OAuth 2.0 - Architecture

In this chapter, we will discuss the architectural style of OAuth 2.0.

Step 1 − First, the user accesses resources using the client application such as Google, Facebook, Twitter, etc.

Step 2 − Next, the client application will be provided with the client id and client password during registering the redirect URI (Uniform Resource Identifier).

Step 3 − The user logs in using the authenticating application. The client ID and client password is unique to the client application on the authorization server.

Step 4 − The authenticating server redirects the user to a redirect Uniform Resource Identifier (URI) using authorization code.

Step 5 − The user accesses the page located at redirect URI in the client application.

Step 6 − The client application will be provided with the authentication code, client id and client password, and send them to the authorization server.

Step 7 − The authenticating application returns an access token to the client application.

Step 8 − Once the client application gets an access token, the user starts accessing the resources of the resource owner using the client application.

OAuth 2.0 has various concepts, which are briefly explained in the following table.