/**
* TripleDESKey
*
* An Actionscript 3 implementation of Triple DES
* Copyright (c) 2007 Henri Torgemane
*
* Derived from:
* The Bouncy Castle Crypto package,
* Copyright (c) 2000-2004 The Legion Of The Bouncy Castle
* (http://www.bouncycastle.org)
*
* 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;
public class TripleDESKey extends DESKey
{
protected var encKey2:Array;
protected var encKey3:Array;
protected var decKey2:Array;
protected var decKey3:Array;
/**
* This supports 2TDES and 3TDES.
* If the key passed is 128 bits, 2TDES is used.
* If the key has 192 bits, 3TDES is used.
* Other key lengths give "undefined" results.
*/
public function TripleDESKey(key:ByteArray)
{
super(key);
encKey2 = generateWorkingKey(false, key, 8);
decKey2 = generateWorkingKey(true, key, 8);
if (key.length>16) {
encKey3 = generateWorkingKey(true, key, 16);
decKey3 = generateWorkingKey(false, key, 16);
} else {
encKey3 = encKey;
decKey3 = decKey;
}
}
public override function dispose():void
{
super.dispose();
var i:uint = 0;
if (encKey2!=null) {
for (i=0;i<encKey2.length;i++) { encKey2[i]=0; }
encKey2=null;
}
if (encKey3!=null) {
for (i=0;i<encKey3.length;i++) { encKey3[i]=0; }
encKey3=null;
}
if (decKey2!=null) {
for (i=0;i<decKey2.length;i++) { decKey2[i]=0; }
decKey2=null
}
if (decKey3!=null) {
for (i=0;i<decKey3.length;i++) { decKey3[i]=0; }
decKey3=null;
}
Memory.gc();
}
public override function encrypt(block:ByteArray, index:uint=0):void
{
desFunc(encKey, block,index, block,index);
desFunc(encKey2, block,index, block,index);
desFunc(encKey3, block,index, block,index);
}
public override function decrypt(block:ByteArray, index:uint=0):void
{
desFunc(decKey3, block, index, block, index);
desFunc(decKey2, block, index, block, index);
desFunc(decKey, block, index, block, index);
}
public override function toString():String {
return "3des";
}
}
}
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