spring-boot-security

name	spring-boot-security
description	Spring Security 6+ standards, Lambda DSL, and Hardening. Use when configuring Spring Security 6+, OAuth2, JWT, or security hardening in Spring Boot. (triggers: **/*SecurityConfig.java, **/*Filter.java, security-filter-chain, lambda-dsl, csrf, cors)

Spring Boot Security Standards

Priority: P0 (CRITICAL)

Implementation Guidelines

Configuration (Spring Security 6+)

• Lambda DSL: ALWAYS use Lambda DSL.
• SecurityFilterChain: Expose as @Bean. Do not extend WebSecurityConfigurerAdapter.
• Statelessness: Enforce SessionCreationPolicy.STATELESS for REST APIs.

Golden Snippet

See Security Configuration for full SecurityFilterChain example.

Authentication vs Authorization

• Authentication: Validation of credentials (Who are you?). Use AuthenticationManager or JwtDecoder.
• Authorization: Verification of access rights (Can you do this?). Use @PreAuthorize.

JWT Best Practices

• Algorithm: Enforce RS256 or HS256. Reject none algorithm.
• Claims: Validate iss, aud, and exp.
• Tokens: Short-lived access tokens (15m), secure refresh tokens (httpOnly cookie).

Hardening Checklist

• CSRF: Disabled for pure APIs? Enabled + Cookie for Browser Apps?
• CORS: Specific origins permitted? No * with credentials?
• Headers: HSTS, Content-Type-Options, X-Frame-Options enabled?
• Secrets: No hardcoded keys? Loaded from Vault/Env?
• Rate Limiting: Applied on login/expensive endpoints?
• Dependencies: Scanned for CVEs?

Anti-Patterns

• No Adapter: Use SecurityFilterChain bean instead of extending legacy classes.
• No .and(): Use Lambda DSL for configuration.
• No Secrets: Load from Vault or Environment variables (never git).
• No antMatchers: Use requestMatchers (Spring Security 6+).

References

• Implementation Examples
• common/security-standards
• architecture