b2: Implement link sharing #2178

backend/b2/api/types.go

@@ -189,6 +189,21 @@ type GetUploadURLResponse struct {
 	AuthorizationToken string `json:"authorizationToken"` // The authorizationToken that must be used when uploading files to this bucket, see b2_upload_file.
 }
 
+// GetDownloadAuthorizationRequest is passed to b2_get_download_authorization
+type GetDownloadAuthorizationRequest struct {
+	BucketID               string `json:"bucketId"`                       // The ID of the bucket that you want to upload to.
+	FileNamePrefix         string `json:"fileNamePrefix"`                 // The file name prefix of files the download authorization token will allow access to.
+	ValidDurationInSeconds int64  `json:"validDurationInSeconds"`         // The number of seconds before the authorization token will expire. The minimum value is 1 second. The maximum value is 604800 which is one week in seconds.
+	B2ContentDisposition   string `json:"b2ContentDisposition,omitempty"` // optional - If this is present, download requests using the returned authorization must include the same value for b2ContentDisposition.
+}
+
+// GetDownloadAuthorizationResponse is received from b2_get_download_authorization
+type GetDownloadAuthorizationResponse struct {
+	BucketID           string `json:"bucketId"`           // The unique ID of the bucket.
+	FileNamePrefix     string `json:"fileNamePrefix"`     // The file name prefix of files the download authorization token will allow access to.
+	AuthorizationToken string `json:"authorizationToken"` // The authorizationToken that must be used when downloading files, see b2_download_file_by_name.
+}
+
 // FileInfo is received from b2_upload_file, b2_get_file_info and b2_finish_large_file
 type FileInfo struct {
 	ID              string            `json:"fileId"`          // The unique identifier for this version of this file. Used with b2_get_file_info, b2_download_file_by_id, and b2_delete_file_version.

backend/b2/b2.go

@@ -134,6 +134,14 @@ This is usually set to a Cloudflare CDN URL as Backblaze offers
 free egress for data downloaded through the Cloudflare network.
 Leave blank if you want to use the endpoint provided by Backblaze.`,
 			Advanced: true,
+		}, {
+			Name: "download_auth_duration",
+			Help: `Time before the authorization token will expire in s or suffix ms|s|m|h|d.
+
+The duration before the download authorization token will expire.
+The minimum value is 1 second. The maximum value is one week.`,
+			Default:  fs.Duration(7 * 24 * time.Hour),
+			Advanced: true,
 		}},
 	})
 }
@@ -150,6 +158,7 @@ type Options struct {
 	ChunkSize                     fs.SizeSuffix `config:"chunk_size"`
 	DisableCheckSum               bool          `config:"disable_checksum"`
 	DownloadURL                   string        `config:"download_url"`
+	DownloadAuthorizationDuration fs.Duration   `config:"download_auth_duration"`
 }
 
 // Fs represents a remote b2 server
@@ -164,6 +173,8 @@ type Fs struct {
 	bucketOK        bool                         // true if we have created the bucket
 	bucketIDMutex   sync.Mutex                   // mutex to protect _bucketID
 	_bucketID       string                       // the ID of the bucket we are working on
+	bucketTypeMutex sync.Mutex                   // mutex to protect _bucketType
+	_bucketType     string                       // the Type of the bucket we are working on
 	info            api.AuthorizeAccountResponse // result of authorize call
 	uploadMu        sync.Mutex                   // lock for upload variable
 	uploads         []*api.GetUploadURLResponse  // result of get upload URL calls
@@ -796,6 +807,42 @@ func (f *Fs) listBucketsToFn(fn listBucketFn) error {
 	return nil
 }
 
+// getbucketType finds the bucketType for the current bucket name
+// can be one of allPublic. allPrivate, or snapshot
+func (f *Fs) getbucketType() (bucketType string, err error) {
+	f.bucketTypeMutex.Lock()
+	defer f.bucketTypeMutex.Unlock()
+	if f._bucketType != "" {
+		return f._bucketType, nil
+	}
+	err = f.listBucketsToFn(func(bucket *api.Bucket) error {
+		if bucket.Name == f.bucket {
+			bucketType = bucket.Type
+		}
+		return nil
+
+	})
+	if bucketType == "" {
+		err = fs.ErrorDirNotFound
+	}
+	f._bucketType = bucketType
+	return bucketType, err
+}
+
+// setBucketType sets the Type for the current bucket name
+func (f *Fs) setBucketType(Type string) {
+	f.bucketTypeMutex.Lock()
+	f._bucketType = Type
+	f.bucketTypeMutex.Unlock()
+}
+
+// clearBucketType clears the Type for the current bucket name
+func (f *Fs) clearBucketType() {
+	f.bucketTypeMutex.Lock()
+	f._bucketType = ""
+	f.bucketTypeMutex.Unlock()
+}
+
 // getBucketID finds the ID for the current bucket name
 func (f *Fs) getBucketID() (bucketID string, err error) {
 	f.bucketIDMutex.Lock()
@@ -890,6 +937,7 @@ func (f *Fs) Mkdir(ctx context.Context, dir string) error {
 		return errors.Wrap(err, "failed to create bucket")
 	}
 	f.setBucketID(response.ID)
+	f.setBucketType(response.Type)
 	f.bucketOK = true
 	return nil
 }
@@ -925,6 +973,7 @@ func (f *Fs) Rmdir(ctx context.Context, dir string) error {
 	}
 	f.bucketOK = false
 	f.clearBucketID()
+	f.clearBucketType()
 	f.clearUploadURL()
 	return nil
 }
@@ -1125,6 +1174,61 @@ func (f *Fs) Hashes() hash.Set {
 	return hash.Set(hash.SHA1)
 }
 
