The Spring Boot Security OAuth2 Stack provides a convenient way to add OAuth2 protection to your Spring Boot applications. In this article, we'll explore the use of Spring Boot and OAuth2 to secure a simple REST API. We'll also add a layer of security to our REST API with Spring Security and JWT.
OAuth2 is an authorization framework that enables applications to obtain limited access to user accounts on an HTTP service. It works by delegating user authentication to the service that hosts the user account and authorizing third-party applications to access the user account. OAuth2 provides a single authorization endpoint and a single token endpoint.
Spring Boot is a Java-based framework used to create stand-alone, production-grade Spring-based applications. It is a convention-over-configuration framework that provides a wide range of non-functional features, such as embedded servers, security, metrics, health checks, and so on.
Spring Security is a framework that provides authentication, authorization, and protection against common attacks. It offers a wide range of authentication mechanisms, such as form-based authentication, HTTP Basic authentication, and so on.
JWT (JSON Web Token) is a compact, URL-safe means of representing claims to be transferred between two parties. The claims in a JWT are encoded as a JSON object that is used as the payload of a JSON Web Signature (JWS) structure or as the plain text of a JSON Web Encryption (JWE) structure, enabling the claims to be digitally signed or integrity protected with a Message Authentication Code (MAC) and/or encrypted.
We'll start by setting up a simple Spring Boot project with the following dependencies:
The project can be created using Spring Initializr with the aforementioned dependencies.
We'll configure our application to use OAuth2 for authentication. OAuth2 is an authorization framework that enables applications to obtain limited access to user accounts on an HTTP service.
We'll need to create an OAuth2ClientProperties bean and configure it with the properties of our OAuth2 client. We'll also need to create a ResourceServerProperties bean and configure it with the properties of our Resource Server.
We'll configure Spring Security to secure our REST API. We'll need to create a WebSecurityConfigurerAdapter and override the configure(HttpSecurity) method. In this method, we'll configure the security rules for our application.
We'll also need to create a JwtAuthenticationFilter and configure it to perform JWT authentication.
We can test our application by sending a POST request to the /login endpoint with a valid username and password. If the authentication is successful, we should receive a JSON response with a JWT token.
We can use this token to access the protected resources of our application by sending a GET request to the /userinfo endpoint with the token in the Authorization header.
In this article, we've seen how to use Spring Boot and OAuth2 to secure a simple REST API. We've also seen how to use Spring Security and JWT to add a layer of security to our REST API.