Using authProvider with MS SDK for graph calls in C#

Question

I'm trying create a C# console application to connect to graph API and get a list of users from AzureAD from a tenant. I have registered the app and the admin has given me the following

• Tenant Name and Tenant ID
• Client ID (also sometimes called App Id)
• Client Secret

Using the sdk the C# code I need to use looks like this (https://docs.microsoft.com/en-us/graph/api/user-list?view=graph-rest-1.0&tabs=cs):

GraphServiceClient graphClient = new GraphServiceClient( authProvider );

var users = await graphClient.Users
    .Request()
    .GetAsync();

However, the console application will run as a batch process so there will be no user interaction at all. So in order to provide the authProvider I followed this article on MS docs site: https://docs.microsoft.com/en-us/graph/sdks/choose-authentication-providers?tabs=CS

And I think for my purpose I need to go for the "Client Credential OAuth flow". The code which is shown on that URL. But here it is too.

IConfidentialClientApplication clientApplication = ClientCredentialProvider.CreateClientApplication(clientId, clientCredential);
ClientCredentialProvider authProvider = new ClientCredentialProvider(clientApplication);

The trouble is that Visual Studio does not recognise ClientCredentialProvider class. I'm not sure which assembly to import. I'm using the following usings in the top.

using Microsoft.Identity.Client;
using Microsoft.IdentityModel.Clients;
using Microsoft.IdentityModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

I'm not very experienced with GitHub repos and I'm using Visual Studio 2015. I would be interested in sample code; I have looked but cannot find any. MS have some lectures but they use another type of auth Provider which is authenticating interactively which is not what I'm looking for. I want obtain the token using the TenantId/ClientId and Client Secret.

Solution

ClientCredentialProvider is part of the Microsoft.Graph.Auth package. You can read more about this package at https://github.com/microsoftgraph/msgraph-sdk-dotnet-auth

Note that this package is currently (as of 2019-05-15) in preview, so you may want to wait before using this in a production application.

Alternatively, the following example uses the Microsoft Authentication Library for .NET (MSAL) directly to set up the Microsoft Graph SDK using app-only authentication:

// The Azure AD tenant ID or a verified domain (e.g. contoso.onmicrosoft.com) 
var tenantId = "{tenant-id-or-domain-name}";

// The client ID of the app registered in Azure AD
var clientId = "{client-id}";

// *Never* include client secrets in source code!
var clientSecret = await GetClientSecretFromKeyVault(); // Or some other secure place.

// The app registration should be configured to require access to permissions
// sufficient for the Microsoft Graph API calls the app will be making, and
// those permissions should be granted by a tenant administrator.
var scopes = new string[] { "https://graph.microsoft.com/.default" };

// Configure the MSAL client as a confidential client
var confidentialClient = ConfidentialClientApplicationBuilder
    .Create(clientId)
    .WithAuthority($"https://login.microsoftonline.com/$tenantId/v2.0")
    .WithClientSecret(clientSecret)
    .Build();

// Build the Microsoft Graph client. As the authentication provider, set an async lambda
// which uses the MSAL client to obtain an app-only access token to Microsoft Graph,
// and inserts this access token in the Authorization header of each API request. 
GraphServiceClient graphServiceClient =
    new GraphServiceClient(new DelegateAuthenticationProvider(async (requestMessage) => {

            // Retrieve an access token for Microsoft Graph (gets a fresh token if needed).
            var authResult = await confidentialClient
                .AcquireTokenForClient(scopes)
                .ExecuteAsync();

            // Add the access token in the Authorization header of the API request.
            requestMessage.Headers.Authorization = 
                new AuthenticationHeaderValue("Bearer", authResult.AccessToken);
        })
    );

// Make a Microsoft Graph API query
var users = await graphServiceClient.Users.Request().GetAsync();

(Note that this example uses the latest version of the Microsoft.Identity.Client package. Earlier versions (before version 3) did not include ConfidentialClientApplicationBuilder.)