Password Security

There are many password cracking programs that run under Red Hat Enterprise Linux although none ship with the operating system. Below is a brief list of some of the more popular password cracking programs:

John The Ripper — A fast and flexible password cracking program. It allows the use of multiple word lists and is capable of brute-force password cracking. It is available online at .

Crack — Perhaps the most well known password cracking software, Crack is also very fast, though not as easy to use as John The Ripper. It can be found online at .

Slurpie — Slurpie is similar to John The Ripper and Crack, but it is designed to run on multiple computers simultaneously, creating a distributed password cracking attack. It can be found along with a number of other distributed attack security evaluation tools online at .

      

 

 

       There are two primary programs used to specify password aging under Red Hat Enterprise Linux: the chage command or the graphical User Manager (system-config-users) application.

The -M option of the chage command specifies the maximum number of days the password is valid. So, for instance, to set a user's password to expire in 90 days, type the following command:

chage -M 90 

   The graphical User Manager application may also be used to create password aging policies. To access this application, go to the Main Menu button (on the Panel) => System Settings => Users & Groups or type the command system-config-users at a shell prompt (for example, in an XTerm or a GNOME terminal). Click on the Users tab, select the user from the user list, and click Properties from the button menu (or choose File => Properties from the pull-down menu).