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.\" $FreeBSD$ 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 syslog 3 , 197.Xr nsswitch.conf 5 , 198.Xr passwd 5 , 199.Xr pam 8 , 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