientConn: %v", err)
+		}
+		if alg != want {
+			t.Errorf("selected key algorithm %s, want %s", alg, want)
+		}
+	}
+
+	// By default, we get the preferred algorithm, which is ECDSA 256.
+
+	clientConf := &ClientConfig{}
+	connect(clientConf, KeyAlgoECDSA256)
+
+	// Client asks for RSA explicitly.
+	clientConf.HostKeyAlgorithms = []string{KeyAlgoRSA}
+	connect(clientConf, KeyAlgoRSA)
+
+	c1, c2, err := netPipe()
+	if err != nil {
+		t.Fatalf("netPipe: %v", err)
+	}
+	defer c1.Close()
+	defer c2.Close()
+
+	go NewServerConn(c1, serverConf)
+	clientConf.HostKeyAlgorithms = []string{"nonexistent-hostkey-algo"}
+	_, _, _, err = NewClientConn(c2, "", clientConf)
+	if err == nil {
+		t.Fatal("succeeded connecting with unknown hostkey algorithm")
+	}
+}

vendor/golang.org/x/crypto/ssh/tcpip.go

@@ -0,0 +1,407 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"net"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// Listen requests the remote peer open a listening socket on
+// addr. Incoming connections will be available by calling Accept on
+// the returned net.Listener. The listener must be serviced, or the
+// SSH connection may hang.
+func (c *Client) Listen(n, addr string) (net.Listener, error) {
+	laddr, err := net.ResolveTCPAddr(n, addr)
+	if err != nil {
+		return nil, err
+	}
+	return c.ListenTCP(laddr)
+}
+
+// Automatic port allocation is broken with OpenSSH before 6.0. See
+// also https://bugzilla.mindrot.org/show_bug.cgi?id=2017.  In
+// particular, OpenSSH 5.9 sends a channelOpenMsg with port number 0,
+// rather than the actual port number. This means you can never open
+// two different listeners with auto allocated ports. We work around
+// this by trying explicit ports until we succeed.
+
+const openSSHPrefix = "OpenSSH_"
+
+var portRandomizer = rand.New(rand.NewSource(time.Now().UnixNano()))
+
+// isBrokenOpenSSHVersion returns true if the given version string
+// specifies a version of OpenSSH that is known to have a bug in port
+// forwarding.
+func isBrokenOpenSSHVersion(versionStr string) bool {
+	i := strings.Index(versionStr, openSSHPrefix)
+	if i < 0 {
+		return false
+	}
+	i += len(openSSHPrefix)
+	j := i
+	for ; j < len(versionStr); j++ {
+		if versionStr[j] < '0' || versionStr[j] > '9' {
+			break
+		}
+	}
+	version, _ := strconv.Atoi(versionStr[i:j])
+	return version < 6
+}
+
+// autoPortListenWorkaround simulates automatic port allocation by
+// trying random ports repeatedly.
+func (c *Client) autoPortListenWorkaround(laddr *net.TCPAddr) (net.Listener, error) {
+	var sshListener net.Listener
+	var err error
+	const tries = 10
+	for i := 0; i < tries; i++ {
+		addr := *laddr
+		addr.Port = 1024 + portRandomizer.Intn(60000)
+		sshListener, err = c.ListenTCP(&addr)
+		if err == nil {
+			laddr.Port = addr.Port
+			return sshListener, err
+		}
+	}
+	return nil, fmt.Errorf("ssh: listen on random port failed after %d tries: %v", tries, err)
+}
+
+// RFC 4254 7.1
+type channelForwardMsg struct {
+	addr  string
+	rport uint32
+}
+
+// ListenTCP requests the remote peer open a listening socket
+// on laddr. Incoming connections will be available by calling
+// Accept on the returned net.Listener.
+func (c *Client) ListenTCP(laddr *net.TCPAddr) (net.Listener, error) {
+	if laddr.Port == 0 && isBrokenOpenSSHVersion(string(c.ServerVersion())) {
+		return c.autoPortListenWorkaround(laddr)
+	}
+
+	m := channelForwardMsg{
+		laddr.IP.String(),
+		uint32(laddr.Port),
+	}
+	// send message
+	ok, resp, err := c.SendRequest("tcpip-forward", true, Marshal(&m))
+	if err != nil {
+		return nil, err
+	}
+	if !ok {
+		return nil, errors.New("ssh: tcpip-forward request denied by peer")
+	}
+
+	// If the original port was 0, then the remote side will
+	// supply a real port number in the response.
+	if laddr.Port == 0 {
+		var p struct {
+			Port uint32
+		}
+		if err := Unmarshal(resp, &p); err != nil {
+			return nil, err
+		}
+		laddr.Port = int(p.Port)
+	}
+
+	// Register this forward, using the port number we obtained.
+	ch := c.forwards.add(*laddr)
+
+	return &tcpListener{laddr, c, ch}, nil
+}
+
+// forwardList stores a mapping between remote
+// forward requests and the tcpListeners.
+type forwardList struct {
+	sync.Mutex
+	entries []forwardEntry
+}
+
+// forwardEntry represents an established mapping of a laddr on a
+// remote ssh server to a channel connected to a tcpListener.
+type forwardEntry struct {
+	laddr net.TCPAddr
+	c     chan forward
+}
+
+// forward represents an incoming forwarded tcpip connection. The
+// arguments to add/remove/lookup should be address as specified in
+// the original forward-request.
+type forward struct {
+	newCh NewChannel   // the ssh client channel underlying this forward
+	raddr *net.TCPAddr // the raddr of the incoming connection
+}
+
+func (l *forwardList) add(addr net.TCPAddr) chan forward {
+	l.Lock()
+	defer l.Unlock()
+	f := forwardEntry{
+		addr,
+		make(chan forward, 1),
+	}
+	l.entries = append(l.entries, f)
+	return f.c
+}
+
+// See RFC 4254, section 7.2
+type forwardedTCPPayload struct {
+	Addr       string
+	Port       uint32
+	OriginAddr string
+	OriginPort uint32
+}
+
+// parseTCPAddr parses the originating address from the remote into a *net.TCPAddr.
+func parseTCPAddr(addr string, port uint32) (*net.TCPAddr, error) {
+	if port == 0 || port > 65535 {
+		return nil, fmt.Errorf("ssh: port number out of range: %d", port)
+	}
+	ip := net.ParseIP(string(addr))
+	if ip == nil {
+		return nil, fmt.Errorf("ssh: cannot parse IP address %q", addr)
+	}
+	return &net.TCPAddr{IP: ip, Port: int(port)}, nil
+}
+
+func (l *forwardList) handleChannels(in <-chan NewChannel) {
+	for ch := range in {
+		var payload forwardedTCPPayload
+		if err := Unmarshal(ch.ExtraData(), &payload); err != nil {
