PAM_SSH(8)		  BSD System Manager's Manual		    PAM_SSH(8)

NAME
     pam_ssh — authentication and session management with SSH private keys

SYNOPSIS
     [service-name] module-type control-flag pam_ssh [options]

DESCRIPTION
     The SSH authentication service module for PAM, pam_ssh provides function‐
     ality for two PAM categories: authentication and session management.  In
     terms of the module-type parameter, they are the “auth” and “session”
     features.

   SSH Authentication Module
     The SSH authentication component provides a function to verify the iden‐
     tity of a user (pam_sm_authenticate()), by prompting the user for a
     passphrase and verifying that it can decrypt the target user's SSH key
     using that passphrase.

     The following options may be passed to the authentication module:

     use_first_pass  If the authentication module is not the first in the
		     stack, and a previous module obtained the user's pass‐
		     word, that password is used to authenticate the user.  If
		     this fails, the authentication module returns failure
		     without prompting the user for a password.  This option
		     has no effect if the authentication module is the first
		     in the stack, or if no previous modules obtained the
		     user's password.

     try_first_pass  This option is similar to the use_first_pass option,
		     except that if the previously obtained password fails,
		     the user is prompted for another password.

     nullok	     Normally, keys with no passphrase are ignored for authen‐
		     tication purposes.  If this option is set, keys with no
		     passphrase will be taken into consideration, allowing the
		     user to log in with a blank password.

   SSH Session Management Module
     The SSH session management component provides functions to initiate
     (pam_sm_open_session()) and terminate (pam_sm_close_session()) sessions.
     The pam_sm_open_session() function starts an SSH agent, passing it any
     private keys it decrypted during the authentication phase, and sets the
     environment variables the agent specifies.  The pam_sm_close_session()
     function kills the previously started SSH agent by sending it a SIGTERM.

     The following options may be passed to the session management module:

     want_agent  Start an agent even if no keys were decrypted during the
		 authentication phase.

FILES
     $HOME/.ssh/identity  SSH1 RSA key
     $HOME/.ssh/id_rsa	  SSH2 RSA key
     $HOME/.ssh/id_dsa	  SSH2 DSA key
     $HOME/.ssh/id_ecdsa  SSH2 ECDSA key

SEE ALSO
     ssh-agent(1), pam.conf(5), pam(8)

AUTHORS
     The pam_ssh module was originally written by Andrew J. Korty
     ⟨ajk@iu.edu⟩.  The current implementation was developed for the FreeBSD
     Project by ThinkSec AS and NAI Labs, the Security Research Division of
     Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
     (“CBOSS”), as part of the DARPA CHATS research program.  This manual page
     was written by Mark R V Murray ⟨markm@FreeBSD.org⟩.

BSD				October 7, 2011 			   BSD