Documentation: middleware / csrfToken

Purpose: Provides CSRF protection by setting token cookie and exposing token to templates.
Lifecycle Role: Early middleware before state-changing routes requiring CSRF protection.
Dependencies:
Upstream: cookie-parser, csurf package
Downstream: POST or state-changing route handlers
Data Flow:
Inputs:
  • Request cookies and headers
Outputs:
  • CSRF token cookie
  • res.locals.csrfToken
Side Effects: Blocks requests missing valid CSRF tokens
Performance and Scalability:
Bottlenecks:
  • Cookie parsing failure disables protection
  • Incorrect token handling breaks forms
Concurrency: None
Security and Stability:
Validation: Tokens verified on requests
Vulnerabilities:
  • Requires secure cookie flags in production
  • Tokens must be unguessable
Architecture Assessment:
Coupling: Middleware integrating third-party packages
Abstraction: Standard CSRF protection abstraction
Recommendations:
  • Ensure HttpOnly, Secure flags on cookies in production
  • Handle token expiration gracefully