Google auth on mobile

SeVeT

Hello, I am trying to achieve working sign in with google.
There is no problem as long as I use my app as desktop.
Problem starts when trying to do it on android app.
I have found two ways of doing this:

1.Setting client OAuth identification in google dev console to web so i can get both client identifier and client identifier shared key so later i set them for QOAuth2AuthorizationCodeFlow.

2.Setting client OAuth identification in google dev console to android app so i get only client identifier so i set it for QOAuth2AuthorizationCodeFlow and fill in my SHA1 key that i sign my app with when building.

In first method, when the browser window opens, everyhing is working till google sends callback - since my app is in background QOAuthHttpServerReplyHandler cannot receive anything and browser waits for handler to receive callback before closing so effectively its stuck. If i close window manually and go back to my app everything is working fine but is there a way to automatically close that window without waiting for handler to receive callback?

In second method I created key, fill it in google dev console and got only client identifier,
so client identifier shared key stays empty. In project settings
I have set Build Android APK step to sign my app with created key.
After opening browser for sign in google respond with ERROR 400: invalid request

Can anyone help me with either one or second solution?
My code for auth is: quite easy and should provide me a token

GoogleOAuth::GoogleOAuth(QObject *parent) : QObject(parent)
{

    this->google = new QOAuth2AuthorizationCodeFlow(this);
     this->google->setScope("email");
     connect(this->google, &QOAuth2AuthorizationCodeFlow::authorizeWithBrowser, &QDesktopServices::openUrl);


     const auto port = static_cast<quint16>(1234);
     this->google->setAuthorizationUrl(QUrl("https://accounts.google.com/o/oauth2/auth"));
     this->google->setAccessTokenUrl(QUrl("https://oauth2.googleapis.com/token"));
     this->google->setClientIdentifier(Zm().googleClientId);
     this->google->setClientIdentifierSharedKey(Zm().googleClientPass);    


     this->google->setModifyParametersFunction([](QAbstractOAuth::Stage stage, QVariantMap* parameters) {
         // Percent-decode the "code" parameter so Google can match it
         if (stage == QAbstractOAuth::Stage::RequestingAccessToken) {
             QByteArray code = parameters->value("code").toByteArray();
             (*parameters)["code"] = QUrl::fromPercentEncoding(code);
         }
     });

     QOAuthHttpServerReplyHandler* replyHandler = new QOAuthHttpServerReplyHandler(port, this);
     this->google->setReplyHandler(replyHandler);

     connect(this->google, &QOAuth2AuthorizationCodeFlow::granted, [=](){
         const QString token = this->google->token();
         qDebug() << " token : " << token;
         emit authorizeGoogle(token);
     });
}


void GoogleOAuth::click()
{
    this->google->grant();
}

Thanks in advance!

Hrrrmph

I was having the same issue. The app won''t process the response until I manually activate it. Adding following line to AndroidManifest.xml fixes it.

<meta-data android:name="android.app.background_running" android:value="true"/>

However there is another problem on how to redirect user back to App and I have not solved it.
QOAuthUriSchemeReplyHandler with custom URI does not work as well. These methods are deprecated in favor of AppAuth. https://developers.google.com/identity/protocols/oauth2/native-app#redirect-uri_custom-scheme

Hrrrmph

Ok solved.
To enable AppLinks (in format https://your-website.com/yourcallback) besides setting up intent filters in AndroidManifest.xml you also need to configure them on google play console and deploy a json file to your website. https://developer.android.com/training/app-links#add-app-links