/**
* PKCS5
*
* A padding implementation of PKCS5.
* Copyright (c) 2007 Henri Torgemane
*
* See LICENSE.txt for full license information.
*/
package com.hurlant.crypto.symmetric
{
import flash.utils.ByteArray;
public class PKCS5 implements IPad
{
private var blockSize:uint;
public function PKCS5(blockSize:uint=0) {
this.blockSize = blockSize;
}
public function pad(a:ByteArray):void {
var c:uint = blockSize-a.length%blockSize;
for (var i:uint=0;i<c;i++){
a[a.length] = c;
}
}
public function unpad(a:ByteArray):void {
var c:uint = a.length%blockSize;
if (c!=0) throw new Error("PKCS#5::unpad: ByteArray.length isn't a multiple of the blockSize");
c = a[a.length-1];
for (var i:uint=c;i>0;i--) {
var v:uint = a[a.length-1];
a.length--;
if (c!=v) throw new Error("PKCS#5:unpad: Invalid padding value. expected ["+c+"], found ["+v+"]");
}
}
public function setBlockSize(bs:uint):void {
blockSize = bs;
}
}
}