GoogleAuthException: Unknown when authenticating with Cloud Endpoints

Question

I'm trying to add authentication to my Cloud Endpoints, but I can't get it to work. I'm using this blog as a guideline: http://devthots.blogspot.nl/2012/07/building-awesome-android-apps-with.html

What I have:

In the AppEngine project:

@Api(name = "noteendpoint", clientIds = { "123456789012-abcdefghijklmnopqrstuvwxyz012345.apps.googleusercontent.com" }, audiences = { "my_project_id.appspot.com" }, namespace = @ApiNamespace(ownerDomain = "example.com", ownerName = "example.com", packagePath = "myapp"))
public class NoteEndpoint {
   // Rest of class, added parameter User to all methods.
}

In my Android app project:

Note note = new Note();     
note.setDescription("Description!");

GoogleAccountCredential credential = 
    GoogleAccountCredential.usingAudience(MainActivity.this, "my_project_id.appspot.com");
credential.setSelectedAccountName(ACCOUNT_NAME);

note.setEmailAddress(credential.getSelectedAccountName());

Builder endpointBuilder = new Noteendpoint.Builder(
    AndroidHttp.newCompatibleTransport(),
new JacksonFactory(), credential);

Noteendpoint endpoint = CloudEndpointUtils.updateBuilder(endpointBuilder).build();
Note result = endpoint.insertNote(note).execute(); // Exception thrown

When I run this, a GoogleAuthException: Unknown is thrown:

07-08 14:16:45.677: E/AndroidRuntime(27381): Caused by: com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAuthIOException
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential$RequestHandler.intercept(GoogleAccountCredential.java:308)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:854)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:410)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:343)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:460)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.example.test.ui.MainActivity$1.doInBackground(MainActivity.java:131)
07-08 14:16:45.677: E/AndroidRuntime(27381):    ... 7 more
07-08 14:16:45.677: E/AndroidRuntime(27381): Caused by: com.google.android.gms.auth.GoogleAuthException: Unknown
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.android.gms.auth.GoogleAuthUtil.getToken(Unknown Source)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.android.gms.auth.GoogleAuthUtil.getToken(Unknown Source)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential.getToken(GoogleAccountCredential.java:277)
07-08 14:16:45.677: E/AndroidRuntime(27381):    at com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential$RequestHandler.intercept(GoogleAccountCredential.java:301)

How can I solve this?

The clientId used for the NoteEndpoint class is copied from "Client id for installed applications", with my debug key sha1.

Using GoogleAccountCredential.usingAudience(MainActivity.this, "server:client_id:my_project_id.appspot.com"); (so with server:client_id: prefixed) doesn't help.

Answer 1

Be careful when you generate the Android Client ID. When you enter the package name, use the application ID written in app/build.gradle. It may be different of the package for your sources classes.

Explanation:

At the project creation, the package name you enter is used by Android as Application ID and used to generate packages for your source classes. During the project development, you may change the package name for your source classes. But be careful, Android Studio doesn't change automatically your application ID !

Answer 2

Using

GoogleAccountCredential credential = GoogleAccountCredential.usingAudience(MainActivity.this, "server:client_id:12312312312-abcdefghijklmnopqrstuvw012345678.apps.googleusercontent.com");

and

@Api(name = "noteendpoint", clientIds = { Ids.WEB_CLIENT_ID,
        Ids.ANDROID_CLIENT_ID }, audiences = { Ids.ANDROID_AUDIENCE }, namespace = @ApiNamespace(ownerDomain = "example.com", ownerName = "example.com", packagePath = "test"))
public class NoteEndpoint {

    public class Ids {
        public static final String WEB_CLIENT_ID = "12312312312312-abcdefghijklmnopqrstuvwxyz012345678.apps.googleusercontent.com";
        public static final String ANDROID_CLIENT_ID = "12312312312312-0123456789abcdefghabcdefghabcdefgha.apps.googleusercontent.com";
        public static final String ANDROID_AUDIENCE = WEB_CLIENT_ID;
    }

solved the problem.