@Test
public void testComputePrf_compareToHkdfUtil() throws Exception {

  HashType hash = HashType.SHA1;
  byte[] ikm = Random.randBytes(123);
  byte[] salt = Random.randBytes(234);
  byte[] info = Random.randBytes(345);
  byte[] result = new byte[456];
  HkdfStreamingPrf prf = new HkdfStreamingPrf(hash, ikm, salt);
  InputStream input = prf.computePrf(info);
  input.read(result);
  assertThat(Hkdf.computeHkdf("HmacSha1", ikm, salt, info, result.length)).isEqualTo(result);
}