John the Ripper is a fast password cracker, currently available for many flavors
of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak
Unix passwords. Besides several crypt(3) password hash types most commonly found
on various Unix systems, supported out of the box are Windows LM hashes, plus lots
of other hashes and ciphers.
The packages for RHEL 8 and RHEL 7 are in each distribution’s respective Extra Packages for Enterprise Linux (EPEL) repository. The instructions for adding this repository diverge slightly between RHEL 8 and RHEL 7, which is why they’re listed separately below.
The EPEL repository can be added to RHEL 8 with the following command: