Update code style and fix bugs

Change Summary

This commit introduces several significant changes to improve the authentication module’s efficiency and security. Key modifications include the implementation of a new token-based authentication system, the refactoring of user session management, and the addition of rate limiting to mitigate potential brute-force attacks.

Technical Details

• auth/token.py:
  • Added a new module for handling JSON Web Tokens (JWT).
  • Implemented functions for token generation (generate_token), validation (validate_token), and expiration handling (is_token_expired).
• auth/session.py:
  • Refactored session management to use JWTs instead of traditional session cookies.
  • Introduced a SessionManager class with methods for creating (create_session) and destroying (destroy_session) sessions.
• config/settings.py:
  • Updated configuration to include JWT secret key and expiration time.
• middleware/rate_limiter.py:
  • Added a rate limiter middleware to restrict the number of login attempts per IP address within a specified time frame.

Key Learnings & Insights

• Security Enhancements:
  • The shift to JWTs provides a stateless authentication mechanism, enhancing security by reducing the risk of session hijacking.
  • Rate limiting effectively protects against brute-force attacks by limiting login attempts.
• Design Patterns:
  • The use of a SessionManager class exemplifies the Singleton design pattern, ensuring a single point of control for session-related operations.
• Best Practices:
  • Storing sensitive information like JWT secret keys in environment variables rather than hardcoding them in the source code.

Impact Assessment

• Performance:
  • The stateless nature of JWTs reduces server load by eliminating the need to store session data server-side.
• Security:
  • Enhanced security through token-based authentication and rate limiting.
• Maintainability:
  • Improved code organization and readability with the introduction of dedicated modules for token and session management.

Developer Notes

• Gotchas:
  • Ensure that the JWT secret key is securely managed and not exposed in version control.
• Edge Cases:
  • Handle scenarios where tokens might be revoked or users might log out from multiple devices simultaneously.
• Future Improvements:
  • Consider implementing token refresh mechanisms to improve user experience without compromising security.