Implementing OAuth2 UserInfo Endpoint with Spring Boot and Spring Security

Hello, Spring enthusiasts! 👋 Today, we’re going to explore how to implement an OAuth2 UserInfo Endpoint using Spring Boot and Spring Security. This endpoint is essential for providing user profile information to clients, enhancing the user experience by allowing applications to retrieve user details securely.

Understanding the OAuth2 UserInfo Endpoint

The OAuth2 UserInfo Endpoint is a standardized URL that returns user profile information in a JSON format. This endpoint is typically used in conjunction with OpenID Connect (OIDC) to provide authenticated user details, such as username, email, and other profile attributes. By implementing this endpoint, you enable clients to access user information securely and efficiently.

Steps to Implement the UserInfo Endpoint

Set Up the Spring Boot Project: Start by creating a new Spring Boot project with the necessary dependencies.
Configure Security: Set up Spring Security to handle OAuth2 authentication and authorization.
Create the UserInfo Endpoint: Implement the endpoint to serve user profile information.
Fetch User Details: Write the logic to retrieve user details from the authentication token.
Test the Endpoint: Ensure the endpoint works correctly by testing it with various clients.

Step 1: Set Up the Spring Boot Project

First, create a new Spring Boot project using Spring Initializr or your favorite IDE. Add the following dependencies:

Spring Web
Spring Security
Spring Security OAuth2 Resource Server
Spring Security OAuth2 Authorization Server

Step 2: Configure Security

In your application.yml or application.properties, configure the security settings:


spring:
  security:
    oauth2:
      resourceserver:
        jwt:
          issuer-uri: https://your-issuer-uri

Step 3: Create the UserInfo Endpoint

Create a new controller to handle the UserInfo endpoint requests:


import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.security.oauth2.jwt.Jwt;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Map;

@RestController
public class UserInfoController {

    @GetMapping("/userinfo")
    public Map getUserInfo(@AuthenticationPrincipal Jwt jwt) {
        // Implement logic to return user information
        return Map.of(
            "sub", jwt.getSubject(),
            "name", jwt.getClaimAsString("name"),
            "email", jwt.getClaimAsString("email")
        );
    }
}

Step 4: Fetch User Details

Implement the logic to retrieve user details from the authentication token:


import org.springframework.security.oauth2.jwt.Jwt;
import org.springframework.stereotype.Service;

import java.util.Map;

@Service
public class UserInfoService {

    public Map getUserInfo(Jwt jwt) {
        return Map.of(
            "sub", jwt.getSubject(),
            "name", jwt.getClaimAsString("name"),
            "email", jwt.getClaimAsString("email")
        );
    }
}

Step 5: Test the Endpoint

Use tools like Postman or curl to test the endpoint. Ensure that the UserInfo endpoint returns the correct user details and handles various scenarios, such as missing claims or invalid tokens.

Conclusion

Implementing an OAuth2 UserInfo Endpoint in Spring Boot with Spring Security enhances your application's user experience by providing a standardized way to retrieve user profile information. By following these steps, you can efficiently manage user details and ensure secure communication between clients and your server. Happy coding! 🚀

Hope this helps you in your Spring journey! Keep exploring and coding. 😊

OAuth2 UserInfo Endpoint with Spring Boot