as3 代码加解密

private var loader:URLLoader;
...
private function init():void
{
   loader = new URLLoader;
   req=URLRequest = new URLRequest("1.txt");
  loader.load(req);
  loader.addEventListener(Event.COMPLETE,oncomlete);         
}
private function oncomplete(e:Event):void
{
  var str:String=loader.data;
  trace("src///////");
  str=secret(str);
  trace("secret///////\n"+str);
  str=unsecret(str);
  trace("unsecret//////////////\n"+str);
      
}

private var add_key:Array=[800,650,400,525,100,250]//间距大于122(z的unicode值)
private var range:Array=[65,91,97,123]//65,70,75,91,97,100,123

private var xor_key:Array=[0xaa,0xbb]

private function secret(src:String):String
{
 var res:String="";
  var i:int,len:int,unicode:int;
 len=src.length
for(i=0;i<len;i++)
{
    unicode=str.charCodeAt(i);
var idx=index(unicode);
res+=String.fromCharCode(xor(add_key[idx]+unicode+random(i)))
}   
    
return res;
}
i
private function xor(v:int):int
{
  var i:int,len:int;
 len=xor_key.length
for(i=0;i<len;i++)
{
    v^=xor_key[i];
}
return v;
}

private function random(i:int):int
{
  swicth(i%4)
{
case 0:
if(i%9==0)
return((1-Math.sin(i))*(i%100)>>0);
else
return((1-Math.sin(i))*(i%200)>>0);
case 1:
return ((1-Math.cos(i))*(i%300)>>0);
case 2:
return ((1-Math.cos(i)*Math.sin(i))*(i%400)>>0);
case 3
if(i%3==0)
return((1-Math.sin(i)*Math.cos(i)*Math.cos(i))*(i%500)>>0);
else
return((1-Math.sin(i)*Math.cos(i)*Math.cos(i))*(i%600)>>0);
}
return 1;  
}

private function index(u:int):int
{
 if(u>64&&u<91||u>96&&u<123)
{
 var i:int,len:int;
len=range.length-1;
for(i=0;i<len;i++)
{
    if(u>=range[i]&&u<range[i+1])
    break;
}
return i
}
else
return 5
}

private function index2(u:int):int
{
  var i:int,len:int;
len=add_key.length-1;
for(i=0;i<len;i++)
{
if(u>=add_key[i]&&u<=add_key[i]+123)
break;
}  
return u-add_key[i];
}

private function unsecret(src:String):String
{
var res:String="";
var i:int,len:int;
var u:int;
len=src.length;
for(i=0;i<len;i++)
{
    u=xor(src.charCodeAt(i)-random(i));
    u=index2(u);
    res+=String.formCharCode(u);
}
return res;
}