var CryptoJS = require('./core');
require('./cipher-core');

/**
 * 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;
  }
};

module.exports = CryptoJS.pad.ZeroPadding;