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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.