How does John the Ripper work?

Question

I am familiar with John the Ripper, nevertheless, I haven't found a source where I can familiarize myself with the theory behind the program. I know that by studying the code I can get to understand how it works, yet I would like to read something where the techinques used by the program are studied in deep. Can anybody give some suggestions? Just to get it straight: I would like somebody to point out a reference where I can find the "theory" behind password cracking. Thanks.

Answer 1

Have you checked out Openwall's publications? They have published articles and presentations with some good material.

Also here is a nice paper that discusses some of the different methods and how they work.

Answer 2

Cracking Password Hash Using “John The Ripper” Well there are many tools for password cracking but john the ripper is one of most famous tool used for password hash cracking. In it is used to crack the password hash from Linux system’s /etc/passwd........

http://blog.hicubes.com/2013/12/tutorial-cracking-password-hash-using-john-the-ripper.html

Answer 3

Rename your John the Ripper folder to john, then

cd /
cd Applications (or) cd Documents
cd john 
cd src 
./configure 
make clean 
make -s

then:

cd ../john 
cd run
./john --format=Raw-MD5 /File/file.txt

Where the hash is the only thing in the file contents and it's formatted as plain text.

You might have a format option on your option bar. ./john for hash formats, and like the last guy said OpenWall has some other tutorials. If you have to install OpenSSL...

https://solitum.net/openssl-os-x-el-capitan-and-brew/

sudo <command> if it says Permission not granted.