Manually validating a JWT access token in a web API

Última actualización: 30/06/2017
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This sample demonstrates how to manually process a JWT access token in a web API using the JSON Web Token Handler For the Microsoft .Net Framework 4.5. This sample is equivalent to the NativeClient-DotNet sample, except in the TodoListService instead of using OWIN middleware to process the token, the token is processed manually in application code. The client is unchanged from the NativeClient-DotNet sample.

The manual JWT validation occurs in the TokenValidationHandler implementation in the Global.aspx.cs file in the TodoListService-ManualJwt project.

For more information about how the protocols work in this scenario and other scenarios, see Authentication Scenarios for Azure AD.

Looking for previous versions of this code sample? Check out the tags on the releases GitHub page.

How To Run This Sample

To run this sample you will need: - Visual Studio 2013 - An Internet connection - An Azure Active Directory (Azure AD) tenant. For more information on how to get an Azure AD tenant, please see How to get an Azure AD tenant - A user account in your Azure AD tenant. This sample will not work with a Microsoft account, so if you signed in to the Azure portal with a Microsoft account and have never created a user account in your directory before, you need to do that now.

Step 1: Clone or download this repository

From your shell or command line:

git clone https://github.com/Azure-Samples/active-directory-dotnet-webapi-manual-jwt-validation.git

Step 2: Register the sample with your Azure Active Directory tenant

There are two projects in this sample. Each needs to be separately registered in your Azure AD tenant.

Register the TodoListService-ManualJwt web API

  1. Sign in to the Azure portal.
  2. On the top bar, click on your account and under the Directory list, choose the Active Directory tenant where you wish to register your application.
  3. Click on More Services in the left hand nav, and choose Azure Active Directory.
  4. Click on App registrations and choose Add.
  5. Enter a friendly name for the application, for example 'TodoListService-ManualJwt' and select 'Web Application and/or Web API' as the Application Type. For the sign-on URL, enter the base URL for the sample, which is by default https://localhost:44324. For the App ID URI, enter https://<your_tenant_name>/TodoListService-ManualJwt, replacing <your_tenant_name> with the name of your Azure AD tenant. Click OK to complete the registration. Click on Create to create the application.
  6. While still in the Azure portal, choose your application, click on Settings and choose Properties.
  7. Find the Application ID value and copy it to the clipboard.

Register the TodoListClient app

  1. Sign in to the Azure portal.
  2. On the top bar, click on your account and under the Directory list, choose the Active Directory tenant where you wish to register your application.
  3. Click on More Services in the left hand nav, and choose Azure Active Directory.
  4. Click on App registrations and choose Add.
  5. Enter a friendly name for the application, for example 'TodoListClient-DotNet' and select 'Native' as the Application Type. For the redirect URI, enter https://TodoListClient. Click on Create to create the application.
  6. While still in the Azure portal, choose your application, click on Settings and choose Properties.
  7. Find the Application ID value and copy it to the clipboard.
  8. Configure Permissions for your application - in the Settings menu, choose the 'Required permissions' section, click on Add, then Select an API, and type 'TodoListService' in the textbox. Then, click on Select Permissions and select 'Access TodoListService'.

Step 3: Configure the sample to use your Azure AD tenant

Configure the TodoListService-ManualJwt project

  1. Open the solution in Visual Studio 2013.
  2. Open the web.config file.
  3. Find the app key ida:Tenant and replace the value with your AAD tenant name.
  4. Find the app key ida:Audience and replace the value with the App ID URI you registered earlier, for example https://<your_tenant_name>/TodoListService-ManualJwt.

Configure the TodoListClient project

  1. Open app.config.
  2. Find the app key ida:Tenant and replace the value with your AAD tenant name.
  3. Find the app key ida:ClientId and replace the value with the Client ID for the TodoListClient from the Azure portal.
  4. Find the app key ida:RedirectUri and replace the value with the Redirect URI for the TodoListClient from the Azure portal, for example http://TodoListClient.
  5. Find the app key todo:TodoListResourceId and replace the value with the App ID URI of the TodoListService-ManualJwt project, for example https://<your_tenant_name>/TodoListService-ManualJwt
  6. Find the app key todo:TodoListBaseAddress and replace the value with the base address of the TodoListService-ManualJwt project, for example https://localhost:44324.

Step 4: Trust the IIS Express SSL certificate

Since the web API is SSL protected, the client of the API (the web app) will refuse the SSL connection to the web API unless it trusts the API's SSL certificate. Use the following steps in Windows Powershell to trust the IIS Express SSL certificate. You only need to do this once. If you fail to do this step, calls to the TodoListService-ManualJwt web API will always throw an unhandled exception where the inner exception message is:

"The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel."

