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| name | Enable your Blazor Server to sign-in users and call Web API with the Microsoft identity platform | |||
| urlFragment | ms-identity-blazor-server | |||
| description | This sample demonstrates an ASP.NET Core Blazor Server application calling an ASP.NET Core Web API that is secured using Azure AD |
- Overview
- Scenario
- Contents
- Prerequisites
- Setup
- Registration
- Running the sample
- Explore the sample
- About the code
- Deployment
- More information
- Community Help and Support
- Contributing
- Code of Conduct
In the third chapter, we extend our ASP.NET Core Blazor Server application to call a downstream ASP.NET Core Web API that is secured using Azure AD.
Continuing from the previous chapter of the tutorial, this chapter adds the following steps:
- Secure an ASP.NET Core Web API with the Microsoft identity platform.
- The client application acquires an Access Token for the Web API.
- The Access Token is used as a bearer token to authorize the user to call the Web API.
From your shell or command line:
cd ms-identity-blazor-server\WebApp-your-API\MyOrg- Navigate to the Azure portal and select the Azure AD service.
- Select the App Registrations blade on the left, then select New registration.
- In the Register an application page that appears, enter your application's registration information:
- In the Name section, enter a meaningful application name that will be displayed to users of the app, for example
ToDoListService-aspnetcore. - Under Supported account types, select Accounts in this organizational directory only.
- In the Name section, enter a meaningful application name that will be displayed to users of the app, for example
- Select Register to create the application.
- In the app's registration screen, find and note the Application (client) ID. You use this value in your app's configuration file(s) later in your code.
- Select Save to save your changes.
- In the app's registration screen, select the Expose an API blade to the left to open the page where you can declare the parameters to expose this app as an Api for which client applications can obtain access tokens for.
The first thing that we need to do is to declare the unique resource URI that the clients will be using to obtain access tokens for this Api. To declare an resource URI, follow the following steps:
- Select
Setnext to the Application ID URI to generate a URI that is unique for this app. - For this sample, accept the proposed Application ID URI (api://{clientId}) by selecting Save.
- Select
- All Apis have to publish a minimum of one scope for the client's to obtain an access token successfully. To publish a scope, follow the following steps:
- Select Add a scope button open the Add a scope screen and Enter the values as indicated below:
- For Scope name, use
access_as_user. - Select Admins and users options for Who can consent?
- For Admin consent display name type
Access ToDoListService-aspnetcore - For Admin consent description type
Allows the app to access ToDoListService-aspnetcore as the signed-in user. - For User consent display name type
Access ToDoListService-aspnetcore - For User consent description type
Allow the application to access ToDoListService-aspnetcore on your behalf. - Keep State as Enabled
- Select the Add scope button on the bottom to save this scope.
- For Scope name, use
- Select Add a scope button open the Add a scope screen and Enter the values as indicated below:
Open the project in your IDE (like Visual Studio or Visual Studio Code) to configure the code.
In the steps below, "ClientID" is the same as "Application ID" or "AppId".
- Open the
Service\appsettings.jsonfile. - Find the key
Domainand replace the existing value with your Azure AD tenant name. - Find the key
TenantIdand replace the existing value with your Azure AD tenant ID. - Find the key
ClientIdand replace the existing value with the application ID (clientId) of theToDoListService-aspnetcoreapplication copied from the Azure portal.
- In App registrations page, find the WebApp-blazor-server app.
- In the app's registration screen, select Authentication in the menu.
- In the Implicit grant section, check the ID tokens option as this sample requires the hybrid flow (code id_token) to be enabled to sign-in the user.
- Select Save to save your changes.
- In the app's registration screen, select the Certificates & secrets blade in the left to open the page where we can generate secrets and upload certificates.
- In the Client secrets section, select New client secret:
- Type a key description (for instance
app secret), - Select one of the available key durations (In 1 year, In 2 years, or Never Expires) as per your security posture.
- The generated key value will be displayed when you select the Add button. Copy the generated value for use in the steps later.
- You'll need this key later in your code's configuration files. This key value will not be displayed again, and is not retrievable by any other means, so make sure to note it from the Azure portal before navigating to any other screen or blade.
- Type a key description (for instance
- In the app's registration screen, select the API permissions blade in the left to open the page where we add access to the APIs that your application needs.
- Select the Add a permission button and then,
- Ensure that the My APIs tab is selected.
- In the list of APIs, select the API
ToDoListService-aspnetcore. - In the Delegated permissions section, select the Access 'ToDoListService-aspnetcore' in the list. Use the search box if necessary.
- Select the Add permissions button at the bottom.
Open the project in your IDE (like Visual Studio or Visual Studio Code) to configure the code.
In the steps below, "ClientID" is the same as "Application ID" or "AppId".
