/js/lib/Socket.IO-node/support/socket.io-client/lib/vendor/web-socket-js/flash-src/com/hurlant/crypto/symmetric/CFBMode.as

/**

 * CFBMode

 * 

 * An ActionScript 3 implementation of the CFB confidentiality mode

 * Copyright (c) 2007 Henri Torgemane

 * 

 * See LICENSE.txt for full license information.

 */

package com.hurlant.crypto.symmetric

{

	import flash.utils.ByteArray;



	/**

	 * This is the "full" CFB.

	 * CFB1 and CFB8 are hiding somewhere else.

	 * 

	 * Note: The constructor accepts an optional padding argument, but ignores it otherwise.

	 */

	public class CFBMode extends IVMode implements IMode

	{

		

		public function CFBMode(key:ISymmetricKey, padding:IPad = null) {

			super(key,null);

		}



		public function encrypt(src:ByteArray):void

		{

			var l:uint = src.length;

			var vector:ByteArray = getIV4e();

			for (var i:uint=0;i<src.length;i+=blockSize) {

				key.encrypt(vector);

				var chunk:uint = (i+blockSize<l)?blockSize:l-i;

				for (var j:uint=0;j<chunk;j++) {

					src[i+j] ^= vector[j];

				}

				vector.position=0;

				vector.writeBytes(src, i, chunk);

			}

		}

		

		public function decrypt(src:ByteArray):void

		{

			var l:uint = src.length;

			var vector:ByteArray = getIV4d();

			var tmp:ByteArray = new ByteArray;

			for (var i:uint=0;i<src.length;i+=blockSize) {

				key.encrypt(vector);

				var chunk:uint = (i+blockSize<l)?blockSize:l-i;

				tmp.position=0;

				tmp.writeBytes(src, i, chunk);

				for (var j:uint=0;j<chunk;j++) {

					src[i+j] ^= vector[j];

				}

				vector.position=0;

				vector.writeBytes(tmp);

			}

		}

		

		public function toString():String {

			return key.toString()+"-cfb";

		}



	}

}