This is a simplistic, naive and probably wrong implementation of HC 256 (See https://en.wikipedia.org/wiki/HC-256) directly from the source code in the paper that is or was at one time available here: http://eprint.iacr.org/2004/092.pdf
It works on gcc on a Mac OS X computer at the time of this writing.
I claim no ownership of any part of this and post it as an academic curiosity only.
M.