Authentication vs. Authorization
Authentication (AuthN) verifies who a user is (e.g., logging in with email and password). Authorization (AuthZ) determines what permissions and resources the authenticated user is allowed to access (e.g., an admin user editing a post versus a student viewing an event).
JSON Web Tokens (JWT) Under the Hood
A JWT is a compact, URL-safe token consisting of three dot-separated Base64Url-encoded parts:
- Header: Specifies the signing algorithm (e.g., HMAC-SHA256 or RSA).
- Payload: Contains claims (user ID, expiration timestamp
exp, user roles). - Signature: Cryptographic hash generated using a secret key or private certificate, ensuring the payload has not been tampered with.
Best practice: Store short-lived access tokens in memory and long-lived refresh tokens in HttpOnly, Secure, SameSite=Strict cookies to prevent token theft via XSS attacks.
Demystifying CORS (Cross-Origin Resource Sharing)
CORS is a browser security mechanism that restricts web applications from making HTTP requests to a different domain than the one that served the web page. To allow authorized clients, backend APIs must return appropriate HTTP response headers:
Access-Control-Allow-Origin: https://mlscsvec.com
Access-Control-Allow-Methods: GET, POST, PUT, DELETE
Access-Control-Allow-Headers: Content-Type, AuthorizationConclusion
Securing authentication flows and configuring strict CORS policies prevents unauthorized data access and ensures trust and compliance across distributed client-server applications.