'SignInScheme' option must be provided

Question

I'm creating an ASP.NET 5 MVC 6 app that will use Facebook/Google authentication only. I'm also trying to use the cookie middleware without the whole ASP.NET Identity -- following this article: https://docs.asp.net/en/latest/security/authentication/cookie.html

So I started with an blank app with no authentication then added the Microsoft.AspNet.Authentication.Cookies and Microsoft.AspNet.Authentication.Facebook NuGet packages in order to have a very minimalistic approach where I don't include anything that I don't need.

I added the following code into Configure in Startup.cs but I'm getting "SignInScheme option must be provided" error. Any idea what I'm missing?

app.UseCookieAuthentication(options =>
            {
                options.AuthenticationScheme = "MyCookieMiddlewareInstance";
                options.LoginPath = new PathString("/Accounts/Login/");
                options.AccessDeniedPath = new PathString("/Error/Unauthorized/");
                options.AutomaticAuthenticate = true;
                options.AutomaticChallenge = true;
            });

            app.UseFacebookAuthentication(options =>
            {
                options.AppId = "myFacebookAppIdGoesHere";
                options.AppSecret = "myFacebookAppSecretGoesHere";
            });

Answer 1

As indicated by the error message you're seeing, you need to set options.SignInScheme in your Facebook middleware options:

app.UseFacebookAuthentication(options => {
    options.AppId = "myFacebookAppIdGoesHere";
    options.AppSecret = "myFacebookAppSecretGoesHere";

    // This value must correspond to the instance of the cookie
    // middleware used to create the authentication cookie.
    options.SignInScheme = "MyCookieMiddlewareInstance";
});

Alternatively, you can also set it globally from ConfigureServices (it will configure every authentication middleware so you don't have to set options.SignInScheme):

public void ConfigureServices(IServiceCollection services) {
    services.AddAuthentication(options => {
        // This value must correspond to the instance of the cookie
        // middleware used to create the authentication cookie.
        options.SignInScheme = "MyCookieMiddlewareInstance";
    });
}