Flutter - Keycloak integration with openId ( redirecting issue )

Question

I want to authenticate flutter app with Keycloak service via internal webview (without open web browser)

To achieve this objective I used OpenID

When app runs will appear Keycloak login page in internal webview. But when entering the username and password correctly, it redirects to another web page which is as follows.

I guess this case happen due to flutter app cannot handle custom redirections. Does anyone know how to fix this??

My code:

urlLauncher(String url) async {
  if (await canLaunch(url)) {
    await launchUrlString(url, mode: LaunchMode.inAppWebView);
  } else {
    print("TOKEN = error");
    throw 'Could not launch $url';
  }
}

// create an authenticator
var authenticator = new Authenticator(
  client,
  redirectUri: Uri.parse(_redirectUrl),
  scopes: scopes,
  urlLancher: urlLauncher,
);

// starts the authentication
var c = await authenticator.authorize();
print("TOKEN = DONE");
// close the webview when finished
await closeInAppWebView();

var res = await c.getTokenResponse();
print("TOKEN = ${res.accessToken}");

pubspec.yaml:

openid_client: ^0.4.6
url_launcher: ^6.1.6

I tried open id , simple auth , flutter app auth also, unfortunately flutter app auth cannot use with internal webview

Answer 1

Future<TokenResponse> authenticate(Uri uri, String clientId,
      List<String> scopes, BuildContext context) async {
    try {
      var issuer = await Issuer.discover(uri);
      var client = Client(issuer, clientId);

      urlLauncher(String url) async {
        Uri uri = Uri.parse(url);
        if (await launchUrl(uri)) {
        } else {
          throw 'Could not launch $url';
        }
      }

      var authenticator = Authenticator(
        client,
        scopes: scopes,
        urlLancher: urlLauncher,
        port: 3000,
      );

      var c = await authenticator.authorize();

      await closeInAppWebView();
      var res = await c.getTokenResponse();
      UserInfo use = await c.getUserInfo();
      authUserId(use.subject.toString());
      email(use.email.toString());
      token(res.accessToken.toString());
      logoutUrl = c.generateLogoutUrl();
      return res;
    } finally {
      context.loaderOverlay.hide();
    }
  }

You can try this out.

Saved the logout URL into a variable cos it'll be needed to logout.