254 lines
7.6 KiB
Groff
254 lines
7.6 KiB
Groff
.\" Copyright (c) 1990, 1993
|
|
.\" The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. 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.
|
|
.\"
|
|
.\" @(#)passwd.1 8.1 (Berkeley) 6/6/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 6, 1993
|
|
.Dt PASSWD 1
|
|
.Os
|
|
.Sh NAME
|
|
.Nm passwd , yppasswd
|
|
.Nd modify a user's password
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl l
|
|
.Op Ar user
|
|
.Nm yppasswd
|
|
.Op Fl l
|
|
.Op Fl y
|
|
.Op Fl d Ar domain
|
|
.Op Fl h Ar host
|
|
.Op Fl o
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility changes the user's local, Kerberos, or NIS password.
|
|
If the user is not the super-user,
|
|
.Nm
|
|
first prompts for the current password and will not continue unless the correct
|
|
password is entered.
|
|
.Pp
|
|
When entering the new password, the characters entered do not echo, in order to
|
|
avoid the password being seen by a passer-by.
|
|
The
|
|
.Nm
|
|
utility prompts for the new password twice in order to detect typing errors.
|
|
.Pp
|
|
The new password should be at least six characters long (which
|
|
may be overridden using the
|
|
.Xr login.conf 5
|
|
.Dq minpasswordlen
|
|
setting for a user's login class) and not purely alphabetic.
|
|
Its total length must be less than
|
|
.Dv _PASSWORD_LEN
|
|
(currently 128 characters).
|
|
.Pp
|
|
The new password should contain a mixture of upper and lower case
|
|
characters (which may be overridden using the
|
|
.Xr login.conf 5
|
|
.Dq mixpasswordcase
|
|
setting for a user's login class).
|
|
Allowing lower case passwords may
|
|
be useful where the password file will be used in situations where only
|
|
lower case passwords are permissible, such as when using Samba to
|
|
authenticate Windows clients.
|
|
In all other situations, numbers, upper
|
|
case letters and meta characters are encouraged.
|
|
.Pp
|
|
Once the password has been verified,
|
|
.Nm
|
|
communicates the new password information to
|
|
the Kerberos authenticating host.
|
|
.Pp
|
|
The following option is available:
|
|
.Bl -tag -width indent
|
|
.It Fl l
|
|
Cause the password to be updated only in the local
|
|
password file, and not with the Kerberos database.
|
|
When changing only the local password,
|
|
.Xr pwd_mkdb 8
|
|
is used to update the password databases.
|
|
.El
|
|
When changing local or NIS password, the next password change date
|
|
is set according to
|
|
.Dq passwordtime
|
|
capability in the user's login class.
|
|
.Pp
|
|
To change another user's Kerberos password, one must first
|
|
run
|
|
.Xr kinit 1
|
|
followed by
|
|
.Nm .
|
|
The super-user is not required to provide a user's current password
|
|
if only the local password is modified.
|
|
.Sh NIS INTERACTION
|
|
The
|
|
.Nm
|
|
utility has built-in support for NIS.
|
|
If a user exists in the NIS password
|
|
database but does not exist locally,
|
|
.Nm
|
|
automatically switches into
|
|
.Dq yppasswd
|
|
mode.
|
|
If the specified
|
|
user does not exist in either the local password database or the
|
|
NIS password maps,
|
|
.Nm
|
|
returns an error.
|
|
.Pp
|
|
When changing an NIS password, unprivileged users are required to provide
|
|
their old password for authentication (the
|
|
.Xr rpc.yppasswdd 8
|
|
daemon requires the original password before
|
|
it will allow any changes to the NIS password maps).
|
|
This restriction applies even to the
|
|
super-user, with one important exception: the password authentication is
|
|
bypassed for the super-user on the NIS master server.
|
|
This means that
|
|
the super-user on the NIS master server can make unrestricted changes to
|
|
anyone's NIS password.
