1. Overview

In this tutorial, we’ll discuss how to implement SSO – Single Sign On – using Spring Security OAuth and Spring Boot.

We’ll use three separate applications:

• An Authorization Server – which is the central authentication mechanism
• Two Client Applications: the applications using SSO

Very simply put, when a user tries to access a secured page in the client app, they’ll be redirected to authenticate first, via the Authentication Server.

And we’re going to use the _Authorization Code _grant type out of OAuth2 to drive the delegation of authentication.

Note: this article is using the Spring OAuth legacy project. For the version of this article using the new Spring Security 5 stack, have a look at our article Simple Single Sign-On with Spring Security OAuth2.

2. The Client App

Let’s start with our Client Application; we’ll, of course, use Spring Boot to minimize the configuration:

#spring security #spring