Minimal SHA-1

I set out to try and create a small implementation of SHA-1. sha1.c contains the original implementation I wrote and minsha1.c contains the shrunk down version.

Running

Both can be compiled with either clang or gcc (might require -std=c99 flag). The input is read from stdin.

clang minsha1.c
./a.out "The quick brown fox jumps over the lazy dog"
2fd4e1c67a2d28fced849ee1bb76e7391b93eb12

Caveats

Due to the way I simplified the string parsing only an input of 55 characters or less will hash correctly

Size

wc -c sha1.c 
    2280 sha1.c
wc -c minsha1.c 
     542 minsha1.c