+			ch.Reject(ConnectionFailed, "could not parse forwarded-tcpip payload: "+err.Error())
+			continue
+		}
+
+		// RFC 4254 section 7.2 specifies that incoming
+		// addresses should list the address, in string
+		// format. It is implied that this should be an IP
+		// address, as it would be impossible to connect to it
+		// otherwise.
+		laddr, err := parseTCPAddr(payload.Addr, payload.Port)
+		if err != nil {
+			ch.Reject(ConnectionFailed, err.Error())
+			continue
+		}
+		raddr, err := parseTCPAddr(payload.OriginAddr, payload.OriginPort)
+		if err != nil {
+			ch.Reject(ConnectionFailed, err.Error())
+			continue
+		}
+
+		if ok := l.forward(*laddr, *raddr, ch); !ok {
+			// Section 7.2, implementations MUST reject spurious incoming
+			// connections.
+			ch.Reject(Prohibited, "no forward for address")
+			continue
+		}
+	}
+}
+
+// remove removes the forward entry, and the channel feeding its
+// listener.
+func (l *forwardList) remove(addr net.TCPAddr) {
+	l.Lock()
+	defer l.Unlock()
+	for i, f := range l.entries {
+		if addr.IP.Equal(f.laddr.IP) && addr.Port == f.laddr.Port {
+			l.entries = append(l.entries[:i], l.entries[i+1:]...)
+			close(f.c)
+			return
+		}
+	}
+}
+
+// closeAll closes and clears all forwards.
+func (l *forwardList) closeAll() {
+	l.Lock()
+	defer l.Unlock()
+	for _, f := range l.entries {
+		close(f.c)
+	}
+	l.entries = nil
+}
+
+func (l *forwardList) forward(laddr, raddr net.TCPAddr, ch NewChannel) bool {
+	l.Lock()
+	defer l.Unlock()
+	for _, f := range l.entries {
+		if laddr.IP.Equal(f.laddr.IP) && laddr.Port == f.laddr.Port {
+			f.c <- forward{ch, &raddr}
+			return true
+		}
+	}
+	return false
+}
+
+type tcpListener struct {
+	laddr *net.TCPAddr
+
+	conn *Client
+	in   <-chan forward
+}
+
+// Accept waits for and returns the next connection to the listener.
+func (l *tcpListener) Accept() (net.Conn, error) {
+	s, ok := <-l.in
+	if !ok {
+		return nil, io.EOF
+	}
+	ch, incoming, err := s.newCh.Accept()
+	if err != nil {
+		return nil, err
+	}
+	go DiscardRequests(incoming)
+
+	return &tcpChanConn{
+		Channel: ch,
+		laddr:   l.laddr,
+		raddr:   s.raddr,
+	}, nil
+}
+
+// Close closes the listener.
+func (l *tcpListener) Close() error {
+	m := channelForwardMsg{
+		l.laddr.IP.String(),
+		uint32(l.laddr.Port),
+	}
+
+	// this also closes the listener.
+	l.conn.forwards.remove(*l.laddr)
+	ok, _, err := l.conn.SendRequest("cancel-tcpip-forward", true, Marshal(&m))
+	if err == nil && !ok {
+		err = errors.New("ssh: cancel-tcpip-forward failed")
+	}
+	return err
+}
+
+// Addr returns the listener's network address.
+func (l *tcpListener) Addr() net.Addr {
+	return l.laddr
+}
+
+// Dial initiates a connection to the addr from the remote host.
+// The resulting connection has a zero LocalAddr() and RemoteAddr().
+func (c *Client) Dial(n, addr string) (net.Conn, error) {
+	// Parse the address into host and numeric port.
+	host, portString, err := net.SplitHostPort(addr)
+	if err != nil {
+		return nil, err
+	}
+	port, err := strconv.ParseUint(portString, 10, 16)
+	if err != nil {
+		return nil, err
+	}
+	// Use a zero address for local and remote address.
+	zeroAddr := &net.TCPAddr{
+		IP:   net.IPv4zero,
+		Port: 0,
+	}
+	ch, err := c.dial(net.IPv4zero.String(), 0, host, int(port))
+	if err != nil {
+		return nil, err
+	}
+	return &tcpChanConn{
+		Channel: ch,
+		laddr:   zeroAddr,
+		raddr:   zeroAddr,
+	}, nil
+}
+
+// DialTCP connects to the remote address raddr on the network net,
+// which must be "tcp", "tcp4", or "tcp6".  If laddr is not nil, it is used
+// as the local address for the connection.
+func (c *Client) DialTCP(n string, laddr, raddr *net.TCPAddr) (net.Conn, error) {
+	if laddr == nil {
+		laddr = &net.TCPAddr{
+			IP:   net.IPv4zero,
+			Port: 0,
+		}
+	}
+	ch, err := c.dial(laddr.IP.String(), laddr.Port, raddr.IP.String(), raddr.Port)
+	if err != nil {
+		return nil, err
+	}
+	return &tcpChanConn{
+		Channel: ch,
+		laddr:   laddr,
+		raddr:   raddr,
+	}, nil
+}
+
+// RFC 4254 7.2
+type channelOpenDirectMsg struct {
+	raddr string
+	rport uint32
+	laddr string
+	lport uint32
+}
+
+func (c *Client) dial(laddr string, lport int, raddr string, rport int) (Channel, error) {
+	msg := channelOpenDirectMsg{
+		raddr: raddr,
+		rport: uint32(rport),
+		laddr: laddr,
+		lport: uint32(lport),
+	}
+	ch, in, err := c.OpenChannel("direct-tcpip", Marshal(&msg))
+	if err != nil {
+		return nil, err
+	}
+	go DiscardRequests(in)
+	return ch, err
+}
+
+type tcpChan struct {
+	Channel // the backing channel
+}
+
+// tcpChanConn fulfills the net.Conn interface without
+// the tcpChan having to hold laddr or raddr directly.
+type tcpChanConn struct {
+	Channel
+	laddr, raddr net.Addr
+}
+
+// LocalAddr returns the local network address.
+func (t *tcpChanConn) LocalAddr() net.Addr {
+	return t.laddr
+}
+
+// RemoteAddr returns the remote network address.
+func (t *tcpChanConn) RemoteAddr() net.Addr {
+	return t.raddr
+}
+
+// SetDeadline sets the read and write deadlines associated
+// with the connection.
+func (t *tcpChanConn) SetDeadline(deadline time.Time) error {
+	if err := t.SetReadDeadline(deadline); err != nil {
+		return err
+	}
+	return t.SetWriteDeadline(deadline)
+}
+
+// SetReadDeadline sets the read deadline.
+// A zero value for t means Read will not time out.
+// After the deadline, the error from Read will implement net.Error
+// with Timeout() == true.
+func (t *tcpChanConn) SetReadDeadline(deadline time.Time) error {
+	return errors.New("ssh: tcpChan: deadline not supported")
+}
+
+// SetWriteDeadline exists to satisfy the net.Conn interface
+// but is not implemented by this type.  It always returns an error.
+func (t *tcpChanConn) SetWriteDeadline(deadline time.Time) error {
+	return errors.New("ssh: tcpChan: deadline not supported")
+}

