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# ssh-add - Unix, Linux Command

# NAME

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

# SYNOPSIS

ssh-add [-cDdLlXx] [-t life] [] 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 `~/.ssh/id_rsa`, `~/.ssh/id_dsa` and `~/.ssh/identity`. Alternative 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 environment variable must contain the name of its socket for ssh-add to work.

The options are as follows:

Tag | Description
--- | ---
-c | Indicates that added identities should be subject to confirmation before being used for authentication. Confirmation is performed 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.
-D | Deletes all identities from the agent.
-d | Instead of adding the identity, removes the identity from the agent.
-e reader
| Remove key in smartcard reader.
-L | Lists public key parameters of all identities currently represented by the agent.
-l | Lists fingerprints of all identities currently represented by the agent.
-s reader
| Add key in smartcard reader.
-t life
| Set a maximum lifetime when adding identities to an agent. The lifetime may be specified in seconds or in a time format specified in sshd_config(5).
-X | Unlock the agent.
-x | Lock the agent with a password.

# ENVIRONMENT

Tag | Description
--- | ---
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

Tag | Description
--- | ---
`~/.ssh/identity`
| Contains the protocol version 1 RSA authentication identity of the user.
`~/.ssh/id_dsa`
| Contains the protocol version 2 DSA authentication identity of the user.
`~/.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-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 protocol versions 1.5 and 2.0.

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