711 lines
36 KiB
Plaintext
711 lines
36 KiB
Plaintext
SSH_CONFIG(5) OpenBSD Programmer's Manual SSH_CONFIG(5)
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NAME
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ssh_config - OpenSSH SSH client configuration files
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SYNOPSIS
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~/.ssh/config
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/etc/ssh/ssh_config
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DESCRIPTION
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ssh(1) obtains configuration data from the following sources in the
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following order:
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1. command-line options
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2. user's configuration file (~/.ssh/config)
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3. system-wide configuration file (/etc/ssh/ssh_config)
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For each parameter, the first obtained value will be used. The
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configuration files contain sections separated by ``Host''
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specifications, and that section is only applied for hosts that match one
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of the patterns given in the specification. The matched host name is the
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one given on the command line.
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Since the first obtained value for each parameter is used, more host-
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specific declarations should be given near the beginning of the file, and
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general defaults at the end.
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The configuration file has the following format:
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Empty lines and lines starting with `#' are comments. Otherwise a line
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is of the format ``keyword arguments''. Configuration options may be
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separated by whitespace or optional whitespace and exactly one `='; the
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latter format is useful to avoid the need to quote whitespace when
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specifying configuration options using the ssh, scp, and sftp -o option.
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Arguments may optionally be enclosed in double quotes (") in order to
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represent arguments containing spaces.
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The possible keywords and their meanings are as follows (note that
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keywords are case-insensitive and arguments are case-sensitive):
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Host Restricts the following declarations (up to the next Host
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keyword) to be only for those hosts that match one of the
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patterns given after the keyword. If more than one pattern is
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provided, they should be separated by whitespace. A single `*'
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as a pattern can be used to provide global defaults for all
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hosts. The host is the hostname argument given on the command
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line (i.e. the name is not converted to a canonicalized host name
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before matching).
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See PATTERNS for more information on patterns.
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AddressFamily
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Specifies which address family to use when connecting. Valid
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arguments are ``any'', ``inet'' (use IPv4 only), or ``inet6''
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(use IPv6 only).
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BatchMode
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If set to ``yes'', passphrase/password querying will be disabled.
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This option is useful in scripts and other batch jobs where no
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user is present to supply the password. The argument must be
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``yes'' or ``no''. The default is ``no''.
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BindAddress
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Use the specified address on the local machine as the source
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address of the connection. Only useful on systems with more than
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one address. Note that this option does not work if
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UsePrivilegedPort is set to ``yes''.
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ChallengeResponseAuthentication
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Specifies whether to use challenge-response authentication. The
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argument to this keyword must be ``yes'' or ``no''. The default
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is ``yes''.
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CheckHostIP
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If this flag is set to ``yes'', ssh(1) will additionally check
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the host IP address in the known_hosts file. This allows ssh to
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detect if a host key changed due to DNS spoofing. If the option
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is set to ``no'', the check will not be executed. The default is
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``yes''.
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Cipher Specifies the cipher to use for encrypting the session in
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protocol version 1. Currently, ``blowfish'', ``3des'', and
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``des'' are supported. des is only supported in the ssh(1)
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client for interoperability with legacy protocol 1
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implementations that do not support the 3des cipher. Its use is
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strongly discouraged due to cryptographic weaknesses. The
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default is ``3des''.
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Ciphers
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Specifies the ciphers allowed for protocol version 2 in order of
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preference. Multiple ciphers must be comma-separated. The
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supported ciphers are ``3des-cbc'', ``aes128-cbc'',
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``aes192-cbc'', ``aes256-cbc'', ``aes128-ctr'', ``aes192-ctr'',
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``aes256-ctr'', ``arcfour128'', ``arcfour256'', ``arcfour'',
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``blowfish-cbc'', and ``cast128-cbc''. The default is:
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aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,
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aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,
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aes256-cbc,arcfour
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ClearAllForwardings
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Specifies that all local, remote, and dynamic port forwardings
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specified in the configuration files or on the command line be
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cleared. This option is primarily useful when used from the
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ssh(1) command line to clear port forwardings set in
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configuration files, and is automatically set by scp(1) and
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sftp(1). The argument must be ``yes'' or ``no''. The default is
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``no''.
