Oauth 2.0 authorization for LinkedIn in Android

Question

Even though there is no such android specific sdk from linkedIn(like facebook and twitter sdk for android).Setting up linkedIn authorization with Oauth 1.0 was still easy us

Answer 1

I got it working, but it took me... some time.

I followed LinkedIn Authentication to manage that.
I still strongly advice to still read this link, as I do not cover all the cases in my examples (errors, error handling, best pratices, parameters usage, precise documentation...)

• First, you need to have your LinkedIn API Key and Secret Key. If you don't, register an app on here.

• Second, you need an Activity in the application that can receive the authorization code. For that, it needs to be set as browsable (launchable from a browser) in the AndroidManifest.xml file :

  Although not recommended, it's possible to use a data tag to retrieve URIs using a custom scheme :

• After that, you need to redirect the user to the LinkedIn's authorization dialog, using a specific URL :

  https://www.linkedin.com/uas/oauth2/authorization?response_type=code
                                     &client_id=YOUR_API_KEY
                                     &scope=SCOPE 
                                     &state=STATE
                                     &redirect_uri=YOUR_REDIRECT_URI
  

  You can use a WebView to directly show it in your application, or let the system handle it through an Intent like :

  Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(/* FULL URL */));
  startActivity(intent);
  

  The only problem here is that the API does not accept schemes other than http or https, meaning you can't just pass the intent URI as the redirect_uri parameter.

  So I created a landing page on my server, with only purpose is to redirect to the application. We can imagine something like (in ugly shorten PHP) (Intent ref.) :

  header('Location: ' . "intent:#Intent;component=your.package/.ResultActivity;S.code=" . $_GET['code'] . ";S.state=" . $_GET['state'] . ";end");
  die();
  

  So everything's set! Now the onCreate(Bundle) of the ResultActivity :

  Intent intent = getIntent();
  String authorizationCode = intent.getStringExtra("code");
  

  There is another way to pass parameters here, if the data tag was used earlier.

• Almost there! Now you just need to perform a simple POST request on that URL :

  https://www.linkedin.com/uas/oauth2/accessToken?grant_type=authorization_code
                                      &code=AUTHORIZATION_CODE
                                      &redirect_uri=YOUR_REDIRECT_URI
                                      &client_id=YOUR_API_KEY
                                      &client_secret=YOUR_SECRET_KEY
  

  Returning a JSON object on success :

  {"expires_in":5184000,"access_token":"AQXdSP_W41_UPs5ioT_t8HESyODB4FqbkJ8LrV_5mff4gPODzOYR"}

Et voilà ! You can now make your API calls using the access_token. Don't forget to store it somewhere so you don't have through these steps again.

I hope this wasn't too long to read and that it can help some people. :)