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

 1/**
 2 * TLSPad
 3 * 
 4 * A padding implementation used by TLS
 5 * Copyright (c) 2007 Henri Torgemane
 6 * 
 7 * See LICENSE.txt for full license information.
 8 */
 9package com.hurlant.crypto.symmetric {
10	import flash.utils.ByteArray;
11	import com.hurlant.util.Hex;
12	import com.hurlant.crypto.tls.TLSError;
13	
14	public class TLSPad implements IPad {
15		private var blockSize:uint;
16		
17		public function TLSPad(blockSize:uint=0) {
18			this.blockSize = blockSize;
19		}
20		public function pad(a:ByteArray):void {
21			var c:uint = blockSize - (a.length+1)%blockSize;
22			for (var i:uint=0;i<=c;i++) {
23				a[a.length] = c;
24			}
25		}
26		public function unpad(a:ByteArray):void {
27			var c:uint = a.length%blockSize;
28			if (c!=0) throw new TLSError("TLSPad::unpad: ByteArray.length isn't a multiple of the blockSize", TLSError.bad_record_mac);
29			c = a[a.length-1];
30			for (var i:uint=c;i>0;i--) {
31				var v:uint = a[a.length-1];
32				a.length--;
33				if (c!=v) throw new TLSError("TLSPad:unpad: Invalid padding value. expected ["+c+"], found ["+v+"]", TLSError.bad_record_mac);
34			}
35			a.length--;
36			// mostly ripped off from PKCS5.as, but with subtle differences
37		}
38		public function setBlockSize(bs:uint):void {
39			blockSize = bs;
40		}
41	}
42}