NAME
pam_pwhistory − PAM module to remember last
passwords
SYNOPSIS
pam_pwhistory.so [debug] [use_authtok] [enforce_for_root] [remember=N] [retry=N] [authtok_type=STRING] |
DESCRIPTION
This module saves the last passwords for each user in order to force password change history and keep the user from alternating between the same password too frequently.
This module does not work together with kerberos. In general, it does not make much sense to use this module in conjunction with NIS or LDAP, since the old passwords are stored on the local machine and are not available on another machine for password history checking.
OPTIONS
debug
Turns on debugging via syslog(3).
use_authtok
When password changing enforce the module to use the new password provided by a previously stacked password module (this is used in the example of the stacking of the pam_cracklib module documented below).
enforce_for_root
If this option is set, the check is enforced for root, too.
remember=N
The last N passwords for each user are saved in /etc/security/opasswd. The default is 10. Value of 0 makes the module to keep the existing contents of the opasswd file unchanged.
retry=N
Prompt user at most N times before returning with error. The default is 1.
authtok_type=STRING
See pam_get_authtok(3) for more details.
MODULE TYPES
PROVIDED
Only the password module type is
provided.
RETURN
VALUES
PAM_AUTHTOK_ERR
No new password was entered, the user aborted password change or new password couldn´t be set.
PAM_IGNORE
Password history was disabled.
PAM_MAXTRIES
Password was rejected too often.
PAM_USER_UNKNOWN
User is not known to system.
EXAMPLES
An example password section would be:
#%PAM−1.0
password required pam_pwhistory.so
password required pam_unix.so
use_authtok
In combination with pam_cracklib:
#%PAM−1.0
password required pam_cracklib.so retry=3
password required pam_pwhistory.so use_authtok
password required pam_unix.so
use_authtok
FILES
/etc/security/opasswd
File with password history
SEE
ALSO
pam.conf(5),
pam.d(5), pam(8)
pam_get_authtok(3)
AUTHOR
pam_pwhistory was written by Thorsten Kukuk
<kukuk@thkukuk.de>
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.