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] [-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 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 com‐
mand 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 the SSH_ASKPASS program mentioned below. Successful confirma‐
tion is signaled by a zero exit status from the SSH_ASKPASS pro‐
gram, 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 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 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_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 ALSOssh(1), ssh-agent(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 June 5, 2024 BSD