HP-UX Reference (11i v1 05/09) - 4 File Formats (vol 8)

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shadow(4) shadow(4)
NAME
shadow - shadow password file
SYNOPSIS
#include <shadow.h>
DESCRIPTION
The /etc/shadow file is created from the
/etc/passwd file by the pwconv command. It is readable
only by a privileged user. It can be modified by the
passwd(1), useradd(1m) , usermod(1m) , and
userdel(1M) commands. Programs may use the interfaces described in the getspent(3C) manpage to
access this information. These functions return a pointer to an
spwd structure, which is defined in the
<shadow.h> header file.
Fields
The /etc/shadow file is an ASCII file consisting of any number of user entries separated by newlines.
Each user entry line consists of the following fields separated by colons:
login name Each login name must match a login name in
/etc/passwd . pwconv puts the
user entries in
/etc/shadow in the same order as the /etc/passwd entries.
encrypted password
The password field of each /etc/passwd entry contains an ‘x’, and the actual
encrypted passwords reside in /etc/shadow . The encrypted password field consists
of 13 characters chosen from a 64-character set of "digits". The characters used to
represent "digits" are . for 0, / for 1, 0
through 9 for 2 through 11, A through Z for
12 through 37, and
a through z for 38 through 63. If this field is null, then there is no
password and no password is demanded on login. Login can be prevented by entering
a character that is not a part of the set of digits (such as *).
last change
The number of days since January 1, 1970 that the password was last modified.
min days The minimum period in days that must expire before the password can be changed.
max days The maximum number of days for which a password is valid. A user who attempts to
login after his password has expired is forced to supply a new one. If min days and
max days are both zero, the user is forced to change his password the next time he
logs in. If min days is greater than max days, then the password cannot be changed.
These restrictions do not apply to the superuser.
warn days The number of days the user is warned before his password expires.
inactivity The maximum number of days of inactivity allowed after a password has expired. The
account is locked if the password is not changed within the specified number of days
after the password expires. If this field is set to zero, then the user is required to
change his password.
expiration The absolute number of days since Jan 1, 1970 after which the account is no longer
valid. A value of zero in this field indicates that the account is locked.
reserved The reserved field is always zero and is reserved for future use.
Notes
The /etc/shadow file is not applicable to a system which has been converted to a trusted system.
FILES
/etc/passwd system password file
/etc/shadow shadow password file
SEE ALSO
login(1), passwd(1), pwconv(1M), pwunconv(1M), useradd(1M), userdel(1M), usermod(1M), crypt(3C),
getspent(3C), putspent(3C), nsswitch.conf(4), passwd(4), shadow(4).
HP-UX 11i Version 1: September 2005 − 1 − Hewlett-Packard Company Section 4−−279