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xamarin.formsxamarin.androidazure-ad-msalazure-ad-b2c

Azure B2C broken when explicitly-declared value for android:exported is used

My Xamarin.Forms application uses Azure AD B2C for authentication. Currently, I have to use Android 12 instead of Android 10. According to the documentation, it required a certain change:

Warning: If an activity, service, or broadcast receiver uses intent filters and doesn't have an explicitly-declared value for android:exported, your app can't be installed on a device that runs Android 12 or higher.

(https://developer.android.com/about/versions/12/behavior-changes-12#security)

This is my code from MsalActivity.cs:

namespace UserDetailsClient.Droid
{
  [Activity(Exported = false)]
  [IntentFilter(new[] { Intent.ActionView },
    Categories = new[] { Intent.CategoryBrowsable, Intent.CategoryDefault },
    DataHost = "auth",
    DataScheme = "msal5c32fe58-4a77-49ea-8b5d-010c4a684e4f")]
  public class MsalActivity : BrowserTabActivity
  {
  }
}

After I added (Exported = false), I was able to deploy and run the app. But now I am not able to log in. The login screen does show up. And the user can enter the credentials, but after submitting, we get stuck on this screen:

enter image description here

Nothing new appears in the output window. How can this be diagnosed and fixed?

Solution

  • No, you need to set the Exported = true. The official document says if the activity has any intent filter, the default value of it is true, so your project in Android 10, it's Exported = true. When you update to Android 12, you need to set it as true too.

    You can check the official document:https://developer.android.com/guide/topics/manifest/activity-element