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Compression
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Specifies whether to use compression. The argument must be
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``yes'' or ``no''. The default is ``no''.
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CompressionLevel
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Specifies the compression level to use if compression is enabled.
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The argument must be an integer from 1 (fast) to 9 (slow, best).
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The default level is 6, which is good for most applications. The
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meaning of the values is the same as in gzip(1). Note that this
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option applies to protocol version 1 only.
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ConnectionAttempts
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Specifies the number of tries (one per second) to make before
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exiting. The argument must be an integer. This may be useful in
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scripts if the connection sometimes fails. The default is 1.
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ConnectTimeout
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Specifies the timeout (in seconds) used when connecting to the
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SSH server, instead of using the default system TCP timeout.
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This value is used only when the target is down or really
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unreachable, not when it refuses the connection.
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ControlMaster
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Enables the sharing of multiple sessions over a single network
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connection. When set to ``yes'', ssh(1) will listen for
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connections on a control socket specified using the ControlPath
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argument. Additional sessions can connect to this socket using
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the same ControlPath with ControlMaster set to ``no'' (the
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default). These sessions will try to reuse the master instance's
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network connection rather than initiating new ones, but will fall
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back to connecting normally if the control socket does not exist,
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or is not listening.
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Setting this to ``ask'' will cause ssh to listen for control
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connections, but require confirmation using the SSH_ASKPASS
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program before they are accepted (see ssh-add(1) for details).
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If the ControlPath cannot be opened, ssh will continue without
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connecting to a master instance.
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X11 and ssh-agent(1) forwarding is supported over these
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multiplexed connections, however the display and agent forwarded
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will be the one belonging to the master connection i.e. it is not
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possible to forward multiple displays or agents.
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Two additional options allow for opportunistic multiplexing: try
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to use a master connection but fall back to creating a new one if
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one does not already exist. These options are: ``auto'' and
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``autoask''. The latter requires confirmation like the ``ask''
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option.
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ControlPath
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Specify the path to the control socket used for connection
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sharing as described in the ControlMaster section above or the
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string ``none'' to disable connection sharing. In the path, `%l'
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will be substituted by the local host name, `%h' will be
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substituted by the target host name, `%p' the port, and `%r' by
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the remote login username. It is recommended that any
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ControlPath used for opportunistic connection sharing include at
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least %h, %p, and %r. This ensures that shared connections are
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uniquely identified.
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ControlPersist
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When used in conjunction with ControlMaster, specifies that the
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master connection should remain open in the background (waiting
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for future client connections) after the initial client
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connection has been closed. If set to ``no'', then the master
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connection will not be placed into the background, and will close
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as soon as the initial client connection is closed. If set to
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``yes'', then the master connection will remain in the background
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indefinitely (until killed or closed via a mechanism such as the
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ssh(1) ``-O exit'' option). If set to a time in seconds, or a
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time in any of the formats documented in sshd_config(5), then the
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backgrounded master connection will automatically terminate after
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it has remained idle (with no client connections) for the
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specified time.
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DynamicForward
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Specifies that a TCP port on the local machine be forwarded over
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the secure channel, and the application protocol is then used to
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determine where to connect to from the remote machine.
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The argument must be [bind_address:]port. IPv6 addresses can be
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specified by enclosing addresses in square brackets. By default,
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the local port is bound in accordance with the GatewayPorts
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setting. However, an explicit bind_address may be used to bind
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the connection to a specific address. The bind_address of
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``localhost'' indicates that the listening port be bound for
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local use only, while an empty address or `*' indicates that the
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port should be available from all interfaces.
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Currently the SOCKS4 and SOCKS5 protocols are supported, and
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ssh(1) will act as a SOCKS server. Multiple forwardings may be
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specified, and additional forwardings can be given on the command
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line. Only the superuser can forward privileged ports.
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EnableSSHKeysign
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Setting this option to ``yes'' in the global client configuration
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file /etc/ssh/ssh_config enables the use of the helper program
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ssh-keysign(8) during HostbasedAuthentication. The argument must
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be ``yes'' or ``no''. The default is ``no''. This option should
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be placed in the non-hostspecific section. See ssh-keysign(8)
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for more information.