vendor/golang.org/x/crypto/ssh/tcpip_test.go

@@ -0,0 +1,20 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"testing"
+)
+
+func TestAutoPortListenBroken(t *testing.T) {
+	broken := "SSH-2.0-OpenSSH_5.9hh11"
+	works := "SSH-2.0-OpenSSH_6.1"
+	if !isBrokenOpenSSHVersion(broken) {
+		t.Errorf("version %q not marked as broken", broken)
+	}
+	if isBrokenOpenSSHVersion(works) {
+		t.Errorf("version %q marked as broken", works)
+	}
+}

vendor/golang.org/x/crypto/ssh/terminal/terminal_test.go

@@ -0,0 +1,291 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package terminal
+
+import (
+	"io"
+	"os"
+	"testing"
+)
+
+type MockTerminal struct {
+	toSend       []byte
+	bytesPerRead int
+	received     []byte
+}
+
+func (c *MockTerminal) Read(data []byte) (n int, err error) {
+	n = len(data)
+	if n == 0 {
+		return
+	}
+	if n > len(c.toSend) {
+		n = len(c.toSend)
+	}
+	if n == 0 {
+		return 0, io.EOF
+	}
+	if c.bytesPerRead > 0 && n > c.bytesPerRead {
+		n = c.bytesPerRead
+	}
+	copy(data, c.toSend[:n])
+	c.toSend = c.toSend[n:]
+	return
+}
+
+func (c *MockTerminal) Write(data []byte) (n int, err error) {
+	c.received = append(c.received, data...)
+	return len(data), nil
+}
+
+func TestClose(t *testing.T) {
+	c := &MockTerminal{}
+	ss := NewTerminal(c, "> ")
+	line, err := ss.ReadLine()
+	if line != "" {
+		t.Errorf("Expected empty line but got: %s", line)
+	}
+	if err != io.EOF {
+		t.Errorf("Error should have been EOF but got: %s", err)
+	}
+}
+
+var keyPressTests = []struct {
+	in             string
+	line           string
+	err            error
+	throwAwayLines int
+}{
+	{
+		err: io.EOF,
+	},
+	{
+		in:   "\r",
+		line: "",
+	},
+	{
+		in:   "foo\r",
+		line: "foo",
+	},
+	{
+		in:   "a\x1b[Cb\r", // right
+		line: "ab",
+	},
+	{
+		in:   "a\x1b[Db\r", // left
+		line: "ba",
+	},
+	{
+		in:   "a\177b\r", // backspace
+		line: "b",
+	},
+	{
+		in: "\x1b[A\r", // up
+	},
+	{
+		in: "\x1b[B\r", // down
+	},
+	{
+		in:   "line\x1b[A\x1b[B\r", // up then down
+		line: "line",
+	},
+	{
+		in:             "line1\rline2\x1b[A\r", // recall previous line.
+		line:           "line1",
+		throwAwayLines: 1,
+	},
+	{
+		// recall two previous lines and append.
+		in:             "line1\rline2\rline3\x1b[A\x1b[Axxx\r",
+		line:           "line1xxx",
+		throwAwayLines: 2,
+	},
+	{
+		// Ctrl-A to move to beginning of line followed by ^K to kill
+		// line.
+		in:   "a b \001\013\r",
+		line: "",
+	},
+	{
+		// Ctrl-A to move to beginning of line, Ctrl-E to move to end,
+		// finally ^K to kill nothing.
+		in:   "a b \001\005\013\r",
+		line: "a b ",
+	},
+	{
+		in:   "\027\r",
+		line: "",
+	},
+	{
+		in:   "a\027\r",
+		line: "",
+	},
+	{
+		in:   "a \027\r",
+		line: "",
+	},
+	{
+		in:   "a b\027\r",
+		line: "a ",
+	},
+	{
+		in:   "a b \027\r",
+		line: "a ",
+	},
+	{
+		in:   "one two thr\x1b[D\027\r",
+		line: "one two r",
+	},
+	{
+		in:   "\013\r",
+		line: "",
+	},
+	{
+		in:   "a\013\r",
+		line: "a",
+	},
+	{
+		in:   "ab\x1b[D\013\r",
+		line: "a",
+	},
+	{
+		in:   "Ξεσκεπάζω\r",
+		line: "Ξεσκεπάζω",
+	},
+	{
+		in:             "£\r\x1b[A\177\r", // non-ASCII char, enter, up, backspace.
+		line:           "",
+		throwAwayLines: 1,
+	},
+	{
+		in:             "£\r££\x1b[A\x1b[B\177\r", // non-ASCII char, enter, 2x non-ASCII, up, down, backspace, enter.
+		line:           "£",
+		throwAwayLines: 1,
+	},
+	{
+		// Ctrl-D at the end of the line should be ignored.
+		in:   "a\004\r",
+		line: "a",
+	},
+	{
+		// a, b, left, Ctrl-D should erase the b.
+		in:   "ab\x1b[D\004\r",
+		line: "a",
+	},
+	{
+		// a, b, c, d, left, left, ^U should erase to the beginning of
+		// the line.
+		in:   "abcd\x1b[D\x1b[D\025\r",
+		line: "cd",
+	},
+	{
+		// Bracketed paste mode: control sequences should be returned
+		// verbatim in paste mode.
+		in:   "abc\x1b[200~de\177f\x1b[201~\177\r",
+		line: "abcde\177",
+	},
+	{
+		// Enter in bracketed paste mode should still work.
+		in:             "abc\x1b[200~d\refg\x1b[201~h\r",
+		line:           "efgh",
+		throwAwayLines: 1,
+	},
+	{
+		// Lines consisting entirely of pasted data should be indicated as such.
+		in:   "\x1b[200~a\r",
+		line: "a",
+		err:  ErrPasteIndicator,
+	},
+}
+
+func TestKeyPresses(t *testing.T) {
+	for i, test := range keyPressTests {
+		for j := 1; j < len(test.in); j++ {
+			c := &MockTerminal{
+				toSend:       []byte(test.in),
+				bytesPerRead: j,
+			}
+			ss := NewTerminal(c, "> ")
+			for k := 0; k < test.throwAwayLines; k++ {
+				_, err := ss.ReadLine()
+				if err != nil {
+					t.Errorf("Throwaway line %d from test %d resulted in error: %s", k, i, err)
+				}
+			}
+			line, err := ss.ReadLine()
+			if line != test.line {
+				t.Errorf("Line resulting from test %d (%d bytes per read) was '%s', expected '%s'", i, j, line, test.line)
+				break
+			}
+			if err != test.err {
+				t.Errorf("Error resulting from test %d (%d bytes per read) was '%v', expected '%v'", i, j, err, test.err)
+				break
+			}
+		}
+	}
+}
+
+func TestPasswordNotSaved(t *testing.T) {
+	c := &MockTerminal{
+		toSend:       []byte("password\r\x1b[A\r"),
+		bytesPerRead: 1,
+	}
+	ss := NewTerminal(c, "> ")
+	pw, _ := ss.ReadPassword("> ")
+	if pw != "password" {
+		t.Fatalf("failed to read password, got %s", pw)
+	}
+	line, _ := ss.ReadLine()
+	if len(line) > 0 {
+		t.Fatalf("password was saved in history")
+	}
+}
+
+var setSizeTests = []struct {
+	width, height int
+}{
+	{40, 13},
+	{80, 24},
+	{132, 43},
+}
+
+func TestTerminalSetSize(t *testing.T) {
+	for _, setSize := range setSizeTests {
+		c := &MockTerminal{
+			toSend:       []byte("password\r\x1b[A\r"),
+			bytesPerRead: 1,
+		}
+		ss := NewTerminal(c, "> ")
+		ss.SetSize(setSize.width, setSize.height)
+		pw, _ := ss.ReadPassword("Password: ")
+		if pw != "password" {
+			t.Fatalf("failed to read password, got %s", pw)
+		}
+		if string(c.received) != "Password: \r\n" {
+			t.Errorf("failed to set the temporary prompt expected %q, got %q", "Password: ", c.received)
+		}
+	}
+}
+
+func TestMakeRawState(t *testing.T) {
+	fd := int(os.Stdout.Fd())
+	if !IsTerminal(fd) {
+		t.Skip("stdout is not a terminal; skipping test")
+	}
+
+	st, err := GetState(fd)
+	if err != nil {
+		t.Fatalf("failed to get terminal state from GetState: %s", err)
+	}
+	defer Restore(fd, st)
+	raw, err := MakeRaw(fd)
+	if err != nil {
+		t.Fatalf("failed to get terminal state from MakeRaw: %s", err)
+	}
+
+	if *st != *raw {
+		t.Errorf("states do not match; was %v, expected %v", raw, st)
+	}
+}

vendor/golang.org/x/crypto/ssh/terminal/util.go

@@ -14,7 +14,7 @@
 // 	        panic(err)
 // 	}
 // 	defer terminal.Restore(0, oldState)
-package terminal
+package terminal // import "golang.org/x/crypto/ssh/terminal"
 
 import (
 	"io"

vendor/golang.org/x/crypto/ssh/terminal/util_solaris.go

@@ -4,7 +4,7 @@
 
 // +build solaris
 
-package terminal
+package terminal // import "golang.org/x/crypto/ssh/terminal"
 
 import (
 	"golang.org/x/sys/unix"

vendor/golang.org/x/crypto/ssh/test/agent_unix_test.go

@@ -0,0 +1,59 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd
+
+package test
+
+import (
+	"bytes"
+	"testing"
+
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/agent"
+)
+
+func TestAgentForward(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	keyring := agent.NewKeyring()
+	if err := keyring.Add(agent.AddedKey{PrivateKey: testPrivateKeys["dsa"]}); err != nil {
+		t.Fatalf("Error adding key: %s", err)
+	}
+	if err := keyring.Add(agent.AddedKey{
+		PrivateKey:       testPrivateKeys["dsa"],
+		ConfirmBeforeUse: true,
+		LifetimeSecs:     3600,
+	}); err != nil {
+		t.Fatalf("Error adding key with constraints: %s", err)
+	}
+	pub := testPublicKeys["dsa"]
+
+	sess, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("NewSession: %v", err)
+	}
+	if err := agent.RequestAgentForwarding(sess); err != nil {
+		t.Fatalf("RequestAgentForwarding: %v", err)
+	}
+
+	if err := agent.ForwardToAgent(conn, keyring); err != nil {
+		t.Fatalf("SetupForwardKeyring: %v", err)
+	}
+	out, err := sess.CombinedOutput("ssh-add -L")
+	if err != nil {
+		t.Fatalf("running ssh-add: %v, out %s", err, out)
+	}
+	key, _, _, _, err := ssh.ParseAuthorizedKey(out)
+	if err != nil {
+		t.Fatalf("ParseAuthorizedKey(%q): %v", out, err)
+	}
+
+	if !bytes.Equal(key.Marshal(), pub.Marshal()) {
+		t.Fatalf("got key %s, want %s", ssh.MarshalAuthorizedKey(key), ssh.MarshalAuthorizedKey(pub))
+	}
+}

vendor/golang.org/x/crypto/ssh/test/cert_test.go

@@ -0,0 +1,47 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd
+
+package test
+
+import (
+	"crypto/rand"
+	"testing"
+
+	"golang.org/x/crypto/ssh"
+)
+
+func TestCertLogin(t *testing.T) {
+	s := newServer(t)
+	defer s.Shutdown()
+
+	// Use a key different from the default.
+	clientKey := testSigners["dsa"]
+	caAuthKey := testSigners["ecdsa"]
+	cert := &ssh.Certificate{
+		Key:             clientKey.PublicKey(),
+		ValidPrincipals: []string{username()},
+		CertType:        ssh.UserCert,
+		ValidBefore:     ssh.CertTimeInfinity,
+	}
+	if err := cert.SignCert(rand.Reader, caAuthKey); err != nil {
+		t.Fatalf("SetSignature: %v", err)
+	}
+
+	certSigner, err := ssh.NewCertSigner(cert, clientKey)
+	if err != nil {
+		t.Fatalf("NewCertSigner: %v", err)
+	}
+
+	conf := &ssh.ClientConfig{
+		User: username(),
+	}
+	conf.Auth = append(conf.Auth, ssh.PublicKeys(certSigner))
+	client, err := s.TryDial(conf)
+	if err != nil {
+		t.Fatalf("TryDial: %v", err)
+	}
+	client.Close()
+}

