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

/**

 * ECBMode

 * 

 * An ActionScript 3 implementation of the ECB confidentiality mode

 * 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;

	import com.hurlant.util.Hex;

	

	/**

	 * ECB mode.

	 * This uses a padding and a symmetric key.

	 * If no padding is given, PKCS#5 is used.

	 */

	public class ECBMode implements IMode, ICipher

	{

		private var key:ISymmetricKey;

		private var padding:IPad;

		

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

			this.key = key;

			if (padding == null) {

				padding = new PKCS5(key.getBlockSize());

			} else {

				padding.setBlockSize(key.getBlockSize());

			}

			this.padding = padding;

		}

		

		public function getBlockSize():uint {

			return key.getBlockSize();

		}

		

		public function encrypt(src:ByteArray):void {

			padding.pad(src);

			src.position = 0;

			var blockSize:uint = key.getBlockSize();

			var tmp:ByteArray = new ByteArray;

			var dst:ByteArray = new ByteArray;

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

				tmp.length=0;

				src.readBytes(tmp, 0, blockSize);

				key.encrypt(tmp);

				dst.writeBytes(tmp);

			}

			src.length=0;

			src.writeBytes(dst);

		}

		public function decrypt(src:ByteArray):void {

			src.position = 0;

			var blockSize:uint = key.getBlockSize();

			

			// sanity check.

			if (src.length%blockSize!=0) {

				throw new Error("ECB mode cipher length must be a multiple of blocksize "+blockSize);

			}

			

			var tmp:ByteArray = new ByteArray;

			var dst:ByteArray = new ByteArray;

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

				tmp.length=0;

				src.readBytes(tmp, 0, blockSize);

				

				key.decrypt(tmp);

				dst.writeBytes(tmp);

			}

			padding.unpad(dst);

			src.length=0;

			src.writeBytes(dst);

		}

		public function dispose():void {

			key.dispose();

			key = null;

			padding = null;

			Memory.gc();

		}

		public function toString():String {

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

		}

	}

}