services | platforms | author | level | client | service | endpoint |
---|---|---|---|---|---|---|
active-directory |
dotnet |
jmprieur |
200 |
Desktop |
ASP.NET Web API |
AAD V1 |
The application uses the Active Directory Authentication Library (ADAL) to get a token from Azure AD using the OAuth 2.0 client credential flow, where the client credential is a certificate.
In this sample, a Windows console application (TodoListDaemonWithCert) calls a web API (TodoListService) using its app identity. This scenario is useful for situations where headless or unattended job or a windows service needs to run with an application identity, instead of a user's identity.
This sample is similar to Daemon-DotNet, except instead of the daemon using a password as a credential to authenticate with Azure AD, it uses a certificate instead.
Once the service started, when you start the TodoListDaemon
desktop application, it repeatedly:
- adds items to the todo list maintained by the service,
- lists the existing todo list items.
No user interaction is involved in this sample.
To run this sample, you'll need:
- Visual Studio 2017
- An Internet connection
- An Azure Active Directory (Azure AD) tenant. For more information on how to get an Azure AD tenant, 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 (formerly Windows Live account). Therefore, 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.
You can clone this repository from Visual Studio. Alternatively, from your shell or command line, use:
git clone https://github.com/Azure-Samples/active-directory-dotnet-daemon-certificate-credential.git
Given that the name of the sample is pretty long, and so are the name of the referenced NuGet pacakges, you might want to clone it in a folder close to the root of your hard drive, to avoid file size limitations on Windows.
There are two projects in this sample. Each needs to be separately registered in your Azure AD tenant. To register these projects, you can:
- either follow the steps in the paragraphs below (Step 2 and Step 3)
- or use PowerShell scripts that:
- automatically create for you the Azure AD applications and related objects (passwords, permissions, dependencies)
- modify the Visual Studio projects' configuration files.
If you want to use this automation, read the instructions in App Creation Scripts. After successfully executing the script, we advice you go through the values of the various settings listed in Step 3) that the script populated. Carefully study the changes made to the configuration files of the various projects in the solution. This will help you build a good understanding of how and where these settings come together to make this scenario work.
For Windows Server 2012, creating a certificate with PowerShell is slightly different: See issue #37
As a first step you'll need to:
- Sign in to the Azure portal.
- On the top bar, click on your account, and then on Switch Directory.
- Once the Directory + subscription pane opens, choose the Active Directory tenant where you wish to register your application, from the Favorites or All Directories list.
- Click on All services in the left-hand nav, and choose Azure Active Directory.
In the next steps, you might need the tenant name (or directory name) or the tenant ID (or directory ID). These are presented in the Properties of the Azure Active Directory window respectively as Name and Directory ID
- In the Azure Active Directory pane, click on App registrations and choose New application registration.
- Enter a friendly name for the application, for example 'TodoListService' and select 'Web app / API' as the Application Type.
- For the sign-on URL, enter the base URL for the sample. By default, this sample uses
https://localhost:44321/
. - Click Create to create the application.
- In the succeeding page, Find the Application ID value and record it for later. You'll need it to configure the Visual Studio configuration file for this project.
- Then click on Settings, and choose Properties.
- For the App ID URI, replace the guid in the generated URI 'https://<your_tenant_name>/<guid>', with the name of your service, for example, 'https://<your_tenant_name>/TodoListService' (replacing
<your_tenant_name>
with the name of your Azure AD tenant)
- In the Azure Active Directory pane, click on App registrations and choose New application registration.
- Enter a friendly name for the application, for example 'TodoListDaemon' and select 'Web app / API' as the Application Type.
Even if this is a desktop application, this is a confidential client application hence the Application Type
- For the Redirect URI, enter
https://<your_tenant_name>/TodoListDaemon
, replacing<your_tenant_name>
with the name of your Azure AD tenant. - Click Create to create the application.
- In the succeeding page, Find the Application ID value and record it for later. You'll need it to configure the Visual Studio configuration file for this project.
- Then click on Settings, and choose Properties.
- For the App ID URI, replace the guid in the generated URI 'https://<your_tenant_name>/<guid>', with the name of your service, for example, 'https://<your_tenant_name>/TodoListDaemon' (replacing
<your_tenant_name>
with the name of your Azure AD tenant)
To complete this step, you will use the New-SelfSignedCertificate
Powershell command. You can find more information about the New-SelfSignedCertificat command here.
Open PowerShell and run New-SelfSignedCertificate with the following parameters to create a self-signed certificate in the user certificate store on your computer:
$cert=New-SelfSignedCertificate -Subject "CN=TodoListDaemonWithCert" -CertStoreLocation "Cert:\CurrentUser\My" -KeyExportPolicy Exportable -KeySpec Signature
If needed, you can later export this certificate using the "Manage User Certificate" MMC snap-in accessible from the Windows Control Panel. You can also add other options to generate the certificate in a different store such as the Computer or service store (See How to: View Certificates with the MMC Snap-in).
