@Test
public void dblTestVectors() {

  // Extracted from the SIV test vectors at https://tools.ietf.org/html/rfc5297#section-2.3
  // (all the double() steps in Appendix A)
  String[] testVectorInputs = {
      "0e04dfafc1efbf040140582859bf073a",
      "edf09de876c642ee4d78bce4ceedfc4f",
      "c8b43b5974960e7ce6a5dd85231e591a",
      "adf31e285d3d1e1d4ddefc1e5bec63e9",
      "826aa75b5e568eed3125bfb266c61d4e",
  };
  String[] testVectorOutputs = {
      "1c09bf5f83df7e080280b050b37e0e74",
      "dbe13bd0ed8c85dc9af179c99ddbf819",
      "916876b2e92c1cf9cd4bbb0a463cb2b3",
      "5be63c50ba7a3c3a9bbdf83cb7d8c755",
      "04d54eb6bcad1dda624b7f64cd8c3a1b",
  };
  byte[] r;
  for (int i = 0; i < testVectorInputs.length; i++) {
    r = AesUtil.dbl(Hex.decode(testVectorInputs[i]));
    assertEquals(testVectorOutputs[i], Hex.encode(r));
  }
}