Updated: 2021/Apr/14


SSH-ADD(1)                  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.

NetBSD 9.99                      July 14 2020                      NetBSD 9.99