vendor/golang.org/x/crypto/ssh/test/doc.go

@@ -0,0 +1,7 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This package contains integration tests for the
+// golang.org/x/crypto/ssh package.
+package test // import "golang.org/x/crypto/ssh/test"

vendor/golang.org/x/crypto/ssh/test/forward_unix_test.go

@@ -0,0 +1,160 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd
+
+package test
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"net"
+	"testing"
+	"time"
+)
+
+func TestPortForward(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	sshListener, err := conn.Listen("tcp", "localhost:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	go func() {
+		sshConn, err := sshListener.Accept()
+		if err != nil {
+			t.Fatalf("listen.Accept failed: %v", err)
+		}
+
+		_, err = io.Copy(sshConn, sshConn)
+		if err != nil && err != io.EOF {
+			t.Fatalf("ssh client copy: %v", err)
+		}
+		sshConn.Close()
+	}()
+
+	forwardedAddr := sshListener.Addr().String()
+	tcpConn, err := net.Dial("tcp", forwardedAddr)
+	if err != nil {
+		t.Fatalf("TCP dial failed: %v", err)
+	}
+
+	readChan := make(chan []byte)
+	go func() {
+		data, _ := ioutil.ReadAll(tcpConn)
+		readChan <- data
+	}()
+
+	// Invent some data.
+	data := make([]byte, 100*1000)
+	for i := range data {
+		data[i] = byte(i % 255)
+	}
+
+	var sent []byte
+	for len(sent) < 1000*1000 {
+		// Send random sized chunks
+		m := rand.Intn(len(data))
+		n, err := tcpConn.Write(data[:m])
+		if err != nil {
+			break
+		}
+		sent = append(sent, data[:n]...)
+	}
+	if err := tcpConn.(*net.TCPConn).CloseWrite(); err != nil {
+		t.Errorf("tcpConn.CloseWrite: %v", err)
+	}
+
+	read := <-readChan
+
+	if len(sent) != len(read) {
+		t.Fatalf("got %d bytes, want %d", len(read), len(sent))
+	}
+	if bytes.Compare(sent, read) != 0 {
+		t.Fatalf("read back data does not match")
+	}
+
+	if err := sshListener.Close(); err != nil {
+		t.Fatalf("sshListener.Close: %v", err)
+	}
+
+	// Check that the forward disappeared.
+	tcpConn, err = net.Dial("tcp", forwardedAddr)
+	if err == nil {
+		tcpConn.Close()
+		t.Errorf("still listening to %s after closing", forwardedAddr)
+	}
+}
+
+func TestAcceptClose(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+
+	sshListener, err := conn.Listen("tcp", "localhost:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	quit := make(chan error, 1)
+	go func() {
+		for {
+			c, err := sshListener.Accept()
+			if err != nil {
+				quit <- err
+				break
+			}
+			c.Close()
+		}
+	}()
+	sshListener.Close()
+
+	select {
+	case <-time.After(1 * time.Second):
+		t.Errorf("timeout: listener did not close.")
+	case err := <-quit:
+		t.Logf("quit as expected (error %v)", err)
+	}
+}
+
+// Check that listeners exit if the underlying client transport dies.
+func TestPortForwardConnectionClose(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+
+	sshListener, err := conn.Listen("tcp", "localhost:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	quit := make(chan error, 1)
+	go func() {
+		for {
+			c, err := sshListener.Accept()
+			if err != nil {
+				quit <- err
+				break
+			}
+			c.Close()
+		}
+	}()
+
+	// It would be even nicer if we closed the server side, but it
+	// is more involved as the fd for that side is dup()ed.
+	server.clientConn.Close()
+
+	select {
+	case <-time.After(1 * time.Second):
+		t.Errorf("timeout: listener did not close.")
+	case err := <-quit:
+		t.Logf("quit as expected (error %v)", err)
+	}
+}

vendor/golang.org/x/crypto/ssh/test/session_test.go

@@ -0,0 +1,365 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows
+
+package test
+
+// Session functional tests.
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"strings"
+	"testing"
+
+	"golang.org/x/crypto/ssh"
+)
+
+func TestRunCommandSuccess(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+	defer session.Close()
+	err = session.Run("true")
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+}
+
+func TestHostKeyCheck(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+
+	conf := clientConfig()
+	hostDB := hostKeyDB()
+	conf.HostKeyCallback = hostDB.Check
+
+	// change the keys.
+	hostDB.keys[ssh.KeyAlgoRSA][25]++
+	hostDB.keys[ssh.KeyAlgoDSA][25]++
+	hostDB.keys[ssh.KeyAlgoECDSA256][25]++
+
+	conn, err := server.TryDial(conf)
+	if err == nil {
+		conn.Close()
+		t.Fatalf("dial should have failed.")
+	} else if !strings.Contains(err.Error(), "host key mismatch") {
+		t.Fatalf("'host key mismatch' not found in %v", err)
+	}
+}
+
+func TestRunCommandStdin(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+	defer session.Close()
+
+	r, w := io.Pipe()
+	defer r.Close()
+	defer w.Close()
+	session.Stdin = r
+
+	err = session.Run("true")
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+}
+
+func TestRunCommandStdinError(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+	defer session.Close()
+
+	r, w := io.Pipe()
+	defer r.Close()
+	session.Stdin = r
+	pipeErr := errors.New("closing write end of pipe")
+	w.CloseWithError(pipeErr)
+
+	err = session.Run("true")
+	if err != pipeErr {
+		t.Fatalf("expected %v, found %v", pipeErr, err)
+	}
+}
+
+func TestRunCommandFailed(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+	defer session.Close()
+	err = session.Run(`bash -c "kill -9 $$"`)
+	if err == nil {
+		t.Fatalf("session succeeded: %v", err)
+	}
+}
+
+func TestRunCommandWeClosed(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+	err = session.Shell()
+	if err != nil {
+		t.Fatalf("shell failed: %v", err)
+	}
+	err = session.Close()
+	if err != nil {
+		t.Fatalf("shell failed: %v", err)
+	}
+}
+
+func TestFuncLargeRead(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("unable to create new session: %s", err)
+	}
+
+	stdout, err := session.StdoutPipe()
+	if err != nil {
+		t.Fatalf("unable to acquire stdout pipe: %s", err)
+	}
+
+	err = session.Start("dd if=/dev/urandom bs=2048 count=1024")
+	if err != nil {
+		t.Fatalf("unable to execute remote command: %s", err)
+	}
+
+	buf := new(bytes.Buffer)
+	n, err := io.Copy(buf, stdout)
+	if err != nil {
+		t.Fatalf("error reading from remote stdout: %s", err)
+	}
+
+	if n != 2048*1024 {
+		t.Fatalf("Expected %d bytes but read only %d from remote command", 2048, n)
+	}
+}
+
+func TestKeyChange(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conf := clientConfig()
+	hostDB := hostKeyDB()
+	conf.HostKeyCallback = hostDB.Check
+	conf.RekeyThreshold = 1024
+	conn := server.Dial(conf)
+	defer conn.Close()
+
+	for i := 0; i < 4; i++ {
+		session, err := conn.NewSession()
+		if err != nil {
+			t.Fatalf("unable to create new session: %s", err)
+		}
+
+		stdout, err := session.StdoutPipe()
+		if err != nil {
+			t.Fatalf("unable to acquire stdout pipe: %s", err)
+		}
+
+		err = session.Start("dd if=/dev/urandom bs=1024 count=1")
+		if err != nil {
+			t.Fatalf("unable to execute remote command: %s", err)
+		}
+		buf := new(bytes.Buffer)
+		n, err := io.Copy(buf, stdout)
+		if err != nil {
+			t.Fatalf("error reading from remote stdout: %s", err)
+		}
+
+		want := int64(1024)
+		if n != want {
+			t.Fatalf("Expected %d bytes but read only %d from remote command", want, n)
+		}
+	}
+
+	if changes := hostDB.checkCount; changes < 4 {
+		t.Errorf("got %d key changes, want 4", changes)
+	}
+}
+
+func TestInvalidTerminalMode(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+	defer session.Close()
+
+	if err = session.RequestPty("vt100", 80, 40, ssh.TerminalModes{255: 1984}); err == nil {
+		t.Fatalf("req-pty failed: successful request with invalid mode")
+	}
+}
+
+func TestValidTerminalMode(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conn := server.Dial(clientConfig())
+	defer conn.Close()
+
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("session failed: %v", err)
+	}
+	defer session.Close()
+
+	stdout, err := session.StdoutPipe()
+	if err != nil {
+		t.Fatalf("unable to acquire stdout pipe: %s", err)
+	}
+
+	stdin, err := session.StdinPipe()
+	if err != nil {
+		t.Fatalf("unable to acquire stdin pipe: %s", err)
+	}
+
+	tm := ssh.TerminalModes{ssh.ECHO: 0}
+	if err = session.RequestPty("xterm", 80, 40, tm); err != nil {
+		t.Fatalf("req-pty failed: %s", err)
+	}
+
+	err = session.Shell()
+	if err != nil {
+		t.Fatalf("session failed: %s", err)
+	}
+
+	stdin.Write([]byte("stty -a && exit\n"))
+
+	var buf bytes.Buffer
+	if _, err := io.Copy(&buf, stdout); err != nil {
+		t.Fatalf("reading failed: %s", err)
+	}
+
+	if sttyOutput := buf.String(); !strings.Contains(sttyOutput, "-echo ") {
+		t.Fatalf("terminal mode failure: expected -echo in stty output, got %s", sttyOutput)
+	}
+}
+
+func TestCiphers(t *testing.T) {
+	var config ssh.Config
+	config.SetDefaults()
+	cipherOrder := config.Ciphers
+	// These ciphers will not be tested when commented out in cipher.go it will
+	// fallback to the next available as per line 292.
+	cipherOrder = append(cipherOrder, "aes128-cbc", "3des-cbc")
+
+	for _, ciph := range cipherOrder {
+		server := newServer(t)
+		defer server.Shutdown()
+		conf := clientConfig()
+		conf.Ciphers = []string{ciph}
+		// Don't fail if sshd doesn't have the cipher.
+		conf.Ciphers = append(conf.Ciphers, cipherOrder...)
+		conn, err := server.TryDial(conf)
+		if err == nil {
+			conn.Close()
+		} else {
+			t.Fatalf("failed for cipher %q", ciph)
+		}
+	}
+}
+
+func TestMACs(t *testing.T) {
+	var config ssh.Config
+	config.SetDefaults()
+	macOrder := config.MACs
+
+	for _, mac := range macOrder {
+		server := newServer(t)
+		defer server.Shutdown()
+		conf := clientConfig()
+		conf.MACs = []string{mac}
+		// Don't fail if sshd doesn't have the MAC.
+		conf.MACs = append(conf.MACs, macOrder...)
+		if conn, err := server.TryDial(conf); err == nil {
+			conn.Close()
+		} else {
+			t.Fatalf("failed for MAC %q", mac)
+		}
+	}
+}
+
+func TestKeyExchanges(t *testing.T) {
+	var config ssh.Config
+	config.SetDefaults()
+	kexOrder := config.KeyExchanges
+	for _, kex := range kexOrder {
+		server := newServer(t)
+		defer server.Shutdown()
+		conf := clientConfig()
+		// Don't fail if sshd doesn't have the kex.
+		conf.KeyExchanges = append([]string{kex}, kexOrder...)
+		conn, err := server.TryDial(conf)
+		if err == nil {
+			conn.Close()
+		} else {
+			t.Errorf("failed for kex %q", kex)
+		}
+	}
+}
+
+func TestClientAuthAlgorithms(t *testing.T) {
+	for _, key := range []string{
+		"rsa",
+		"dsa",
+		"ecdsa",
+		"ed25519",
+	} {
+		server := newServer(t)
+		conf := clientConfig()
+		conf.SetDefaults()
+		conf.Auth = []ssh.AuthMethod{
+			ssh.PublicKeys(testSigners[key]),
+		}
+
+		conn, err := server.TryDial(conf)
+		if err == nil {
+			conn.Close()
+		} else {
+			t.Errorf("failed for key %q", key)
+		}
+
+		server.Shutdown()
+	}
+}