+// getDownloadAuthorization returns authorization token for downloading
+// without accout.
+func (f *Fs) getDownloadAuthorization(remote string) (authorization string, err error) {
+	validDurationInSeconds := time.Duration(f.opt.DownloadAuthorizationDuration).Nanoseconds() / 1e9
+	if validDurationInSeconds <= 0 || validDurationInSeconds > 604800 {
+		return "", errors.New("--b2-download-auth-duration must be between 1 sec and 1 week")
+	}
+	bucketID, err := f.getBucketID()
+	if err != nil {
+		return "", err
+	}
+	opts := rest.Opts{
+		Method: "POST",
+		Path:   "/b2_get_download_authorization",
+	}
+	var request = api.GetDownloadAuthorizationRequest{
+		BucketID:               bucketID,
+		FileNamePrefix:         remote,
+		ValidDurationInSeconds: validDurationInSeconds,
+	}
+	var response api.GetDownloadAuthorizationResponse
+	err = f.pacer.Call(func() (bool, error) {
+		resp, err := f.srv.CallJSON(&opts, &request, &response)
+		return f.shouldRetry(resp, err)
+	})
+	if err != nil {
+		return "", errors.Wrap(err, "failed to get download authorization")
+	}
+	return response.AuthorizationToken, nil
+}
+
+// PublicLink returns a link for downloading without accout.
+func (f *Fs) PublicLink(ctx context.Context, remote string) (link string, err error) {
+	var RootURL string
+	if f.opt.DownloadURL == "" {
+		RootURL = f.info.DownloadURL
+	} else {
+		RootURL = f.opt.DownloadURL
+	}
+	absPath := "/" + path.Join(f.root, remote)
+	link = RootURL + "/file/" + urlEncode(f.bucket) + absPath
+	bucketType, err := f.getbucketType()
+	if err != nil {
+		return "", err
+	}
+	if bucketType == "allPrivate" || bucketType == "snapshot" {
+		AuthorizationToken, err := f.getDownloadAuthorization(remote)
+		if err != nil {
+			return "", err
+		}
+		link += "?Authorization=" + AuthorizationToken
+	}
+	return link, nil
+}
+
 // ------------------------------------------------------------
 
 // Fs returns the parent Fs
@@ -1657,6 +1761,7 @@ var (
 	_ fs.PutStreamer  = &Fs{}
 	_ fs.CleanUpper   = &Fs{}
 	_ fs.ListRer      = &Fs{}
+	_ fs.PublicLinker = &Fs{}
 	_ fs.Object       = &Object{}
 	_ fs.MimeTyper    = &Object{}
 	_ fs.IDer         = &Object{}

docs/content/overview.md

@@ -136,7 +136,7 @@ operations more efficient.
 | 1Fichier                     | No    | No   | No   | No      | No      | No    | No           | No           |   No  |
 | Amazon Drive                 | Yes   | No   | Yes  | Yes     | No [#575](https://github.com/ncw/rclone/issues/575) | No  | No  | No [#2178](https://github.com/ncw/rclone/issues/2178) | No  |
 | Amazon S3                    | No    | Yes  | No   | No      | No      | Yes   | Yes          | No [#2178](https://github.com/ncw/rclone/issues/2178) | No  |
-| Backblaze B2                 | No    | Yes  | No   | No      | Yes     | Yes   | Yes          | No [#2178](https://github.com/ncw/rclone/issues/2178) | No  |
+| Backblaze B2                 | No    | Yes  | No   | No      | Yes     | Yes   | Yes          | Yes | No  |
 | Box                          | Yes   | Yes  | Yes  | Yes     | No [#575](https://github.com/ncw/rclone/issues/575) | No  | Yes | Yes | No  |
 | Dropbox                      | Yes   | Yes  | Yes  | Yes     | No [#575](https://github.com/ncw/rclone/issues/575) | No  | Yes | Yes | Yes |
 | FTP                          | No    | No   | Yes  | Yes     | No      | No    | Yes          | No [#2178](https://github.com/ncw/rclone/issues/2178) | No  |