.\" $NetBSD: passwd.5,v 1.12.2.2 1999/12/17 23:14:50 he Exp $ .\" .\" Copyright (c) 1988, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" Portions Copyright (c) 1994, Jason Downs. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" From: @(#)passwd.5 8.1 (Berkeley) 6/5/93 .\" $FreeBSD$ .\" .Dd June 30, 2022 .Dt PASSWD 5 .Os .Sh NAME .Nm passwd , .Nm master.passwd , .Nm pwd.db , .Nm spwd.db .Nd format of the password file .Sh DESCRIPTION The .Nm files are the local source of password information. They can be used in conjunction with the Hesiod domains .Sq Li passwd and .Sq Li uid , and the .Tn NIS maps .Sq Li passwd.byname , .Sq Li passwd.byuid , .Sq Li master.passwd.byname , and .Sq Li master.passwd.byuid , as controlled by .Xr nsswitch.conf 5 . .Pp For consistency, none of these files should ever be modified manually. .Pp The .Nm master.passwd file is readable only by root, and consists of newline separated records, one per user, containing ten colon .Pq Ql \&: separated fields. These fields are as follows: .Bl -tag -width ".Ar password" -offset indent .It Ar name User's login name. .It Ar password User's .Em encrypted password. .It Ar uid User's id. .It Ar gid User's login group id. .It Ar class User's login class. .It Ar change Password change time. .It Ar expire Account expiration time. .It Ar gecos General information about the user. .It Ar home_dir User's home directory. .It Ar shell User's login shell. .El .Pp The .Nm file is generated from the .Nm master.passwd file by .Xr pwd_mkdb 8 , has the .Ar class , .Ar change , and .Ar expire fields removed, and the .Ar password field replaced by a .Ql * character. .Pp The .Ar name field is the login used to access the computer account, and the .Ar uid field is the number associated with it. They should both be unique across the system (and often across a group of systems) since they control file access. .Pp While it is possible to have multiple entries with identical login names and/or identical user id's, it is usually a mistake to do so. Routines that manipulate these files will often return only one of the multiple entries, and that one by random selection. .Pp The login name must not begin with a hyphen .Pq Ql \&- , and cannot contain 8-bit characters, tabs or spaces, or any of these symbols: .Ql \&,:+&#%^\&(\&)!@~*?<>=|\e\\&/" . The dollar symbol .Pq Ql \&$ is allowed only as the last character for use with Samba. No field may contain a colon .Pq Ql \&: as this has been used historically to separate the fields in the user database. .Pp Case is significant. Login names .Ql Lrrr and .Ql lrrr represent different users. Be aware of this when interoperating with systems that do not have case-sensitive login names. .Pp In the .Nm master.passwd file, the .Ar password field is the .Em encrypted form of the password, see .Xr crypt 3 . If the .Ar password field is empty, no password will be required to gain access to the machine. This is almost invariably a mistake, so authentication components such as PAM can forcibly disallow remote access to passwordless accounts. Because this file contains the encrypted user passwords, it should not be readable by anyone without appropriate privileges. .Pp A password of .Ql * indicates that password authentication is disabled for that account (logins through other forms of authentication, e.g., using .Xr ssh 1 keys, will still work). The field only contains encrypted passwords, and .Ql * can never be the result of encrypting a password. .Pp An encrypted password prefixed by .Ql *LOCKED* means that the account is temporarily locked out and no one can log into it using any authentication. For a convenient command-line interface to account locking, see .Xr pw 8 . .Pp The .Ar group field is the group that the user will be placed in upon login. Since this system supports multiple groups (see .Xr groups 1 ) this field currently has little special meaning. .Pp The .Ar class field is a key for a user's login class. Login classes are defined in .Xr login.conf 5 , which is a .Xr termcap 5 style database of user attributes, accounting, resource, and environment settings. .Pp The .Ar change field is the number of seconds from the epoch, .Dv UTC , until the password for the account must be changed. This field may be left empty to turn off the password aging feature; a value of zero is equivalent to leaving the field empty. .Pp The .Ar expire field is the number of seconds from the epoch, .Dv UTC , until the account expires. This field may be left empty to turn off the account aging feature; a value of zero is equivalent to leaving