How to get started using DotNetOpenAuth

I created a simple page using the code provided by this page (the first sample):

http://www.dotnetopenauth.net/developers/code-snippets/programmatic-openid-relying-party/

But I can't seem to get it to work, I can redirect to the provider but when the provider redirects back to my page, I get error 500, "The request was rejected 开发者_JAVA百科by the HTTP filter".

I already checked ISAPI filters which I have none.

I've never seen that error before. Is this page hosted by the Visual Studio Personal Web Server (Casini) or IIS? I suspect you have an HTTP filter installed in IIS (or perhaps your web.config file) that is rejecting the incoming message for some reason.

Note that you need to turn off ASP.NET's default page request validation on any page that can receive an OpenID authentication response because those responses can include character sequences that look like HTML/Javascript-injection attacks but in fact is harmless.

I discovered that I'm using Isa in the server, so I just followed this instructions to get it working.

http://blog.brianfarnhill.com/2009/02/19/sharepoint-gets-the-error-the-request-was-rejected-by-the-http-filter/