Copy and paste the following lines in the same PowerShell window. They generate a text file in the current folder containing information that you can use to upload your certificate to Azure AD:
$bin = $cert.RawData
$base64Value = [System.Convert]::ToBase64String($bin)
$bin = $cert.GetCertHash()
$base64Thumbprint = [System.Convert]::ToBase64String($bin)
$keyid = [System.Guid]::NewGuid().ToString()
$jsonObj = @{customKeyIdentifier=$base64Thumbprint;keyId=$keyid;type="AsymmetricX509Cert";usage="Verify";value=$base64Value}
$keyCredentials=ConvertTo-Json @($jsonObj) | Out-File "keyCredentials.txt"
The content of the generated "keyCredentials.txt" file has the following schema:
[
{
"customKeyIdentifier": "$base64Thumbprint_from_above",
"keyId": "$keyid_from_above",
"type": "AsymmetricX509Cert",
"usage": "Verify",
"value": "$base64Value_from_above"
}
]
To associate the certificate credential with the TodoListDaemon
app object in Azure AD, you'll need to edit the application manifest.
In the Azure portal app registration page for the TodoListDaemon
, click on Manifest. An editor window opens enabling you to edit the manifest.
You need to replace the value of the keyCredentials
property (that is []
if you don't have any certificate credentials yet), with the content of the keyCredential.txt file.
To do this replacement in the manifest, you have two options:
-
Option 1: Edit the manifest in place by clicking Edit, replacing the
keyCredentials
value, and then clicking Save.Note that if you refresh the web page, the key is displayed with different properties than what you have input. In particular, you can now see the endDate, and stateDate, and the value is shown as null. This is normal.
-
Option 2: Download the manifest to your computer, edit it with your favorite text editor, save a copy of it, and Upload this copy. You might want to choose this option if you want to keep track of the history of the manifest.
Note that the keyCredentials
property is multi-valued, so you may upload multiple certificates for richer key management. In that case copy only the text between the curly brackets.
- Configure Permissions for your application. To that extent, in the Settings menu, choose the 'Required permissions' section and then,
click on Add, then Select an API, and type
TodoListService
in the textbox. Then, click on Select Permissions and select Access 'TodoListService'.
In the steps below, "ClientID" is the same as "Application ID" or "AppId".
Open the solution in Visual Studio to configure the projects
- Open the
TodoListService\Web.Config
file - Find the app key
ida:Tenant
and replace the existing value with your Azure AD tenant name. - Find the app key
ida:Audience
and replace the existing value with the App ID URI you registered earlier for the TodoListService app. For instance usehttps://<your_tenant_name>/TodoListService
, where<your_tenant_name>
is the name of your Azure AD tenant.
- Open the
TodoListDaemonWithCert\App.Config
file - Find the app key
ida:Tenant
and replace the existing value with your Azure AD tenant name. - Find the app key
ida:ClientId
and replace the existing value with the application ID (clientId) of theTodoListDaemon
application copied from the Azure portal. - Find the app key
ida:CertName
and replace the existing value with Certificate. - Find the app key
todo:TodoListResourceId
and replace the existing value with the App ID URI you registered earlier for the TodoListService app. For instance usehttps://<your_tenant_name>/TodoListService
, where<your_tenant_name>
is the name of your Azure AD tenant. - Find the app key
todo:TodoListBaseAddress
and replace the existing value with the base address of the TodoListService project (by defaulthttps://localhost:44321/
).
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. To do this, you can for instance:
- Right click on the solution in the solution explorer and choose Set Startup projects from the context menu.
- choose Multiple startup projects
- TodoListDaemonWithCert: Start
- TodoListService: Start Start without debugging
- In the Visual Studio tool bar, press the start button: a web window appears running the service and a console application runs the daemon application under debugger. you can set breakpoints to understand the call to ADAL.NET.
The daemon will add items to the To Do list and then read them back.
This project has one WebApp / Web API projects. To deploy them to Azure Web Sites, you'll need, for each one, to:
- create an Azure Web Site
- publish the Web App / Web APIs to the web site, and
- update its client(s) to call the web site instead of IIS Express.
- Sign in to the Azure portal.
- Click Create a resource in the top left-hand corner, select Web + Mobile --> Web App, select the hosting plan and region, and give your web site a name, for example,
TodoListService-contoso.azurewebsites.net
. Click Create Web Site. - Once the web site is created, click on it to manage it. For this set of steps, download the publish profile by clicking Get publish profile and save it. Other deployment mechanisms, such as from source control, can also be used.
- Switch to Visual Studio and go to the TodoListService project. Right click on the project in the Solution Explorer and select Publish. Click Import Profile on the bottom bar, and import the publish profile that you downloaded earlier.
