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ssh-add - Unix, Linux Command


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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:

TagDescription
-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

TagDescription
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

TagDescription
~/.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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