Offline Password Cracking with John the Ripper – Tutorial
John the Ripper is intended to be both elements rich and quick. It combines a few breaking modes in one program and is completely configurable for your specific needs.
Extracting hashes From Linux
Every Linux user know that the passwords hashed are stored in /etc/passwd, one can see the file using command root@kali:~# cat /etc/passwd
We can see the password hashed as X, to unmask the password we should use unshadow to unmask the passwords.
root@kali:~# unshadow
Usage: unshadow PASSWORD-FILE SHADOW-FILE
Now you should use the unshadow command in order to unmask/decrypt the passwords.
root@kali:~# unshadow /etc/passwd /etc/shadow > hashfile/etc/passwd : Password location /etc/shadow : Shadow file hashfile : Output file