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EscapeChar
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Sets the escape character (default: `~'). The escape character
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can also be set on the command line. The argument should be a
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single character, `^' followed by a letter, or ``none'' to
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disable the escape character entirely (making the connection
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transparent for binary data).
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ExitOnForwardFailure
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Specifies whether ssh(1) should terminate the connection if it
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cannot set up all requested dynamic, tunnel, local, and remote
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port forwardings. The argument must be ``yes'' or ``no''. The
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default is ``no''.
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ForwardAgent
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Specifies whether the connection to the authentication agent (if
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any) will be forwarded to the remote machine. The argument must
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be ``yes'' or ``no''. The default is ``no''.
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Agent forwarding should be enabled with caution. Users with the
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ability to bypass file permissions on the remote host (for the
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agent's Unix-domain socket) can access the local agent through
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the forwarded connection. An attacker cannot obtain key material
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from the agent, however they can perform operations on the keys
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that enable them to authenticate using the identities loaded into
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the agent.
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ForwardX11
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Specifies whether X11 connections will be automatically
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redirected over the secure channel and DISPLAY set. The argument
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must be ``yes'' or ``no''. The default is ``no''.
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X11 forwarding should be enabled with caution. Users with the
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ability to bypass file permissions on the remote host (for the
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user's X11 authorization database) can access the local X11
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display through the forwarded connection. An attacker may then
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be able to perform activities such as keystroke monitoring if the
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ForwardX11Trusted option is also enabled.
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ForwardX11Timeout
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Specify a timeout for untrusted X11 forwarding using the format
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described in the TIME FORMATS section of sshd_config(5). X11
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connections received by ssh(1) after this time will be refused.
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The default is to disable untrusted X11 forwarding after twenty
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minutes has elapsed.
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ForwardX11Trusted
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If this option is set to ``yes'', remote X11 clients will have
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full access to the original X11 display.
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If this option is set to ``no'', remote X11 clients will be
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considered untrusted and prevented from stealing or tampering
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with data belonging to trusted X11 clients. Furthermore, the
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xauth(1) token used for the session will be set to expire after
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20 minutes. Remote clients will be refused access after this
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time.
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The default is ``no''.
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See the X11 SECURITY extension specification for full details on
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the restrictions imposed on untrusted clients.
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GatewayPorts
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Specifies whether remote hosts are allowed to connect to local
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forwarded ports. By default, ssh(1) binds local port forwardings
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to the loopback address. This prevents other remote hosts from
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connecting to forwarded ports. GatewayPorts can be used to
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specify that ssh should bind local port forwardings to the
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wildcard address, thus allowing remote hosts to connect to
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forwarded ports. The argument must be ``yes'' or ``no''. The
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default is ``no''.
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GlobalKnownHostsFile
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Specifies a file to use for the global host key database instead
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of /etc/ssh/ssh_known_hosts.
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GSSAPIAuthentication
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Specifies whether user authentication based on GSSAPI is allowed.
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The default is ``no''. Note that this option applies to protocol
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version 2 only.
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GSSAPIDelegateCredentials
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Forward (delegate) credentials to the server. The default is
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``no''. Note that this option applies to protocol version 2
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only.
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HashKnownHosts
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Indicates that ssh(1) should hash host names and addresses when
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they are added to ~/.ssh/known_hosts. These hashed names may be
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used normally by ssh(1) and sshd(8), but they do not reveal
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identifying information should the file's contents be disclosed.
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The default is ``no''. Note that existing names and addresses in
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known hosts files will not be converted automatically, but may be
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manually hashed using ssh-keygen(1).
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HostbasedAuthentication
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Specifies whether to try rhosts based authentication with public
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key authentication. The argument must be ``yes'' or ``no''. The
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default is ``no''. This option applies to protocol version 2
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only and is similar to RhostsRSAAuthentication.
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HostKeyAlgorithms
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Specifies the protocol version 2 host key algorithms that the
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client wants to use in order of preference. The default for this
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option is: ``ssh-rsa,ssh-dss''.
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HostKeyAlias
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Specifies an alias that should be used instead of the real host
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name when looking up or saving the host key in the host key
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database files. This option is useful for tunneling SSH
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connections or for multiple servers running on a single host.
