Access token validation failure when creating Microsoft Graph webhook using the "Web API on-behalf-of flow"

Question

What I am trying to do is to use the "Web API on-behalf-of flow" scenario Microsoft described in this article to create a web hook.

So I started with the Microsoft github example and made sure that I can successfully get the users profile via the Graph API.

Then I modified the code where it gets the users profile to create the web hook, so the code looks like this:

// Authentication and get the access token on behalf of a WPF desktop app.
// This part is unmodified from the sample project except for readability.

const string authority = "https://login.microsoftonline.com/mycompany.com";
const string resource = "https://graph.windows.net";
const string clientId = "my_client_id";
const string clientSecret = "my_client_secret";
const string assertionType = "urn:ietf:params:oauth:grant-type:jwt-bearer";

var user = ClaimsPrincipal.Current.FindFirst(ClaimTypes.NameIdentifier).Value;
var authenticationContext = new AuthenticationContext(authority,new DbTokenCache(user));
var assertion = ((BootstrapContext) ClaimsPrincipal.Current.Identities.First().BootstrapContext).Token;
var userName = ClaimsPrincipal.Current.FindFirst(ClaimTypes.Upn) != null
    ? ClaimsPrincipal.Current.FindFirst(ClaimTypes.Upn).Value
    : ClaimsPrincipal.Current.FindFirst(ClaimTypes.Email).Value;

var result = await authenticationContext.AcquireTokenAsync(resource,new ClientCredential(clientId,clientSecret),new UserAssertion(assertion,assertionType,userName));

var accessToken = result.AccessToken;


// After getting the access token on behalf of the desktop WPF app,
// subscribes to get notifications when the user receives an email.
// This is the part that I put in.

var subscription = new Subscription
{
    Resource = "me/mailFolders('Inbox')/messages",
    ChangeType = "created",
    NotificationUrl = "https://mycompany.com/subscription/listen",
    ClientState = Guid.NewGuid().ToString(),
    ExpirationDateTime = DateTime.UtcNow + new TimeSpan(0, 0, 4230, 0)
};

const string subscriptionsEndpoint = "https://graph.microsoft.com/v1.0/subscriptions/";
var request = new HttpRequestMessage(HttpMethod.Post, subscriptionsEndpoint);

var contentString = JsonConvert.SerializeObject(subscription, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
request.Content = new StringContent(contentString, System.Text.Encoding.UTF8, "application/json");
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

var response = await new HttpClient().SendAsync(request);

if (response.IsSuccessStatusCode)
{
    // Parse the JSON response.
    var stringResult = await response.Content.ReadAsStringAsync();
    subscription = JsonConvert.DeserializeObject<Subscription>(stringResult);
}

The error I get from the response is:

{
 "error":
 {
    "code": "InvalidAuthenticationToken",
    "message": "Access token validation failure.",
    "innerError":
    {
      "request-id": "f64537e7-6663-49e1-8256-6e054b5a3fc2",
      "date": "2017-03-27T02:36:04"
    }
  }
}

The webhook creation code was taken straight from the ASP.NET webhook github sample project, which, I have also made sure that I can run successfully.

The same access token code works with the original user profile reading code:

// Call the Graph API and retrieve the user's profile.

const string requestUrl = "https://graph.windows.net/mycompany.com/me?api-version=2013-11-08";
request = new HttpRequestMessage(HttpMethod.Get, requestUrl);
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
var response = await new HttpClient().SendAsync(request);

So I want to find out:

1. Is creating a webhook via the graph API using the on-behalf-of flow even supported? Not sure if this SO question is what I'm looking for here.
2. If it is supported, what am I missing here?
3. If it is not supported, is there an alternative to achieve it? E.g. is there anything from the existing Office 365 API that I can use?

Answer 1

"message": "Access token validation failure.",

The error means you got incorrect access token for the resource . According to your code ,you get the access token for resource :https://graph.windows.net( Azure AD Graph API) , But then you used that access token to access Microsoft Graph API(https://graph.microsoft.com) ,so access token validation failed .