Quick aes reference

aes-how-to.c

// Based on https://github.com/clarus/phd-experiments/blob/master/embedded-compcert/test/c/aes.c
// For quick reference

// rijndael-alg-fst.{h,c} source:
// https://fastcrypto.org/vmac/rijndael-alg-fst.c
// https://fastcrypto.org/vmac/rijndael-alg-fst.h

// build with:
// gcc main.c rijndael-alg-fst.c

#include "rijndael-alg-fst.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

u8* encrypt256(u8 *key, u8 plain[16]){
        u32 ckey[4*(MAXNR+1)];
        u8* temp = malloc(16); // or u8 temp[16]
        int nr;

        nr = rijndaelKeySetupEnc(ckey, key, 256);
        //                                   ^ 256 as in 256 bit key
        rijndaelEncrypt(ckey, nr, plain, temp);
        return temp;
}

int main(int argc, char ** argv)
{
        u8* ext = encrypt256((u8 *)"qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq", (u8 *)"dupadupadupadupa");
        //                             ^ 256 bit key                           ^ 16 byte block
        for(int a = 0; a<16; a++){
                printf("%x", ext[a]);
        }
  return 0;
}