Howto allow "Illegal characters in path"?

Question

I have a MVC.NET application with one route as follows:

routes.MapRoute("member", "member/{id}/{*name}", new { controller = "member", action = "Details", id = "" }, new { id = @"\d+" });

Thus, a link could be something like this: http://domain/member/123/any_kind_of_username

This works fine in general but if the path contains illegal characters (e.g. a double qoute: http://domain/member/123/my_"user"_name) I get a "System.ArgumentException: Illegal characters in path."

After much googling the best suggestions seems to be to make sure that the url doesn't contain any such characters. Unfortunately, that is out of my control in this case.

Is there a way to work around this?

Answer 1

Scott Hanselman posted a good summary on allowing illegal characters in the path.

If you really want to allow characters that are restricted, remove them from the list by editing your web.config (this will probably only work in .NET 4 and on IIS7):

<system.web>
    <httpRuntime requestValidationMode="2.0" relaxedUrlToFileSystemMapping="true" requestPathInvalidCharacters="&lt;,&gt;,*,%,:,&amp;,\" />
</system.web>

You may also need to do as hbruce suggests:

<system.webServer>
    <security>
        <requestFiltering allowDoubleEscaping="true"/>
    </security>
</system.webServer>

There are still some certain paths that will not work, (such as /search/% ) as you will get the 400 "Bad Request - Invalid URL" message. The only workaround I've found is to use that part as a querystring: /search?q=% with the above steps.