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HostName
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Specifies the real host name to log into. This can be used to
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specify nicknames or abbreviations for hosts. If the hostname
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contains the character sequence `%h', then this will be replaced
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with the host name specified on the commandline (this is useful
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for manipulating unqualified names). The default is the name
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given on the command line. Numeric IP addresses are also
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permitted (both on the command line and in HostName
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specifications).
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IdentitiesOnly
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Specifies that ssh(1) should only use the authentication identity
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files configured in the ssh_config files, even if ssh-agent(1)
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offers more identities. The argument to this keyword must be
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``yes'' or ``no''. This option is intended for situations where
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ssh-agent offers many different identities. The default is
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``no''.
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IdentityFile
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Specifies a file from which the user's RSA or DSA authentication
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identity is read. The default is ~/.ssh/identity for protocol
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version 1, and ~/.ssh/id_rsa and ~/.ssh/id_dsa for protocol
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version 2. Additionally, any identities represented by the
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authentication agent will be used for authentication. ssh(1)
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will try to load certificate information from the filename
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obtained by appending -cert.pub to the path of a specified
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IdentityFile.
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The file name may use the tilde syntax to refer to a user's home
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directory or one of the following escape characters: `%d' (local
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user's home directory), `%u' (local user name), `%l' (local host
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name), `%h' (remote host name) or `%r' (remote user name).
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It is possible to have multiple identity files specified in
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configuration files; all these identities will be tried in
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sequence.
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KbdInteractiveAuthentication
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Specifies whether to use keyboard-interactive authentication.
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The argument to this keyword must be ``yes'' or ``no''. The
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default is ``yes''.
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KbdInteractiveDevices
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Specifies the list of methods to use in keyboard-interactive
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authentication. Multiple method names must be comma-separated.
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The default is to use the server specified list. The methods
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available vary depending on what the server supports. For an
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OpenSSH server, it may be zero or more of: ``bsdauth'', ``pam'',
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and ``skey''.
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LocalCommand
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Specifies a command to execute on the local machine after
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successfully connecting to the server. The command string
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extends to the end of the line, and is executed with the user's
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shell. The following escape character substitutions will be
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performed: `%d' (local user's home directory), `%h' (remote host
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name), `%l' (local host name), `%n' (host name as provided on the
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command line), `%p' (remote port), `%r' (remote user name) or
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`%u' (local user name).
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The command is run synchronously and does not have access to the
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session of the ssh(1) that spawned it. It should not be used for
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interactive commands.
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This directive is ignored unless PermitLocalCommand has been
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enabled.
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LocalForward
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Specifies that a TCP port on the local machine be forwarded over
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the secure channel to the specified host and port from the remote
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machine. The first argument must be [bind_address:]port and the
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second argument must be host:hostport. IPv6 addresses can be
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specified by enclosing addresses in square brackets. Multiple
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forwardings may be specified, and additional forwardings can be
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given on the command line. Only the superuser can forward
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privileged ports. By default, the local port is bound in
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accordance with the GatewayPorts setting. However, an explicit
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bind_address may be used to bind the connection to a specific
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address. The bind_address of ``localhost'' indicates that the
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listening port be bound for local use only, while an empty
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address or `*' indicates that the port should be available from
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all interfaces.
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LogLevel
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Gives the verbosity level that is used when logging messages from
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ssh(1). The possible values are: QUIET, FATAL, ERROR, INFO,
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VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. The default is INFO.
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DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify
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higher levels of verbose output.
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MACs Specifies the MAC (message authentication code) algorithms in
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order of preference. The MAC algorithm is used in protocol
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version 2 for data integrity protection. Multiple algorithms
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must be comma-separated. The default is:
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hmac-md5,hmac-sha1,umac-64@openssh.com,
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hmac-ripemd160,hmac-sha1-96,hmac-md5-96
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NoHostAuthenticationForLocalhost
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This option can be used if the home directory is shared across
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machines. In this case localhost will refer to a different
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machine on each of the machines and the user will get many
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warnings about changed host keys. However, this option disables
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host authentication for localhost. The argument to this keyword
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must be ``yes'' or ``no''. The default is to check the host key
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for localhost.
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NumberOfPasswordPrompts
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Specifies the number of password prompts before giving up. The
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argument to this keyword must be an integer. The default is 3.
