docs: protected void engineReset() {
          int i = 60;
          do {
             pad[i    ] = (byte)0x00;
             pad[i + 1] = (byte)0x00;
             pad[i + 2] = (byte)0x00;
             pad[i + 3] = (byte)0x00;
          } while ((i -= 4) >= 0);
          padding = 0;
          bytes = 0;
          init();
      }