JWT Authentication With Spring Boot’s Inbuilt OAuth2 Resource Server

Using Spring Boot’s inbuilt OAuth2 Resource Server with security best practices for JWT based authentication

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TL;DR

This article proposes a better approach to achieve JWT authentication for your SPA web application backend REST APIs using Spring Boot’s inbuilt OAuth2 Resource Server. In summary, the proposed approach is:

• More Secure — Use an RSA private key instead of a single secret token (symmetric key) to sign JWTs and RSA public key for signature verification.
• Convenient — An endpoint (“/login”) to obtain a signed JWT in exchange for valid user credentials.
• Authorization — Spring Security’s method security can be used since the JWT information is available as Authentication at controller level; Can use “@PreAuthorize”, “@PostAuthorize” annotations with SPEL for complex authorization needs.
• Extendable — Can be extended to support federated authentication (ex: “Login with Google”, etc.) and to support refresh_tokens and client side JWT validation using “/jwt” endpoint.
• Best Practices — Use Spring Boot’s inbuilt OAuth2 Resource Server for inbound request authentication with JWT.