the field empty. .Pp The .Ar gecos field normally contains comma .Pq Ql \&, separated subfields as follows: .Pp .Bl -tag -width ".Ar office" -offset indent -compact .It Ar name user's full name .It Ar office user's office number .It Ar wphone user's work phone number .It Ar hphone user's home phone number .El .Pp The full .Ar name may contain an ampersand .Pq Ql & which will be replaced by the capitalized login .Ar name when the .Ar gecos field is displayed or used by various programs such as .Xr finger 1 , .Xr sendmail 8 , etc. .Pp The .Ar office and phone number subfields are used by the .Xr finger 1 program, and possibly other applications. .Pp The user's home directory, .Ar home_dir , is the full .Ux path name where the user will be placed on login. .Pp The .Ar shell field is the command interpreter the user prefers. If there is nothing in the .Ar shell field, the Bourne shell .Pq Pa /bin/sh is assumed. The conventional way to disable logging into an account once and for all, as it is done for system accounts, is to set its .Ar shell to .Pa /sbin/nologin .Pq see Xr nologin 8 . .Sh HESIOD SUPPORT If .Sq Li dns is specified for the .Sq Li passwd database in .Xr nsswitch.conf 5 , then .Nm lookups occur from the .Sq Li passwd Hesiod domain. .Sh NIS SUPPORT If .Sq Li nis is specified for the .Sq Li passwd database in .Xr nsswitch.conf 5 , then .Nm lookups occur from the .Sq Li passwd.byname , .Sq Li passwd.byuid , .Sq Li master.passwd.byname , and .Sq Li master.passwd.byuid .Tn NIS maps. .Sh COMPAT SUPPORT If .Sq Li compat is specified for the .Sq Li passwd database, and either .Sq Li dns or .Sq Li nis is specified for the .Sq Li passwd_compat database in .Xr nsswitch.conf 5 , then the .Nm file also supports standard .Sq Li + Ns / Ns Li - exclusions and inclusions, based on user names and netgroups. .Pp Lines beginning with a .Ql - (minus sign) are entries marked as being excluded from any following inclusions, which are marked with a .Ql + (plus sign). .Pp If the second character of the line is a .Ql @ (at sign), the operation involves the user fields of all entries in the netgroup specified by the remaining characters of the .Ar name field. Otherwise, the remainder of the .Ar name field is assumed to be a specific user name. .Pp The .Ql + token may also be alone in the .Ar name field, which causes all users from either the Hesiod domain .Nm (with .Sq Li passwd_compat: dns ) or .Sq Li passwd.byname and .Sq Li passwd.byuid .Tn NIS maps (with .Sq Li passwd_compat: nis ) to be included. .Pp If the entry contains non-empty .Ar uid or .Ar gid fields, the specified numbers will override the information retrieved from the Hesiod domain or the .Tn NIS maps. Likewise, if the .Ar gecos , .Ar dir or .Ar shell entries contain text, it will override the information included via Hesiod or .Tn NIS . On some systems, the .Ar passwd field may also be overridden. .Sh FILES .Bl -tag -width ".Pa /etc/master.passwd" -compact .It Pa /etc/passwd .Tn ASCII password file, with passwords removed .It Pa /etc/pwd.db .Xr db 3 Ns -format password database, with passwords removed .It Pa /etc/master.passwd .Tn ASCII password file, with passwords intact .It Pa /etc/spwd.db .Xr db 3 Ns -format password database, with passwords intact .El .Sh COMPATIBILITY The password file format has changed since .Bx 4.3 . The following awk script can be used to convert your old-style password file into a new style password file. The additional fields .Ar class , .Ar change and .Ar expire are added, but are turned off by default .Pq setting these fields to zero is equivalent to leaving them blank . Class is currently not implemented, but change and expire are; to set them, use the current day in seconds from the epoch + whatever number of seconds of offset you want. .Bd -literal -offset indent BEGIN { FS = ":"} { print $1 ":" $2 ":" $3 ":" $4 "::0:0:" $5 ":" $6 ":" $7 } .Ed .Sh SEE ALSO .Xr chpass 1 , .Xr login 1 , .Xr passwd 1 , .Xr crypt 3 , .Xr getpwent 3 , .Xr login.conf 5 , .Xr netgroup 5 , .Xr nsswitch.conf 5 , .Xr adduser 8 , .Xr nologin 8 , .Xr pw 8 , .Xr pwd_mkdb 8 , .Xr vipw 8 , .Xr yp 8 .Pp .%T "Managing NFS and NIS" (O'Reilly & Associates) .Sh HISTORY A .Nm file format first appeared in .At v1 . .Pp The .Tn NIS .Nm file format first appeared in SunOS. .Pp The Hesiod support first appeared in .Fx 4.1 . It was imported from the .Nx Project, where it first appeared in .Nx 1.4 . .Sh BUGS User information should (and eventually will) be stored elsewhere. .Pp Placing .Sq Li compat exclusions in the file after any inclusions will have unexpected results.