John the Ripper: The Basics: Cracking Hashes, Archives, and SSH Keys

The official room banner for John the Ripper: The Basics. Image Credit: TryHackMe.

Introduction

Welcome to my walkthrough of John the Ripper: The Basics, the fourth and final room in the Cryptography module of the Cyber Security 101 path!

In my previous article, Hashing Basics, we covered what hash functions are, why hash collisions are unavoidable, how passwords should (and shouldn’t) be stored, and how to recognize different hash formats. This room takes all of that theory and puts it directly into practice with John the Ripper, one of the most versatile and widely used password-cracking tools in the security field. Rather than just talking about cracking hashes, we’ll actually be doing it — against raw hashes, Windows and Linux authentication hashes, password-protected archives, and even SSH private keys.

Catch up on my previous article, Hashing Basics, by clicking the banner below.

The official room banner for Hashing Basics. Image Credit: TryHackMe.

What we will cover

• The theory behind why hashes are hard to reverse, and how dictionary attacks get around that
• John the Ripper’s basic syntax, and how to identify a hash before cracking it