The Sustainsys Saml2 Owin middleware is designed to be used with an Owin authentication pipeline and is compatible with ASP.NET Identity. Sustainsys Saml2 provides external login in the same way as the built in Google, Facebook and Twitter providers.
To use the Sustainsys Saml2 middleware, it needs to be configured in
Startup.Auth.Cs.
app.UseSaml2Authentication(new Saml2AuthenticationOptions());
The options class only contains the Owin-specific configuration (such as the name used to identify the login provider). The rest of the configuration is read from the web.config/app.config and configured in the same way as when using the http module or the MVC controller.
If you would like to provide the Saml2-related configuration in code, specify false for
the loadConfiguration constructor parameter and then build the options based on your own
logic. For example:
var mySaml2Options = new Saml2AuthenticationOptions(false)
// more logic to set SPOptions, etc.
app.UseSaml2Authentication(mySaml2Options);
You can see a full example of this in the SampleOwinApplication project included in the source code. See the Startup.Auth.cs file
An Owin-based application issues an AuthenticationResponseChallenge to ask the middleware to begin the authentication procedure. In that challenge, there is a properties dictionary. To use a specified idp, the entity id of the idp should be entered in that dictionary under the key "idp".
In a typical MVC application that requires some changes to the generated code
to enable passing a property to the AuthenticationProperties dictionary.
Another, more simple way to pass a value is to put it directly in the Owin environment dictionary under the key "saml2.idp".
Here's an example of how to set the Owin environment value through ASP.NET MVC
var context = HttpContext.GetOwinContext();
context.Environment.Add("saml2.idp", new EntityId(YOUR_IDP_ENTITY_ID));