ssh-add

SSH-ADD(1)                 BSD General Commands Manual                SSH-ADD(1)

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

SYNOPSIS
     ssh-add [-cDdKkLlqvXx] [-E fingerprint_hash] [-S provider] [-t life]
             [file ...]
     ssh-add -s pkcs11
     ssh-add -e pkcs11
     ssh-add -T pubkey ...

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, ~/.ssh/id_ecdsa_sk, ~/.ssh/id_ed25519, and
     ~/.ssh/id_ed25519_sk.  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.  If the argument list consists of “-”
             then ssh-add will read public keys to be removed from standard
             input.

     -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      Load resident keys from a FIDO authenticator.

     -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 provider
             Specifies a path to a library that will be used when adding FIDO
             authenticator-hosted keys, overriding the default of using the
             internal USB HID support.

     -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.

ENVIRONMENT
     DISPLAY, SSH_ASKPASS and SSH_ASKPASS_REQUIRE
             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.

             SSH_ASKPASS_REQUIRE allows further control over the use of an
             askpass program.  If this variable is set to “never” then ssh-add
             will never attempt to use one.  If it is set to “prefer”, then
             ssh-add will prefer to use the askpass program instead of the TTY
             when requesting passwords.  Finally, if the variable is set to
             “force”, then the askpass program will be used for all passphrase
             input regardless of whether DISPLAY is set.

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

     SSH_SK_PROVIDER
             Specifies a path to a library that will be used when loading any
             FIDO authenticator-hosted keys, overriding the default of using the
             built-in USB HID support.

FILES
     ~/.ssh/id_dsa
     ~/.ssh/id_ecdsa
     ~/.ssh/id_ecdsa_sk
     ~/.ssh/id_ed25519
     ~/.ssh/id_ed25519_sk
     ~/.ssh/id_rsa
             Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
             authenticator-hosted Ed25519 or 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-askpass(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.

BSD                               July 14, 2020                              BSD