To configure your computer to trust the IIS Express SSL certificate, begin by opening a Windows Powershell command window as Administrator.

Query your personal certificate store to find the thumbprint of the certificate for CN=localhost:

PS C:\windows\system32> dir Cert:\LocalMachine\My


    Directory: Microsoft.PowerShell.Security\Certificate::LocalMachine\My


Thumbprint                                Subject
----------                                -------
C24798908DA71693C1053F42A462327543B38042  CN=localhost

Next, add the certificate to the Trusted Root store:

PS C:\windows\system32> $cert = (get-item cert:\LocalMachine\My\C24798908DA71693C1053F42A462327543B38042)
PS C:\windows\system32> $store = (get-item cert:\Localmachine\Root)
PS C:\windows\system32> $store.Open("ReadWrite")
PS C:\windows\system32> $store.Add($cert)
PS C:\windows\system32> $store.Close()

You can verify the certificate is in the Trusted Root store by running this command:

PS C:\windows\system32> dir Cert:\LocalMachine\Root

Step 5: Run the sample

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.

Explore the sample by signing in, adding items to the To Do list, removing the user account, and starting again. Notice that if you stop the application without removing the user account, the next time you run the application you won't be prompted to sign-in again - that is the sample implements a persistent cache for ADAL, and remembers the tokens from the previous run.

How To Deploy This Sample to Azure

Coming soon.

About The Code

Coming soon.

How To Recreate This Sample

First, in Visual Studio 2013 create an empty solution to host the projects. Then, follow these steps to create each project.

Creating the TodoListService-ManualJwt Project

  1. In the solution, create a new ASP.Net MVC web API project called TodoListService-ManualJwt and while creating the project, ensure Authentication is set to No Authentication.
  2. Set SSL Enabled to be True. Note the SSL URL.
  3. In the project properties, Web properties, set the Project Url to be the SSL URL.
  4. Add the latest stable JSON Web Token Handler For the Microsoft .Net Framework 4.5 NuGet, System.IdentityModel.Tokens.Jwt, version 4.x to the project. Note: Version 5.x will not work with this sample, as it requires .Net Framework 5.x.
  5. Add an assembly reference to System.IdentityModel.
  6. In the Models folder add a new class called TodoItem.cs. Copy the implementation of TodoItem from this sample into the class.
  7. Add a new, empty, Web API 2 controller called TodoListController.
  8. Copy the implementation of the TodoListController from this sample into the controller.
  9. Open Global.asax, and copy the implementation from this sample into the controller. Note that a single line is added at the end of Application_Start(), GlobalConfiguration.Configuration.MessageHandlers.Add(new TokenValidationHandler());.
  10. In web.config create keys for ida:AADInstance, ida:Tenant, and ida:Audience and set them accordingly. For the public Azure cloud, the value of ida:AADInstance is https://login.microsoftonline.com/{0}.

Creating the TodoListClient Project

  1. In the solution, create a new Windows --> WPF Application called TodoListClient.
  2. Add the (stable) Active Directory Authentication Library (ADAL) NuGet, Microsoft.IdentityModel.Clients.ActiveDirectory, version 1.0.3 (or higher) to the project.
  3. Add assembly references to System.Net.Http, System.Web.Extensions, and System.Configuration.
  4. Add a new class to the project called TodoItem.cs. Copy the code from the sample project file of same name into this class, completely replacing the code in the file in the new project.
  5. Add a new class to the project called CacheHelper.cs. Copy the code from the sample project file of same name into this class, completely replacing the code in the file in the new project.
  6. Add a new class to the project called CredManCache.cs. Copy the code from the sample project file of same name into this class, completely replacing the code in the file in the new project.
  7. Copy the markup from `MainWindow.xaml' in the sample project into the file of same name in the new project, completely replacing the markup in the file in the new project.
  8. Copy the code from MainWindow.xaml.cs in the sample project into the file of same name in the new project, completely replacing the code in the file in the new project.
  9. In app.config create keys for ida:AADInstance, ida:Tenant, ida:ClientId, ida:RedirectUri, todo:TodoListResourceId, and todo:TodoListBaseAddress and set them accordingly. For the public Azure cloud, the value of ida:AADInstance is https://login.microsoftonline.com/{0}.

Finally, in the properties of the solution itself, set both projects as startup projects.