1.\" $NetBSD: passwd.1,v 1.18 2001/12/01 16:43:22 wiz Exp $ 2.\" 3.\" Copyright (c) 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" from: @(#)passwd.1 8.1 (Berkeley) 6/6/93 35.\" 36.Dd June 6, 1993 37.Dt PASSWD 1 38.Os 39.Sh NAME 40.Nm passwd , 41.Nm yppasswd , 42.Nm kpasswd 43.Nd modify a user's password 44.Sh SYNOPSIS 45.Nm passwd 46.Op Fl l 47.Op Ar user 48.Nm passwd 49.Op Fl y 50.Op Ar user 51.Nm passwd 52.Op Fl 4 53.Op Fl k 54.Op Fl i Ar instance 55.Op Fl r Ar realm 56.Op Fl u Ar fullname 57.Op Ar user 58.Nm passwd 59.Op Fl 5 60.Op Fl k 61.Op Fl u Ar fullname 62.Op Ar user 63.Nm kpasswd 64.Op Fl 4 65.Op Fl k 66.Op Fl i Ar instance 67.Op Fl r Ar realm 68.Op Fl u Ar fullname 69.Op Ar user 70.Nm kpasswd 71.Op Fl 5 72.Op Fl k 73.Op Fl u Ar fullname 74.Op Ar user 75.Nm yppasswd 76.Op Ar user 77.Sh DESCRIPTION 78.Nm 79changes the user's local, YP, or kerberos password. First, the user is 80prompted for their current password. 81If the current password is correctly typed, a new password is 82requested. 83The new password must be entered twice to avoid typing errors. 84.Pp 85The new password should be at least six characters long and not 86purely alphabetic. 87Its total length must be less than 88.Dv _PASSWORD_LEN 89(currently 128 characters). 90Numbers, upper case letters and meta characters 91are encouraged. 92.Pp 93All options may not be available on all systems. 94.Bl -tag -width flag 95.It Fl l 96This option causes the password to be updated only in the local 97password file. When changing only the local password, 98.Xr pwd_mkdb 8 99is used to update the password databases. 100.It Fl y 101This forces the YP password database entry to be changed, even if 102the user has an entry in the local database. The 103.Xr rpc.yppasswdd 8 104daemon should be running on the YP master server. 105.Nm yppasswd 106is the equivalent of 107.Nm 108with the 109.Fl y 110flag. 111.It Fl 4 112This option causes passwd to change the user's kerberos password, 113using the kerberos 4 admin protocol. 114.It Fl 5 115This option causes passwd to change the user's kerberos password, 116using the kerberos 5 admin protocol. 117.It Fl k 118This option causes passwd to change the user's kerberos password, 119using either the kerberos 4 or kerberos 5 admin protocol. 120If both kerberos 4 and kerberos 5 libraries and config files are 121installed on the host, kerberos 5 will be used to change the password. 122.Nm kpasswd 123is the equivalent of 124.Nm 125with the 126.Fl k 127flag. 128.It Fl i Ar instance 129This option selects a non-default Kerberos 4 instance for the 130Kerberos password to be changed. 131.It Fl r Ar realm 132This option selects a non-default Kerberos 4 realm for the Kerberos 133password to be changed. 134.It Fl u Ar fullname 135This option specifies the entire principal.instance@realm (for Kerberos 1364) or principal/instance@realm (for Kerberos 5) for the Kerberos 137password to be changed. 138.El 139.Pp 140This is the behavior if no flags are specified: 141If Kerberos is active then 142.Nm 143will talk to the Kerberos server, attempting to use Kerberos 5, then 144Kerberos 4 protocols to change the password (even if the user has an 145entry in the local database.) 146If Kerberos is unavailable, an attempt is made to use the YP database. 147If the password is not in the YP database, then 148an attempt is made to use the local password database. 149.Pp 150The super-user is not required to provide a user's current password 151if only the local password is modified. 152.Pp 153The type of cipher used to encrypt the password depends on the configuration 154in 155.Xr passwd.conf 5 . 156It can be different for local and YP passwords. 157.Sh FILES 158.Bl -tag -width /etc/master.passwd -compact 159.It Pa /etc/master.passwd 160The user database 161.It Pa /etc/passwd 162A Version 7 format password file 163.It Pa /etc/passwd.XXXXXX 164Temporary copy of the password file 165.El 166.Sh SEE ALSO 167.Xr chpass 1 , 168.Xr login 1 , 169.Xr passwd 5 , 170.Xr passwd.conf 5 , 171.Xr pwd_mkdb 8 , 172.Xr vipw 8 173.Rs 174.%A Robert Morris 175.%A Ken Thompson 176.%T "UNIX password security" 177.Re 178.Sh HISTORY 179A 180.Nm 181command appeared in 182.At v6 . 183