public partial class Startup
{
    private readonly IConfiguration _configuration;
    private readonly IHostingEnvironment _env;

    public Startup(IHostingEnvironment env)
    {
        if (env == null)
        {
            throw new ArgumentNullException("env");
        }

        _env = env;
        _configuration = new Configuration()
            .AddIniFile(@"App_Data/config.ini")
            .AddIniFile(@"App_Data/git.ini")
            .AddEnvironmentVariables("Confidence_");
    }

    // For more information on how to configure your application, visit http://go.microsoft.com/fwlink/?LinkID=398940
    public IServiceProvider ConfigureServices(IServiceCollection services)
    {
        services.AddDataProtection();
        services.Configure<AppOptions>(options =>
        {
            options.ServeCdnContent = Convert.ToBoolean(_configuration.Get("App:ServeCdnContent"));
            options.CdnServerBaseUrl = _configuration.Get("App:CdnServerBaseUrl");
            options.GenerateLowercaseUrls = Convert.ToBoolean(_configuration.Get("App:GenerateLowercaseUrls"));
            options.EnableBundlingAndMinification = Convert.ToBoolean(_configuration.Get("App:EnableBundlingAndMinification"));
            options.LatestCommitSha = _configuration.Get("git:sha");
        });

        services.Configure<AppMongoOptions>(options =>
        {
            options.DatabaseName = _configuration.Get("Mongo:AppDatabaseName");
            options.ConnectionString = _configuration.Get("Mongo:AppConnectionString");
        });

        services.Configure<ExternalAuthenticationOptions>(options =>
        {
            options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        });

        services.AddMvc();
        services.AddCaching();
        services.AddSession();

        IContainer container = CreateAutofacContainer(services);

        return container.Resolve<IServiceProvider>();
    }

    public void Configure(IApplicationBuilder app)
    {
        // Add the following to the request pipeline only in development environment.
        if (string.Equals(_env.EnvironmentName, "Development", StringComparison.OrdinalIgnoreCase) == false)
        {
            // Add Error handling middleware which catches all application specific errors and
            // send the request to the following path or controller action.
            app.UseErrorHandler("/Home/Error");
        }

        ConfigureAuth(app);

        app.UseStaticFiles();
        app.UseMvc(routes => 
        {
            routes.MapRoute("areaRoute", "{area:exists}/{controller}/{action}");
            routes.MapRoute("defaultRoute", "{controller=Home}/{action=Index}");

            routes.MapRoute(
                "controllerRoute",
                "{controller}",
                new { controller = "Home" });
        });
    }

    private IContainer CreateAutofacContainer(IServiceCollection services)
    {
        var builder = new ContainerBuilder();
        AutofacRegistration.Populate(builder, services);
        builder.RegisterAssemblyModules(Assembly.GetExecutingAssembly());

        return builder.Build();
    }
}

public partial class Startup
{
    private static string Authority = string.Empty;
    private static string ClientId = string.Empty;
    private static string AppKey = string.Empty;
    private static string GraphResourceId = string.Empty;

    public void ConfigureAuth(IApplicationBuilder app)
    {
        Authority = string.Format(_configuration.Get("AzureAd:AadInstance"), _configuration.Get("AzureAd:Tenant"));
        ClientId = _configuration.Get("AzureAd:ClientId");
        AppKey = _configuration.Get("AzureAd:AppKey");
        GraphResourceId = _configuration.Get("AzureAd:GraphResourceId");

        // Configure the Session Middleware, Used for Storing Tokens
        app.UseSession();

        // Configure OpenId Connect Authentication Middleware
        app.UseCookieAuthentication(options => 
        {
            options.SessionStore = new MemoryCacheSessionStore();
            options.AutomaticAuthentication = true;
        });

        app.UseOpenIdConnectAuthentication(options =>
        {
            options.AutomaticAuthentication = true;
            options.ClientId = _configuration.Get("AzureAd:ClientId");
            options.Authority = Authority;
            options.PostLogoutRedirectUri = _configuration.Get("AzureAd:PostLogoutRedirectUri");
            options.Notifications = new OpenIdConnectAuthenticationNotifications
            {
                AuthenticationFailed = OnAuthenticationFailed
            };
        });
    }

    private Task OnAuthenticationFailed(AuthenticationFailedNotification<OpenIdConnectMessage, OpenIdConnectAuthenticationOptions> notification)
    {
        notification.HandleResponse();
        notification.Response.Redirect("/Home/Error?message=" + notification.Exception.Message);
        return Task.FromResult(0);
    }
}