Optimized implementation of twofish block cipher algorithm in C written by @drewcsillag

with stream encryption / decryption API similar to OpenSSL EVP.

Encryption supported:

• twofish-256-ecb twofish_256_ecb_init
• twofish-256-cbc twofish_256_cbc_init
• twofish-192-ecb twofish_192_ecb_init
• twofish-192-cbc twofish_192_cbc_init
• twofish-128-ecb twofish_128_ecb_init
• twofish-128-cbc twofish_128_cbc_init

bindings:

• ruby

original README:

Originally written around 2000-2001 or so.

A highly optimized implementation of the twofish encryption algorithm in C, and one not at all optimized in Python.

Basically, I use the Python version in myref.py to precompute some tables into tables.h. From there, there are two C implementations. The first in opt.c, I attempted to do some funky things in copying the function and keying the function directly, as opposed to providing keystate to the function. It turns out, at least at the time, to not be faster than the more sane version, i.e. the one you should actually use, that is in opt2.c. In fact, on more modern Linux versions, opt.c probably doesn't even work because of the weird way it tries to do things.

The Makefile builds the whole thing, and produces an executable named twofish-benchmark. If you want to incorporate this into your own software, just kill the main function and have a blast.

The version in myref.py should be fairly readable, as it was designed with the idea to reflect the algorithm's definition. The optimized C versions are not designed at all to be readable so much as fast.