.\"     Title: pam_listfile
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets v1.73.1 <http://docbook.sf.net/>
.\"      Date: 04/16/2008
.\"    Manual: Linux-PAM Manual
.\"    Source: Linux-PAM Manual
.\"
.TH "PAM_LISTFILE" "8" "04/16/2008" "Linux-PAM Manual" "Linux\-PAM Manual"
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.SH "NAME"
pam_listfile - deny or allow services based on an arbitrary file
.SH "SYNOPSIS"
.HP 16
\fBpam_listfile\.so\fR item=[tty|user|rhost|ruser|group|shell] sense=[allow|deny] file=\fI/path/filename\fR onerr=[succeed|fail] [apply=[\fIuser\fR|\fI@group\fR]] [quiet]
.SH "DESCRIPTION"
.PP
pam_listfile is a PAM module which provides a way to deny or allow services based on an arbitrary file\.
.PP
The module gets the
\fBitem\fR
of the type specified \-\-
\fIuser\fR
specifies the username,
\fIPAM_USER\fR; tty specifies the name of the terminal over which the request has been made,
\fIPAM_TTY\fR; rhost specifies the name of the remote host (if any) from which the request was made,
\fIPAM_RHOST\fR; and ruser specifies the name of the remote user (if available) who made the request,
\fIPAM_RUSER\fR
\-\- and looks for an instance of that item in the
\fBfile=\fR\fB\fIfilename\fR\fR\.
\fIfilename\fR
contains one line per item listed\. If the item is found, then if
\fBsense=\fR\fB\fIallow\fR\fR,
\fIPAM_SUCCESS\fR
is returned, causing the authorization request to succeed; else if
\fBsense=\fR\fB\fIdeny\fR\fR,
\fIPAM_AUTH_ERR\fR
is returned, causing the authorization request to fail\.
.PP
If an error is encountered (for instance, if
\fIfilename\fR
does not exist, or a poorly\-constructed argument is encountered), then if
\fIonerr=succeed\fR,
\fIPAM_SUCCESS\fR
is returned, otherwise if
\fIonerr=fail\fR,
\fIPAM_AUTH_ERR\fR
or
\fIPAM_SERVICE_ERR\fR
(as appropriate) will be returned\.
.PP
An additional argument,
\fBapply=\fR, can be used to restrict the application of the above to a specific user (\fBapply=\fR\fB\fIusername\fR\fR) or a given group (\fBapply=\fR\fB\fI@groupname\fR\fR)\. This added restriction is only meaningful when used with the
\fItty\fR,
\fIrhost\fR
and
\fIshell\fR
items\.
.PP
Besides this last one, all arguments should be specified; do not count on any default behavior\.
.PP
No credentials are awarded by this module\.
.SH "OPTIONS"
.PP
.PP
\fBitem=[tty|user|rhost|ruser|group|shell]\fR
.RS 4
What is listed in the file and should be checked for\.
.RE
.PP
\fBsense=[allow|deny]\fR
.RS 4
Action to take if found in file, if the item is NOT found in the file, then the opposite action is requested\.
.RE
.PP
\fBfile=\fR\fB\fI/path/filename\fR\fR
.RS 4
File containing one item per line\. The file needs to be a plain file and not world writeable\.
.RE
.PP
\fBonerr=[succeed|fail]\fR
.RS 4
What to do if something weird happens like being unable to open the file\.
.RE
.PP
\fBapply=[\fR\fB\fIuser\fR\fR\fB|\fR\fB\fI@group\fR\fR\fB]\fR
.RS 4
Restrict the user class for which the restriction apply\. Note that with
\fBitem=[user|ruser|group]\fR
this does not make sense, but for
\fBitem=[tty|rhost|shell]\fR
it have a meaning\.
.RE
.PP
\fBquiet\fR
.RS 4
Do not treat service refusals or missing list files as errors that need to be logged\.
.RE
.SH "MODULE SERVICES PROVIDED"
.PP
The services
\fBauth\fR,
\fBaccount\fR,
\fBpassword\fR
and
\fBsession\fR
are supported\.
.SH "RETURN VALUES"
.PP
.PP
PAM_AUTH_ERR
.RS 4
Authentication failure\.
.RE
.PP
PAM_BUF_ERR
.RS 4
Memory buffer error\.
.RE
.PP
PAM_IGNORE
.RS 4
The rule does not apply to the
\fBapply\fR
option\.
.RE
.PP
PAM_SERVICE_ERR
.RS 4
Error in service module\.
.RE
.PP
PAM_SUCCESS
.RS 4
Success\.
.RE
.SH "EXAMPLES"
.PP
Classic \'ftpusers\' authentication can be implemented with this entry in
\fI/etc/pam\.d/ftpd\fR:
.sp
.RS 4
.nf
#
# deny ftp\-access to users listed in the /etc/ftpusers file
#
auth    required       pam_listfile\.so \e
        onerr=succeed item=user sense=deny file=/etc/ftpusers
      
.fi
.RE
.sp
Note, users listed in
\fI/etc/ftpusers\fR
file are (counterintuitively)
\fInot\fR
allowed access to the ftp service\.
.PP
To allow login access only for certain users, you can use a
\fI/etc/pam\.d/login\fR
entry like this:
.sp
.RS 4
.nf
#
# permit login to users listed in /etc/loginusers
#
auth    required       pam_listfile\.so \e
        onerr=fail item=user sense=allow file=/etc/loginusers
      
.fi
.RE
.sp
For this example to work, all users who are allowed to use the login service should be listed in the file
\fI/etc/loginusers\fR\. 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
\fI/etc/loginusers\fR, or by listing a user who is able to
\fIsu\fR
to the root account\.
.SH "SEE ALSO"
.PP

\fBpam.conf\fR(5),
\fBpam.d\fR(8),
\fBpam\fR(8)
.SH "AUTHOR"
.PP
pam_listfile was written by Michael K\. Johnson <johnsonm@redhat\.com> and Elliot Lee <sopwith@cuc\.edu>\.