IPublicClientApplication.AcquireTokenInteractive API throws NullReferenceException

Which Version of MSAL are you using ?

v4 of Microsoft.Identity.Client

Platform .net 4.7

What authentication flow has the issue?

• Desktop / Mobile
  • Interactive

Other? - please describe;

Is this a new or existing app? New app

Repro

// create public client using WithAdfsAuthority IPublicClientApplication _app = PublicClientApplicationBuilder.Create(ClientId) .WithAdfsAuthority(“<>”, false) .Build();

// Authenticate the user interactive AuthenticationResult result =await _app.AcquireTokenInteractive(Scopes).ExecuteAsync().ConfigureAwait(false);

// clear the cache var accounts = (await _app.GetAccountsAsync()).ToList(); while (accounts.Any()) { await _app.RemoveAsync(accounts.First()); accounts = (await _app.GetAccountsAsync()).ToList(); }

// try to authenticate the user again: AuthenticationResult result =await _app.AcquireTokenInteractive(Scopes).ExecuteAsync().ConfigureAwait(false);

Expected behavior User is asked for creds and authenticated

Actual behavior That API throws NullReferenceException with the following callstack.

at Microsoft.Identity.Client.Instance.AdfsUpnHelper.GetDomainFromUpn(String upn) at Microsoft.Identity.Client.Instance.AuthorityEndpointResolutionManager.TryGetCacheValue(AuthorityInfo authorityInfo, String userPrincipalName, AuthorityEndpoints& endpoints) at Microsoft.Identity.Client.Instance.AuthorityEndpointResolutionManager.<ResolveEndpointsAsync>d__3.MoveNext() — End of stack trace from previous location where exception was thrown — at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.Identity.Client.Internal.Requests.RequestBase.<ResolveAuthorityEndpointsAsync>d__20.MoveNext() — End of stack trace from previous location where exception was thrown — at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.Identity.Client.Internal.Requests.InteractiveRequest.<ExecuteAsync>d__9.MoveNext() — End of stack trace from previous location where exception was thrown — at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.Identity.Client.Internal.Requests.RequestBase.<RunAsync>d__14.MoveNext() — End of stack trace from previous location where exception was thrown — at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.Identity.Client.ApiConfig.Executors.PublicClientExecutor.<ExecuteAsync>d__2.MoveNext() — End of stack trace from previous location where exception was thrown — at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult() at TodoListClient.MainWindow.<SignIn>d__18.MoveNext() in H:\oauthExamples\active-directory-dotnet-native-desktop\TodoListClient\MainWindow.xaml.cs:line 332

Possible Solution Handle UPN being not present

Additional context/ Logs / Screenshots Add any other context about the problem here, such as logs and screebshots. Logging is described at https://github.com/AzureAD/microsoft-authentication-library-for-dotnet/wiki/logging

[jmprieur]

@saketkataruka @fdbeirao : the fixe is now available in MSAL.NET 4.1 cc: @jennyf19

[fdbeirao]

Hey @jennyf19 . I don’t think there was something you could have done. ADFS is a quite complex beast, and when something goes wrong it’s always going to be difficult. Together with a “random” NRE, it becomes slightly harder even.

I was providing consulting for a friend who is using this library. Even after downloading the debug symbols, the NRE was still in a somewhat unrelated place (null.Contains("@")). Most of the struggle was with Visual Studio, for losing bits and pieces of the call stack due to the usage of async/awaits. It was quite a stroke of luck that we found this Issue, after searching for “TryGetCacheValue” here on GitHub.

Also, the “bug” was also only triggered after the second login to the system, because the second execution of TryGetCacheValue would have a value in the cache, but the first didn’t (so it returned false immediately). 🤷🏻‍♂️

Thank you for the fix and the follow up 🙏🏻