Installing and Using John the Ripper - Password cracker

Compile a source fileDownload a source code from http://openwall.com/john/
Extract source files: tar xvzf john-1.7.0.2.tar.gz

1) cd john-1.7.0.2/src
2) Then we need to rum make command which will return a list of available systems that John the Ripper password cracker can be compiled on.
3) Choose your appropriate architecture, and compile: make linux-x86-any
4) Go and run the john the ripper binary:
cd ../run/
ls
./john

Using John the ripper:
For testing purposes you should create a testing user "johnripper" with password "password".

poison:~ # useradd johnripper
poison:~ # passwd johnripper
Changing password for johnripper.
New Password:
Reenter New Password:
Password changed.
poison:~ #

Time to Crack password:
John the Ripper's password cracker needs to access a shadow file in order to be able crack a password. You need to run "john" as superuser "root". Be sure that John Binary is in your path, or you are in directory where john Binary resides. Try and see how long it will take to crack your super secure password of: "password"

./john -users=johnripper /etc/shadow