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Diffstat (limited to 'crypto/openssh/ssh-agent.1')
-rw-r--r-- | crypto/openssh/ssh-agent.1 | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/crypto/openssh/ssh-agent.1 b/crypto/openssh/ssh-agent.1 new file mode 100644 index 0000000..23c699d --- /dev/null +++ b/crypto/openssh/ssh-agent.1 @@ -0,0 +1,194 @@ +.\" $OpenBSD: ssh-agent.1,v 1.16 2000/09/07 20:27:54 deraadt Exp $ +.\" +.\" 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-AGENT 1 +.Os +.Sh NAME +.Nm ssh-agent +.Nd authentication agent +.Sh SYNOPSIS +.Nm ssh-agent +.Op Fl c Li | Fl s +.Op Fl k +.Oo +.Ar command +.Op Ar args ... +.Oc +.Sh DESCRIPTION +.Nm +is a program to hold private keys used for public key authentication +(RSA, DSA). +The idea is that +.Nm +is started in the beginning of an X-session or a login session, and +all other windows or programs are started as clients to the ssh-agent +program. +Through use of environment variables the agent can be located +and automatically used for authentication when logging in to other +machines using +.Xr ssh 1 . +.Pp +The options are as follows: +.Bl -tag -width Ds +.It Fl c +Generate C-shell commands on +.Dv stdout . +This is the default if +.Ev SHELL +looks like it's a csh style of shell. +.It Fl s +Generate Bourne shell commands on +.Dv stdout . +This is the default if +.Ev SHELL +does not look like it's a csh style of shell. +.It Fl k +Kill the current agent (given by the +.Ev SSH_AGENT_PID +environment variable). +.El +.Pp +If a commandline is given, this is executed as a subprocess of the agent. +When the command dies, so does the agent. +.Pp +The agent initially does not have any private keys. +Keys are added using +.Xr ssh-add 1 . +When executed without arguments, +.Xr ssh-add 1 +adds the +.Pa $HOME/.ssh/identity +file. +If the identity has a passphrase, +.Xr ssh-add 1 +asks for the passphrase (using a small X11 application if running +under X11, or from the terminal if running without X). +It then sends the identity to the agent. +Several identities can be stored in the +agent; the agent can automatically use any of these identities. +.Ic ssh-add -l +displays the identities currently held by the agent. +.Pp +The idea is that the agent is run in the user's local PC, laptop, or +terminal. +Authentication data need not be stored on any other +machine, and authentication passphrases never go over the network. +However, the connection to the agent is forwarded over SSH +remote logins, and the user can thus use the privileges given by the +identities anywhere in the network in a secure way. +.Pp +There are two main ways to get an agent setup: +Either you let the agent +start a new subcommand into which some environment variables are exported, or +you let the agent print the needed shell commands (either +.Xr sh 1 +or +.Xr csh 1 +syntax can be generated) which can be evalled in the calling shell. +Later +.Xr ssh 1 +look at these variables and use them to establish a connection to the agent. +.Pp +A unix-domain socket is created +.Pq Pa /tmp/ssh-XXXXXXXX/agent.<pid> , +and the name of this socket is stored in the +.Ev SSH_AUTH_SOCK +environment +variable. +The socket is made accessible only to the current user. +This method is easily abused by root or another instance of the same +user. +.Pp +The +.Ev SSH_AGENT_PID +environment variable holds the agent's PID. +.Pp +The agent exits automatically when the command given on the command +line terminates. +.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. +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 file is not used by +.Nm +but is normally added to the agent using +.Xr ssh-add 1 +at login time. +.It Pa $HOME/.ssh/id_dsa +Contains the DSA authentication identity of the user. +.Pq Pa /tmp/ssh-XXXXXXXX/agent.<pid> , +Unix-domain sockets used to contain the connection to the +authentication agent. +These sockets should only be readable by the owner. +The sockets should get automatically removed when the agent exits. +.El +.Sh AUTHOR +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 ssl 8 ) +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-add 1 , +.Xr ssh-keygen 1 , +.Xr sshd 8 , +.Xr ssl 8 |