Cracking Hashes with John the Ripper
Description
When passwords are stored on a production server, the current security advice is to store them in a hashed form. A hash is a one-way cryptographic function used to transform an input (which is unbounded in size) into a fixed length output, a message digest (MD).
As long as the input is the same, the hash function will always output the same MD. Using this feature, a system can calculate a user's password MD and store this in a globally readable directory. When the user returns and enters their password to authenticate their identity, this value is hashed and then compared with the stored MD. If they match then the user must have entered the same password as they had when the MD was first generated by the system.
You will be looking at different hashing algorithms, each of which were commonly used to store passwords on Windows and UNIX systems.
You will be using John the Ripper to crack some password files.
This lab is part of a series on cyber network security.
Learning Objectives
Upon completion of this lab you will be able to:
-
Demonstrate to delegates how compromised hashes can be cracked using John the Ripper
Intended Audience
This lab is intended for:
- Cyber and network security specialists
Prerequisites
You should possess:
- A basic understanding of Windows operating system environments