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PasswordAuthentication
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Specifies whether to use password authentication. The argument
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to this keyword must be ``yes'' or ``no''. The default is
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``yes''.
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PermitLocalCommand
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Allow local command execution via the LocalCommand option or
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using the !command escape sequence in ssh(1). The argument must
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be ``yes'' or ``no''. The default is ``no''.
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PKCS11Provider
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Specifies which PKCS#11 provider to use. The argument to this
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keyword is the PKCS#11 shared libary ssh(1) should use to
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communicate with a PKCS#11 token providing the user's private RSA
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key.
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Port Specifies the port number to connect on the remote host. The
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default is 22.
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PreferredAuthentications
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Specifies the order in which the client should try protocol 2
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authentication methods. This allows a client to prefer one
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method (e.g. keyboard-interactive) over another method (e.g.
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password). The default is:
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gssapi-with-mic,hostbased,publickey,
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keyboard-interactive,password
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Protocol
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Specifies the protocol versions ssh(1) should support in order of
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preference. The possible values are `1' and `2'. Multiple
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versions must be comma-separated. When this option is set to
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``2,1'' ssh will try version 2 and fall back to version 1 if
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version 2 is not available. The default is `2'.
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ProxyCommand
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Specifies the command to use to connect to the server. The
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command string extends to the end of the line, and is executed
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with the user's shell. In the command string, any occurrence of
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`%h' will be substituted by the host name to connect, `%p' by the
|
|
port, and `%r' by the remote user name. The command can be
|
|
basically anything, and should read from its standard input and
|
|
write to its standard output. It should eventually connect an
|
|
sshd(8) server running on some machine, or execute sshd -i
|
|
somewhere. Host key management will be done using the HostName
|
|
of the host being connected (defaulting to the name typed by the
|
|
user). Setting the command to ``none'' disables this option
|
|
entirely. Note that CheckHostIP is not available for connects
|
|
with a proxy command.
|
|
|
|
This directive is useful in conjunction with nc(1) and its proxy
|
|
support. For example, the following directive would connect via
|
|
an HTTP proxy at 192.0.2.0:
|
|
|
|
ProxyCommand /usr/bin/nc -X connect -x 192.0.2.0:8080 %h %p
|
|
|
|
PubkeyAuthentication
|
|
Specifies whether to try public key authentication. The argument
|
|
to this keyword must be ``yes'' or ``no''. The default is
|
|
``yes''. This option applies to protocol version 2 only.
|
|
|
|
RekeyLimit
|
|
Specifies the maximum amount of data that may be transmitted
|
|
before the session key is renegotiated. The argument is the
|
|
number of bytes, with an optional suffix of `K', `M', or `G' to
|
|
indicate Kilobytes, Megabytes, or Gigabytes, respectively. The
|
|
default is between `1G' and `4G', depending on the cipher. This
|
|
option applies to protocol version 2 only.
|
|
|
|
RemoteForward
|
|
Specifies that a TCP port on the remote machine be forwarded over
|
|
the secure channel to the specified host and port from the local
|
|
machine. The first argument must be [bind_address:]port and the
|
|
second argument must be host:hostport. IPv6 addresses can be
|
|
specified by enclosing addresses in square brackets. Multiple
|
|
forwardings may be specified, and additional forwardings can be
|
|
given on the command line. Privileged ports can be forwarded
|
|
only when logging in as root on the remote machine.
|
|
|
|
If the port argument is `0', the listen port will be dynamically
|
|
allocated on the server and reported to the client at run time.
|
|
|
|
If the bind_address is not specified, the default is to only bind
|
|
to loopback addresses. If the bind_address is `*' or an empty
|
|
string, then the forwarding is requested to listen on all
|
|
interfaces. Specifying a remote bind_address will only succeed
|
|
if the server's GatewayPorts option is enabled (see
|
|
sshd_config(5)).
|
|
|
|
RhostsRSAAuthentication
|
|
Specifies whether to try rhosts based authentication with RSA
|
|
host authentication. The argument must be ``yes'' or ``no''.
|
|
The default is ``no''. This option applies to protocol version 1
|
|
only and requires ssh(1) to be setuid root.
