Unshadow, john
From Notes_Wiki
Using unshadow and john to crack Linux passwords
We can use unshadow and john to crack Linux passwords in following manner:
- First use 'unshadow /etc/passwd /etc/shadow > hashes.txt' to get unified passwd files with password hashes in it. Historically '/etc/passwd' file used to store password hashes. Later '/etc/shadow' was introduced just to store hashes. Using this we get passwd file in old format.
- Then use 'john hashes.txt' to crack passwords.
Note: John supports sessions and we can start interrupted john sessions from the same point. Use 'john' to find about various command line options that john supports.