Wednesday, September 20, 2017

Access User Profile API via Google OAuth 2.0 Playground ?

The OAuth Playground is an application/tool by Google for learning how OAuth works. It presents you with a three-step process for selecting the services you want to authorize, generating an access token, and making API requests.
In OAuth terminologies, Google OAuth playground will act as a client Application which does contain client id, Client secret and OAuth Endpoints required to access Service provider.
It also supports custom endpoints as well i.e. using Google OAuth playground you can connect to another service provider as well apart from Google like Salesforce.
Resource Owner: You
Client Application: Google OAuth 2.0 Playground

Service Provider: Google
In this blog, I’ll only focus on Google API and will try to retrieve user profile via playground.

Step 2: You will see a list of scope using which you can access particular resources. As our aim is to fetch user profile so will scroll down and select from Google People API v1 scope.

Step 3:  Click on Authorize APIs button and If you are not logged into google then it will ask for your user credentials and after successful authentication, it will show the authorization consent page. Click on Accept button.

Step 4: Now we have the Authorization Code but if you check Request/Response section then you will notice that playground application hits AUTHORIZATION ENDPOINTS

Authorization request:

We hit this request to the authorization endpoint to obtain an authorization code

response_type  ->  it always should be code, specifies that request is sent to the authorization endpoint to obtain an authorization code. ( Required)
client_id -> The Id issued to this application by Authorization server at the time of registration. (Required)
redirect_uri -> URI registered on the authorization server as a RedirectURI or callback URL. 
Scope -> Access scope of the request

and after successful authentication and authorization, Playground is getting the Authorization Code on its registered redirect URL.

Authorization response:

It contains the Auth code in exchange of which we will get the access token.



code -> Authorization code (Required)

Step 5: To get the access token, Click on Exchange authorization code for tokens button and you will get the access and refresh token.

Check Request/Response section, Playground hits TOKEN ENDPOINTS to get the access token.

Token request:

We hit token endpoint to obtain an access token by exchanging the Auth code.


client_id -> The Id issued to this application by Authorization server at the time of registration. (Required)
client_secret -> The key secret issued to this application by Authorization server at the time of registration. (Required)
Grant_type -> Must be set to authorization_code. (Required)
Code -> The Authorization code received by the Authorization server.

redirect_uri -> URI registered on the authorization server as a RedirectURI or callback URL. (Required)

Token Response:

The token response contains an access token along with other information in a JSON format.
  "access_token": "ya29.GlvMBFEQ8efg2id-lwfWJJIZl0_7rlCRyCKVWvv3v_cXIUlnYXVn6D04nUEIh9AFB65pdZcfms5TaDz692-2hmadFg0o6R1X7hdYUKuFwA9v2NvXqiLwOIFpUJlV",
  "token_type": "Bearer",
  "expires_in": 3600,
  "refresh_token": "1/KVEh2UxFjMt5zynnbm9qajpnkDsREQTA3kldrAvcqKQ",
  "id_token": "eyJhbGciOiJSUzI1NiIsImtpZCI6IjhiNmE3ZDhhM2I0NTQ4YWU1MjBmZDJkMTY2ZWEzN2U2ZGRjY2JkOWYifQ.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.sS2Du_uR0Y-Sr2BlxBkbYSbzNfXDLy_Baj1ZbX21x-tWUHTe5R9v9ZR8S7gwfmVjAPAjHm-ivQg4aOBzQs8U9YmCei2tg1vLFTg51KsTWXK6u4WEbgHQQaPOORAfeKrZtKaUjvQgTKy007Dqdv_nzT6dt9b-vezTDLHX-fV9lx-k_-ApD9BKdrBjsqx8tAJ1cC_vg4NY_M--6ztYSf8xKG_aAF296Mq_aUakVGSl2pA5n3k0SMXyJlkIaWCilz2jQjBt_Hi_zeKdezCIU4jHTr8lstyz_SV9V2nueWV7n82K2RzS3uo-PtMDUWceNRr0r6dhWh_JxXivCqH2twh9pw"

access_token -> token using which you can access the user details from resource server.
token_type -> define the nature of token
expire_in -> number of seconds after which the access token get expired.

refresh_token -> using refresh token, we can get new access token once the above access token is no longer valid.

Step 6: Select V2 UserInfo from list possible operations to get the user profile.

Step 7: Click on Send the request button and it will access the user profile by passing access token as authorization bearer in the headers and display it in JSON format.

Conclusion: Google playground is an amazing tool to learn OAuth flow with Google as well as with custom application. If you are planning to build your Authorization server then you can use it as a testing tool as Google playground is a standard OAuth Client web application.

If you need an idea on how can we get it done the same thing via JAVA web application then you must check my blog over here. I have done something similar where my Service provider is Salesforce instead of Google.

Friday, September 15, 2017

Registering an Application with Facebook

This guide walks you through the steps of registering an application to integrate with Facebook.
Register a new application

From, click on "My Apps" at the top of the page to go to the application dashboard. The dashboard shows a list of applications that the developer has already created or you can create a new one by clicking on Add a new App. 

A dialog prompts you to name your application.

Enter Display Name, Contact Email and Choose a category from drop down list and click on Create App ID. After you click, Facebook performs a Captcha check to verify that you’re not setting up applications through an automated process.

Once you’ve satisfied the verification process, your application is created. The next page you see is your application’s application page.

Click on the Settings button and it will open you a setting page of your application.

Now we can configure various details about our application. The choices you make here depend on what kind of application you plan to build and what you want your application to do. For IAM, we just need to add App Domains and Site URL. Click on + Add Platform and select Platform as Website and enter your Site URL. Site URL is shibboleth Idp URL and App Domains is the domain name of the URL.

and click on Save Changes. 

The main thing to note from the application settings page is the App ID and App Secret near the top. These values are your application’s credentials to Facebook. We need these credentials to connect to facebook via Shibboleth Idp.

and the last step, go to App Review → drag button to the left to make your application public. You will see message as "your app is currently live and available to the public"

Monday, September 4, 2017

JWT: Symmetric and Asymmetric key Implementation

Prerequisite: Understanding of JWT or read here to understand what is JSON Web token.

As we already know that JWT is special because it is digitally signed and we can verify the authenticity of JWT using signature.
Today, we will discuss on how we can actually sign this JWT using Symmetric and Asymmetric key.

Symmetric key: Symmetric key uses the same key for the signature generation as well as at the time of token verification. So, extra precaution is required during the exchange of the secret key between sender and receiver.Use symmetric key if there is one sender and one receiver, the exchanging of the key will be easy. 
Eg: One web application talking to the backend services.

Asymmetric key: It uses a key pair. The key pair consists of a public key and a private key. JSON data will be signed using the private key and can be verified using the public key.
Use Asymmetric key if you have one sender and multiple receivers as you cannot share the same key to all the end parties.
Eg: Centralized application.

There are various open source libraries using which we can create and verify the access token like Stormpath and Auth0 libraries.

Click here to download the source code from GITHUB.