Microsoft Entra External ID Integration with Blazor Web Application

Introduction

As organizations offer more digital services to partners, customers, and third-party developers, managing external user identities becomes very important. Microsoft Entra External ID helps address this challenge by providing a secure, scalable, and standards-based identity solution that seamlessly integrates with modern applications. In this article, I’ll show you how to integrate Microsoft Entra External ID with an ASP.NET Core MVC application. We’ll go through the process of setting up authentication, handling user claims, and enforcing authorization for external users. Whether you're designing a multi-tenant SaaS platform or building a secure, user-friendly app, this guide will help you put identity management into practice.

Get started with Integration

Step 1. Open Visual Studio 2022, click on Create a New Project, select ASP.NET Core Web App (MVC) Template, provide a project name, and click Next to get a wizard below.

Step 2. In the service dependencies wizard, add the dotnet misidentify tool to add a Microsoft identity platform, and click Next

Step 3. Select the tenant and click Create New to register a new External Entra ID application or select an existing application,  as shown in the figure below.

Step 4. The next step is to add Microsoft Graph or any other API. For a demo, I'm just going to skip this process.

Finally, click next; it will scaffold all required NuGet packages and changes in the Program.cs, appsettings.json

Step 5. In this step, switch to entra.microsoft.com and ensure you are in the External ID tenant, go to the user flow. Please refer to my article to check how to create a user flow. Select the user flow and click on Application to link our application to the user flow, as shown in the figures below.

Step 6. Finally, run the application. It will display the Microsoft Entra External ID user flow sign-in screen. Sign in using your social account credentials. After successful authentication, the application will navigate to the Home screen, as shown in the figures below.

Summary

We have seen a step-by-step guide for integrating Microsoft Entra External ID with an ASP.NET Core MVC application. It explains essential concepts such as setting up authentication for external users, managing user claims, and enforcing secure access controls. By utilizing Microsoft’s identity platform, developers can strengthen application security and provide a seamless experience for external collaborators like customers, partners, and vendors. The guide supports both the technical implementation and strategic planning involved in identity management.

Source code - GitHub