SHADOW(5) File Formats and Conversions SHADOW(5)
NAME
shadow - encrypted password file
DESCRIPTION
shadow contains the encrypted password information for user's accounts and optional the
password aging information. Included is:
o login name
o encrypted password
o days since Jan 1, 1970 that password was last changed
o days before password may be changed
o days after which password must be changed
o days before password is to expire that user is warned
o days after password expires that account is disabled
o days since Jan 1, 1970 that account is disabled
o a reserved field
The password field must be filled. The encrypted password consists of 13 to 24 characters
from the 64 character 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.
Refer to crypt(3) for details on how this string is interpreted.
If the password field contains some string that is not valid result of crypt(3), for
instance ! or *, the user will not be able to use a unix password to log in, subject to
pam(7).
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.
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.
This information supersedes any password or password age information present in
/etc/passwd.
This file must not be readable by regular users if password security is to be maintained.
FILES
/etc/passwd
User account information.
/etc/shadow
Secure user account information.
SEE ALSO
chage(1), login(1), su(1), passwd(1), passwd(5), pwconv(8), pwunconv(8), sulogin(8).
File Formats and Conversions 12/06/2009 SHADOW(5)
Generated by $Id: phpMan.php,v 4.49 2006/02/26 13:18:18 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2012-05-26 06:29 @38.107.179.236 Crawled by CCBot/1.0 (+http://www.commoncrawl.org/bot.html)