|
|
|
|
RSAAuthentication
|
|
Specifies whether to try RSA authentication. The argument to
|
|
this keyword must be ``yes'' or ``no''. RSA authentication will
|
|
only be attempted if the identity file exists, or an
|
|
authentication agent is running. The default is ``yes''. Note
|
|
that this option applies to protocol version 1 only.
|
|
|
|
SendEnv
|
|
Specifies what variables from the local environ(7) should be sent
|
|
to the server. Note that environment passing is only supported
|
|
for protocol 2. The server must also support it, and the server
|
|
must be configured to accept these environment variables. Refer
|
|
to AcceptEnv in sshd_config(5) for how to configure the server.
|
|
Variables are specified by name, which may contain wildcard
|
|
characters. Multiple environment variables may be separated by
|
|
whitespace or spread across multiple SendEnv directives. The
|
|
default is not to send any environment variables.
|
|
|
|
See PATTERNS for more information on patterns.
|
|
|
|
ServerAliveCountMax
|
|
Sets the number of server alive messages (see below) which may be
|
|
sent without ssh(1) receiving any messages back from the server.
|
|
If this threshold is reached while server alive messages are
|
|
being sent, ssh will disconnect from the server, terminating the
|
|
session. It is important to note that the use of server alive
|
|
messages is very different from TCPKeepAlive (below). The server
|
|
alive messages are sent through the encrypted channel and
|
|
therefore will not be spoofable. The TCP keepalive option
|
|
enabled by TCPKeepAlive is spoofable. The server alive mechanism
|
|
is valuable when the client or server depend on knowing when a
|
|
connection has become inactive.
|
|
|
|
The default value is 3. If, for example, ServerAliveInterval
|
|
(see below) is set to 15 and ServerAliveCountMax is left at the
|
|
default, if the server becomes unresponsive, ssh will disconnect
|
|
after approximately 45 seconds. This option applies to protocol
|
|
version 2 only.
|
|
|
|
ServerAliveInterval
|
|
Sets a timeout interval in seconds after which if no data has
|
|
been received from the server, ssh(1) will send a message through
|
|
the encrypted channel to request a response from the server. The
|
|
default is 0, indicating that these messages will not be sent to
|
|
the server. This option applies to protocol version 2 only.
|
|
|
|
StrictHostKeyChecking
|
|
If this flag is set to ``yes'', ssh(1) will never automatically
|
|
add host keys to the ~/.ssh/known_hosts file, and refuses to
|
|
connect to hosts whose host key has changed. This provides
|
|
maximum protection against trojan horse attacks, though it can be
|
|
annoying when the /etc/ssh/ssh_known_hosts file is poorly
|
|
maintained or when connections to new hosts are frequently made.
|
|
This option forces the user to manually add all new hosts. If
|
|
this flag is set to ``no'', ssh will automatically add new host
|
|
keys to the user known hosts files. If this flag is set to
|
|
``ask'', new host keys will be added to the user known host files
|
|
only after the user has confirmed that is what they really want
|
|
to do, and ssh will refuse to connect to hosts whose host key has
|
|
changed. The host keys of known hosts will be verified
|
|
automatically in all cases. The argument must be ``yes'',
|
|
``no'', or ``ask''. The default is ``ask''.
|
|
|
|
TCPKeepAlive
|
|
Specifies whether the system should send TCP keepalive messages
|
|
to the other side. If they are sent, death of the connection or
|
|
crash of one of the machines will be properly noticed. However,
|
|
this means that connections will die if the route is down
|
|
temporarily, and some people find it annoying.
|
|
|
|
The default is ``yes'' (to send TCP keepalive messages), and the
|
|
client will notice if the network goes down or the remote host
|
|
dies. This is important in scripts, and many users want it too.
|
|
|
|
To disable TCP keepalive messages, the value should be set to
|
|
``no''.
|
|
|
|
Tunnel Request tun(4) device forwarding between the client and the
|
|
server. The argument must be ``yes'', ``point-to-point'' (layer
|
|
3), ``ethernet'' (layer 2), or ``no''. Specifying ``yes''
|
|
requests the default tunnel mode, which is ``point-to-point''.
|
|
The default is ``no''.
|
|
|
|
TunnelDevice
|
|
Specifies the tun(4) devices to open on the client (local_tun)
|
|
and the server (remote_tun).
