/*
CryptoJS v3.1.2
code.google.com/p/crypto-js
(c) 2009-2013 by Jeff Mott. All rights reserved.
code.google.com/p/crypto-js/wiki/License
*/
/**

 * ANSI X.923 padding strategy.

 */

CryptoJS.pad.AnsiX923 = {

    pad: function (data, blockSize) {

        // Shortcuts

        var dataSigBytes = data.sigBytes;

        var blockSizeBytes = blockSize * 4;



        // Count padding bytes

        var nPaddingBytes = blockSizeBytes - dataSigBytes % blockSizeBytes;



        // Compute last byte position

        var lastBytePos = dataSigBytes + nPaddingBytes - 1;



        // Pad

        data.clamp();

        data.words[lastBytePos >>> 2] |= nPaddingBytes << (24 - (lastBytePos % 4) * 8);

        data.sigBytes += nPaddingBytes;

    },



    unpad: function (data) {

        // Get number of padding bytes from last byte

        var nPaddingBytes = data.words[(data.sigBytes - 1) >>> 2] & 0xff;



        // Remove padding

        data.sigBytes -= nPaddingBytes;

    }

};

