Redirect user after successful (fake) login in OpenID Offline Provider

Many days ago, I asked this question and I'm set with a working offline OpenID provider (I guess).

What I want is a simple login text box for OpenID identifier which will automatically accept the user and consider the user as logged in, then I want him to be redirected to the main products page (Products => Index).

But, what I didn't know (and didn't find on the internet) is how to go on after the fake authentication process.

I tried to do this:

[HttpPost]
public ActionResult Login(string openid)//openid is the identifier taken from the login 开发者_运维知识库textbox
{
    var rely = new OpenIdRelyingParty();
    var req = rely.CreateRequest(openid);
    req.RedirectToProvider();
    return RedirectToAction("Index", "Products");
}

First of all, it is not being redirected in the 4th line (instead the login page is refreshed) and second, no authenticated user is really there, I mean when I checked User in Watch window, it is not null but Username is empty and there is no authenticated identity which, I guess, means that there is no cookies set.

P.S: 1. No exceptions are being thrown. But when I try to call FormsAuthentication.RedirectFromLogin() method I get an exception (Server cannot modify cookies after HTTP headers have been set). 2. Index action method is marked with [Authorize] attribute, and so when someone tries to browse Products it is redirected to the login screen, but when he logs in (fake login), shouldn't he be redirected back to Products page?

I tried this also:

[HttpPost]
public ActionResult Login(string openid)
{
    var rely = new OpenIdRelyingParty();
    return rely.CreateRequest(openid).RedirectingResponse.AsActionResult();
}

But no luck.

What did I miss? and how to make it work as expected? I can depend on myself but I need a decent documentation for OpenID especially for the offline local provider.

Check this example: OpenID and OAuth using DotNetOpenAuth in ASP.NET MVC

public ActionResult OpenId(string openIdUrl)
{
    var response = Openid.GetResponse();
    if (response == null)
    {
        // User submitting Identifier
        Identifier id;
        if (Identifier.TryParse(openIdUrl, out id))
        {
            try
            {
                var request = Openid.CreateRequest(openIdUrl);
                var fetch = new FetchRequest();
                fetch.Attributes.AddRequired(WellKnownAttributes.Contact.Email);
                fetch.Attributes.AddRequired(WellKnownAttributes.Name.First);
                fetch.Attributes.AddRequired(WellKnownAttributes.Name.Last);
                request.AddExtension(fetch);
                return request.RedirectingResponse.AsActionResult();
            }
            catch (ProtocolException ex)
            {
                _logger.Error("OpenID Exception...", ex);
                return RedirectToAction("LoginAction");
            }
        }
        _logger.Info("OpenID Error...invalid url. url='" + openIdUrl + "'");
        return RedirectToAction("Login");
    }

    // OpenID Provider sending assertion response
    switch (response.Status)
    {
        case AuthenticationStatus.Authenticated:
            var fetch = response.GetExtension<FetchResponse>();
            string firstName = "unknown";
            string lastName = "unknown";
            string email = "unknown";
            if(fetch!=null)
            {
                firstName = fetch.GetAttributeValue(WellKnownAttributes.Name.First);
                lastName = fetch.GetAttributeValue(WellKnownAttributes.Name.Last);
                email = fetch.GetAttributeValue(WellKnownAttributes.Contact.Email);
            }
            // Authentication       
            FormsAuthentication.SetAuthCookie(userName: email, createPersistentCookie: false);
            // Redirection
            return RedirectToAction("Index", "Products");
        case AuthenticationStatus.Canceled:
            _logger.Info("OpenID: Cancelled at provider.");
            return RedirectToAction("Login");
        case AuthenticationStatus.Failed:
            _logger.Error("OpenID Exception...", response.Exception);
            return RedirectToAction("Login");
    }
    return RedirectToAction("Login");
}

Basically, your action method is called twice:

The first time by your form being submitted by the user.

The second time is a call back (redirect) from the OpenID provider. This time, there will be a value for the response. If response.Status is valid, you can log your user in using the FormsAuthentication class and finally you can redirect him to your main products page.