shadow/man/shadow.5

92 lines
3.8 KiB
Groff

.\"$Id: shadow.5,v 1.15 2005/04/12 16:31:06 kloczek Exp $
.\" Copyright 1989 - 1990, Julianne Frances Haugh
.\" 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 Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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.
.TH SHADOW 5
.SH NAME
shadow \- encrypted password file
.SH DESCRIPTION
\fIshadow\fR contains the encrypted password information for user's accounts
and optional the password aging information. Included is
.IP "" .5i
Login name
.IP "" .5i
Encrypted password
.IP "" .5i
Days since Jan 1, 1970 that password was last changed
.IP "" .5i
Days before password may be changed
.IP "" .5i
Days after which password must be changed
.IP "" .5i
Days before password is to expire that user is warned
.IP "" .5i
Days after password expires that account is disabled
.IP "" .5i
Days since Jan 1, 1970 that account is disabled
.IP "" .5i
A reserved field
.PP
The password field must be filled. The encryped password consists of 13 to
24 characters from the 64 characters alphabet a thru z, A thru Z, 0 thru 9,
\&\. and /. Optionally it can start with a "$" character. This means the
encrypted password was generated using another (not DES) algorithm. For
example if it starts with "$1$" it means the MD5\-based algorithm was used.
.PP
Refer to \fBcrypt\fR(3) for details on how this string is interpreted.
.PP
The date of the last password change is given as the number of days since
Jan 1, 1970. The password may not be changed again until the proper number
of days have passed, and must be changed after the maximum number of days.
If the minimum number of days required is greater than the maximum number of
day allowed, this password may not be changed by the user.
.PP
An account is considered to be inactive and is disabled if the password is
not changed within the specified number of days after the password expires.
An account will also be disabled on the specified day regardless of other
password expiration information.
.PP
This information supercedes any password or password age information present
in \fI/etc/passwd\fR.
.PP
This file must not be readable by regular users if password security is to
be maintained.
.SH FILES
\fI/etc/passwd\fR \- user account information
.br
\fI/etc/shadow\fR \- secure user account information
.SH SEE ALSO
.BR chage (1),
.BR login (1),
.BR passwd (1),
.BR su (1),
.BR passwd (5),
.BR pwconv (8),
.BR pwunconv (8),
.BR sulogin (8)
.SH AUTHOR
Julianne Frances Haugh (jockgrrl@ix.netcom.com)