SSH-ADD(1)

NAME
ssh-add - adds private key identities to the authentication agent

SYNOPSIS
ssh-add [-cDdLlXx] [-t life] [file ...]
ssh-add -s pkcs11
ssh-add -e pkcs11

DESCRIPTION
ssh-add adds private key identities to the authentication agent, ssh-agent(1). When run without arguments, it adds the files ~/.ssh/id_rsa, ~/.ssh/id_dsa, ~/.ssh/id_ecdsa and ~/.ssh/identity. After loading a private key, ssh-add will try to load corresponding certificate information from the filename obtained by appending -cert.pub to the name of the private key file. 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:

-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 identities, removes identities from the agent. If ssh-add has been run without arguments, the keys for the default identities will be removed. Otherwise, the argument list will be interpreted as a list of paths to public key files and matching keys will be removed from the agent. If no public key is found at a given path, ssh-add will append .pub and retry.

-e pkcs11
    Remove keys provided by the PKCS#11 shared library pkcs11.

-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 pkcs11
    Add keys provided by the PKCS#11 shared library pkcs11.

-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

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.
The reseeding of the OpenSSL random generator is usually done from /dev/urandom. If the SSH_USE_STRONG_RNG environment variable is set to value other than 0 the OpenSSL random generator is reseeded from /dev/random. The number of bytes read is defined by the SSH_USE_STRONG_RNG value. Minimum is 6 bytes. This setting is not recommended on the computers without the hardware random generator because insufficient entropy causes the connection to be blocked until enough entropy is available.

FILES

~/.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_ecdsa
    Contains the protocol version 2 ECDSA 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.

EXIT STATUS
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 protocol versions 1.5 and 2.0.