private int byteToInt(byte[] seqNum) {
      int answer = 0;
      for (int i = 0; i < 4; i++) {
        answer <<= 8;
        answer |= ((int) seqNum[i] & 0xff);
      }
      return answer;
    }
Helper class for providing integrity protection.
hbase-common/src/main/java/org/apache/hadoop/hbase/io/crypto/aes/CryptoAES.java