ssh.0

OpenSSH 是 SSH （Secure SHell） 协议的免费开源实现。它用安全、加密的网络连接工具代替了 telnet、ftp、 rlogin、rsh 和 rcp 工具。OpenSSH 支持

             protocol version 1.  Compression is desirable on modem lines and
             other slow connections, but will only slow down things on fast
             networks.  The default value can be set on a host-by-host basis
             in the configuration files; see the Compression option.

     -c cipher_spec
             Selects the cipher specification for encrypting the session.

             Protocol version 1 allows specification of a single cipher.  The
             suported values are ``3des'', ``blowfish'' and ``des''.  3des
             (triple-des) is an encrypt-decrypt-encrypt triple with three dif-
             ferent keys.  It is believed to be secure.  blowfish is a fast
             block cipher; it appears very secure and is much faster than
             3des.  des is only supported in the ssh client for interoperabil-
             ity with legacy protocol 1 implementations that do not support
             the 3des cipher.  Its use is strongly discouraged due to crypto-
             graphic weaknesses.  The default is ``3des''.

             For protocol version 2 cipher_spec is a comma-separated list of
             ciphers listed in order of preference.  The supported ciphers are
             ``3des-cbc'', ``aes128-cbc'', ``aes192-cbc'', ``aes256-cbc'',
             ``aes128-ctr'', ``aes192-ctr'', ``aes256-ctr'', ``arcfour'',
             ``blowfish-cbc'', and ``cast128-cbc''.  The default is

               ``aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,
                 aes192-cbc,aes256-cbc''

     -D port
             Specifies a local ``dynamic'' application-level port forwarding.
             This works by allocating a socket to listen to port on the local
             side, and whenever a connection is made to this port, the connec-
             tion is forwarded over the secure channel, and the application
             protocol is then used to determine where to connect to from the
             remote machine.  Currently the SOCKS4 and SOCKS5 protocols are
             supported, and ssh will act as a SOCKS server.  Only root can
             forward privileged ports.  Dynamic port forwardings can also be
             specified in the configuration file.

     -e ch | ^ch | none
             Sets the escape character for sessions with a pty (default: `~').
             The escape character is only recognized at the beginning of a
             line.  The escape character followed by a dot (`.') closes the
             connection; followed by control-Z suspends the connection; and
             followed by itself sends the escape character once.  Setting the
             character to ``none'' disables any escapes and makes the session
             fully transparent.

     -F configfile
             Specifies an alternative per-user configuration file.  If a con-
             figuration file is given on the command line, the system-wide
             configuration file (/etc/ssh/ssh_config) will be ignored.  The
             default for the per-user configuration file is $HOME/.ssh/config.

     -f      Requests ssh to go to background just before command execution.
             This is useful if ssh is going to ask for passwords or passphras-
             es, but the user wants it in the background.  This implies -n.
             The recommended way to start X11 programs at a remote site is
             with something like ssh -f host xterm.

     -g      Allows remote hosts to connect to local forwarded ports.

     -I smartcard_device
             Specifies which smartcard device to use.  The argument is the de-
             vice ssh should use to communicate with a smartcard used for
             storing the user's private RSA key.

     -i identity_file
             Selects a file from which the identity (private key) for RSA or
             DSA authentication is read.  The default is $HOME/.ssh/identity
             for protocol version 1, and $HOME/.ssh/id_rsa and
             $HOME/.ssh/id_dsa for protocol version 2.  Identity files may al-
             so be specified on a per-host basis in the configuration file.
             It is possible to have multiple -i options (and multiple identi-
             ties specified in configuration files).

     -k      Disables forwarding (delegation) of GSSAPI credentials to the
             server.

     -L [bind_address:]port:host:hostport
             Specifies that the given port on the local (client) host is to be
             forwarded to the given host and port on the remote side.  This
             works by allocating a socket to listen to port on the local side,
             optionally bound to the specified bind_address.  Whenever a con-
             nection is made to this port, the connection is forwarded over
             the secure channel, and a connection is made to host port
             hostport from the remote machine.  Port forwardings can also be
             specified in the configuration file.  IPv6 addresses can be spec-
             ified with an alternative syntax: [bind_address/]port/host/host-
             port or by enclosing the address in square brackets.  Only the
             superuser can forward privileged ports.  By default, the local
             port is bound in accordance with the GatewayPorts setting.  How-
             ever, an explicit bind_address may be used to bind the connection
             to a specific address.  The bind_address of ``localhost'' indi-
             cates that the listening port be bound for local use only, while
             an empty address or `*' indicates that the port should be avail-
             able from all interfaces.

     -l login_name
             Specifies the user to log in as on the remote machine.  This also
             may be specified on a per-host basis in the configuration file.

     -M      Places the ssh client into ``master'' mode for connection shar-
             ing.  Refer to the description of ControlMaster in ssh_config(5)
             for details.

