| Current File : //usr/share/man/man4/shadow.4 |
'\" te
.\" Copyright 1989 AT&T
.\" Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
.TH shadow 4 "7 Jun 2011" "SunOS 5.11" "File Formats"
.SH NAME
shadow \- shadow password file
.SH DESCRIPTION
.sp
.LP
\fB/etc/shadow\fR is an access-restricted ASCII system file that stores users' encrypted passwords and related information. The shadow file can be used in conjunction with other shadow sources, including the \fBNIS\fR maps \fBpasswd.byname\fR and \fBpasswd.byuid\fR. Programs use the \fBgetspnam\fR(3C) routines to access this information.
.sp
.LP
The fields for each user entry are separated by colons. Each user is separated from the next by a NEWLINE. Unlike the \fB/etc/passwd\fR file, \fB/etc/shadow\fR does not have general read permission.
.sp
.LP
Each entry in the shadow file has the form:
.sp
.in +2
.nf
\fIusername\fR:\fIpassword\fR:\fIlastchg\fR:\fImin\fR:\fImax\fR:\fIwarn\fR:\fIinactive\fR:\fIexpire\fR:\fIflag\fR
.fi
.in -2
.sp
.LP
The fields are defined as follows:
.sp
.ne 2
.mk
.na
\fB\fIusername\fR\fR
.ad
.RS 12n
.rt
The user's login name (UID).
.RE
.sp
.ne 2
.mk
.na
\fB\fIpassword\fR\fR
.ad
.RS 12n
.rt
An encrypted password for the user generated by \fBcrypt\fR(3C), a \fIlock\fR string to indicate that the login is not accessible, or no string, which shows that there is no password for the login.
.sp
The lock string is defined as \fB*LK*\fR in the first four characters of the password field.
.RE
.sp
.ne 2
.mk
.na
\fB\fIlastchg\fR\fR
.ad
.RS 12n
.rt
The number of days between January 1, 1970, and the date that the password was last modified. The \fIlastchg\fR value is a decimal number, as interpreted by \fBstrtol\fR(3C).
.RE
.sp
.ne 2
.mk
.na
\fB\fImin\fR\fR
.ad
.RS 12n
.rt
The minimum number of days required between password changes. This field must be set to 0 or above to enable password aging.
.RE
.sp
.ne 2
.mk
.na
\fB\fImax\fR\fR
.ad
.RS 12n
.rt
The maximum number of days the password is valid.
.RE
.sp
.ne 2
.mk
.na
\fB\fIwarn\fR\fR
.ad
.RS 12n
.rt
The number of days before password expires that the user is warned.
.RE
.sp
.ne 2
.mk
.na
\fB\fIinactive\fR\fR
.ad
.RS 12n
.rt
The number of days of inactivity allowed for that user. This is counted on a per-machine basis; the information about the last login is taken from the machine's \fBlastlog\fR file.
.RE
.sp
.ne 2
.mk
.na
\fB\fIexpire\fR\fR
.ad
.RS 12n
.rt
An absolute date expressed as the number of days since the Unix Epoch (January 1, 1970). When this number is reached the login can no longer be used. For example, an \fIexpire\fR value of \fB13514\fR specifies a login expiration of January 1, 2007.
.RE
.sp
.ne 2
.mk
.na
\fB\fIflag\fR\fR
.ad
.RS 12n
.rt
Reserved. May be set to arbitrary values. Traditionally, the low order for bits are a failed login count.
.sp
The bits in the remainder may or may not be zero. They may be used at any time for any other purposes.
.RE
.sp
.LP
A value of \fB-1\fR for \fImin\fR, \fImax\fR, or \fIwarn\fR disables password aging.
.sp
.LP
The encrypted password consists of at most \fBCRYPT_MAXCIPHERTEXTLEN\fR characters chosen from a 64-character alphabet (\fB\&.\fR, \fB/\fR, \fB0\(mi9\fR, \fBA\(miZ\fR, \fBa\(miz\fR). Two additional special characters: the dollar sign (\fB$\fR) and the comma (\fB,\fR), can also be used and are defined in \fBcrypt\fR(3C). To update this file, use the \fBpasswd\fR(1), \fBuseradd\fR(1M), \fBusermod\fR(1M), or \fBuserdel\fR(1M) commands.
.sp
.LP
To make system administration manageable, \fB/etc/shadow\fR entries should appear in exactly the same order as \fB/etc/passwd\fR entries; this includes ``+'' and ``-'' entries if the \fBcompat\fR source is being used (see \fBnsswitch.conf\fR(4)).
.sp
.LP
Values for the various time-related fields are interpreted as Greenwich Mean Time.
.SH FILES
.sp
.ne 2
.mk
.na
\fB\fB/etc/shadow\fR\fR
.ad
.RS 22n
.rt
Shadow password file
.RE
.sp
.ne 2
.mk
.na
\fB\fB/etc/passwd\fR\fR
.ad
.RS 22n
.rt
Password file
.RE
.sp
.ne 2
.mk
.na
\fB\fB/etc/nsswitch.conf\fR\fR
.ad
.RS 22n
.rt
Name-service switch configuration file
.RE
.sp
.ne 2
.mk
.na
\fB\fB/var/adm/lastlog\fR\fR
.ad
.RS 22n
.rt
Time of last login
.RE
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp
.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i)
lw(2.75i) |lw(2.75i)
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
.TE
.SH SEE ALSO
.sp
.LP
\fBlogin\fR(1), \fBpasswd\fR(1), \fBuseradd\fR(1M), \fBuserdel\fR(1M), \fBusermod\fR(1M), \fBstrtol\fR(3C), \fBcrypt\fR(3C), \fBcrypt_gensalt\fR(3C), \fBgetspnam\fR(3C), \fBputspent\fR(3C), \fBnsswitch.conf\fR(4), \fBpasswd\fR(4), \fBattributes\fR(5), \fBpam_unix_account\fR(5), \fBpam_unix_auth\fR(5)
.SH NOTES
.sp
.LP
If password aging is turned on in any name service the \fIpasswd:\fR line in the \fB/etc/nsswitch.conf\fR file must have a format specified in the \fBnsswitch.conf\fR(4) man page.
.sp
.LP
If the \fB/etc/nsswitch.conf\fR \fBpasswd\fR policy is not in one of the supported formats, logins will not be allowed upon password expiration, because the software does not know how to handle password updates under these conditions. See \fBnsswitch.conf\fR(4) for additional information.
.sp
.LP
The authorizations required to modify the various shadow fields are as follows:
.sp
.in +2
.nf
password change one's own password none required
password change another users password solaris.passwd.assign
password delete, set no login solaris.passwd.assign
password set initial password for solaris.account.activate
newly created account
password lock, unlock existing account solaris.account.setpolicy
min min days for password change solaris.account.setpolicy
max max days for password change solaris.account.setpolicy
warn warn days for password change solaris.account.setpolicy
inactive inactivity days allowed solaris.account.setpolicy
expire expiry date solaris.account.setpolicy
.fi
.in -2
.sp