openssh/ssh-add.1

.\"  -*- nroff -*-
.\"
.\" Author: Tatu Ylonen <ylo@cs.hut.fi>
.\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
.\"                    All rights reserved
.\"
.\" As far as I am concerned, the code I have written for this software
.\" can be used freely for any purpose.  Any derived versions of this
.\" software must be clearly marked as such, and if the derived work is
.\" incompatible with the protocol description in the RFC file, it must be
.\" called by a name other than "ssh" or "Secure Shell".
.\"
.\"
.\" Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
.\" Copyright (c) 1999 Aaron Campbell. All rights reserved.
.\" Copyright (c) 1999 Theo de Raadt. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd September 25, 1999
.Dt SSH-ADD 1
.Os
.Sh NAME
.Nm ssh-add
.Nd adds RSA or DSA identities for the authentication agent
.Sh SYNOPSIS
.Nm ssh-add
.Op Fl lLdD
.Op Ar
.Sh DESCRIPTION
.Nm
adds RSA or DSA identities to the authentication agent,
.Xr ssh-agent 1 .
When run without arguments, it adds the file
.Pa $HOME/.ssh/identity .
Alternative file names can be given on the command line.
If any file requires a passphrase,
.Nm
asks for the passphrase from the user.
The Passphrase it is read from the user's tty.
.Pp
The authentication agent must be running and must be an ancestor of
the current process for
.Nm
to work.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl l
Lists fingerprints of all identities currently represented by the agent.
.It Fl L
Lists public key parameters of all identities currently represented by the agent.
.It Fl d
Instead of adding the identity, removes the identity from the agent.
.It Fl D
Deletes all identities from the agent.
.El
.Sh FILES
.Bl -tag -width Ds
.It Pa $HOME/.ssh/identity
Contains the RSA authentication identity of the user.
This file should not be readable by anyone but the user.
Note that
.Nm
ignores this file if it is accessible by others.
It is possible to
specify a passphrase when generating the key; that passphrase will be
used to encrypt the private part of this file.
This is the default file added by
.Nm
when no other files have been specified.
.It Pa $HOME/.ssh/id_dsa
Contains the DSA authentication identity of the user.
.El
.Sh ENVIRONMENT
.Bl -tag -width Ds
.It Ev "DISPLAY" and "SSH_ASKPASS"
If
.Nm
needs a passphrase, it will read the passphrase from the current
terminal if it was run from a terminal.
If
.Nm
does not have a terminal associated with it but
.Ev DISPLAY
and
.Ev SSH_ASKPASS
are set, it will execute the program specified by
.Ev SSH_ASKPASS
and open an X11 window to read the passphrase.
This is particularly useful when calling
.Nm
from a
.Pa .Xsession
or related script.
(Note that on some machines it
may be necessary to redirect the input from
.Pa /dev/null
to make this work.)
.El
.Sh AUTHORS
Tatu Ylonen <ylo@cs.hut.fi>
.Pp
OpenSSH
is a derivative of the original (free) ssh 1.2.12 release, but with bugs
removed and newer features re-added.
Rapidly after the 1.2.12 release,
newer versions bore successively more restrictive licenses.
This version of OpenSSH
.Bl -bullet
.It
has all components of a restrictive nature (i.e., patents, see
.Xr crypto 3 )
directly removed from the source code; any licensed or patented components
are chosen from
external libraries.
.It
has been updated to support ssh protocol 1.5.
.It
contains added support for
.Xr kerberos 8
authentication and ticket passing.
.It
supports one-time password authentication with
.Xr skey 1 .
.El
.Sh SEE ALSO
.Xr ssh 1 ,
.Xr ssh-agent 1 ,
.Xr ssh-keygen 1 ,
.Xr sshd 8 ,
.Xr crypto 3