Tutorial: Register a web application in Azure Active Directory B2C

Before your applications can interact with Azure Active Directory B2C (Azure AD B2C), they must be registered in a tenant that you manage. This tutorial shows you how to register a web application using the Azure portal.

A "web application" refers to a traditional web application that performs most of the application logic on the server. They may be built using frameworks like ASP.NET Core, Maven (Java), Flask (Python), and Express (Node.js).

Important

If you're using a single-page application ("SPA") instead (e.g. using Angular, Vue, or React), learn how to register a single-page application.

If you're using a native app instead (e.g. iOS, Android, mobile & desktop), learn how to register a native client application.

Prerequisites

If you don't have an Azure subscription, create a free account before you begin.

If you haven't already created your own Azure AD B2C Tenant, create one now. You can use an existing Azure AD B2C tenant.

Register a web application

To register a web application in your Azure AD B2C tenant, you can use our new unified App registrations experience or our legacy Applications (Legacy) experience. Learn more about the new experience.

  1. Sign in to the Azure portal.

  2. Make sure you're using the directory that contains your Azure AD B2C tenant. Select the Directories + subscriptions icon in the portal toolbar.

  3. On the Portal settings | Directories + subscriptions page, find your Azure AD B2C directory in the Directory name list, and then select Switch.

  4. In the Azure portal, search for and select Azure AD B2C.

  5. Select App registrations, and then select New registration.

  6. Enter a Name for the application. For example, webapp1.

  7. Under Supported account types, select Accounts in any identity provider or organizational directory (for authenticating users with user flows).

  8. Under Redirect URI, select Web, and then enter https://jwt.ms in the URL text box.

    The redirect URI is the endpoint to which the user is sent by the authorization server (Azure AD B2C, in this case) after completing its interaction with the user, and to which an access token or authorization code is sent upon successful authorization. In a production application, it's typically a publicly accessible endpoint where your app is running, like https://contoso.com/auth-response. For testing purposes like this tutorial, you can set it to https://jwt.ms, a Microsoft-owned web application that displays the decoded contents of a token (the contents of the token never leave your browser). During app development, you might add the endpoint where your application listens locally, like https://localhost:5000. You can add and modify redirect URIs in your registered applications at any time.

    The following restrictions apply to redirect URIs:

    • The reply URL must begin with the scheme https.
    • The reply URL is case-sensitive. Its case must match the case of the URL path of your running application. For example, if your application includes as part of its path .../abc/response-oidc, do not specify .../ABC/response-oidc in the reply URL. Because the web browser treats paths as case-sensitive, cookies associated with .../abc/response-oidc may be excluded if redirected to the case-mismatched .../ABC/response-oidc URL.
  9. Under Permissions, select the Grant admin consent to openid and offline_access permissions check box.

  10. Select Register.

Create a client secret

For a web application, you need to create an application secret. The client secret is also known as an application password. The secret will be used by your application to exchange an authorization code for an access token.

  1. In the Azure AD B2C - App registrations page, select the application you created, for example webapp1.
  2. In the left menu, under Manage, select Certificates & secrets.
  3. Select New client secret.
  4. Enter a description for the client secret in the Description box. For example, clientsecret1.
  5. Under Expires, select a duration for which the secret is valid, and then select Add.
  6. Record the secret's Value for use in your client application code. This secret value is never displayed again after you leave this page. You use this value as the application secret in your application's code.

Note

For security purposes, you can roll over the application secret periodically, or immediately in case of emergency. Any application that integrates with Azure AD B2C should be prepared to handle a secret rollover event, no matter how frequently it may occur. You can set two application secrets, allowing your application to keep using the old secret during an application secret rotation event. To add another client secret, repeat steps in this section.

Enable ID token implicit grant

The defining characteristic of the implicit grant is that tokens, such as ID and access tokens, are returned directly from Azure AD B2C to the application. For web apps, such as ASP.NET Core web apps and https://jwt.ms, that request an ID token directly from the authorization endpoint, enable the implicit grant flow in the app registration.

  1. In the left menu, under Manage, select Authentication.
  2. Under Implicit grant, select both the Access tokens and ID tokens check boxes.
  3. Select Save.

Next steps

In this article, you learned how to:

  • Register a web application
  • Create a client secret

Next, learn how to create user flows to enable your users to sign up, sign in, and manage their profiles.