vendor/golang.org/x/crypto/ssh/test/tcpip_test.go

@@ -0,0 +1,46 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows
+
+package test
+
+// direct-tcpip functional tests
+
+import (
+	"io"
+	"net"
+	"testing"
+)
+
+func TestDial(t *testing.T) {
+	server := newServer(t)
+	defer server.Shutdown()
+	sshConn := server.Dial(clientConfig())
+	defer sshConn.Close()
+
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("Listen: %v", err)
+	}
+	defer l.Close()
+
+	go func() {
+		for {
+			c, err := l.Accept()
+			if err != nil {
+				break
+			}
+
+			io.WriteString(c, c.RemoteAddr().String())
+			c.Close()
+		}
+	}()
+
+	conn, err := sshConn.Dial("tcp", l.Addr().String())
+	if err != nil {
+		t.Fatalf("Dial: %v", err)
+	}
+	defer conn.Close()
+}

vendor/golang.org/x/crypto/ssh/test/test_unix_test.go

@@ -0,0 +1,268 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd plan9
+
+package test
+
+// functional test harness for unix.
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"os/exec"
+	"os/user"
+	"path/filepath"
+	"testing"
+	"text/template"
+
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/testdata"
+)
+
+const sshd_config = `
+Protocol 2
+HostKey {{.Dir}}/id_rsa
+HostKey {{.Dir}}/id_dsa
+HostKey {{.Dir}}/id_ecdsa
+Pidfile {{.Dir}}/sshd.pid
+#UsePrivilegeSeparation no
+KeyRegenerationInterval 3600
+ServerKeyBits 768
+SyslogFacility AUTH
+LogLevel DEBUG2
+LoginGraceTime 120
+PermitRootLogin no
+StrictModes no
+RSAAuthentication yes
+PubkeyAuthentication yes
+AuthorizedKeysFile	{{.Dir}}/authorized_keys
+TrustedUserCAKeys {{.Dir}}/id_ecdsa.pub
+IgnoreRhosts yes
+RhostsRSAAuthentication no
+HostbasedAuthentication no
+PubkeyAcceptedKeyTypes=*
+`
+
+var configTmpl = template.Must(template.New("").Parse(sshd_config))
+
+type server struct {
+	t          *testing.T
+	cleanup    func() // executed during Shutdown
+	configfile string
+	cmd        *exec.Cmd
+	output     bytes.Buffer // holds stderr from sshd process
+
+	// Client half of the network connection.
+	clientConn net.Conn
+}
+
+func username() string {
+	var username string
+	if user, err := user.Current(); err == nil {
+		username = user.Username
+	} else {
+		// user.Current() currently requires cgo. If an error is
+		// returned attempt to get the username from the environment.
+		log.Printf("user.Current: %v; falling back on $USER", err)
+		username = os.Getenv("USER")
+	}
+	if username == "" {
+		panic("Unable to get username")
+	}
+	return username
+}
+
+type storedHostKey struct {
+	// keys map from an algorithm string to binary key data.
+	keys map[string][]byte
+
+	// checkCount counts the Check calls. Used for testing
+	// rekeying.
+	checkCount int
+}
+
+func (k *storedHostKey) Add(key ssh.PublicKey) {
+	if k.keys == nil {
+		k.keys = map[string][]byte{}
+	}
+	k.keys[key.Type()] = key.Marshal()
+}
+
+func (k *storedHostKey) Check(addr string, remote net.Addr, key ssh.PublicKey) error {
+	k.checkCount++
+	algo := key.Type()
+
+	if k.keys == nil || bytes.Compare(key.Marshal(), k.keys[algo]) != 0 {
+		return fmt.Errorf("host key mismatch. Got %q, want %q", key, k.keys[algo])
+	}
+	return nil
+}
+
+func hostKeyDB() *storedHostKey {
+	keyChecker := &storedHostKey{}
+	keyChecker.Add(testPublicKeys["ecdsa"])
+	keyChecker.Add(testPublicKeys["rsa"])
+	keyChecker.Add(testPublicKeys["dsa"])
+	return keyChecker
+}
+
+func clientConfig() *ssh.ClientConfig {
+	config := &ssh.ClientConfig{
+		User: username(),
+		Auth: []ssh.AuthMethod{
+			ssh.PublicKeys(testSigners["user"]),
+		},
+		HostKeyCallback: hostKeyDB().Check,
+	}
+	return config
+}
+
+// unixConnection creates two halves of a connected net.UnixConn.  It
+// is used for connecting the Go SSH client with sshd without opening
+// ports.
+func unixConnection() (*net.UnixConn, *net.UnixConn, error) {
+	dir, err := ioutil.TempDir("", "unixConnection")
+	if err != nil {
+		return nil, nil, err
+	}
+	defer os.Remove(dir)
+
+	addr := filepath.Join(dir, "ssh")
+	listener, err := net.Listen("unix", addr)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer listener.Close()
+	c1, err := net.Dial("unix", addr)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	c2, err := listener.Accept()
+	if err != nil {
+		c1.Close()
+		return nil, nil, err
+	}
+
+	return c1.(*net.UnixConn), c2.(*net.UnixConn), nil
+}
+
+func (s *server) TryDial(config *ssh.ClientConfig) (*ssh.Client, error) {
+	sshd, err := exec.LookPath("sshd")
+	if err != nil {
+		s.t.Skipf("skipping test: %v", err)
+	}
+
+	c1, c2, err := unixConnection()
+	if err != nil {
+		s.t.Fatalf("unixConnection: %v", err)
+	}
+
+	s.cmd = exec.Command(sshd, "-f", s.configfile, "-i", "-e")
+	f, err := c2.File()
+	if err != nil {
+		s.t.Fatalf("UnixConn.File: %v", err)
+	}
+	defer f.Close()
+	s.cmd.Stdin = f
+	s.cmd.Stdout = f
+	s.cmd.Stderr = &s.output
+	if err := s.cmd.Start(); err != nil {
+		s.t.Fail()
+		s.Shutdown()
+		s.t.Fatalf("s.cmd.Start: %v", err)
+	}
+	s.clientConn = c1
+	conn, chans, reqs, err := ssh.NewClientConn(c1, "", config)
+	if err != nil {
+		return nil, err
+	}
+	return ssh.NewClient(conn, chans, reqs), nil
+}
+
+func (s *server) Dial(config *ssh.ClientConfig) *ssh.Client {
+	conn, err := s.TryDial(config)
+	if err != nil {
+		s.t.Fail()
+		s.Shutdown()
+		s.t.Fatalf("ssh.Client: %v", err)
+	}
+	return conn
+}
+
+func (s *server) Shutdown() {
+	if s.cmd != nil && s.cmd.Process != nil {
+		// Don't check for errors; if it fails it's most
+		// likely "os: process already finished", and we don't
+		// care about that. Use os.Interrupt, so child
+		// processes are killed too.
+		s.cmd.Process.Signal(os.Interrupt)
+		s.cmd.Wait()
+	}
+	if s.t.Failed() {
+		// log any output from sshd process
+		s.t.Logf("sshd: %s", s.output.String())
+	}
+	s.cleanup()
+}
+
+func writeFile(path string, contents []byte) {
+	f, err := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0600)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+	if _, err := f.Write(contents); err != nil {
+		panic(err)
+	}
+}
+
+// newServer returns a new mock ssh server.
+func newServer(t *testing.T) *server {
+	if testing.Short() {
+		t.Skip("skipping test due to -short")
+	}
+	dir, err := ioutil.TempDir("", "sshtest")
+	if err != nil {
+		t.Fatal(err)
+	}
+	f, err := os.Create(filepath.Join(dir, "sshd_config"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = configTmpl.Execute(f, map[string]string{
+		"Dir": dir,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	f.Close()
+
+	for k, v := range testdata.PEMBytes {
+		filename := "id_" + k
+		writeFile(filepath.Join(dir, filename), v)
+		writeFile(filepath.Join(dir, filename+".pub"), ssh.MarshalAuthorizedKey(testPublicKeys[k]))
+	}
+
+	var authkeys bytes.Buffer
+	for k, _ := range testdata.PEMBytes {
+		authkeys.Write(ssh.MarshalAuthorizedKey(testPublicKeys[k]))
+	}
+	writeFile(filepath.Join(dir, "authorized_keys"), authkeys.Bytes())
+
+	return &server{
+		t:          t,
+		configfile: f.Name(),
+		cleanup: func() {
+			if err := os.RemoveAll(dir); err != nil {
+				t.Error(err)
+			}
+		},
+	}
+}

