> i need in C thats in C++
This is a load of BS, you're not even trying.
Did you even bother to look in the file, or did you just assume it was all C++ from the extension?
Well I have, and the whole algorithm is in C. The only bit of (crappy) C++ is in the test code at the end. If you can't figure out what to do from there, then what are you doing messing with encryption.
You gotta realise an awful lot of people (you included) can't tell C++ from a hole in the ground, because they just take the file extension the IDE gives them.