13 OAuth 2 – Implementing the authorization server

In this chapter, we discuss implementing an authorization server with Spring Security. As you learned in chapter 12, the Authorization Server is one of the components acting in the OAuth 2 architecture (figure 13.1). The role of the Authorization Server is to authenticate the user and provide a token to the client. The client uses this token to access resources exposed by the resource server on behalf of the user.

Also, in chapter 12, you learned that the OAuth 2 framework defines multiple flows for obtaining the token. We call these flows “grants.” You’ll choose one of the different flows according to your scenario.  The behavior of the Authorization Server is different depending on the chosen grant. In this chapter, you’ll learn how to configure an authorization server with Spring Security for the most common OAuth 2 grant types:

13.1  Writing your own authorization server implementation

13.2  Defining user management

13.3  Registering clients with the Authorization Server

13.4  Using the password grant

13.5  Using the authorization code grant

13.6  Using the client credentials grant

13.7  Using the refresh token grant

13.8  Summary