byte[] input, String algorithm, SecretKey key, HashFunction hashFunc) throws Exception {
    Mac mac = Mac.getInstance(algorithm);
    mac.init(key);
    mac.update(input);

    assertEquals(HashCode.fromBytes(mac.doFinal()), hashFunc.hashBytes(input));
    assertEquals(HashCode.fromBytes(mac.doFinal(input)), hashFunc.hashBytes(input));
  }

  // Tests from RFC2022: https://tools.ietf.org/html/rfc2202