This commit allows ssh_login to use socks proxies. Net::SSH::Transport::Session could take a :proxy option,

but it expects a factory object not a string, when setting :proxy => datastore['Proxies'] user got:
"Auxiliary failed: NoMethodError private method `open' called for \"socks4:localhost:1080\":String."
VALID_OPTIONS in ssh.rb now takes :proxies option which is passed to the Rex socket in
Net::SSH::Transport::Session.new.

Testing: block all outgoing to SSH server, try to connect with a proxy. Try with :proxy option,
then merge this pull request and try again.

lib/net/ssh.rb

@@ -72,7 +72,8 @@ module Net
       :rekey_limit, :rekey_packet_limit, :timeout, :verbose,
       :global_known_hosts_file, :user_known_hosts_file, :host_key_alias,
       :host_name, :user, :properties, :passphrase, :msframework, :msfmodule,
-      :record_auth_info, :skip_private_keys, :accepted_key_callback, :disable_agent
+      :record_auth_info, :skip_private_keys, :accepted_key_callback, :disable_agent,
+      :proxies
     ]
 
     # The standard means of starting a new SSH connection. When used with a

lib/net/ssh/transport/session.rb

@@ -74,6 +74,7 @@ module Net; module SSH; module Transport
           Rex::Socket::Tcp.create(
           	'PeerHost' => @host,
           	'PeerPort' => @port,
+		'Proxies' => options[:proxies],
           	'Context'  => {
           	  'Msf'          => options[:msframework],
           	  'MsfExploit'   => options[:msfmodule]

modules/auxiliary/scanner/ssh/ssh_login.rb

@@ -70,7 +70,8 @@ class Metasploit3 < Msf::Auxiliary
 			:port          => port,
 			:disable_agent => true,
 			:password      => pass,
-			:config        => false
+			:config        => false,
+			:proxies       => datastore['Proxies']
 		}
 
 		opt_hash.merge!(:verbose => :debug) if datastore['SSH_DEBUG']