Welcome to the most active Linux Forum on the web.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 10-16-2012, 09:39 AM   #1
LQ Newbie
Registered: Oct 2012
Posts: 1

Rep: Reputation: Disabled
Using PAM, strong passwords with pam_passwdqc and the "similar" keyword

My first foray into the world of Linux and PAM.

The man page description appears "vague" with respect to the "similar" keyword, ie: Whether a new password is allowed to be similar to the old one. The passwords are considered to be similar when there is a sufficiently long common substring and the new password with the substring removed would be weak.

How "similar" IS "similar" allowed to be?

Anyone. Thx.
Old 11-02-2012, 05:20 AM   #2
Senior Member
Registered: Jan 2005
Location: Melbourne, Australia
Distribution: Debian Stretch (Fluxbox WM)
Posts: 1,389
Blog Entries: 52

Rep: Reputation: 355Reputation: 355Reputation: 355Reputation: 355
It looks for long common substrings between the old and new password, removes them from the new password, and then checks if what is left over passes the strength rules.

So for example, merely tacking '1234' on the end of the password will fail. Or changing 'abcdefghijklmnop' to 'abcdefghXijklmnop'.

Last edited by neonsignal; 11-02-2012 at 05:22 AM.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
gimp 2.6.1 ar.po keyword "msgctxt" unknown error skubik Linux - Software 11 08-04-2010 03:10 PM
"Unknown keyword in config file" when trying to boot from CD jkh107 Fedora - Installation 7 03-26-2009 12:29 AM
how to grep a "keyword" beside another keyword? xiawinter Linux - Software 7 12-29-2007 12:50 AM
C/C++ functions similar to BASH's "cp", "mv", "mkdir", etc? kornerr Programming 10 04-23-2006 09:48 AM
Cannot Install "pam_passwdqc" on RedHat scottjwoodford Linux - Security 4 06-01-2005 11:33 AM > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 09:54 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration