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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | MODULE TYPES PROVIDED | RETURN VALUES | EXAMPLES | SEE ALSO | AUTHOR | COLOPHON |
PAM_LISTFILE(8) Linux-PAM Manual PAM_LISTFILE(8)
pam_listfile - deny or allow services based on an arbitrary file
pam_listfile.so item=[tty|user|rhost|ruser|group|shell]
sense=[allow|deny] file=/path/filename
onerr=[succeed|fail] [apply=[user|@group]] [quiet]
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.
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.
All module types (auth, account, password and session) are provided.
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.
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.
pam.conf(5), pam.d(5), pam(8)
pam_listfile was written by Michael K. Johnson <johnsonm@redhat.com>
and Elliot Lee <sopwith@cuc.edu>.
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.gz fetched from
⟨http://www.linux-pam.org/library/⟩ on 2017-07-05. 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)