This is an old revision of the document!
Detailed tutorials have been posted to the john-users list, separately for Linux (using Fedora 12 as the specific example) and for Solaris 10. These include optional OpenMP parallelization instructions and examples (to use multiple CPUs and/or CPU cores).
In 1.7.9-jumbo-6 and newer (when compiled with OpenSSL 0.9.8 or newer), there's support for ”–format=sha512crypt” and ”–format=sha256crypt”, which does not depend on the underlying OS and is typically about 35% faster than glibc's implementation on x86-64.
There's support for sha512crypt implemented in CUDA (for NVIDIA graphics cards) and OpenCL (for NVIDIA, AMD/ATI, and even CPUs). There's also support for the less common sha256crypt in CUDA (thus, NVIDIA only). To use these, John the Ripper needs to be built with a -gpu (both CUDA and OpenCL), -cuda, or -opencl make target, and then a proper format name needs to be requested, e.g. with ”–format=sha512crypt-opencl”.
As of this writing, the OpenCL code for sha512crypt is actually faster than the CUDA code, so it should be used on NVIDIA cards as well. In fact, it's faster on NVIDIA than on AMD (even though it's the other way around for most other password hashes). For example, it achieves about 11400 c/s (at the default of rounds=5000) on GTX 570 at 1600 MHz.
You probably want to use John the Ripper 1.7.6 or newer for this - please see above. However, if you must:
This topic was brought up on john-users, got to YouTube, and someone wrote a blog article on it. Please refer to the latter.
It is not clear why the article proposes that the source files be edited manually instead of the patch being applied, so you may just do the latter. The patch itself may be downloaded from this wiki.
Also, if instructions from the article are followed “literally”, then the resulting shadowfile will possibly end up with mode 644 in a mode 755 home directory of a user - that is, readable to other users of the system used to crack/audit the passwords. To prevent this from happening, umask 077 should be issued before the sudo unshadow … command.
Back to John the Ripper tutorials.