.NET MVC Routing w/ Url Encoding Problems

Question

I have the following routing code:

routes.MapRoute(
            "email-validated/{sessionId}",
            "email-validated/{sessionId}",
            new { controller = "User", action = "EmailValidated", sessionId = UrlParameter.Optional }
            );

When I hit the route w/ something that is url encoded it won't match the route for %2f, %2b and some other escaped characters. It also won't match for non url encoded (things w/ + etc) For instance

This works:

email-validated/XQiKC6KMM%2cmko4nOvzGRwPu9oaZFoCtXsFFJg3ZTf9S5rsBbLGjnz3FN3SJ0apEZcqK1PIcCY28mRMykB39XnFLKaL7390CDfLZiV77cso

This doesn't work ( containts %2f etc):

email-validated/XQiKC6KMM%2fmko4nOvzGRwPu9oaZFoCtXsFFJg3ZTf9S5rsBbLGjnz3FN3SJ0apEZcqK1PIcCY28mRMykB39XnFLKaL7390CDfLZiV77cso

This doesn't work (contains + etc)

email-validated/XQiKC6KMM+mko4nOvzGRwPu9oaZFoCtXsFFJg3ZTf9S5rsBbLGjnz3FN3SJ0apEZcqK1PIcCY28mRMykB39XnFLKaL7390CDfLZiV77cso

Answer 1

If you can, you need to make your sessionId URL safe. The sessionId is Base64 encoded, and there are three URL problem characters in Base64, "/", "+" and "=". Use the following to encode your sessionId when creating your link:

    public string ToUrlSafeBase64String(string Base64String)
    {
        // avoid any slashes, plus signs or equal signs
        // the following makes this base64 string url safe
        Base64String = Base64String.Replace("/", "_");
        Base64String = Base64String.Replace("+", "-");
        return Base64String.Replace("=", String.Empty);
    }

Then, use the following to re-create the original Base64 encoded string:

    public string FromUrlSafeBase64String(string Base64String)
    {
        // add back any slashes, plus signs or equal signs
        // the following makes this url safe string a base64 string
        Base64String = Base64String.Replace("_", "/");
        Base64String = Base64String.Replace( "-", "+");
        return Base64String.PadRight(Base64String.Length + (4 - Base64String.Length % 4) % 4, '=');
    }

Answer 2

It looks like the routing path handles escaped /'s and +'s weirdly. Try passing it in as a query string argument instead.

Make your endpoint:

routes.MapRoute(
            "email-validated",
            "email-validated",
            new { controller = "User", action = "EmailValidated" }
            );

Call it with a request like:

email-validated/?sessionId=XQiKC6KMM%2fmko4nOvzGRwPu9oaZFoCtXsFFJg3ZTf9S5rsBbLGjnz3FN3SJ0apEZcqK1PIcCY28mRMykB39XnFLKaL7390CDfLZiV77cso

And then change your function from

EmailValidatedFunction(string sessionId)
{
   //...do stuff with sessionId here
}

to:

EmailValidatedFunction()
{
   string sessionId = Request["sessionId"];
   //...do stuff with sessionId here
}