ASP.NET Web Forms Site - integration with multiple ADFS using OWIN KATANA - asp.net

Question

I'm configuring an old existing web forms site as a multi-tenant environment. One requirement is to be able to integrate with multiple client ADFS.
I have followed this post and have successfully implemented an MVC application supporting multiple ADFS. However I still face an issue,
that is not reproducible with the MVC app. In my web forms site, only the first ADFS provider registered succeeds. The second one always
throws SignatureVerificationFailedException after authenticating and returning back to my site (the exception happens at my side).
This is no matter whether I use app.Map(...) or app.Use(...) in the OWIN startup configuration.
I tried converting my web site to web application, but same result. I guess it is something connected with the way requests are handled in WEB FORMS, which is different than MVC.
Should I handle the middleware mapping in some different way?
What am I missing? Or this is not possible at all?...
Here is my OWIN startup configuration:
app.Properties["Microsoft.Owin.Security.Constants.DefaultSignInAsAuthenticationType"] = Config.ExternalAuthentication.Cookie;
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationType = Config.ExternalAuthentication.Cookie,
AuthenticationMode = Microsoft.Owin.Security.AuthenticationMode.Passive
});
string wreply = Config.ExternalAuthentication.Wreply;
string wtrealm = Config.ExternalAuthentication.Wtrealm;
List<Company> adfsCompanies = BL.GetCompaniesWithADFS();
app.Map("/Public/Login.aspx", configuration =>
{
foreach (Company company in adfsCompanies)
{
//configure middleware
var middleware = new WsFederationAuthenticationOptions()
{
MetadataAddress = company.ADFSMetadataUrl,
AuthenticationType = company.TenantName,
Caption = company.Name,
Wreply = wreply,
Wtrealm = wtrealm,
BackchannelCertificateValidator = null
};
//add to pipeline
configuration.UseWsFederationAuthentication(middleware);
}
});
Here is my challenge request:
context.GetOwinContext().Authentication.Challenge(
new AuthenticationProperties { RedirectUri = callbackUrl },
provider);
response.StatusCode = 401;
response.End();
No matter what I do, only the first registered ADFS middleware succeeds, no matter which one. I also tried attaching the middlewares to different pipeline stages with no success.
Thanks in advance for any help!

Answer 1

For multiple wsfed middleware each should set a unique WsFederationAuthenticationOptions.CallbackPath, e.g. "/ws1". You'll also need to include this value in the wreply.

Answer 2

I'm just giving some more details to the solution suggested by #Tratcher, in order to keep the question clean and simple:
1) According to MSDN, CallbackPath if not set is calculated from Wreply;
2) after distinguishing Wreply for each provider it turned out that was not enough, because other problems appeared. Then I found (using my MVC working sample) that furthermore Wtrealm and Wreply should have the same value;
3) Setting different URLs for different providers in ASP.NET Web Forms turned out to not be so easy. Fake URLs did not work. Using URL Rewrite - also. The most straightforward solution is to use different callback page for each provider (e.g. ExternalLoginFirstADFS.aspx, ExternalLoginSecondADFS.aspx, ...). This, although working fine, is not the best, so I decided to configure a Route for each provider at Application_Start event in Global.asax like this:
void Application_Start(object sender, EventArgs e)
{
...
RegisterRoutes(System.Web.Routing.RouteTable.Routes);
}
public static void RegisterRoutes(System.Web.Routing.RouteCollection routes)
{
List<Organization> adfsCompanies = OrgElementEntity.GetCompaniesWithADFS();
foreach(Organization company in adfsCompanies)
{
routes.MapPageRoute("",
String.Format("Public/ExternalLogin{0}.aspx", company.TenantName),
"~/Public/ExternalLogin.aspx");
}
}
Furthermore, it turned out that there is no need too use app.Map(...) at OwinStartup. Just adding each middleware through app.UseWsFederationAuthentication(...) seems to be fine!