Password security auditing and recovery tool
John the Ripper is a fast password cracker, currently available for many flavors of Unix and for Windows. 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, various macOS password hashes, as well as many non-hashes such as SSH private keys, encrypted filesystems such as macOS .dmg files and "sparse bundles", encrypted archives such as ZIP, RAR, and 7z, encrypted document files such as PDF and Microsoft Office's, plus lots of other hashes and ciphers.