Cracking Password-Protected SSH Keys with John the Ripper

I have just found this announcement sent by Solar Designer from the Openwall Project.


It seems that they have added support to crack password-protected SSH private keys:

This community-enhanced release integrates preliminary support for several non-hashes, implemented under Dhiru Kholia's GSoC 2011 project. Specifically, it supports cracking of OpenSSH's passphrase-protected SSH protocol 2 private keys, password-protected PDF files with 40-bit and 128-bit RC4 encryption, and some password-protected RAR archives.

Yes, Dhiru's SSH key cracker includes OpenMP parallelization. There's a limitation, though: this requires OpenSSL 1.0.0 or newer, for thread-safety of the interfaces being used. When building or running with older versions of OpenSSL, OpenMP parallelization in the SSH cracker is automatically disabled. (You can always use MPI instead.)