.\"     Title: pam_group
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets v1.74.0 <http://docbook.sf.net/>
.\"      Date: 10/27/2010
.\"    Manual: Linux-PAM Manual
.\"    Source: Linux-PAM Manual
.\"  Language: English
.\"
.TH "PAM_GROUP" "8" "10/27/2010" "Linux-PAM Manual" "Linux-PAM Manual"
.\" -----------------------------------------------------------------
.\" * (re)Define some macros
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" toupper - uppercase a string (locale-aware)
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.de toupper
.tr aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ
\\$*
.tr aabbccddeeffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz
..
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" SH-xref - format a cross-reference to an SH section
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.de SH-xref
.ie n \{\
.\}
.toupper \\$*
.el \{\
\\$*
.\}
..
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" SH - level-one heading that works better for non-TTY output
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.de1 SH
.\" put an extra blank line of space above the head in non-TTY output
.if t \{\
.sp 1
.\}
.sp \\n[PD]u
.nr an-level 1
.set-an-margin
.nr an-prevailing-indent \\n[IN]
.fi
.in \\n[an-margin]u
.ti 0
.HTML-TAG ".NH \\n[an-level]"
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
\." make the size of the head bigger
.ps +3
.ft B
.ne (2v + 1u)
.ie n \{\
.\" if n (TTY output), use uppercase
.toupper \\$*
.\}
.el \{\
.nr an-break-flag 0
.\" if not n (not TTY), use normal case (not uppercase)
\\$1
.in \\n[an-margin]u
.ti 0
.\" if not n (not TTY), put a border/line under subheading
.sp -.6
\l'\n(.lu'
.\}
..
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" SS - level-two heading that works better for non-TTY output
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.de1 SS
.sp \\n[PD]u
.nr an-level 1
.set-an-margin
.nr an-prevailing-indent \\n[IN]
.fi
.in \\n[IN]u
.ti \\n[SN]u
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.ps \\n[PS-SS]u
\." make the size of the head bigger
.ps +2
.ft B
.ne (2v + 1u)
.if \\n[.$] \&\\$*
..
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" BB/BE - put background/screen (filled box) around block of text
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.de BB
.if t \{\
.sp -.5
.br
.in +2n
.ll -2n
.gcolor red
.di BX
.\}
..
.de EB
.if t \{\
.if "\\$2"adjust-for-leading-newline" \{\
.sp -1
.\}
.br
.di
.in
.ll
.gcolor
.nr BW \\n(.lu-\\n(.i
.nr BH \\n(dn+.5v
.ne \\n(BHu+.5v
.ie "\\$2"adjust-for-leading-newline" \{\
\M[\\$1]\h'1n'\v'+.5v'\D'P \\n(BWu 0 0 \\n(BHu -\\n(BWu 0 0 -\\n(BHu'\M[]
.\}
.el \{\
\M[\\$1]\h'1n'\v'-.5v'\D'P \\n(BWu 0 0 \\n(BHu -\\n(BWu 0 0 -\\n(BHu'\M[]
.\}
.in 0
.sp -.5v
.nf
.BX
.in
.sp .5v
.fi
.\}
..
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" BM/EM - put colored marker in margin next to block of text
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.de BM
.if t \{\
.br
.ll -2n
.gcolor red
.di BX
.\}
..
.de EM
.if t \{\
.br
.di
.ll
.gcolor
.nr BH \\n(dn
.ne \\n(BHu
\M[\\$1]\D'P -.75n 0 0 \\n(BHu -(\\n[.i]u - \\n(INu - .75n) 0 0 -\\n(BHu'\M[]
.in 0
.nf
.BX
.in
.fi
.\}
..
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "Name"
pam_group \- PAM module for group access
.SH "Synopsis"
.fam C
.HP \w'\fBpam_group\&.so\fR\ 'u
\fBpam_group\&.so\fR
.fam
.SH "DESCRIPTION"
.PP
The pam_group PAM module does not authenticate the user, but instead it grants group memberships (in the credential setting phase of the authentication module) to the user\&. Such memberships are based on the service they are applying for\&.
.PP
By default rules for group memberships are taken from config file
\FC/etc/security/group\&.conf\F[]\&.
.PP
This module\'s usefulness relies on the file\-systems accessible to the user\&. The point being that once granted the membership of a group, the user may attempt to create a
\fBsetgid\fR
binary with a restricted group ownership\&. Later, when the user is not given membership to this group, they can recover group membership with the precompiled binary\&. The reason that the file\-systems that the user has access to are so significant, is the fact that when a system is mounted
\fInosuid\fR
the user is unable to create or execute such a binary file\&. For this module to provide any level of security, all file\-systems that the user has write access to should be mounted
\fInosuid\fR\&.
.PP
The pam_group module functions in parallel with the
\FC/etc/group\F[]
file\&. If the user is granted any groups based on the behavior of this module, they are granted
\fIin addition\fR
to those entries
\FC/etc/group\F[]
(or equivalent)\&.
.SH "OPTIONS"
.PP
This module does not recognise any options\&.
.SH "MODULE TYPES PROVIDED"
.PP
Only the
\fBauth\fR
module type is provided\&.
.SH "RETURN VALUES"
.PP
PAM_SUCCESS
.RS 4
group membership was granted\&.
.RE
.PP
PAM_ABORT
.RS 4
Not all relevant data could be gotten\&.
.RE
.PP
PAM_BUF_ERR
.RS 4
Memory buffer error\&.
.RE
.PP
PAM_CRED_ERR
.RS 4
Group membership was not granted\&.
.RE
.PP
PAM_IGNORE
.RS 4

\fBpam_sm_authenticate\fR
was called which does nothing\&.
.RE
.PP
PAM_USER_UNKNOWN
.RS 4
The user is not known to the system\&.
.RE
.SH "FILES"
.PP
\FC/etc/security/group\&.conf\F[]
.RS 4
Default configuration file
.RE
.SH "SEE ALSO"
.PP

\fBgroup.conf\fR(5),
\fBpam.d\fR(5),
\fBpam\fR(8)\&.
.SH "AUTHORS"
.PP
pam_group was written by Andrew G\&. Morgan <morgan@kernel\&.org>\&.