wsfed

            services
                .AddAuthentication(options =>
                {
                    options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
                    options.DefaultChallengeScheme = WsFederationDefaults.AuthenticationScheme;
                })
                .AddCookie(options => options.Cookie.Name = "aspnetcorewsfed")
                .AddWsFederation(options =>
                {
                    var settings = WebAppSettings.WsFederation;
                    if (settings == null)
                    {
                        throw new InvalidOperationException("WsFederationSettings not set");
                    }

                    options.MetadataAddress = settings.StsUrl + settings.MetadataPath;
                    options.Wtrealm = settings.Realm;

                    options.Events.OnRedirectToIdentityProvider += context =>
                    {
                        if (context.Request.IsAjaxRequest())
                        {
                            context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
                            context.HandleResponse();
                        }

                        return Task.CompletedTask;
                    };
                });