SSH-ADD(1) BSD General Commands Manual SSH-ADD(1)
NAME
ssh-add -- adds private key identities to the authentication agent
SYNOPSIS
ssh-add [-cDdkLlXx] [-E fingerprint_hash] [-t life] [file ...]
ssh-add -s pkcs11
ssh-add -e pkcs11
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_ed25519 and
~/.ssh/identity. 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 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.
-s pkcs11
Add keys provided by the PKCS#11 shared library pkcs11.
-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).
-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 /dev/urandom. If the SSH_USE_STRONG_RNG environment vari-
able is set to value other than 0 the OpenSSL random generator is
reseeded from /dev/random. The number of bytes read is defined
by the SSH_USE_STRONG_RNG value. Minimum is 14 bytes. This set-
ting is not recommended on the computers without the hardware
random generator because insufficient entropy causes the connec-
tion to be blocked until enough entropy is available.
FILES
~/.ssh/identity
Contains the protocol version 1 RSA authentication identity of
the user.
~/.ssh/id_dsa
Contains the protocol version 2 DSA authentication identity of
the user.
~/.ssh/id_ecdsa
Contains the protocol version 2 ECDSA authentication identity of
the user.
~/.ssh/id_ed25519
Contains the protocol version 2 Ed25519 authentication identity
of the user.
~/.ssh/id_rsa
Contains the protocol version 2 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 November 11, 2024 BSD