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 handler programs speci-
       fied 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 terminals 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 servicename, and	if  such  a  file  exists,
       authentication  succeeds.  This	way pam_console may be utilized to run some system applications (reboots, config tools) without root pass-
       word, 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 <johnsonm@redhat.com>
       Support of console.handlers and other improvements by Tomas Mraz <tmraz@redhat.com>

Red Hat 							     2005/10/4							    pam_console(8)