- Click on Settings and in the
Connection tab
, update the Destination URL so that it is https, for example https://TodoListService-contoso.azurewebsites.net. Click Next. - On the Settings tab, make sure
Enable Organizational Authentication
is NOT selected. Click Save. Click on Publish on the main screen. - Visual Studio will publish the project and automatically open a browser to the URL of the project. If you see the default web page of the project, the publication was successful.
- Navigate to the Azure portal.
- On the top bar, click on your account and under the Directory list, choose the Active Directory tenant containing the
TodoListService
application. - On the applications tab, select the
TodoListService
application. - From the Settings -> Reply URLs menu, update the Sign-On URL, and Reply URL fields to the address of your service, for example https://TodoListService-contoso.azurewebsites.net. Save the configuration.
- In Visual Studio, go to the
TodoListDaemon
project. - Open
TodoListDaemonWithCert\App.Config
. Only one change is needed - update thetodo:TodoListBaseAddress
key value to be the address of the website you published, for example, https://TodoListService-contoso.azurewebsites.net. - Run the client! If you are trying multiple different client types (for example, .Net, Windows Store, Android, iOS) you can have them all call this one published web API.
NOTE: Remember, the To Do list is stored in memory in this TodoListService sample. Azure Web Sites will spin down your web site if it is inactive, and your To Do list will get emptied. Also, if you increase the instance count of the web site, requests will be distributed among the instances. ToDo list will, therefore, not be the same on each instance.
The code acquiring a token is entirely located in the TodoListDaemonWithCert\Program.cs
file.
The AuthenticationContext
is created line 76
authContext = new AuthenticationContext(authority);
Then a ClientAssertionCertificate
is instantiated line 87, from the TodoListDaemon
application's Client ID and a certificate (cert
) which was found from the certificate store (see lines 72-89).
certCred = new ClientAssertionCertificate(clientId, cert);
This instance of ClientAssertionCertificate
is used in the GetAccessToken()
method is as an argument to AcquireTokenAsync
to get a token for the Web API (line 147)
GetAccessToken()
is itself called from PostTodo()
and GetTodo()
methods.
result = await authContext.AcquireTokenAsync(todoListResourceId, certCred);
This token is then used as a bearer token to call the Web API (line 186 and 216)
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", result.AccessToken)
If you've looked at the code in this sample and are wondering how authorization works, you're not alone. See this Stack Overflow question. The TodoList Service in this solution simply validates that the client was able to authenticate against the tenant that the service is configured to work with. Effectively, any application in that tenant will be able to use the service.
First, in Visual Studio 2017 (or above) create an empty solution to host the projects. Then, follow these steps to create each project.
- In the solution, create a new ASP.Net MVC web API project called TodoListService and while creating the project, click the Change Authentication button, select Organizational Accounts, Cloud - Single Organization, enter the name of your Azure AD tenant, and set the Access Level to Single Sign On. You will be prompted to sign in to your Azure AD tenant. NOTE: You must sign in with a user that is in the tenant; you cannot, during this step, sign in with a Microsoft account.
- In the
Models
folder, add a new class calledTodoItem.cs
. Copy the implementation of TodoItem from this sample into the class. - Add a new, empty, Web API 2 controller called
TodoListController
. - Copy the implementation of the TodoListController from this sample into the controller. Don't forget to add the
[Authorize]
attribute to the class. - In
TodoListController
resolving missing references by addingusing
statements forSystem.Collections.Concurrent
,TodoListService.Models
,System.Security.Claims
.
- In the solution, create a new Windows --> Console Application called TodoListDaemon.
- Add the (stable) Active Directory Authentication Library (ADAL) NuGet, Microsoft.IdentityModel.Clients.ActiveDirectory, version 1.0.3 (or higher) to the project.
- Add assembly references to
System.Net.Http
,System.Web.Extensions
, andSystem.Configuration
. - Add a new class to the project called
TodoItem.cs
. Copy the code from the sample project file of the same name into this class, completely replacing the code in the new file. - Copy the code from
Program.cs
in the sample project into the file of the same name in the new project, completely replacing the code in the new file. - In
app.config
create keys forida:AADInstance
,ida:Tenant
,ida:ClientId
,ida:CertName
,todo:TodoListResourceId
, andtodo:TodoListBaseAddress
and set them accordingly. For the global Azure cloud, the value ofida:AADInstance
ishttps://login.microsoftonline.com/{0}
.
Finally, in the properties of the solution itself, set both projects as startup projects.
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 [adal
dotnet
].
If you find a bug in the sample, please raise the issue on GitHub Issues.
To provide a recommendation, visit the following 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 [email protected] with any additional questions or comments.
For more information, see ADAL.NET's conceptual documentation:
For more information about how OAuth 2.0 protocols work in this scenario and other scenarios, see Authentication Scenarios for Azure AD.
- How to use a pre-existing certificate instead of generating a self signed certificate.