John The Ripper

John The Ripper (JtR) is a password cracking program.

Basic Usage

Dumb Brute Force

To brute force a password and to have John iterate through all the possible sequences:

john --incremental --stdout

This defaults to the incremental mode parameters. You can specify a different mode, say to use only integers:

john --incremental=digits --stdout

Further Reading

• http://www.openwall.com/john/doc/RULES.shtml
• http://www.openwall.com/john/doc/EXAMPLES.shtml
• http://linuxconfig.org/password-cracking-with-john-the-ripper-on-linux
• http://contest-2010.korelogic.com/rules.html
• http://backreference.org/2009/10/26/password-recovery-with-john-the-ripper/