crypto-js/pad-ansix923.js

;(function (root, factory, undef) {
	if (typeof exports === "object") {
		// CommonJS
		module.exports = exports = factory(require("./core"), require("./cipher-core"));
	}
	else if (typeof define === "function" && define.amd) {
		// AMD
		define(["./core", "./cipher-core"], factory);
	}
	else {
		// Global (browser)
		factory(root.CryptoJS);
	}
}(this, function (CryptoJS) {

	/**
	 * 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;
	    }
	};


	return CryptoJS.pad.Ansix923;

}));