Question

I have an MVC route like this www.example.com/Find?Key= with the Key being a Base64 string. The problem is that the Base64 string sometimes has a trailing equal sign (=) such as:

huhsdfjbsdf2394=

When that happens, for some reason my route doesn’t get hit anymore.

What should I do to resolve this?

My route:

routes.MapRoute(
    "FindByKeyRoute", 
    "Find",
    new { controller = "Search", action = "FindByKey" }
);

If I have http://www.example.com/Find?Key=bla then it works.

If I have http://www.example.com/Find?Key=bla= then it doesn’t work anymore.

Important Addition:
I’m writing against an IIS7 instance that doesn’t allow % or similar encoding. That’s why I didn’t use UrlEncode to begin with.

Answer 1

EDIT: Original suggestion which apparently doesn’t work

I’m sure the reason is that it thinks it’s a query parameter called Key. Could you make it a parameter, with that part being the value, e.g.

www.example.com/Find?Route=Key=

I expect that would work (as the parser would be looking for an & to start the next parameter) but it’s possible it’ll confuse things still.

Suggestion which I believe will work

Alternatively, replace “=” in the base64 encoded value with something else on the way out, and re-replace it on the way back in, if you see what I mean. Basically use a different base64 decodabet.

Alternative suggestion which should work

Before adding base64 to the URL:

private static readonly char[] Base64Padding = new char[] { '=' };
...
base64 = base64.TrimEnd(Base64Padding);

Then before calling Convert.FromBase64String() (which is what I assume you’re doing) on the inbound request:

// Round up to a multiple of 4 characters.
int paddingLength = (4 - (base64.Length % 4)) % 4; 
base64 = base64.PadRight(base64.Length + paddingLength, '=');