John the Ripper (command line)

John the Ripper is the application that underlies Johnny. You may be like us, and be more comfortable on the command line than in a GUI when using the password cracking tools, like John the Ripper. You may go for the CLI because it uses fewer resources than the GUI, or because you are working through a ssh connection to a server without a GUI interface. It is easy to use John the Ripper, and there are a lot more options and ways to use John by using the command lines that have not yet been added to Johnny.

You can see all the various hashing algorithms supported by John and test the speed of your system for cracking by running the following command:

john –test

This will run through all the various hashing algorithms supported by John and give you the time it will take for the various hashes. The following image shows the read-out from the test flag:

We're going to run John against a set of hashes obtained from an earlier exploitation of a system. Note the flags...