Question

if (strrpos($_POST['security_data'], $OrderReference) === false || 
    md5($_POST['security_data'] . $sekey) != $_POST['security_hash']) 
{ 
  return; 
}

I don’t understand why is strrpos in there and === “3 equals”
and what is the dot “.” doing in $_POST['security_data'] . $sekey

Thank You

Answer 1

Here’s a translation to C#:

string hash = MD5.Create().ComputeHash(Request.Form["security_data"] + sekey);    
if (!Request.Form["security_data"].Contains(OrderReference) 
    || hash != Request.Form["security_hash"])
{
     return;
}