man
1 SSH-ADD
SSH-ADD(1) BSD General Commands Manual SSH-ADD(1)
NAME
ssh-add -- adds private key identities to the OpenSSH authentication
agent
SYNOPSIS
ssh-add [-cDdKkLlqvXx] [-E fingerprint_hash] [-S provider] [-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, ~/.ssh/id_ecdsa_sk,
~/.ssh/id_ed25519, and ~/.ssh/id_ed25519_sk. 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 de-
fault identities and their corresponding certificates will be re-
moved. 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. If the argu-
ment list consists of "-" then ssh-add will read public keys to
be removed from standard input.
-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 Load resident keys from a FIDO authenticator.
-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 provider
Specifies a path to a library that will be used when adding FIDO
authenticator-hosted keys, overriding the default of using the
internal USB HID support.
-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, SSH_ASKPASS and SSH_ASKPASS_REQUIRE
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.
SSH_ASKPASS_REQUIRE allows further control over the use of an
askpass program. If this variable is set to "never" then ssh-add
will never attempt to use one. If it is set to "prefer", then
ssh-add will prefer to use the askpass program instead of the TTY
when requesting passwords. Finally, if the variable is set to
"force", then the askpass program will be used for all passphrase
input regardless of whether DISPLAY is set.
SSH_AUTH_SOCK
Identifies the path of a UNIX-domain socket used to communicate
with the agent.
SSH_SK_PROVIDER
Specifies a path to a library that will be used when loading any
FIDO authenticator-hosted keys, overriding the default of using
the built-in USB HID support.
FILES
~/.ssh/id_dsa
~/.ssh/id_ecdsa
~/.ssh/id_ecdsa_sk
~/.ssh/id_ed25519
~/.ssh/id_ed25519_sk
~/.ssh/id_rsa
Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519, au-
thenticator-hosted Ed25519 or 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 July 14, 2020 BSD