Secure-Authentication

HTTP-Only cookies are a crucial component of secure web authentication. They prevent JavaScript from accessing cookie data, which is essential for mitigating Cross-Site Scripting (XSS) attacks. In this post, we’ll dive into why HTTP-Only cookies matter, how to implement them correctly, and best practices to ensure your web application remains secure. The Problem Imagine this scenario: You’ve built a robust authentication system using session cookies. Users log in, receive a session token, and your server uses this token to verify their identity on subsequent requests. Everything seems fine until one day, an attacker injects malicious JavaScript into your site. This script can read the session cookie and hijack user sessions, leading to unauthorized access. ...

Visual Overview: sequenceDiagram participant User participant App as Client App participant AuthServer as Authorization Server participant Resource as Resource Server User->>App: 1. Click Login App->>AuthServer: 2. Authorization Request AuthServer->>User: 3. Login Page User->>AuthServer: 4. Authenticate AuthServer->>App: 5. Authorization Code App->>AuthServer: 6. Exchange Code for Token AuthServer->>App: 7. Access Token + Refresh Token App->>Resource: 8. API Request with Token Resource->>App: 9. Protected Resource Proof Key for Code Exchange (PKCE) has become a standard security enhancement to the OAuth 2.0 Authorization Code Flow—especially in public clients like mobile and single-page applications. But PKCE isn’t just for frontend apps. When combined with a stateless backend built with Kotlin and Spring Boot, it strengthens your security posture, particularly when you’re avoiding client secrets. ...