vendor/golang.org/x/crypto/ssh/test/testdata_test.go

@@ -0,0 +1,64 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// IMPLEMENTATION NOTE: To avoid a package loop, this file is in three places:
+// ssh/, ssh/agent, and ssh/test/. It should be kept in sync across all three
+// instances.
+
+package test
+
+import (
+	"crypto/rand"
+	"fmt"
+
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/testdata"
+)
+
+var (
+	testPrivateKeys map[string]interface{}
+	testSigners     map[string]ssh.Signer
+	testPublicKeys  map[string]ssh.PublicKey
+)
+
+func init() {
+	var err error
+
+	n := len(testdata.PEMBytes)
+	testPrivateKeys = make(map[string]interface{}, n)
+	testSigners = make(map[string]ssh.Signer, n)
+	testPublicKeys = make(map[string]ssh.PublicKey, n)
+	for t, k := range testdata.PEMBytes {
+		testPrivateKeys[t], err = ssh.ParseRawPrivateKey(k)
+		if err != nil {
+			panic(fmt.Sprintf("Unable to parse test key %s: %v", t, err))
+		}
+		testSigners[t], err = ssh.NewSignerFromKey(testPrivateKeys[t])
+		if err != nil {
+			panic(fmt.Sprintf("Unable to create signer for test key %s: %v", t, err))
+		}
+		testPublicKeys[t] = testSigners[t].PublicKey()
+	}
+
+	// Create a cert and sign it for use in tests.
+	testCert := &ssh.Certificate{
+		Nonce:           []byte{},                       // To pass reflect.DeepEqual after marshal & parse, this must be non-nil
+		ValidPrincipals: []string{"gopher1", "gopher2"}, // increases test coverage
+		ValidAfter:      0,                              // unix epoch
+		ValidBefore:     ssh.CertTimeInfinity,           // The end of currently representable time.
+		Reserved:        []byte{},                       // To pass reflect.DeepEqual after marshal & parse, this must be non-nil
+		Key:             testPublicKeys["ecdsa"],
+		SignatureKey:    testPublicKeys["rsa"],
+		Permissions: ssh.Permissions{
+			CriticalOptions: map[string]string{},
+			Extensions:      map[string]string{},
+		},
+	}
+	testCert.SignCert(rand.Reader, testSigners["rsa"])
+	testPrivateKeys["cert"] = testPrivateKeys["ecdsa"]
+	testSigners["cert"], err = ssh.NewCertSigner(testCert, testSigners["ecdsa"])
+	if err != nil {
+		panic(fmt.Sprintf("Unable to create certificate signer: %v", err))
+	}
+}

vendor/golang.org/x/crypto/ssh/testdata/doc.go

@@ -0,0 +1,8 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This package contains test data shared between the various subpackages of
+// the golang.org/x/crypto/ssh package. Under no circumstance should
+// this data be used for production code.
+package testdata // import "golang.org/x/crypto/ssh/testdata"

vendor/golang.org/x/crypto/ssh/testdata/keys.go

@@ -0,0 +1,120 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testdata
+
+var PEMBytes = map[string][]byte{
+	"dsa": []byte(`-----BEGIN DSA PRIVATE KEY-----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+-----END DSA PRIVATE KEY-----
+`),
+	"ecdsa": []byte(`-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEINGWx0zo6fhJ/0EAfrPzVFyFC9s18lBt3cRoEDhS3ARooAoGCCqGSM49
+AwEHoUQDQgAEi9Hdw6KvZcWxfg2IDhA7UkpDtzzt6ZqJXSsFdLd+Kx4S3Sx4cVO+
+6/ZOXRnPmNAlLUqjShUsUBBngG0u2fqEqA==
+-----END EC PRIVATE KEY-----
+`),
+	"rsa": []byte(`-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----
+`),
+	"ed25519": []byte(`-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW
+QyNTUxOQAAACA+3f7hS7g5UWwXOGVTrMfhmxyrjqz7Sxxbx7I1j8DvvwAAAJhAFfkOQBX5
+DgAAAAtzc2gtZWQyNTUxOQAAACA+3f7hS7g5UWwXOGVTrMfhmxyrjqz7Sxxbx7I1j8Dvvw
+AAAEAaYmXltfW6nhRo3iWGglRB48lYq0z0Q3I3KyrdutEr6j7d/uFLuDlRbBc4ZVOsx+Gb
+HKuOrPtLHFvHsjWPwO+/AAAAE2dhcnRvbm1AZ2FydG9ubS14cHMBAg==
+-----END OPENSSH PRIVATE KEY-----
+`),
+	"user": []byte(`-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEILYCAeq8f7V4vSSypRw7pxy8yz3V5W4qg8kSC3zJhqpQoAoGCCqGSM49
+AwEHoUQDQgAEYcO2xNKiRUYOLEHM7VYAp57HNyKbOdYtHD83Z4hzNPVC4tM5mdGD
+PLL8IEwvYu2wq+lpXfGQnNMbzYf9gspG0w==
+-----END EC PRIVATE KEY-----
+`),
+}
+
+var PEMEncryptedKeys = []struct {
+	Name          string
+	EncryptionKey string
+	PEMBytes      []byte
+}{
+	0: {
+		Name:          "rsa-encrypted",
+		EncryptionKey: "r54-G0pher_t3st$",
+		PEMBytes: []byte(`-----BEGIN RSA PRIVATE KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: AES-128-CBC,3E1714DE130BC5E81327F36564B05462
+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-----END RSA PRIVATE KEY-----
+`),
+	},
+
+	1: {
+		Name:          "dsa-encrypted",
+		EncryptionKey: "qG0pher-dsa_t3st$",
+		PEMBytes: []byte(`-----BEGIN DSA PRIVATE KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: AES-128-CBC,7CE7A6E4A647DC01AF860210B15ADE3E
+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+-----END DSA PRIVATE KEY-----
+`),
+	},
+}

