How to login to Google API with Service Account in C# - Invalid Credentials

Question

I\'m beating myself bloody trying to get a simple service acccount login to work in C#, to Google API and Google Analytics. My company is already getting data into Analytics, an

Answer 1

In 2020 you don't need to do all this and the GoogleCredential works fine. The code in the question looks correct except for one line:

credentials.CreateScoped(new string[] { DriveService.Scope.Drive });

The CreateScoped method returns a copy of the credentials. If you reassign it back to itself it just works.

For the sake of completeness, this is my test code that works perfectly:

using (var stream =
            new FileStream("drive-credentials.json", FileMode.Open, FileAccess.Read))
        {                
            var credentials = GoogleCredential.FromStream(stream);
            if (credentials.IsCreateScopedRequired)
            {
                credentials = credentials.CreateScoped(new string[] { DriveService.Scope.Drive });
            }


            var service = new DriveService(new BaseClientService.Initializer()
            {
                HttpClientInitializer = credentials,
                ApplicationName = "application name",                    
            });

            FilesResource.ListRequest listRequest = service.Files.List();
            listRequest.PageSize = 10;
            listRequest.Fields = "nextPageToken, files(id, name)";

            // List files.
            IList files = listRequest.Execute()
                .Files;
        }