Introduction:
As organizations increasingly extend their digital services to partners, customers, and third-party developers, managing external identities becomes a strategic imperative. Microsoft Entra External ID is designed to streamline this challenge by offering a scalable, secure, and standards-based identity solution that integrates seamlessly with modern application architectures. In this article, I will guide you through integrating Microsoft Entra External ID with an ASP.NET Core MVC application, demonstrating how to configure authentication, handle user claims, and enforce authorization for external users. Whether you’re a software architect planning a multi-tenant SaaS platform or a developer aiming to enhance security and usability, this guide bridges the gap between identity management and practical implementation.
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.
- Framework – Anything above .NET 8.0
- Authentication type – Microsoft identity platform
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 on Create new to register a new External Entra ID application, and provide a Display name as shown in the figure below.
Step 4: Clicking on Register will register the application in Microsoft Entra External ID. I won’t add Microsoft Graph or any other API for this demo.
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 previous 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 prompt the MS Entra External ID User flow sign-in screen, enter your social account credentials, after successful authentication, it will launch the Home screen as shown in the figures below
Summary:
This article provides a step-by-step guide to integrating Microsoft Entra External ID with an ASP.NET Core MVC application. It covers key concepts such as configuring authentication for external identities, handling user claims, and implementing secure access controls. By leveraging Microsoft’s identity platform, developers can enhance application security and deliver a seamless user experience for external collaborators, including customers, partners, and vendors. The walkthrough supports technical implementation and strategic decision-making in identity management.