vendor/golang.org/x/crypto/ssh/testdata_test.go

@@ -0,0 +1,63 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// IMPLEMENTATION NOTE: To avoid a package loop, this file is in three places:
+// ssh/, ssh/agent, and ssh/test/. It should be kept in sync across all three
+// instances.
+
+package ssh
+
+import (
+	"crypto/rand"
+	"fmt"
+
+	"golang.org/x/crypto/ssh/testdata"
+)
+
+var (
+	testPrivateKeys map[string]interface{}
+	testSigners     map[string]Signer
+	testPublicKeys  map[string]PublicKey
+)
+
+func init() {
+	var err error
+
+	n := len(testdata.PEMBytes)
+	testPrivateKeys = make(map[string]interface{}, n)
+	testSigners = make(map[string]Signer, n)
+	testPublicKeys = make(map[string]PublicKey, n)
+	for t, k := range testdata.PEMBytes {
+		testPrivateKeys[t], err = ParseRawPrivateKey(k)
+		if err != nil {
+			panic(fmt.Sprintf("Unable to parse test key %s: %v", t, err))
+		}
+		testSigners[t], err = NewSignerFromKey(testPrivateKeys[t])
+		if err != nil {
+			panic(fmt.Sprintf("Unable to create signer for test key %s: %v", t, err))
+		}
+		testPublicKeys[t] = testSigners[t].PublicKey()
+	}
+
+	// Create a cert and sign it for use in tests.
+	testCert := &Certificate{
+		Nonce:           []byte{},                       // To pass reflect.DeepEqual after marshal & parse, this must be non-nil
+		ValidPrincipals: []string{"gopher1", "gopher2"}, // increases test coverage
+		ValidAfter:      0,                              // unix epoch
+		ValidBefore:     CertTimeInfinity,               // The end of currently representable time.
+		Reserved:        []byte{},                       // To pass reflect.DeepEqual after marshal & parse, this must be non-nil
+		Key:             testPublicKeys["ecdsa"],
+		SignatureKey:    testPublicKeys["rsa"],
+		Permissions: Permissions{
+			CriticalOptions: map[string]string{},
+			Extensions:      map[string]string{},
+		},
+	}
+	testCert.SignCert(rand.Reader, testSigners["rsa"])
+	testPrivateKeys["cert"] = testPrivateKeys["ecdsa"]
+	testSigners["cert"], err = NewCertSigner(testCert, testSigners["ecdsa"])
+	if err != nil {
+		panic(fmt.Sprintf("Unable to create certificate signer: %v", err))
+	}
+}

