openwall/john
FreeJohn the Ripper jumbo - advanced offline password cracker, which supports hundreds of hash and cipher types, and runs on many operating systems, CPUs, GPUs, and even some FPGAs
FreeFree tier
About openwall/john
John the Ripper is a fast, open-source offline password cracking tool designed primarily for detecting weak Unix passwords. The community-enhanced 'jumbo' version supports hundreds of hash and cipher types, including Unix crypt, Kerberos/AFS, Windows LM, and DES-based tripcodes. It runs on many platforms (Unix, macOS, Windows, DOS, BeOS, OpenVMS) and leverages CPUs, GPUs, and even FPGAs. It features wordlist mode with mangling rules, incremental mode, and the ability to resume interrupted sessions. Cracked passwords are saved in a pot file for later retrieval.
Key Features
Supports hundreds of hash and cipher types, including Unix crypt, Kerberos/AFS, Windows LM, and DES-based tripcodes
Runs on many operating systems: Unix, macOS, Windows, DOS, BeOS, OpenVMS
Leverages CPUs, GPUs, and even FPGAs for accelerated cracking
Wordlist mode with rule-based word mangling
Incremental (brute-force) cracking mode
Resume interrupted sessions with state saving (john.rec)
Displays cracking status on demand
Community-enhanced 'jumbo' version with active contributions and automated testing
Pros & Cons
Pros
- Open-source and free to use
- Supports an extensive range of hash and cipher types
- Cross-platform compatibility (Unix, macOS, Windows, DOS, BeOS, OpenVMS)
- Hardware acceleration via GPUs and FPGAs
- Active community contributions and automated testing ensure ongoing improvements
Cons
- Quality of community contributions may vary; bugs are to be expected
- Primarily designed for offline password auditing, not online cracking
- Command-line interface may be intimidating for non-technical users
Best For
Detecting weak Unix passwordsSecurity auditing of password hashesPassword recovery in penetration testingOffline password strength assessment
FAQ
How do I run John the Ripper?
Supply it with password files and optionally specify a cracking mode, e.g., 'john passwd' or 'john --wordlist=password.lst --rules passwd'.
How do I view cracked passwords?
Run 'john --show passwd' to retrieve cracked passwords stored in the john.pot file.
How do I resume an interrupted session?
Run 'john --rest' to continue from the saved state file (john.rec).
Is John the Ripper free?
Yes, it is open-source and free to use. The jumbo version is maintained by the community and available on GitHub.