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

/**

 * SimpleIVMode

 * 

 * A convenience class that automatically places the IV

 * at the beginning of the encrypted stream, so it doesn't have to

 * be handled explicitely.

 * Copyright (c) 2007 Henri Torgemane

 * 

 * See LICENSE.txt for full license information.

 */

package com.hurlant.crypto.symmetric

{

	import flash.utils.ByteArray;

	import com.hurlant.util.Memory;

	

	public class SimpleIVMode implements IMode, ICipher

	{

		protected var mode:IVMode;

		protected var cipher:ICipher;

		

		public function SimpleIVMode(mode:IVMode) {

			this.mode = mode;

			cipher = mode as ICipher;

		}

		

		public function getBlockSize():uint {

			return mode.getBlockSize();

		}

		

		public function dispose():void {

			mode.dispose();

			mode = null;

			cipher = null;

			Memory.gc();

		}

		

		public function encrypt(src:ByteArray):void {

			cipher.encrypt(src);

			var tmp:ByteArray = new ByteArray;

			tmp.writeBytes(mode.IV);

			tmp.writeBytes(src);

			src.position=0;

			src.writeBytes(tmp);

		}

		

		public function decrypt(src:ByteArray):void {

			var tmp:ByteArray = new ByteArray;

			tmp.writeBytes(src, 0, getBlockSize());

			mode.IV = tmp;

			tmp = new ByteArray;

			tmp.writeBytes(src, getBlockSize());

			cipher.decrypt(tmp);

			src.length=0;

			src.writeBytes(tmp);

		}

		public function toString():String {

			return "simple-"+cipher.toString();

		}

	}

}