[Bug] Unity Windows Standalone il2cpp: NotSupportedException: System.Reflection.Emit.DynamicMethod::.ctor

Which Version of MSAL are you using ? MSAL 4.30

Platform net45 compiled with Unity Standalone il2cpp configuration

What authentication flow has the issue?

• Desktop / Mobile
  • Interactive
  • Integrated Windows Auth
  • Username Password
  • Device code flow (browserless)
• Web App
  • Authorization code
  • OBO
• Daemon App
  • Service to Service calls

Other? - please describe;

Is this a new or existing app? c. This is a new app or experiment

Repro Create a Unity project and add MSAL authentication code similar to the below in a Unity component. Target Standalone and use the IL2CPP scripting backend.

private void BeforeAccessNotification(TokenCacheNotificationArgs args)
{
    lock (FileLock)
    {
        args.TokenCache.DeserializeMsalV3(File.Exists(CacheFilePath)
            ? ProtectedData.Unprotect(File.ReadAllBytes(CacheFilePath), null, DataProtectionScope.CurrentUser)
            : null);
    }
}

private void AfterAccessNotification(TokenCacheNotificationArgs args)
{
    // if the access operation resulted in a cache update
    if (args.HasStateChanged)
    {
        lock (FileLock)
        {
            // reflect changes in the persistent store
            File.WriteAllBytes(
                CacheFilePath,
                ProtectedData.Protect(
                    args.TokenCache.SerializeMsalV3(),
                    null,
                    DataProtectionScope.CurrentUser));
        }
    }
}

PublicClientApplicationBuilder builder = PublicClientApplicationBuilder.Create(clientId);
builder = builder.WithRedirectUri("http://localhost");
builder = builder.WithAuthority(AadAuthorityAudience.AzureAdAndPersonalMicrosoftAccount);
builder = builder.WithLogging(MsalLog, LogLevel.Error, true);
var PublicClientApp = builder.Build();
PublicClientApp.UserTokenCache.SetBeforeAccess(BeforeAccessNotification);
PublicClientApp.UserTokenCache.SetAfterAccess(AfterAccessNotification);

var authResult = await PublicClientApp.AcquireTokenSilent(scopes, Account).ExecuteAsync();

Expected behavior No dynamic code generation.

Actual behavior NotSupportedException: System.Reflection.Emit.DynamicMethod::.ctor

Possible Solution Building locally and removing the HAVE_CAS define seems to resolve the issue.

Additional context/ Logs / Screenshots Player.log

[pmaytak]

@bgavrilMS

Method	Mean (with flag, current)	Mean (without flag)
Serialize_MsalTokenResponse_Test	4.256 μs	7.438 μs
Deserialize_MsalTokenResponse_Test	8.685 μs	13.194 μs
Serialize_InstanceDiscoveryResponse_Test	30.063 μs	42.920 μs
Deserialize_InstanceDiscoveryResponse_Test	47.900 μs	78.104 μs
Serialize_OAuth2ResponseBase_Test	1.574 μs	2.347 μs
Deserialize_OAuth2ResponseBase_Test	2.724 μs	4.348 μs
Serialize_Desrialize_Cache	146μs	160μs

[bgavrilMS]

I also ran a test for serializing / deserializing the token cache (I added a row in the table above). All in all, it does not seem to be bad. I think we can:

• implement this for both public client & confidential client (very simple change)
• implement this only for public client (a bit more work)

@henrik-me - thoughts?