idea.c compile error on mac os x

[Andrew Tong]

I get a "redefinition" error when trying to compile the IDEA algorithm 
module on Mac OS X 10.1.2 + DevTools Dec-01.
----------------------
[localhost:~/Desktop] user1% cc --version
2.95.2
[localhost:~/Desktop] user1% cc -Wall -O2 -shared -fPIC -o idea idea.c
idea.c:71: redefinition of `ushort'
/usr/include/sys/types.h:80: `ushort' previously declared here
----------------------
Any advice greatly appreciated.