In this article, we dive into the practical implementation of OAuth 2.0 and OpenID Connect in a Spring Boot application. By the end of this guide, you’ll have a working example of an Authorization Server, Resource Server, and Client Application. Let’s get started!

Understanding the Flow

Before jumping into the code, here’s a quick summary of the components we’ll implement:

1. Authorization Server: Issues access tokens and handles authentication.
2. Resource Server: Protects the APIs and verifies access tokens.
3. Client Application: Interacts with the Authorization Server to obtain tokens and calls secured APIs on the Resource Server.

Step 1: Set Up the Authorization Server

Dependencies

Add the following dependencies to your pom.xml:

Configuration

Create a configuration class to set up the Authorization Server:

Step 2: Build the Resource Server

Dependencies

Add the following dependencies:

Configuration

API Implementation

Step 3: Set Up the Client Application

Dependencies

Configuration

Application yml

server:
  port: 8080

spring:
application:
name: oAuthIntegration
security:
oauth2:
client:
registration:
google:
client-id: YOUR_GOOGLE_CLIENT_ID
client-secret: YOUR_GOOGLE_CLIENT_SECRET
redirect-uri: “http://localhost:8080/login/oauth2/code/google”
# linkedin:
# client-id: YOUR_LINKEDIN_CLIENT_ID
# client-secret: YOUR_LINKEDIN_CLIENT_SECRET
# redirect-uri: “http://localhost:8080/login/oauth2/code/linkedin”
# github:
# client-id: YOUR_GITHUB_CLIENT_ID
# client-secret: YOUR_GITHUB_CLIENT_SECRET
# redirect-uri: “http://localhost:8080/login/oauth2/code/github”

Adding Social Login and Customization

If there is someother oAuth 2.0 provider like Github, Linkedin, Google, then you need to do configuration to get the clientID and secret-key, here providing example for google.

Configuring Google Login

After setting up your project:

1. Create a Google Cloud project at Google Cloud Console and generate credentials.

1. Configure the OAuth Consent Screen, choosing “External” for broader user access.

1. Define authorized redirect URIs in the format: http://localhost:8080/login/oauth2/code/google.
2. Retrieve the Client ID and Client Secret, and add them to your application.yml.

Github Repository

Conclusion

This code-centric guide demonstrates how to set up OAuth 2.0 with OpenID Connect in Spring Boot applications. With this foundation, you can expand and secure your applications for production environments. Happy coding!