/**
 * Zero padding strategy.
 */
CryptoJS.pad.ZeroPadding = {
  pad: function (data, blockSize) {
    // Shortcut
    var blockSizeBytes = blockSize * 4

    // Pad
    data.clamp()
    data.sigBytes += blockSizeBytes - ((data.sigBytes % blockSizeBytes) || blockSizeBytes)
  },

  unpad: function (data) {
    // Shortcut
    var dataWords = data.words

    // Unpad
    var i = data.sigBytes - 1
    while (!((dataWords[i >>> 2] >>> (24 - (i % 4) * 8)) & 0xff)) {
      i--
    }
    data.sigBytes = i + 1
  }
}