code: public static long hash(byte[] digest, int index) {
          long f = ((long) (digest[3 + index * 4] & 0xFF) << 24)
              | ((long) (digest[2 + index * 4] & 0xFF) << 16)
              | ((long) (digest[1 + index * 4] & 0xFF) << 8)
              | (digest[index * 4] & 0xFF);
          return f & 0xFFFFFFFFL;
      }
docs: Hash long.
  
  @param digest the digest
  @param index  the number
  @return the long