ssh-add —
adds private key identities to the authentication agent
ssh-add |
[-cDdkLlqvXx] [-E
fingerprint_hash] [-t
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_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-domain 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.