pam_console(8)                                    System Administrator's Manual                                   pam_console(8)



NAME
       pam_console - determine user owning the system console

SYNOPSIS
       session optional pam_console.so
       auth required pam_console.so

DESCRIPTION
       pam_console.so  is  designed to give users at the physical console (virtual terminals and local xdm-managed X sessions by
       default, but that is configurable) capabilities that they would not otherwise have, and to take those  capabilities  away
       when  the  are  no  longer  logged  in  at the console.  It provides two main kinds of capabilities: file permissions and
       authentication.

       When a user logs in at the console and no other user is currently logged in at the console, pam_console.so will run  han-
       dler  programs  specified  in the file /etc/security/console.handlers such as pam_console_apply which changes permissions
       and ownership of files as described in the file /etc/security/console.perms.  That user may then log in on  other  termi-
       nals  that  are considered part of the console, and as long as the user is still logged in at any one of those terminals,
       that user will own those devices.  When the user logs out of the last terminal, the console may be taken by the next user
       to  log  in.  Other users who have logged in at the console during the time that the first user was logged in will not be
       given ownership of the devices unless they log in on one of the terminals; having done so on any one terminal,  the  next
       user  will own those devices until he or she has logged out of every terminal that is part of the physical console.  Then
       the race can start for the next user.  In practice, this is not a problem; the physical console is not generally  in  use
       by many people at the same time, and pam_console.so just tries to do the right thing in weird cases.

       When  an  application attempts to authenticate the user and this user is already logged in at the console, pam_console.so
       checks whether there is a file in /etc/security/console.apps/ directory with the same name as  the  application  service-
       name,  and if such a file exists, authentication succeeds. This way pam_console may be utilized to run some system appli-
       cations (reboots, config tools) without root password, or to enter user password on the first system login only.


ARGUMENTS
       debug  turns on debugging

       allow_nonroot_tty
              gain console locks and change permissions even if the TTY's owner is not root.

       handlersfile=filename
              tells pam_console.so to get the list of the handlers from a different file than /etc/security/console.handlers

EXAMPLE
       /etc/pam.d/some-system-tool:
       auth sufficient pam_rootok.so
       auth required pam_console.so

       /etc/pam.d/some-login-service:
       auth sufficient pam_console.so
       auth required pam_unix.so
       session required pam_unix.so
       session optional pam_console.so

FILES
       /var/run/console/
       /var/run/console/console.lock
       /etc/security/console.apps
       /etc/security/console.handlers

SECURITY NOTES
       When pam_console "auth" is used for login services which provide possibility of remote login, it  is  necessary  to  make
       sure  the  application  correctly  sets  PAM_RHOST  variable, or to deny remote logins completely.  Currently, /bin/login
       (invoked from telnetd) and gdm is OK, others may be not.

SEE ALSO
       console.perms(5)
       console.apps(5)
       console.handlers(5)
       pam_console_apply(8)
       /usr/share/doc/pam*/html/index.html

BUGS
       Let's hope not, but if you find any, please report them via the "Bug Track" link at http://bugzilla.redhat.com/bugzilla/

AUTHORS
       Michael K. Johnson <johnsonmATredhat.com>
       Support of console.handlers and other improvements by Tomas Mraz <tmrazATredhat.com>



Red Hat                                                     2005/10/4                                             pam_console(8)