keychain.txt

NAME
    keychain - re-use ssh-agent and/or gpg-agent between logins

SYNOPSIS
    keychain [ -hklQqV ] [ --clear --confhost --gpg2 --help --ignore-missing
     --list --noask --nocolor --nogui --nolock --quick --quiet --version ]
    [ --agents *list* ] [ --attempts *num* ] [ --dir *dirname* ]
    [ --host *name* ] [ --lockwait *seconds* ]
    [ --stop *which* ] [ --timeout *minutes* ] [ keys... ]

DESCRIPTION
    keychain is a manager for ssh-agent, typically run from ~/.bash_profile.
    It allows your shells and cron jobs to easily share a single ssh-agent
    process. By default, the ssh-agent started by keychain is long-running
    and will continue to run, even after you have logged out from the
    system. If you want to change this behavior, take a look at the --clear
    and --timeout options, described below.

    When keychain is run, it checks for a running ssh-agent, otherwise it
    starts one. It saves the ssh-agent environment variables to
    ~/.keychain/${HOSTNAME}-sh, so that subsequent logins and
    non-interactive shells such as cron jobs can source the file and make
    passwordless ssh connections.

    In addition, when keychain runs, it verifies that the key files
    specified on the command-line are known to ssh-agent, otherwise it loads
    them, prompting you for a password if necessary. Typically, private key
    files are specified by filename only, without path, although it is
    possible to specify an absolute or relative path to the private key file
    as well. If just a private key filename is used, which is typical usage,
    keychain will look for the specified private key files in ~/.ssh,
    ~/.ssh2, or with the -c/--confhost option, inspect the ~/.ssh/config
    file and use the IdentityFile option to determine the location of the
    private key. Private keys can be symlinks to the actual private key.

    Keychain expects associated public key files to exist in the same
    directory as the private key files, with a .pub extension. If the
    private key is a symlink, the public key can be found alongside the
    symlink, or in the same directory as the symlink target (This capability
    requires the 'readlink' command to be available on the system.)

    As an additional feature, if a private key has an extension ".ext",
    keychain will look for privkey.ext.pub first, and if not found, will
    look for privkeyname.pub.

    Keychain also supports gpg-agent in the same ways that ssh-agent is
    supported. By default keychain attempts to start ssh-agent only. You can
    modify this behavior using the --agents option.

    Keychain supports most UNIX-like operating systems, including Cygwin. It
    works with Bourne-compatible, csh-compatible and fish shells.

OPTIONS
    --agents *list*
        Start the agents listed. By default keychain will start ssh-agent if
        it is found in your path. The list should be comma-separated, for
        example "gpg,ssh"

    --attempts *num*
        Try num times to add keys before giving up. The default is 1.

    --clear
        Delete all of ssh-agent's keys. Typically this is used in
        .bash_profile. The theory behind this is that keychain should assume
        that you are an intruder until proven otherwise. However, while this
        option increases security, it still allows your cron jobs to use
        your ssh keys when you're logged out.

    --confhost
        By default, keychain will look for key pairs in the ~/.ssh/
        directory. The --confhost option will inform keychain to look in
        ~/.ssh/config for IdentityFile settings defined for particular
        hosts, and use these paths to locate keys.

    --confirm
        Keys are subject to interactive confirmation by the SSH_ASKPASS
        program before being used for authentication. See the -c option for
        ssh-add(1).

    --absolute
        Any arguments to "--dir" are interpreted to be absolute. The default
        behavior is to append "/.keychain" to the argument for backwards
        compatibility.

    --dir *dirname*
        Keychain will use dirname rather than $HOME/.keychain

    --query
        Keychain will print lines in KEY=value format representing the
        values which are set by the agents.

    --eval
        Keychain will print lines to be evaluated in the shell on stdout. It
        respects the SHELL environment variable to determine if Bourne shell
        or C shell output is expected.

    --env *filename*
        After parsing options, keychain will load additional environment
        settings from "filename". By default, if "--env" is not given, then
        keychain will attempt to load from ~/.keychain/[hostname]-env or
        alternatively ~/.keychain/env. The purpose of this file is to
        override settings such as PATH, in case ssh is stored in a
        non-standard place.

    --gpg2
        This option changes the default gpg calls to use gpg2 instead to
        support distributions such as Ubuntu which has both gpg and gpg2

    -h --help
        Show help that looks remarkably like this man-page. As of 2.6.10,
        help is sent to stdout so it can be easily piped to a pager.

    --host *name*
        Set alternate hostname for creation of pidfiles

    --ignore-missing
        Don't warn if some keys on the command-line can't be found. This is
        useful for situations where you have a shared .bash_profile, but
        your keys might not be available on every machine where keychain is
        run.

    --inherit *which*
        Attempt to inherit agent variables from the environment. This can be
        useful in a variety of circumstances, for example when ssh-agent is
        started by gdm. The following values are valid for "which":

        local       Inherit when a pid (e.g. SSH_AGENT_PID) is set in the
                    environment. This disallows inheriting a forwarded
                    agent.

        any         Inherit when a sock (e.g. SSH_AUTH_SOCK) is set in the
                    environment. This allows inheriting a forwarded agent.

        local-once  Same as "local", but only inherit if keychain isn't
                    already providing an agent.

        any-once    Same as "any", but only inherit if keychain isn't
                    already providing an agent.

