/**
 * 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;
        for (var i = data.sigBytes - 1; i >= 0; i--) {
            if (((dataWords[i >>> 2] >>> (24 - (i % 4) * 8)) & 0xff)) {
                data.sigBytes = i + 1;
                break;
            }
        }
    }
};