A program to find an already running SSH agent

Note that this only works for sh like shells (zsh, sh, bash, etc) if you use csh or similar change it so it prints a setenv instead. I made an alias to eval it's output, eg

alias findagent='eval `~/bin/findagent`'

So I just run 'findagent' on login and everything works - this is especially handy if you run things in a screen session.

Furthermore you can use pam_ssh(8) to login by authenticating against your SSH passphrase. This is handy as it means you only have to enter your passphrase once (during login) and gives you a reasonable facimile of single sign on. Unfortunately it requires fairly major modifications to the pam configuration files because each one is essentially a copy rather than including in a main one. I modified /etc/pam.d/system to look like so

#
# $FreeBSD: src/etc/pam.d/system,v 1.1 2003/06/14 12:35:05 des Exp $
#
# System-wide defaults
#

# auth
auth            sufficient      pam_opie.so             no_warn no_fake_prompts
auth            requisite       pam_opieaccess.so       no_warn allow_local
#auth           sufficient      pam_krb5.so             no_warn try_first_pass
#auth           sufficient      pam_ssh.so              no_warn try_first_pass
auth            sufficient      pam_ssh.so
auth            required        pam_unix.so             no_warn use_first_pass nullok

# account
#account        required        pam_krb5.so
account         required        pam_login_access.so
account         required        pam_unix.so

# session
session         optional        pam_ssh.so              want_agent
session         required        pam_lastlog.so          no_fail

# password
#password       sufficient      pam_krb5.so             no_warn try_first_pass
password        required        pam_unix.so             no_warn try_first_pass

#
# $FreeBSD: src/etc/pam.d/kde,v 1.6 2003/04/30 21:57:54 markm Exp $
#
# PAM configuration for the "kde" service
#

# auth
auth            required        pam_nologin.so          no_warn
auth            include         system

# account
account         include         system

# session
session         include         system

#
# $FreeBSD: src/etc/pam.d/su,v 1.16 2003/07/09 18:40:49 des Exp $
#
# PAM configuration for the "su" service
#

# auth
auth            sufficient      pam_rootok.so           no_warn
auth            sufficient      pam_self.so             no_warn
auth            requisite       pam_group.so            no_warn group=wheel root_only fail_safe
auth            include         system

# account
account         include         system

# session
session         required        pam_permit.so