In this article we can see how to configure Azure Active Directory for a .Net Core 2.2 Web Application.

Step 1: Create new Web Application

Create new Web Application of .Net Core 2.2 version.

Add Nuget Package following:

• Microsoft.IdentityModel.Clients.ActiveDirectory

Step 2: Run the Application

Run the application & Copy the URL of it.

Step 3: App Registration

You can Refer this application below.

https://jeanpaul.cloud/2019/12/13/how-to-do-app-registration-for-enterprise-application/

Step 4: App User

Add a new user to the Enterprise Application.

Step 5: Modify the Configuration File

Modify the Configuration File as following:

{
   “Authentication”: {
     “ClientId”: “CLIENT ID FROM APP REG”,
     “ClientSecret”: “CLIENT SECRET FROM APP REG”,
     “Authority”: https://login.microsoftonline.com/ACTIVE DIRECTORY GUID,
     “PostLogoutRedirectUri”: “https://localhost:44372/”,
     “CallbackPath”: “/signin-oidc”,
     “ResponseType”: “code id_token”
   }
}

Leave the last 2 parameters as it the default OIDC middleware parameters.

Step 6: Replace Startup.cs

Replace Startup.cs with the following code.

(mainly the changes are in ConfigureServices() and Configure() method)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Authentication.OpenIdConnect;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Extensions;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.IdentityModel.Clients.ActiveDirectory;

namespace AADenableBlog
{
     public class Startup
     {
         public Startup(IConfiguration configuration)
         {
             Configuration = configuration;
         }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
             services.AddAuthentication(auth =>
             {
                 auth.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
                 auth.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
             })
               .AddCookie()
               .AddOpenIdConnect(opts =>
               {
                   Configuration.GetSection(“Authentication”).Bind(opts);

                  opts.Events = new OpenIdConnectEvents
                   {
                       OnAuthorizationCodeReceived = async ctx =>
                       {
                           HttpRequest request = ctx.HttpContext.Request;

                          string currentUri = UriHelper.BuildAbsolute(request.Scheme, request.Host, request.PathBase, request.Path);
                           var credential = new ClientCredential(ctx.Options.ClientId, ctx.Options.ClientSecret);

                          var authContext = new AuthenticationContext(ctx.Options.Authority);

                          string resource = “https://graph.microsoft.com”;
                           AuthenticationResult result = await authContext.AcquireTokenByAuthorizationCodeAsync(
                               ctx.ProtocolMessage.Code, new Uri(currentUri), credential, resource);

                          ctx.HandleCodeRedemption(result.AccessToken, result.IdToken);
                       }
                   };
               });

            services.Configure<CookiePolicyOptions>(options =>
             {
                 options.CheckConsentNeeded = context => true;
                 options.MinimumSameSitePolicy = SameSiteMode.None;
             });

             services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
         }

        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
         {
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
             }
             else
             {
                 app.UseExceptionHandler(“/Home/Error”);
                 app.UseHsts();
             }

            app.UseHttpsRedirection();
             app.UseStaticFiles();
             app.UseAuthentication();
             app.UseCookiePolicy();

            app.UseMvc(routes =>
             {
                 routes.MapRoute(
                     name: “default”,
                     template: “{controller=Home}/{action=Index}/{id?}”);
             });
         }
     }
}

Step 7: Modify Controller

Modify the Home Controller as following:

Run the application & It should prompt you for the Login.  Enter the Credentials.

You can see the Login prompt.

Enter your New User credentials and you will be redirected to the Home Screen.

Download

The source can be downloaded here.

https://azuretrendz.files.wordpress.com/2019/12/aadenableblog.zip

Summary

In this article we have seen how to configure Azure Active Directory for a .Net Core 2.2 Web Application.

In this post we can see how to do an App Registration for a Web application so that it will become Enterprise Application.

Step 1  Open Azure Portal > Active Directory

Open Azure Portal > Go to Active Directory from Resources.

Step 2  Open App Registrations

Open App Registrations blade as shown below.

Step 3 Create New App Service

Click on the New Registration button. 

• Enter Name for the service
• Leave the default options
• Enter the Redirect URI as the URL of your web application / web api
• Eg: http://localhost:4802

Click the Register button

Copy the Client ID  as displayed over there.

Step 3 Create Credentials

Go to the Certificates & secrets blade. 

• Click on New client secret
• Save changes

Copy the Password generated

Now you have the Client ID and the Client Secret for the App Registration.  Now any application authenticated using these will be given privilege of this App Registration.

Step 4  Open Enterprise Applications

Open Enterprise Applications blade from Active Directory.  Search for the name.

If you can find your Application – Congratulations!

You have just created an Enterprise Applications.  Now you can do the following & more with it.

• Add Owners
• Add Users
• Internal & External
• Enable Self-Servcie
• Audit Logs
• Troubleshoot

References

https://docs.microsoft.com/en-us/azure/active-directory/manage-apps/what-is-application-management

Summary

In this post we have seen how to perform an App Registration.

OAuth 2 is an Authorization Framework.  It allows 3rd party application to get access to an HTTP Service.  It is primarily used as Token for API Access.

OpenID Connect is an Authentication Framework.  It is primarily used as ID Token for SSO.

Azure AD Seamless SSO automatically signs in users from their corporate devices to Azure Active Directory.

References.

Internet Engineering Task Force https://tools.ietf.org/html/rfc6749