|
|
|
|
The argument must be local_tun [:remote_tun]. The devices may be
|
|
specified by numerical ID or the keyword ``any'', which uses the
|
|
next available tunnel device. If remote_tun is not specified, it
|
|
defaults to ``any''. The default is ``any:any''.
|
|
|
|
UsePrivilegedPort
|
|
Specifies whether to use a privileged port for outgoing
|
|
connections. The argument must be ``yes'' or ``no''. The
|
|
default is ``no''. If set to ``yes'', ssh(1) must be setuid
|
|
root. Note that this option must be set to ``yes'' for
|
|
RhostsRSAAuthentication with older servers.
|
|
|
|
User Specifies the user to log in as. This can be useful when a
|
|
different user name is used on different machines. This saves
|
|
the trouble of having to remember to give the user name on the
|
|
command line.
|
|
|
|
UserKnownHostsFile
|
|
Specifies a file to use for the user host key database instead of
|
|
~/.ssh/known_hosts.
|
|
|
|
VerifyHostKeyDNS
|
|
Specifies whether to verify the remote key using DNS and SSHFP
|
|
resource records. If this option is set to ``yes'', the client
|
|
will implicitly trust keys that match a secure fingerprint from
|
|
DNS. Insecure fingerprints will be handled as if this option was
|
|
set to ``ask''. If this option is set to ``ask'', information on
|
|
fingerprint match will be displayed, but the user will still need
|
|
to confirm new host keys according to the StrictHostKeyChecking
|
|
option. The argument must be ``yes'', ``no'', or ``ask''. The
|
|
default is ``no''. Note that this option applies to protocol
|
|
version 2 only.
|
|
|
|
See also VERIFYING HOST KEYS in ssh(1).
|
|
|
|
VisualHostKey
|
|
If this flag is set to ``yes'', an ASCII art representation of
|
|
the remote host key fingerprint is printed in addition to the hex
|
|
fingerprint string at login and for unknown host keys. If this
|
|
flag is set to ``no'', no fingerprint strings are printed at
|
|
login and only the hex fingerprint string will be printed for
|
|
unknown host keys. The default is ``no''.
|
|
|
|
XAuthLocation
|
|
Specifies the full pathname of the xauth(1) program. The default
|
|
is /usr/X11R6/bin/xauth.
|
|
|
|
PATTERNS
|
|
A pattern consists of zero or more non-whitespace characters, `*' (a
|
|
wildcard that matches zero or more characters), or `?' (a wildcard that
|
|
matches exactly one character). For example, to specify a set of
|
|
declarations for any host in the ``.co.uk'' set of domains, the following
|
|
pattern could be used:
|
|
|
|
Host *.co.uk
|
|
|
|
The following pattern would match any host in the 192.168.0.[0-9] network
|
|
range:
|
|
|
|
Host 192.168.0.?
|
|
|
|
A pattern-list is a comma-separated list of patterns. Patterns within
|
|
pattern-lists may be negated by preceding them with an exclamation mark
|
|
(`!'). For example, to allow a key to be used from anywhere within an
|
|
organisation except from the ``dialup'' pool, the following entry (in
|
|
authorized_keys) could be used:
|
|
|
|
from="!*.dialup.example.com,*.example.com"
|
|
|
|
FILES
|
|
~/.ssh/config
|
|
This is the per-user configuration file. The format of this file
|
|
is described above. This file is used by the SSH client.
|
|
Because of the potential for abuse, this file must have strict
|
|
permissions: read/write for the user, and not accessible by
|
|
others.
|
|
|
|
/etc/ssh/ssh_config
|
|
Systemwide configuration file. This file provides defaults for
|
|
those values that are not specified in the user's configuration
|
|
file, and for those users who do not have a configuration file.
|
|
This file must be world-readable.
|
|
|
|
SEE ALSO
|
|
ssh(1)
|
|
|
|
AUTHORS
|
|
OpenSSH is a derivative of the original and free ssh 1.2.12 release by
|
|
Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
|
|
de Raadt and Dug Song removed many bugs, re-added newer features and
|
|
created OpenSSH. Markus Friedl contributed the support for SSH protocol
|
|
versions 1.5 and 2.0.
|
|
|
|
OpenBSD 4.8 August 4, 2010 OpenBSD 4.8
|