SSH-ADD(1) BSD General Commands Manual SSH-ADD(1)
NAME
ssh-add -- adds private key identities to the authentication agent
SYNOPSIS
ssh-add [-cDdkLlqvXx] [-E fingerprint_hash] [-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, and ~/.ssh/id_ed25519.
After loading a private key, ssh-add will try to load corresponding cer-
tificate 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 environ-
ment 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 certifi-
cates 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 finger-
prints. 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 repre-
sented 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 speci-
fied 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 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_USE_STRONG_RNG
The reseeding of the OpenSSL random generator is usually done
from getrandom(1) without any specific flags. If the
SSH_USE_STRONG_RNG environment variable is set to value other
than 0 the OpenSSL random generator is reseeded from getrandom(1)
with GRND_RANDOM flag specified. The number of bytes read is
defined by the SSH_USE_STRONG_RNG value. Minimum is 14 bytes.
This setting is not recommended on the computers without the
hardware random generator because insufficient entropy causes the
connection to be blocked until enough entropy is available.
FILES
~/.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
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 cre-
ated OpenSSH. Markus Friedl contributed the support for SSH protocol
versions 1.5 and 2.0.
BSD January 21, 2019 BSD