     -m mac_spec
             Additionally, for protocol version 2 a comma-separated list of
             MAC (message authentication code) algorithms can be specified in
             order of preference.  See the MACs keyword for more information.

     -N      Do not execute a remote command.  This is useful for just for-
             warding ports (protocol version 2 only).

     -n      Redirects stdin from /dev/null (actually, prevents reading from
             stdin).  This must be used when ssh is run in the background.  A
             common trick is to use this to run X11 programs on a remote ma-
             chine.  For example, ssh -n shadows.cs.hut.fi emacs & will start
             an emacs on shadows.cs.hut.fi, and the X11 connection will be au-
             tomatically forwarded over an encrypted channel.  The ssh program
             will be put in the background.  (This does not work if ssh needs
             to ask for a password or passphrase; see also the -f option.)

     -O ctl_cmd
             Control an active connection multiplexing master process.  When
             the -O option is specified, the ctl_cmd argument is interpreted
             and passed to the master process.  Valid commands are: ``check''
             (check that the master process is running) and ``exit'' (request
             the master to exit).

     -o option
             Can be used to give options in the format used in the configura-
             tion file.  This is useful for specifying options for which there
             is no separate command-line flag.  For full details of the op-
             tions listed below, and their possible values, see ssh_config(5).

                   AddressFamily
                   BatchMode
                   BindAddress
                   ChallengeResponseAuthentication
                   CheckHostIP
                   Cipher
                   Ciphers
                   ClearAllForwardings
                   Compression
                   CompressionLevel
                   ConnectionAttempts
                   ConnectTimeout
                   ControlMaster
                   ControlPath
                   DynamicForward
                   EscapeChar
                   ForwardAgent
                   ForwardX11
                   ForwardX11Trusted
                   GatewayPorts
                   GlobalKnownHostsFile
                   GSSAPIAuthentication
                   GSSAPIDelegateCredentials
                   HashKnownHosts
                   Host
                   HostbasedAuthentication
                   HostKeyAlgorithms
                   HostKeyAlias
                   HostName
                   IdentityFile
                   IdentitiesOnly
                   KbdInteractiveDevices
                   LocalForward
                   LogLevel
                   MACs
                   NoHostAuthenticationForLocalhost
                   NumberOfPasswordPrompts
                   PasswordAuthentication
                   Port
                   PreferredAuthentications
                   Protocol
                   ProxyCommand
                   PubkeyAuthentication
                   RemoteForward
                   RhostsRSAAuthentication
                   RSAAuthentication
                   SendEnv
                   ServerAliveInterval
                   ServerAliveCountMax
                   SmartcardDevice
                   StrictHostKeyChecking
                   TCPKeepAlive
                   UsePrivilegedPort
                   User
                   UserKnownHostsFile
                   VerifyHostKeyDNS
                   XAuthLocation

     -p port
             Port to connect to on the remote host.  This can be specified on
             a per-host basis in the configuration file.

     -q      Quiet mode.  Causes all warning and diagnostic messages to be
             suppressed.

     -R [bind_address:]port:host:hostport
             Specifies that the given port on the remote (server) host is to
             be forwarded to the given host and port on the local side.  This
             works by allocating a socket to listen to port on the remote
             side, and whenever a connection is made to this port, the connec-
             tion is forwarded over the secure channel, and a connection is
             made to host port hostport from the local machine.

             Port forwardings can also be specified in the configuration file.
             Privileged ports can be forwarded only when logging in as root on
             the remote machine.  IPv6 addresses can be specified by enclosing
             the address in square braces or using an alternative syntax:
             [bind_address/]host/port/hostport.

             By default, the listening socket on the server will be bound to
             the loopback interface only.  This may be overriden by specifying
             a bind_address.  An empty bind_address, or the address `*', indi-
             cates that the remote socket should listen on all interfaces.
             Specifying a remote bind_address will only succeed if the serv-
             er's GatewayPorts option is enabled (see sshd_config(5)).

     -S ctl_path
             Specifies the location of a control socket for connection shar-
             ing.  Refer to the description of ControlPath and ControlMaster
             in ssh_config(5) for details.

     -s      May be used to request invocation of a subsystem on the remote
             system.  Subsystems are a feature of the SSH2 protocol which fa-
             cilitate the use of SSH as a secure transport for other applica-
             tions (eg. sftp(1)).  The subsystem is specified as the remote
             command.

     -T      Disable pseudo-tty allocation.

     -t      Force pseudo-tty allocation.  This can be used to execute arbi-
             trary screen-based programs on a remote machine, which can be
             very useful, e.g., when implementing menu services.  Multiple -t
             options force tty allocation, even if ssh has no local tty.

     -V      Display the version number and exit.

     -v      Verbose mode.  Causes ssh to print debugging messages about its
             progress.  This is helpful in debugging connection, authentica-