|
|
The super-user on NIS client systems and NIS slave
|
|
servers still needs to provide a password before the update will be processed.
|
|
.Pp
|
|
The following additional options are supported for use with NIS:
|
|
.Bl -tag -width indent
|
|
.It Fl y
|
|
Override
|
|
.Nm Ns 's
|
|
checking heuristics and forces
|
|
it into NIS mode.
|
|
.It Fl l
|
|
When NIS is enabled, the
|
|
.Fl l
|
|
flag can be used to force
|
|
.Nm
|
|
into
|
|
.Dq local only
|
|
mode.
|
|
This flag can be used to change the entry
|
|
for a local user when an NIS user exists with the same login name.
|
|
For example, you will sometimes find entries for system
|
|
.Dq placeholder
|
|
users such as
|
|
.Pa bin
|
|
or
|
|
.Pa daemon
|
|
in both the NIS password maps and the local user database.
|
|
By
|
|
default,
|
|
.Nm
|
|
will try to change the NIS password.
|
|
The
|
|
.Fl l
|
|
flag can be used to change the local password instead.
|
|
.It Fl d Ar domain
|
|
Specify what domain to use when changing an NIS password.
|
|
By default,
|
|
.Nm
|
|
assumes that the system default domain should be used.
|
|
This flag is
|
|
primarily for use by the superuser on the NIS master server: a single
|
|
NIS server can support multiple domains.
|
|
It is also possible that the
|
|
domainname on the NIS master may not be set (it is not necessary for
|
|
an NIS server to also be a client) in which case the
|
|
.Nm
|
|
command needs to be told what domain to operate on.
|
|
.It Fl h Ar host
|
|
Specify the name of an NIS server.
|
|
This option, in conjunction
|
|
with the
|
|
.Fl d
|
|
option, can be used to change an NIS password on a non-local NIS
|
|
server.
|
|
When a domain is specified with the
|
|
.Fl d
|
|
option and
|
|
.Nm
|
|
is unable to determine the name of the NIS master server (possibly because
|
|
the local domainname is not set), the name of the NIS master is assumed to
|
|
be
|
|
.Dq localhost .
|
|
This can be overridden with the
|
|
.Fl h
|
|
flag.
|
|
The specified hostname need not be the name of an NIS master: the
|
|
name of the NIS master for a given map can be determined by querying any
|
|
NIS server (master or slave) in a domain, so specifying the name of a
|
|
slave server will work equally well.
|
|
.It Fl o
|
|
Do not automatically override the password authentication checks for the
|
|
super-user on the NIS master server; assume 'old' mode instead.
|
|
This
|
|
flag is of limited practical use but is useful for testing.
|
|
.El
|
|
.Sh FILES
|
|
.Bl -tag -width /etc/master.passwd -compact
|
|
.It Pa /etc/master.passwd
|
|
the user database
|
|
.It Pa /etc/passwd
|
|
a Version 7 format password file
|
|
.It Pa /etc/passwd.XXXXXX
|
|
temporary copy of the password file
|
|
.It Pa /etc/login.conf
|
|
login class capabilities database
|
|
.It Pa /etc/auth.conf
|
|
configure authentication services
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr chpass 1 ,
|
|
.Xr kinit 1 ,
|
|
.Xr login 1 ,
|
|
.Xr login.conf 5 ,
|
|
.Xr passwd 5 ,
|
|
.Xr kerberos 8 ,
|
|
.Xr kpasswdd 8 ,
|
|
.Xr pw 8 ,
|
|
.Xr pwd_mkdb 8 ,
|
|
.Xr vipw 8
|
|
.Rs
|
|
.%A Robert Morris
|
|
.%A Ken Thompson
|
|
.%T "UNIX password security"
|
|
.Re
|
|
.Sh NOTES
|
|
The
|
|
.Nm yppasswd
|
|
command is really only a link to
|
|
.Nm .
|
|
.Sh HISTORY
|
|
A
|
|
.Nm
|
|
command appeared in
|
|
.At v6 .
|