byte[] key = fillByteArray(20, 0xaa);
    byte[] data = fillByteArray(50, 0xdd);

    checkSha1("125d7342b9ac11cd91a39af48aa17b4f63f175d3", key, data);
  }

  public void testRfc2202_hmacSha1_case4() {
    byte[] key = base16().lowerCase().decode("0102030405060708090a0b0c0d0e0f10111213141516171819");
    byte[] data = fillByteArray(50, 0xcd);