ssh-add - adds RSA or DSA identities to the authentication agent

Synopsis
ssh-add [-lLdDxXc] [-t life] [file …]
ssh-add -s reader
ssh-add -e reader

Description
ssh-add adds RSA or DSA identities to the authentication agent,
ssh-agent(1). When run without arguments, it adds the files
$HOME/.ssh/id_rsa, $HOME/.ssh/id_dsa and $HOME/.ssh/identity. Alterna-
tive file names can be given on the command line. If any file requires
a passphrase, ssh-add asks for the passphrase from the user. The
passphrase is read from the user’s tty. ssh-add retries the last
passphrase if multiple identity files are given.

The authentication agent must be running and the SSH_AUTH_SOCK environ-
ment variable must contain the name of its socket for ssh-add to work.

The options are as follows:

-l Lists fingerprints of all identities currently represented by
the agent.

-L Lists public key parameters of all identities currently repre-
sented by the agent.

-d Instead of adding the identity, removes the identity from the
agent.

-D Deletes all identities from the agent.

-x Lock the agent with a password.

-X Unlock the agent.

-t life
Set a maximum lifetime when adding identities to an agent. The
lifetime may be specified in seconds or in a time format speci-
fied in sshd_config(5).

-c Indicates that added identities should be subject to confirma-
tion before being used for authentication. Confirmation is per-
formed by the SSH_ASKPASS program mentioned below. Successful
confirmation is signaled by a zero exit status from the
SSH_ASKPASS program, rather than text entered into the
requester.

-s reader
Add key in smartcard reader.

-e reader
Remove key in smartcard reader.

Environment
DISPLAY and SSH_ASKPASS
If ssh-add needs a passphrase, it will read the passphrase from
the current terminal if it was run from a terminal. If ssh-add
does not have a terminal associated with it but DISPLAY and
SSH_ASKPASS are set, it will execute the program specified by
SSH_ASKPASS and open an X11 window to read the passphrase. This
is particularly useful when calling ssh-add from a .Xsession or
related script. (Note that on some machines it may be necessary
to redirect the input from /dev/null to make this work.)

SSH_AUTH_SOCK
Identifies the path of a unix-domain socket used to communicate
with the agent.

Files
$HOME/.ssh/identity
Contains the protocol version 1 RSA authentication identity of
the user.

$HOME/.ssh/id_dsa
Contains the protocol version 2 DSA authentication identity of
the user.

$HOME/.ssh/id_rsa
Contains the protocol version 2 RSA authentication identity of
the user.

Identity files should not be readable by anyone but the user. Note that
ssh-add ignores identity files if they are accessible by others.

Diagnostics
Exit status is 0 on success, 1 if the specified command fails, and 2 if
ssh-add is unable to contact the authentication agent.

See Also
ssh(1), ssh-agent(1), ssh-keygen(1), sshd(8)

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 pro-
tocol versions 1.5 and 2.0.