        By default, keychain-2.5.0 and later will behave as if "--inherit
        local-once" is specified. You should specify "--noinherit" if you
        want the older behavior.

    -l --list
        List signatures of all active SSH keys, and exit, similar to
        "ssh-add -l".

    -L --list-fp
        List fingerprints of all active SSH keys, and exit, similar to
        "ssh-add -L".

    --lockwait *seconds*
        How long to wait for the lock to become available. Defaults to 5
        seconds. Specify a value of zero or more. If the lock cannot be
        acquired within the specified number of seconds, then this keychain
        process will forcefully acquire the lock.

    --noask
        This option tells keychain do everything it normally does (ensure
        ssh-agent is running, set up the ~/.keychain/[hostname]-{c}sh files)
        except that it will not prompt you to add any of the keys you
        specified if they haven't yet been added to ssh-agent.

    --nocolor
        Disable color highlighting for non ANSI-compatible terms.

    --nogui
        Don't honor SSH_ASKPASS, if it is set. This will cause ssh-add to
        prompt on the terminal instead of using a graphical program.

    --noinherit
        Don't inherit any agent processes, overriding the default "--inherit
        local-once"

    --nolock
        Don't attempt to use a lockfile while manipulating files, pids and
        keys.

    -k --stop *which*
        Kill currently running agent processes. The following values are
        valid for "which":

        all      Kill all agent processes and quit keychain immediately.
                 Prior to keychain-2.5.0, this was the behavior of the bare
                 "--stop" option.

        others   Kill agent processes other than the one keychain is
                 providing. Prior to keychain-2.5.0, keychain would do this
                 automatically. The new behavior requires that you specify
                 it explicitly if you want it.

        mine     Kill keychain's agent processes, leaving other agents
                 alone.

    --systemd
        Inject environment variables into the systemd --user session.

    -Q --quick
        If an ssh-agent process is running then use it. Don't verify the
        list of keys, other than making sure it's non-empty. This option
        avoids locking when possible so that multiple terminals can be
        opened simultaneously without waiting on each other.

    -q --quiet
        Only print messages in case of warning, error or required
        interactivity. As of version 2.6.10, this also suppresses
        "Identities added" messages for ssh-agent.

    --timeout *minutes*
        Allows a timeout to be set for identities added to ssh-agent. When
        this option is used with a keychain invocation that starts ssh-agent
        itself, then keychain uses the appropriate ssh-agent option to set
        the default timeout for ssh-agent. The --timeout option also gets
        passed to ssh-add invocations, so any keys added to a running
        ssh-agent will be individually configured to have the timeout
        specified, overriding any ssh-agent default.

        Most users can simply use the timeout setting they desire and get
        the result they want -- with all identities having the specified
        timeout, whether added by keychain or not. More advanced users can
        use one invocation of keychain to set the default timeout, and
        optionally set different timeouts for keys added by using a
        subsequent invocation of keychain.

    -V --version
        Show version information.

EXAMPLES
    This snippet should work in most shells to load two ssh keys and one gpg
    key:

        eval `keychain --eval id_rsa id_dsa 0123ABCD`

    For the fish shell, use the following format:

        if status --is-interactive
            keychain --eval --quiet -Q id_rsa | source
        end

    If you have trouble with that in csh:

        setenv SHELL /bin/csh
        eval `keychain --eval id_rsa id_dsa 0123ABCD`

    This is equivalent for Bourne shells (including bash and zsh) but
    doesn't use keychain's --eval feature:

        keychain id_rsa id_dsa 0123ABCD
        [ -z "$HOSTNAME" ] && HOSTNAME=`uname -n`
        [ -f $HOME/.keychain/$HOSTNAME-sh ] && \
                . $HOME/.keychain/$HOSTNAME-sh
        [ -f $HOME/.keychain/$HOSTNAME-sh-gpg ] && \
                . $HOME/.keychain/$HOSTNAME-sh-gpg

    This is equivalent for C shell (including tcsh):

        keychain id_rsa id_dsa 0123ABCD
        host=`uname -n`
        if (-f $HOME/.keychain/$host-csh) then
                source $HOME/.keychain/$host-csh
        endif
        if (-f $HOME/.keychain/$host-csh-gpg) then
                source $HOME/.keychain/$host-csh-gpg
        endif

    To load keychain variables from a script (for example from cron) and
    abort unless id_dsa is available:

        # Load keychain variables and check for id_dsa
        [ -z "$HOSTNAME" ] && HOSTNAME=`uname -n`
        . $HOME/.keychain/$HOSTNAME-sh 2>/dev/null
        ssh-add -l 2>/dev/null | grep -q id_dsa || exit 1

SEE ALSO
    ssh-agent(1)

NOTES
    Keychain was created and is currently maintained by Daniel Robbins. If
    you need to report a bug or request an enhancement, please post to the
    Funtoo Linux bug tracker <http://bugs.funtoo.org>. For more information
    about keychain, please visit <http://www.funtoo.org/Keychain>.