pam_listfile(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | MODULE TYPES PROVIDED | RETURN VALUES | EXAMPLES | SEE ALSO | AUTHOR | COLOPHON

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

NAME         top

       pam_listfile - deny or allow services based on an arbitrary file

SYNOPSIS         top

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

DESCRIPTION         top

       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         top

       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         top

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

RETURN VALUES         top

       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         top

       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         top

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

AUTHOR         top

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

COLOPHON         top

       This page is part of the linux-pam (Pluggable Authentication
       Modules for Linux) project.  Information about the project can be
       found at ⟨http://www.linux-pam.org/⟩.  If you have a bug report
       for this manual page, see ⟨//www.linux-pam.org/⟩.  This page was
       obtained from the tarball Linux-PAM-1.3.0.tar.bz2 fetched from
       ⟨http://www.linux-pam.org/library/⟩ on 2021-08-27.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

Linux-PAM Manual               04/01/2016                PAM_LISTFILE(8)