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.\"
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12.\" modification, are permitted provided that the following conditions
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14.\" 1. Redistributions of source code must retain the above copyright
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16.\" 2. Redistributions in binary form must reproduce the above copyright
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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
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22.\"
23.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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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 Ux Ss Authentication Module
66The
67.Ux
68authentication component provides functions to verify the identity of
69a user
70.Pq Fn pam_sm_authenticate ,
71which obtains the relevant
72.Xr passwd 5
73entry.
74It prompts the user for a password and verifies that this is correct with
75.Xr crypt 3 .
76.Pp
77The following options may be passed to the authentication module:
78.Bl -tag -width ".Cm use_first_pass"
79.It Cm debug
80.Xr syslog 3
81debugging information at
82.Dv LOG_DEBUG
83level.
84.It Cm use_first_pass
85If the authentication module is not the first in the stack, and a
86previous module obtained the user's password, that password is used to
87authenticate the user.
88If this fails, the authentication module returns failure without
89prompting the user for a password.
90This option has no effect if the authentication module is the first in
91the stack, or if no previous modules obtained the user's password.
92.It Cm try_first_pass
93This option is similar to the
94.Cm use_first_pass
95option, except that if the previously obtained password fails, the
96user is prompted for another password.
97.It Cm auth_as_self
98This option will require the user to authenticate themselves as
99themselves, not as the account they are attempting to access.
100This is primarily for services like
101.Xr su 1 ,
102where the user's ability to retype their own password might be deemed
103sufficient.
104.It Cm nullok
105If the password database has no password for the entity being
106authenticated, then this option will forgo password prompting, and
107silently allow authentication to succeed.
108.Pp
109.Sy NOTE:
110If
111.Nm
112is invoked by a process that does not have the privileges required to
113access the password database (in most cases, this means root
114privileges), the
115.Cm nullok
116option may cause
117.Nm
118to allow any user to log in with any password.
119.It Cm local_pass
120Use only the local password database, even if NIS is in use.
121This will cause an authentication failure if the system is configured
122to only use NIS.
123.It Cm nis_pass
124Use only the NIS password database.
125This will cause an authentication failure if the system is not
126configured to use NIS.
127.El
128.Ss Ux Ss Account Management Module
129The
130.Ux
131account management component provides a function to perform account
132management,
133.Fn pam_sm_acct_mgmt .
134The function verifies that the authenticated user is allowed to log
135into the local user account by checking the following criteria:
136.Bl -dash -offset indent
137.It
138locked status of the account compatible with
139.Xr pw 8
140.Cm lock ;
141.It
142the password expiry date from
143.Xr passwd 5 ;
144.It
145.Xr login.conf 5
146restrictions on the remote host, login time, and tty.
147.El
148.Pp
149The following options may be passed to the management module:
150.Bl -tag -width ".Cm use_first_pass"
151.It Cm debug
152.Xr syslog 3
153debugging information at
154.Dv LOG_DEBUG
155level.
156.El
157.Ss Ux Ss Password Management Module
158The
159.Ux
160password management component provides a function to perform password
161management,
162.Fn pam_sm_chauthtok .
163The function changes
164the user's password.
165.Pp
166The following options may be passed to the password module:
167.Bl -tag -width ".Cm use_first_pass"
168.It Cm debug
169.Xr syslog 3
170debugging information at
171.Dv LOG_DEBUG
172level.
173.It Cm no_warn
174suppress warning messages to the user.
175These messages include reasons why the user's authentication attempt
176was declined.
177.It Cm local_pass
178forces the password module to change a local password in favour of a
179NIS one.
180.It Cm nis_pass
181forces the password module to change a NIS password in favour of a
182local one.
183.El
184.Sh FILES
185.Bl -tag -width ".Pa /etc/master.passwd" -compact
186.It Pa /etc/master.passwd
187default
188.Ux
189password database.
190.El
191.Sh SEE ALSO
192.Xr passwd 1 ,
193.Xr getlogin 2 ,
194.Xr crypt 3 ,
195.Xr getpwent 3 ,
196.Xr pam 3 ,
197.Xr syslog 3 ,
198.Xr nsswitch.conf 5 ,
199.Xr passwd 5 ,
200.Xr pw 8 ,
201.Xr yp 8
202.Sh BUGS
203The
204.Nm
205module ignores the
206.Dv PAM_CHANGE_EXPIRED_AUTHTOK
207flag.
208