1.\" Copyright (c) 2001 Mark R V Murray
2.\" All rights reserved.
3.\" Copyright (c) 2001 Networks Associates Technology, Inc.
4.\" All rights reserved.
5.\"
6.\" This software was developed for the FreeBSD Project by ThinkSec AS and
7.\" NAI Labs, the Security Research Division of Network Associates, Inc.
8.\" under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9.\" DARPA CHATS research program.
10.\"
11.\" Redistribution and use in source and binary forms, with or without
12.\" modification, are permitted provided that the following conditions
13.\" are met:
14.\" 1. Redistributions of source code must retain the above copyright
15.\"    notice, this list of conditions and the following disclaimer.
16.\" 2. Redistributions in binary form must reproduce the above copyright
17.\"    notice, this list of conditions and the following disclaimer in the
18.\"    documentation and/or other materials provided with the distribution.
19.\" 3. The name of the author may not be used to endorse or promote
20.\"    products derived from this software without specific prior written
21.\"    permission.
22.\"
23.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33.\" SUCH DAMAGE.
34.\"
35.\" $FreeBSD: head/lib/libpam/modules/pam_unix/pam_unix.8 227044 2011-11-02 23:40:21Z des $
36.\"
37.Dd June 20, 2009
38.Dt PAM_UNIX 8
39.Os
40.Sh NAME
41.Nm pam_unix
42.Nd UNIX PAM module
43.Sh SYNOPSIS
44.Op Ar service-name
45.Ar module-type
46.Ar control-flag
47.Pa pam_unix
48.Op Ar options
49.Sh DESCRIPTION
50The
51.Ux
52authentication service module for PAM,
53.Nm
54provides functionality for three PAM categories:
55authentication, account management, and password management.
56In terms of the
57.Ar module-type
58parameter, they are the
59.Dq Li auth ,
60.Dq Li account ,
61and
62.Dq Li password
63features.
64It also provides a null function for session management.
65.Ss Eo
66.Ux
67Authentication Module
68.Ec
69The
70.Ux
71authentication component provides functions to verify the identity of
72a user
73.Pq Fn pam_sm_authenticate ,
74which obtains the relevant
75.Xr passwd 5
76entry.
77It prompts the user for a password and verifies that this is correct with
78.Xr crypt 3 .
79.Pp
80The following options may be passed to the authentication module:
81.Bl -tag -width ".Cm use_first_pass"
82.It Cm debug
83.Xr syslog 3
84debugging information at
85.Dv LOG_DEBUG
86level.
87.It Cm use_first_pass
88If the authentication module is not the first in the stack, and a
89previous module obtained the user's password, that password is used to
90authenticate the user.
91If this fails, the authentication module returns failure without
92prompting the user for a password.
93This option has no effect if the authentication module is the first in
94the stack, or if no previous modules obtained the user's password.
95.It Cm try_first_pass
96This option is similar to the
97.Cm use_first_pass
98option, except that if the previously obtained password fails, the
99user is prompted for another password.
100.It Cm auth_as_self
101This option will require the user to authenticate themselves as
102themselves, not as the account they are attempting to access.
103This is primarily for services like
104.Xr su 1 ,
105where the user's ability to retype their own password might be deemed
106sufficient.
107.It Cm nullok
108If the password database has no password for the entity being
109authenticated, then this option will forgo password prompting, and
110silently allow authentication to succeed.
111.Pp
112.Sy NOTE:
113If
114.Nm
115is invoked by a process that does not have the privileges required to
116access the password database (in most cases, this means root
117privileges), the
118.Cm nullok
119option may cause
120.Nm
121to allow any user to log in with any password.
122.It Cm local_pass
123Use only the local password database, even if NIS is in use.
124This will cause an authentication failure if the system is configured
125to only use NIS.
126.It Cm nis_pass
127Use only the NIS password database.
128This will cause an authentication failure if the system is not
129configured to use NIS.
130.El
131.Ss Eo
132.Ux
133Account Management Module
134.Ec
135The
136.Ux
137account management component provides a function to perform account
138management,
139.Fn pam_sm_acct_mgmt .
140The function verifies that the authenticated user is allowed to log
141into the local user account by checking the following criteria:
142.Bl -dash -offset indent
143.It
144locked status of the account compatible with
145.Xr pw 8
146.Cm lock ;
147.It
148the password expiry date from
149.Xr passwd 5 ;
150.It
151.Xr login.conf 5
152restrictions on the remote host, login time, and tty.
153.El
154.Pp
155The following options may be passed to the management module:
156.Bl -tag -width ".Cm use_first_pass"
157.It Cm debug
158.Xr syslog 3
159debugging information at
160.Dv LOG_DEBUG
161level.
162.El
163.Ss Eo
164.Ux
165Password Management Module
166.Ec
167The
168.Ux
169password management component provides a function to perform password
170management,
171.Fn pam_sm_chauthtok .
172The function changes
173the user's password.
174.Pp
175The following options may be passed to the password module:
176.Bl -tag -width ".Cm use_first_pass"
177.It Cm debug
178.Xr syslog 3
179debugging information at
180.Dv LOG_DEBUG
181level.
182.It Cm no_warn
183suppress warning messages to the user.
184These messages include reasons why the user's authentication attempt
185was declined.
186.It Cm local_pass
187forces the password module to change a local password in favour of a
188NIS one.
189.It Cm nis_pass
190forces the password module to change a NIS password in favour of a
191local one.
192.El
193.Sh FILES
194.Bl -tag -width ".Pa /etc/master.passwd" -compact
195.It Pa /etc/master.passwd
196default
197.Ux
198password database.
199.El
200.Sh SEE ALSO
201.Xr passwd 1 ,
202.Xr getlogin 2 ,
203.Xr crypt 3 ,
204.Xr getpwent 3 ,
205.Xr pam 3 ,
206.Xr syslog 3 ,
207.Xr nsswitch.conf 5 ,
208.Xr passwd 5 ,
209.Xr pw 8 ,
210.Xr yp 8
211.Sh BUGS
212The
213.Nm
214module ignores the
215.Dv PAM_CHANGE_EXPIRED_AUTHTOK
216flag.
217