vendor/golang.org/x/crypto/ssh/transport.go

@@ -0,0 +1,333 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bufio"
+	"errors"
+	"io"
+)
+
+const (
+	gcmCipherID    = "aes128-gcm@openssh.com"
+	aes128cbcID    = "aes128-cbc"
+	tripledescbcID = "3des-cbc"
+)
+
+// packetConn represents a transport that implements packet based
+// operations.
+type packetConn interface {
+	// Encrypt and send a packet of data to the remote peer.
+	writePacket(packet []byte) error
+
+	// Read a packet from the connection
+	readPacket() ([]byte, error)
+
+	// Close closes the write-side of the connection.
+	Close() error
+}
+
+// transport is the keyingTransport that implements the SSH packet
+// protocol.
+type transport struct {
+	reader connectionState
+	writer connectionState
+
+	bufReader *bufio.Reader
+	bufWriter *bufio.Writer
+	rand      io.Reader
+
+	io.Closer
+}
+
+// packetCipher represents a combination of SSH encryption/MAC
+// protocol.  A single instance should be used for one direction only.
+type packetCipher interface {
+	// writePacket encrypts the packet and writes it to w. The
+	// contents of the packet are generally scrambled.
+	writePacket(seqnum uint32, w io.Writer, rand io.Reader, packet []byte) error
+
+	// readPacket reads and decrypts a packet of data. The
+	// returned packet may be overwritten by future calls of
+	// readPacket.
+	readPacket(seqnum uint32, r io.Reader) ([]byte, error)
+}
+
+// connectionState represents one side (read or write) of the
+// connection. This is necessary because each direction has its own
+// keys, and can even have its own algorithms
+type connectionState struct {
+	packetCipher
+	seqNum           uint32
+	dir              direction
+	pendingKeyChange chan packetCipher
+}
+
+// prepareKeyChange sets up key material for a keychange. The key changes in
+// both directions are triggered by reading and writing a msgNewKey packet
+// respectively.
+func (t *transport) prepareKeyChange(algs *algorithms, kexResult *kexResult) error {
+	if ciph, err := newPacketCipher(t.reader.dir, algs.r, kexResult); err != nil {
+		return err
+	} else {
+		t.reader.pendingKeyChange <- ciph
+	}
+
+	if ciph, err := newPacketCipher(t.writer.dir, algs.w, kexResult); err != nil {
+		return err
+	} else {
+		t.writer.pendingKeyChange <- ciph
+	}
+
+	return nil
+}
+
+// Read and decrypt next packet.
+func (t *transport) readPacket() ([]byte, error) {
+	return t.reader.readPacket(t.bufReader)
+}
+
+func (s *connectionState) readPacket(r *bufio.Reader) ([]byte, error) {
+	packet, err := s.packetCipher.readPacket(s.seqNum, r)
+	s.seqNum++
+	if err == nil && len(packet) == 0 {
+		err = errors.New("ssh: zero length packet")
+	}
+
+	if len(packet) > 0 {
+		switch packet[0] {
+		case msgNewKeys:
+			select {
+			case cipher := <-s.pendingKeyChange:
+				s.packetCipher = cipher
+			default:
+				return nil, errors.New("ssh: got bogus newkeys message.")
+			}
+
+		case msgDisconnect:
+			// Transform a disconnect message into an
+			// error. Since this is lowest level at which
+			// we interpret message types, doing it here
+			// ensures that we don't have to handle it
+			// elsewhere.
+			var msg disconnectMsg
+			if err := Unmarshal(packet, &msg); err != nil {
+				return nil, err
+			}
+			return nil, &msg
+		}
+	}
+
+	// The packet may point to an internal buffer, so copy the
+	// packet out here.
+	fresh := make([]byte, len(packet))
+	copy(fresh, packet)
+
+	return fresh, err
+}
+
+func (t *transport) writePacket(packet []byte) error {
+	return t.writer.writePacket(t.bufWriter, t.rand, packet)
+}
+
+func (s *connectionState) writePacket(w *bufio.Writer, rand io.Reader, packet []byte) error {
+	changeKeys := len(packet) > 0 && packet[0] == msgNewKeys
+
+	err := s.packetCipher.writePacket(s.seqNum, w, rand, packet)
+	if err != nil {
+		return err
+	}
+	if err = w.Flush(); err != nil {
+		return err
+	}
+	s.seqNum++
+	if changeKeys {
+		select {
+		case cipher := <-s.pendingKeyChange:
+			s.packetCipher = cipher
+		default:
+			panic("ssh: no key material for msgNewKeys")
+		}
+	}
+	return err
+}
+
+func newTransport(rwc io.ReadWriteCloser, rand io.Reader, isClient bool) *transport {
+	t := &transport{
+		bufReader: bufio.NewReader(rwc),
+		bufWriter: bufio.NewWriter(rwc),
+		rand:      rand,
+		reader: connectionState{
+			packetCipher:     &streamPacketCipher{cipher: noneCipher{}},
+			pendingKeyChange: make(chan packetCipher, 1),
+		},
+		writer: connectionState{
+			packetCipher:     &streamPacketCipher{cipher: noneCipher{}},
+			pendingKeyChange: make(chan packetCipher, 1),
+		},
+		Closer: rwc,
+	}
+	if isClient {
+		t.reader.dir = serverKeys
+		t.writer.dir = clientKeys
+	} else {
+		t.reader.dir = clientKeys
+		t.writer.dir = serverKeys
+	}
+
+	return t
+}
+
+type direction struct {
+	ivTag     []byte
+	keyTag    []byte
+	macKeyTag []byte
+}
+
+var (
+	serverKeys = direction{[]byte{'B'}, []byte{'D'}, []byte{'F'}}
+	clientKeys = direction{[]byte{'A'}, []byte{'C'}, []byte{'E'}}
+)
+
+// generateKeys generates key material for IV, MAC and encryption.
+func generateKeys(d direction, algs directionAlgorithms, kex *kexResult) (iv, key, macKey []byte) {
+	cipherMode := cipherModes[algs.Cipher]
+	macMode := macModes[algs.MAC]
+
+	iv = make([]byte, cipherMode.ivSize)
+	key = make([]byte, cipherMode.keySize)
+	macKey = make([]byte, macMode.keySize)
+
+	generateKeyMaterial(iv, d.ivTag, kex)
+	generateKeyMaterial(key, d.keyTag, kex)
+	generateKeyMaterial(macKey, d.macKeyTag, kex)
+	return
+}
+
+// setupKeys sets the cipher and MAC keys from kex.K, kex.H and sessionId, as
+// described in RFC 4253, section 6.4. direction should either be serverKeys
+// (to setup server->client keys) or clientKeys (for client->server keys).
+func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (packetCipher, error) {
+	iv, key, macKey := generateKeys(d, algs, kex)
+
+	if algs.Cipher == gcmCipherID {
+		return newGCMCipher(iv, key, macKey)
+	}
+
+	if algs.Cipher == aes128cbcID {
+		return newAESCBCCipher(iv, key, macKey, algs)
+	}
+
+	if algs.Cipher == tripledescbcID {
+		return newTripleDESCBCCipher(iv, key, macKey, algs)
+	}
+
+	c := &streamPacketCipher{
+		mac: macModes[algs.MAC].new(macKey),
+	}
+	c.macResult = make([]byte, c.mac.Size())
+
+	var err error
+	c.cipher, err = cipherModes[algs.Cipher].createStream(key, iv)
+	if err != nil {
+		return nil, err
+	}
+
+	return c, nil
+}
+
+// generateKeyMaterial fills out with key material generated from tag, K, H
+// and sessionId, as specified in RFC 4253, section 7.2.
+func generateKeyMaterial(out, tag []byte, r *kexResult) {
+	var digestsSoFar []byte
+
+	h := r.Hash.New()
+	for len(out) > 0 {
+		h.Reset()
+		h.Write(r.K)
+		h.Write(r.H)
+
+		if len(digestsSoFar) == 0 {
+			h.Write(tag)
+			h.Write(r.SessionID)
+		} else {
+			h.Write(digestsSoFar)
+		}
+
+		digest := h.Sum(nil)
+		n := copy(out, digest)
+		out = out[n:]
+		if len(out) > 0 {
+			digestsSoFar = append(digestsSoFar, digest...)
+		}
+	}
+}
+
+const packageVersion = "SSH-2.0-Go"
+
+// Sends and receives a version line.  The versionLine string should
+// be US ASCII, start with "SSH-2.0-", and should not include a
+// newline. exchangeVersions returns the other side's version line.
+func exchangeVersions(rw io.ReadWriter, versionLine []byte) (them []byte, err error) {
+	// Contrary to the RFC, we do not ignore lines that don't
+	// start with "SSH-2.0-" to make the library usable with
+	// nonconforming servers.
+	for _, c := range versionLine {
+		// The spec disallows non US-ASCII chars, and
+		// specifically forbids null chars.
+		if c < 32 {
+			return nil, errors.New("ssh: junk character in version line")
+		}
+	}
+	if _, err = rw.Write(append(versionLine, '\r', '\n')); err != nil {
+		return
+	}
+
+	them, err = readVersion(rw)
+	return them, err
+}
+
+// maxVersionStringBytes is the maximum number of bytes that we'll
+// accept as a version string. RFC 4253 section 4.2 limits this at 255
+// chars
+const maxVersionStringBytes = 255
+
+// Read version string as specified by RFC 4253, section 4.2.
+func readVersion(r io.Reader) ([]byte, error) {
+	versionString := make([]byte, 0, 64)
+	var ok bool
+	var buf [1]byte
+
+	for len(versionString) < maxVersionStringBytes {
+		_, err := io.ReadFull(r, buf[:])
+		if err != nil {
+			return nil, err
+		}
+		// The RFC says that the version should be terminated with \r\n
+		// but several SSH servers actually only send a \n.
+		if buf[0] == '\n' {
+			ok = true
+			break
+		}
+
+		// non ASCII chars are disallowed, but we are lenient,
+		// since Go doesn't use null-terminated strings.
+
+		// The RFC allows a comment after a space, however,
+		// all of it (version and comments) goes into the
+		// session hash.
+		versionString = append(versionString, buf[0])
+	}
+
+	if !ok {
+		return nil, errors.New("ssh: overflow reading version string")
+	}
+
+	// There might be a '\r' on the end which we should remove.
+	if len(versionString) > 0 && versionString[len(versionString)-1] == '\r' {
+		versionString = versionString[:len(versionString)-1]
+	}
+	return versionString, nil
+}

vendor/golang.org/x/crypto/ssh/transport_test.go

@@ -0,0 +1,109 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/binary"
+	"strings"
+	"testing"
+)
+
+func TestReadVersion(t *testing.T) {
+	longversion := strings.Repeat("SSH-2.0-bla", 50)[:253]
+	cases := map[string]string{
+		"SSH-2.0-bla\r\n":    "SSH-2.0-bla",
+		"SSH-2.0-bla\n":      "SSH-2.0-bla",
+		longversion + "\r\n": longversion,
+	}
+
+	for in, want := range cases {
+		result, err := readVersion(bytes.NewBufferString(in))
+		if err != nil {
+			t.Errorf("readVersion(%q): %s", in, err)
+		}
+		got := string(result)
+		if got != want {
+			t.Errorf("got %q, want %q", got, want)
+		}
+	}
+}
+
+func TestReadVersionError(t *testing.T) {
+	longversion := strings.Repeat("SSH-2.0-bla", 50)[:253]
+	cases := []string{
+		longversion + "too-long\r\n",
+	}
+	for _, in := range cases {
+		if _, err := readVersion(bytes.NewBufferString(in)); err == nil {
+			t.Errorf("readVersion(%q) should have failed", in)
+		}
+	}
+}
+
+func TestExchangeVersionsBasic(t *testing.T) {
+	v := "SSH-2.0-bla"
+	buf := bytes.NewBufferString(v + "\r\n")
+	them, err := exchangeVersions(buf, []byte("xyz"))
+	if err != nil {
+		t.Errorf("exchangeVersions: %v", err)
+	}
+
+	if want := "SSH-2.0-bla"; string(them) != want {
+		t.Errorf("got %q want %q for our version", them, want)
+	}
+}
+
+func TestExchangeVersions(t *testing.T) {
+	cases := []string{
+		"not\x000allowed",
+		"not allowed\n",
+	}
+	for _, c := range cases {
+		buf := bytes.NewBufferString("SSH-2.0-bla\r\n")
+		if _, err := exchangeVersions(buf, []byte(c)); err == nil {
+			t.Errorf("exchangeVersions(%q): should have failed", c)
+		}
+	}
+}
+
+type closerBuffer struct {
+	bytes.Buffer
+}
+
+func (b *closerBuffer) Close() error {
+	return nil
+}
+
+func TestTransportMaxPacketWrite(t *testing.T) {
+	buf := &closerBuffer{}
+	tr := newTransport(buf, rand.Reader, true)
+	huge := make([]byte, maxPacket+1)
+	err := tr.writePacket(huge)
+	if err == nil {
+		t.Errorf("transport accepted write for a huge packet.")
+	}
+}
+
+func TestTransportMaxPacketReader(t *testing.T) {
+	var header [5]byte
+	huge := make([]byte, maxPacket+128)
+	binary.BigEndian.PutUint32(header[0:], uint32(len(huge)))
+	// padding.
+	header[4] = 0
+
+	buf := &closerBuffer{}
+	buf.Write(header[:])
+	buf.Write(huge)
+
+	tr := newTransport(buf, rand.Reader, true)
+	_, err := tr.readPacket()
+	if err == nil {
+		t.Errorf("transport succeeded reading huge packet.")
+	} else if !strings.Contains(err.Error(), "large") {
+		t.Errorf("got %q, should mention %q", err.Error(), "large")
+	}
+}