#include "../hmac_sha256.h"

#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define SHA256_HASH_SIZE 32

int main() {
  const char* str_data = "Hello World!";
  const char* str_key = "super-secret-key";
  uint8_t out[SHA256_HASH_SIZE];
  char out_str[SHA256_HASH_SIZE * 2 + 1];
  unsigned i;

  // Call hmac-sha256 function
  hmac_sha256(str_key, strlen(str_key), str_data, strlen(str_data), &out,
              sizeof(out));

  // Convert `out` to string with printf
  memset(&out_str, 0, sizeof(out_str));
  for (i = 0; i < sizeof(out); i++) {
    snprintf(&out_str[i*2], 3, "%02x", out[i]);
  }

  // Print out the result
  printf("Message: %s\n", str_data);
  printf("Key: %s\n", str_key);
  printf("HMAC: %s\n", out_str);

  // This assertion fails if something went wrong
  assert(strncmp(
             out_str,
             "4b393abced1c497f8048860ba1ede46a23f1ff5209b18e9c428bddfbb690aad8",
             SHA256_HASH_SIZE * 2) == 0);
  return 0;
}