ssh-add Man page

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. 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. Successful confirmation is signaled by a zero
exit status from ssh-askpass, 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.

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, ssh-agent, ssh-askpass, ssh-keygen, 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 March 30, 2015 BSD