xdg-open: unexpected argument 'https:%2F%2Fwww.googleapis.com%2Fauth%2Fgmail.compose'

[j-hudecek]

Hi, I'm running GMail API in ASP.NET Core 2.0 on Ubuntu 16.04 and I can't get the OAuth to work.
My code looks like this:

        UserCredential credential;
        if (emails == null || emails.Length == 0)
            return Task.CompletedTask;
        using (var stream =
            new FileStream("client_secret.json", FileMode.Open, FileAccess.Read))
        {
            string credPath = "gmail.json";
            log.Info("Creating FileDataStore "+credPath);
            var fds = new FileDataStore(credPath, true);
            log.Info("Loading secrets");
            var secrets = GoogleClientSecrets.Load(stream).Secrets;
            log.Info("Running AuthorizeAsync");
            credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                secrets,
                Scopes,
                "user",
                CancellationToken.None,
                fds).Result;
            log.Info("Credential file saved to: " + credPath);
        }

        // Create Gmail API service.
        var service = new GmailService(new BaseClientService.Initializer()
        {
            HttpClientInitializer = credential,
            ApplicationName = ApplicationName,
        });

It works from a windows machine, I get a nice OAuth flow. But on Ubuntu I see

Sep 28 11:17:43 vm dotnet-app[67214]: xdg-open: unexpected argument 'https:%2F%2Fwww.googleapis.com%2Fauth%2Fgmail.compose'
Sep 28 11:17:43 vm dotnet-app[67214]: Try 'xdg-open --help' for more information.

in the output of dotnet and this in the log:

2017-09-28 11:17:42,860 INFO app.Services.EmailSender - Creating FileDataStore gmail.json
2017-09-28 11:17:42,860 INFO app.Services.EmailSender - Loading secrets
2017-09-28 11:17:43,016 INFO app.Services.EmailSender - Running AuthorizeAsync

and that never finishes, the app just times out there

[chrisdunelm]

This exception is caused by an error in starting a web browser on the local machine.
On Linux this uses xdg-open command, called from LocalServerCodeReceiver.cs, but it appears to be failing in this instance. Is there a browser installed on the Linux machine?

You say this is an ASP.NET Core application; so is the code shown running within a web server?
In which case GoogleWebAuthorizationBroker.AuthorizeAsync is not appropriate as it is for OAuth in an application running on the client's machine, not a server machine.

[j-hudecek]

indeed it's inappropriate to use it. But it should still work, right? There is only lynx installed and I can start it with xdg-open with a correct URL. but this one seems to be url-encoded.

[chrisdunelm]

You are correct that this should work ;) The URL should not be url-encoded.
We'll keep this issue open until it is fixed.

[chrisdunelm]

This is caused by the oauth URL containing a scope query parameter that contains a space character which is incorrectly not URL-encoded. This space character is being interpreted as spltting what should be a single URL arg into two args.
Hence the xdg-open: unexpected argument error which only occurs when xdg-open is passed multiple args.
The URL shown in the error is the second scope that has been requested, not the actual URL to browse to for auth (which is http://account.google.com/o/oauth2/...)

I'll prepare a PR to fix the scope URL-encoding.