- Open the
Client\appsettings.jsonfile. - Find the key
ClientSecretand replace the existing value with the key you saved during the creation of theWebApp-blazor-serverapp, in the Azure portal. - Find the key
TodoListScopeand replace the existing value with Scope. - Find the key
TodoListBaseAddressand replace the existing value with the base address of the ToDoListService-aspnetcore project (by defaulthttps://localhost:44351).
You can run the sample by using either Visual Studio or command line interface as shown below:
Clean the solution, rebuild the solution, and run it. You might want to go into the solution properties and set both projects as startup projects, with the service project starting first.
When you start the Web API from Visual Studio, depending on the browser you use, you'll get:
- an empty web page (with Microsoft Edge)
- or an error HTTP 401 (with Chrome)
This behavior is expected as the browser is not authenticated. The Web application will be authenticated, so it will be able to access the Web API.
cd Client
dotnet restoreThen:
In a separate console window, execute the following commands
cd Service
dotnet restoredotnet dev-certs https --clean
dotnet dev-certs https --trustLearn more about HTTPS in .NET Core.
In both the console windows execute the below command:
dotnet runOpen your browser and navigate to https://localhost:44318.
-
Open your browser and navigate to
https://localhost:44318. -
Select the Sign in button on the top right corner. When the user signs-in for the first time , a consent screen is presented. This consent screen lets the user consent for the application to access the web API.
You will see claims from the signed-in user's token.
-
Select ToDoList from navigation bar and you can create, edit or delete the todo list items.
ℹ️ Did the sample not work for you as expected? Then please reach out to us using the GitHub Issues page.
Were we successful in addressing your learning objective? Do consider taking a moment to share your experience with us.
For details about the code to enable your Blazor Server application to sign-in users, see About the code section, of the README.md file located at WebApp-OIDC/MyOrg.
This section, here, is only about the additional code added to let the Web app call the protected Web API.
-
In
Startup.cs, add below lines of code in ConfigureServices method:services.AddMicrosoftIdentityWebAppAuthentication(Configuration) .EnableTokenAcquisitionToCallDownstreamApi(new string[] { Configuration["TodoList:TodoListScope"] }) .AddInMemoryTokenCaches();
This enables your application to use the Microsoft identity platform endpoint to sign-in users and to call the protected Web API.
The following code registers client service to use the HttpClient by dependency injection.
services.AddToDoListService(Configuration);
-
ToDoList.razor component displays list of items created by signed-in user. List can be updated and deleted.
ToDoListBase.cscalls GetToDoListService method to retrieve the todo list.public class ToDoListBase : ComponentBase { [Inject] ToDoListService ToDoListService { get; set; } [Inject] MicrosoftIdentityConsentAndConditionalAccessHandler ConsentHandler { get; set; } [Inject] NavigationManager Navigation { get; set; } protected IEnumerable<ToDo> toDoList = new List<ToDo>(); protected ToDo toDo = new ToDo(); protected override async Task OnInitializedAsync() { await GetToDoListService(); } [AuthorizeForScopes(ScopeKeySection = "TodoList:TodoListScope")] private async Task GetToDoListService() { try { toDoList = await ToDoListService.GetAsync(); } catch (Exception ex) { Console.WriteLine(ex.Message); ConsentHandler.HandleException(ex); } } protected async Task DeleteItem(int Id) { await ToDoListService.DeleteAsync(Id); await GetToDoListService(); } }
-
ToDoListService.csclass in client project defines method to call protected API. PrepareAuthenticatedClient method retrieves the Access Token for the web API and sets authorization and accept headers for the request.private async Task PrepareAuthenticatedClient() { var accessToken = await _tokenAcquisition.GetAccessTokenForUserAsync(new[] { _TodoListScope }); Debug.WriteLine($"access token-{accessToken}"); _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken); _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json")); }
Refer to the Azure deployment guide to deploy this sample code to an Azure App Service.
- Microsoft identity platform (Azure Active Directory for developers)
- Overview of Microsoft Authentication Library (MSAL)
- Quickstart: Register an application with the Microsoft identity platform (Preview)
- Quickstart: Configure a client application to access web APIs (Preview)
For more information about how OAuth 2.0 protocols work in this scenario and other scenarios, see Authentication Scenarios for Azure AD.
Use Stack Overflow to get support from the community.
Ask your questions on Stack Overflow first and browse existing issues to see if someone has asked your question before.
Make sure that your questions or comments are tagged with [azure-active-directory ms-identity msal].
If you find a bug in the sample, raise the issue on GitHub Issues.
To provide feedback on or suggest features for Azure Active Directory, visit User Voice page.
If you'd like to contribute to this sample, see CONTRIBUTING.MD.
This project has adopted the Microsoft Open Source Code of Conduct. For more information, see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.


