@Test
public void testComputePrf_rfc589vector7() throws Exception {

  HashType hash = HashType.SHA1;
  byte[] ikm = Hex.decode("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b");
  // Since HMAC anyhow pads, this is the same as an absent salt.
  byte[] salt = Hex.decode("");
  byte[] info = Hex.decode("");
  byte[] expectedResult =
      Hex.decode(
          "0ac1af7002b3d761d1e55298da9d0506"
              + "b9ae52057220a306e07b6b87e8df21d0"
              + "ea00033de03984d34918");
  HkdfStreamingPrf prf = new HkdfStreamingPrf(hash, ikm, salt);
  InputStream input = prf.computePrf(info);
  byte[] output = new byte[expectedResult.length];
  assertThat(input.read(output)).isEqualTo(expectedResult.length);
  assertThat(output).isEqualTo(expectedResult);
}