Spring Security 6, JWT Authentication & RBAC Authorization
Secure REST microservices using Spring Security 6 SecurityFilterChain, BCrypt password hashing, stateless JWT Token authentication, and Role-Based Access Control (RBAC).
Spring Security 6 Filter Chain Architecture
### Spring Security Filter Chain Pipeline
1. **SecurityFilterChain Bean**: Configures CORS, CSRF (disabled for stateless APIs), and authorization rules (`.requestMatchers("/api/admin/**").hasRole("ADMIN")`).
2. **JwtAuthenticationFilter**: Intercepts HTTP Authorization header (`Bearer <jwt>`), validates signature, and populates `SecurityContextHolder`.
