John the Ripper
Password security auditing and recovery tool supporting hundreds of hash, archive, and document formats across CPU, GPU, and FPGA accelerators.
Technical Architecture & Overview
John the Ripper is a password security auditing and recovery tool maintained by Solar Designer and the Openwall community. The open-source jumbo version supports hundreds of hash and cipher types, including Unix crypt(3), Windows NTLM, macOS hashes, WPA-PSK, encrypted archives, document files, filesystems, and private keys. It runs on many operating systems and can use CPU, GPU, and FPGA acceleration.
Targeted Technical Use Cases
Perform offline password strength audits and recover or verify forgotten credentials on systems under authorized management.
Evaluation & Trade-offs
Core Strengths
- +Extensive support for hash, archive, and document formats.
- +Autodetects common hash types and supports custom cracking modes.
- +Portable across many operating systems and architectures.
Trade-Offs & Limitations
- -GPU support runs through OpenCL and requires the GPU vendor's OpenCL drivers.
- -Much of the jumbo code is community-contributed and not all of it is mature, so some bugs are expected.
Defensive Security Application
Reveal weak passwords in controlled environments to validate that password storage resists offline cracking.
Frequently Asked Questions
What is John the Ripper?→
John the Ripper is a password security auditing and recovery tool maintained by Solar Designer and the Openwall community. The open-source jumbo version supports hundreds of hash and cipher types, including Unix crypt(3), Windows NTLM, macOS hashes, WPA-PSK, encrypted archives, document files, filesystems, and private keys. It runs on many operating systems and can use CPU, GPU, and FPGA acceleration.
What is John the Ripper used for?→
Perform offline password strength audits and recover or verify forgotten credentials on systems under authorized management.
What are the strengths of John the Ripper?→
- +Extensive support for hash, archive, and document formats.
- +Autodetects common hash types and supports custom cracking modes.
- +Portable across many operating systems and architectures.
What are the limitations of John the Ripper?→
- +GPU support runs through OpenCL and requires the GPU vendor's OpenCL drivers.
- +Much of the jumbo code is community-contributed and not all of it is mature, so some bugs are expected.
How is John the Ripper used defensively?→
Reveal weak passwords in controlled environments to validate that password storage resists offline cracking.