Question

Hi
Have use this code before. Find it useful on Web. But Dont know how to convert it for wp7. Will some1 take a shot at it?

script language="JavaScript"

 len=0; 

 function CalcKey() 
 {

    len=0; 
    var temp=document.Encrypt.Key.value; 

    for(i=0;i<temp.length;i++) 
    { 
    len=len+temp.charCodeAt(i); 
    }


    if(len==0) 
    { 
    alert('Please Enter the appropriate Key'); 
    document.Encrypt.Key.focus(); 
    }

    return len; 
 }





function Encryption() 
{

    CalcKey(); 
    document.Encrypt.Encrypted.value=""; 
    var txt=document.Encrypt.normal.value;

    var net=""; 
    var fin=0;

    if(len>0) 
    {

      if(txt.length>0) 
      {

         for(i=0;i<txt.length;i++) 
         { 
           fin=txt.charCodeAt(i)+len;  
         if(fin>99) 
         { 
             net=net+fin;  
         } 
     else 
     { 
      net=net+'0'+fin; 
      }

      } 
       document.Encrypt.Encrypted.value=net; 
       document.Encrypt.normal.value=""; 
     } 
     else 
     { 
      alert('Please Enter the Text to be Encrypted'); 
       document.Encrypt.normal.focus();
      }  
    } 
 }



function Decryption()

{

var txt=document.Encrypt.Encrypted.value;

var j=3; 
var temp1; 
var res="";


CalcKey(); 

if(len>0)

{

if(txt.length>0)

{

for(i=0;i<txt.length;i+=3)

{

var temp=txt.substring(i,j); 
temp1=(parseInt(temp)-len); 
var t=unescape('%'+temp1.toString(16));

if(t=='%d' || t=='%a')

{ 
res=res+' ';

} 
else

{ 
res=res+t

} 

j+=3;

}

document.Encrypt.normal.value=res; 
document.Encrypt.Encrypted.value="";

}

else 
{

alert('Please Enter the Encrypted Text');

document.Encrypt.Encrypted.focus();

}

}

}

Answer 1

It looks like this code simply escapes/unescapes text from a form like “HelloWorld” to some kind of integer shifted by its current position.

You can definitely port this algorithm across to C# – you’ll need to use

• some kind of ((int)c).ToString() in order to write
• Char.ParseInt to read bits of the string back in

Alternatively there are existing encryption methods you can use – http://robtiffany.com/windows-phone-7/dont-forget-to-encrypt-your-windows-phone-7-data