adds private key identities to the OpenSSH authentication
life] [file ...]
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_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,
asks for the passphrase from the user. The passphrase is read from the
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:
- 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.
- Deletes all identities from the agent.
- 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
- Specifies the hash algorithm used when displaying key fingerprints. Valid
options are: “md5” and “sha256”. The default
- Remove keys provided by the PKCS#11 shared library
- Load resident keys from a FIDO authenticator.
- When loading keys into or deleting keys from the agent, process plain
private keys only and skip certificates.
- Lists public key parameters of all identities currently represented by the
- Lists fingerprints of all identities currently represented by the
- Be quiet after a successful operation.
- 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.
- Add keys provided by the PKCS#11 shared library
- Tests whether the private keys that correspond to the specified
pubkey files are usable by performing sign and
verify operations on each.
- Set a maximum lifetime when adding identities to an agent. The lifetime
may be specified in seconds or in a time format specified in
- Verbose mode. Causes
ssh-add to print debugging
messages about its progress. This is helpful in debugging problems.
-v options increase the verbosity. The
maximum is 3.
- Unlock the agent.
- Lock the agent with a password.
SSH_ASKPASS and SSH_ASKPASS_REQUIRE
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
SSH_ASKPASS are set, it will execute the program
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
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.
- Identifies the path of a UNIX-domain socket used
to communicate with the agent.
- 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.
- Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
authenticator-hosted Ed25519 or RSA authentication identity of the
Identity files should not be readable by anyone but the user. Note
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.