10 .Op Fl c Ar cipher_spec
11 .Op Fl e Ar escape_char
12 .Op Fl i Ar identity_file
13 .Op Fl K Ar connection_spec
26 .Op Fl o Ar openssh_option
38 .Oo Ar user Ns @ Ns Oc Ar hostname
42 is a SSHv2 client for logging into a remote machine and executing commands. It provides encrypted and secure communications across a possibly insecure network. Arbitrary TCP/IP ports can also be forwarded over the secure connection.
45 connects and logs into
49 or the current username). The user must prove her/his identity through a public\-key or a password. Alternatively, if a connection is already open to a server, a new shell can be opened over the connection without having to reauthenticate.
55 is executed instead of a shell. If the
59 is treated as an SSHv2 subsystem name.
61 Conch supports the public-key, keyboard-interactive, and password authentications.
63 The public-key method allows the RSA or DSA algorithm to be used. The client uses his/her private key,
67 to sign the session identifier, known only by the client and server. The server checks that the matching public key is valid for the user, and that the signature is correct.
69 If public-key authentication fails,
71 can authenticate by sending an encrypted password over the connection.
72 .Ss Connection sharing
74 has the ability to multiplex multiple shells, commands and TCP/IP ports over the same secure connection. To disable multiplexing for a connection, use the
80 option determines how the client connects to the remote host. It is a comma-separated list of the methods to use, in order of preference. The two connection methods are
82 (for connecting over a multiplexed connection) and
84 (to connect directly).
85 To disable connecting over a multiplexed connection, do not include
87 in the preference list.
89 As an example of how connection sharing works, to speed up CVS over SSH:
92 --noshell --fork -l cvs_user cvs_host
94 set CVS_RSH=\fBconch\fR
96 Now, when CVS connects to cvs_host as cvs_user, instead of making a new connection to the server,
98 will add a new channel to the existing connection. This saves the cost of repeatedly negotiating the cryptography and authentication.
100 The options are as follows:
103 Enables authentication agent forwarding.
105 Disables authentication agent forwarding (default).
108 .It Fl c Ar cipher_spec
109 Selects encryption algorithms to be used for this connection, as a comma-separated list of ciphers in order of preference. The list that
111 supports is (in order of default preference): aes256-ctr, aes256-cbc, aes192-ctr, aes192-cbc, aes128-ctr, aes128-cbc, cast128-ctr, cast128-cbc, blowfish-ctr, blowfish, idea-ctr, idea-cbc, 3des-ctr, 3des-cbc.
112 .It Fl e Ar ch | ^ch | none
113 Sets the escape character for sessions with a PTY (default:
115 The escape character is only recognized at the beginning of a line (after a newline).
116 The escape character followed by a dot
118 closes the connection;
119 followed by ^Z suspends the connection;
120 and followed by the escape character sends the escape character once.
121 Setting the character to
123 disables any escapes.
125 Fork to background after authentication.
127 Do not allow connection sharing over this connection.
128 .It Fl i Ar identity_spec
129 The file from which the identity (private key) for RSA or DSA authentication is read.
131 .Pa $HOME/.ssh/id_rsa
133 .Pa $HOME/.ssh/id_dsa .
134 It is possible to use this option more than once to use more than one private key.
135 .It Fl K Ar connection_spec
136 Selects methods for connection to the server, as a comma-separated list of methods in order of preference. See
137 .Cm Connection sharing
138 for more information.
141 .Ar port : host : hostport
144 Specifies that the given port on the client host is to be forwarded to the given host and port on the remote side. This allocates a socket to listen to
146 on the local side, and when connections are made to that socket, they are forwarded over the secure channel and a connection is made to
150 from the remote machine.
151 Only root can forward privieged ports.
153 Log in using this username.
155 Selects MAC (message authentication code) algorithms, as a comma-separated list in order of preference. The list that
157 supports is (in order of preference): hmac-sha1, hmac-md5.
159 Do not execute a shell or command.
161 Redirect input from /dev/null.
162 .It Fl o Ar openssh_option
163 Ignored OpenSSH options.
165 The port to connect to on the server.
168 .Ar port : host : hostport
171 Specifies that the given port on the remote host is to be forwarded to the given host and port on the local side. This allocates a socket to listen to
173 on the remote side, and when connections are made to that socket, they are forwarded over the secure channel and a connection is made to
177 from the client host.
178 Only root can forward privieged ports.
180 Reconnect to the server if the connection is lost.
184 (mandatory) as a SSHv2 subsystem.
186 Do not allocate a TTY.
188 Allocate a TTY even if command is given.
190 Display version number only.
194 Disable X11 connection forwarding (default).
197 Written by Paul Swartz <z3p@twistedmatrix.com>.
199 To report a bug, visit \fIhttp://twistedmatrix.com/bugs/\fR
201 Copyright \(co 2002-2008 Twisted Matrix Laboratories.
203 This is free software; see the source for copying conditions. There is NO
204 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.