adds private key identities to the authentication agent
ssh-add [-cDdkLlqvXx] [-E fingerprint_hash] [-t life] [file...] ssh-add -s pkcs11 ssh-add -e pkcs11 ssh-add -T pubkey ...
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/id_ed25519 . 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 ssh-askpass(1). Successful confirmation is signaled by a zero exit status from ssh-askpass(1), 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 and their corresponding certificates will be removed. Otherwise, the argument list will be interpreted as a list of paths to public key files to specify keys and certificates to be removed from the agent. If no public key is found at a given path, ssh-add will append .pub and retry.
- -E fingerprint_hash Specifies the hash algorithm used when displaying key fingerprints. Valid options are: ``md5'' and ``sha256 .'' The default is ``sha256 .''
- -e pkcs11 Remove keys provided by the PKCS#11 shared library pkcs11 .
- -k When loading keys into or deleting keys from the agent, process plain private keys only and skip certificates.
- -L Lists public key parameters of all identities currently represented by the agent.
- -l Lists fingerprints of all identities currently represented by the agent.
- -q Be quiet after a successful operation.
- -s pkcs11 Add keys provided by the PKCS#11 shared library pkcs11 .
- -T pubkey ... Tests whether the private keys that correspond to the specified pubkey files are usable by performing sign and verify operations on each.
- -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).
- -v Verbose mode. Causes ssh-add to print debugging messages about its progress. This is helpful in debugging problems. Multiple -v options increase the verbosity. The maximum is 3.
- -X Unlock the agent.
- -x Lock the agent with a password.
- "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 (by default ``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 socket used to communicate with the agent.
- ~/.ssh/id_dsa Contains the DSA authentication identity of the user.
- ~/.ssh/id_ecdsa Contains the ECDSA authentication identity of the user.
- ~/.ssh/id_ed25519 Contains the Ed25519 authentication identity of the user.
- ~/.ssh/id_rsa Contains the 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 is 0 on success, 1 if the specified command fails, and 2 if ssh-add is unable to contact the authentication agent.
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.