PAM_LISTFILE(8) 						 Linux-PAM Manual						   PAM_LISTFILE(8)

NAME

       pam_listfile - deny or allow services based on an arbitrary file

SYNOPSIS

       pam_listfile.so item=[tty|user|rhost|ruser|group|shell] sense=[allow|deny] file=/path/filename onerr=[succeed|fail] [apply=[user|@group]]
		       [quiet]

DESCRIPTION

       pam_listfile is a PAM module which provides a way to deny or allow services based on an arbitrary file.

       The module gets the item of the type specified -- user specifies the username, PAM_USER; tty specifies the name of the terminal over which
       the request has been made, PAM_TTY; rhost specifies the name of the remote host (if any) from which the request was made, PAM_RHOST; and
       ruser specifies the name of the remote user (if available) who made the request, PAM_RUSER -- and looks for an instance of that item in the
       file=filename.  filename contains one line per item listed. If the item is found, then if sense=allow, PAM_SUCCESS is returned, causing the
       authorization request to succeed; else if sense=deny, PAM_AUTH_ERR is returned, causing the authorization request to fail.

       If an error is encountered (for instance, if filename does not exist, or a poorly-constructed argument is encountered), then if
       onerr=succeed, PAM_SUCCESS is returned, otherwise if onerr=fail, PAM_AUTH_ERR or PAM_SERVICE_ERR (as appropriate) will be returned.

       An additional argument, apply=, can be used to restrict the application of the above to a specific user (apply=username) or a given group
       (apply=@groupname). This added restriction is only meaningful when used with the tty, rhost and shell items.

       Besides this last one, all arguments should be specified; do not count on any default behavior.

       No credentials are awarded by this module.

OPTIONS

       item=[tty|user|rhost|ruser|group|shell]
	   What is listed in the file and should be checked for.

       sense=[allow|deny]
	   Action to take if found in file, if the item is NOT found in the file, then the opposite action is requested.

       file=/path/filename
	   File containing one item per line. The file needs to be a plain file and not world writable.

       onerr=[succeed|fail]
	   What to do if something weird happens like being unable to open the file.

       apply=[user|@group]
	   Restrict the user class for which the restriction apply. Note that with item=[user|ruser|group] this does not make sense, but for
	   item=[tty|rhost|shell] it have a meaning.

       quiet
	   Do not treat service refusals or missing list files as errors that need to be logged.

MODULE TYPES PROVIDED

       All module types (auth, account, password and session) are provided.

RETURN VALUES

       PAM_AUTH_ERR
	   Authentication failure.

       PAM_BUF_ERR
	   Memory buffer error.

       PAM_IGNORE
	   The rule does not apply to the apply option.

       PAM_SERVICE_ERR
	   Error in service module.

       PAM_SUCCESS
	   Success.

EXAMPLES

       Classic 'ftpusers' authentication can be implemented with this entry in /etc/pam.d/ftpd:

	   #
	   # deny ftp-access to users listed in the /etc/ftpusers file
	   #
	   auth    required	  pam_listfile.so 
		   onerr=succeed item=user sense=deny file=/etc/ftpusers

       Note, users listed in /etc/ftpusers file are (counterintuitively) not allowed access to the ftp service.

       To allow login access only for certain users, you can use a /etc/pam.d/login entry like this:

	   #
	   # permit login to users listed in /etc/loginusers
	   #
	   auth    required	  pam_listfile.so 
		   onerr=fail item=user sense=allow file=/etc/loginusers

       For this example to work, all users who are allowed to use the login service should be listed in the file /etc/loginusers. Unless you are
       explicitly trying to lock out root, make sure that when you do this, you leave a way for root to log in, either by listing root in
       /etc/loginusers, or by listing a user who is able to su to the root account.

SEE ALSO

       pam.conf(5), pam.d(5), pam(8)

AUTHOR

       pam_listfile was written by Michael K. Johnson <johnsonm@redhat.com> and Elliot Lee <sopwith@cuc.edu>.

Linux-PAM Manual						    09/19/2013							   PAM_LISTFILE(8)