OAuth Best Practices

OAuth 2.1 introduces refinements to enhance the security and usability of OAuth flows, especially around refresh tokens. Understanding how refresh tokens work in OAuth 2.1, their lifecycle, and best practices is essential for developers and security architects aiming to build robust authentication systems. What Are Refresh Tokens? Refresh tokens are long-lived credentials issued by the authorization server alongside access tokens. Their purpose is to obtain new access tokens without requiring the user to re-authenticate, enabling seamless user sessions. ...

Proof Key for Code Exchange (PKCE) has become a critical enhancement to the OAuth 2.0 Authorization Code Flow, especially for public clients such as mobile and single-page applications. By adding a cryptographically secure verification step, PKCE significantly reduces risks like authorization code interception and replay attacks. What is PKCE and Why Was It Introduced? Originally designed for native and public clients unable to securely store a client secret, PKCE addresses a fundamental security gap in OAuth 2.0. It prevents attackers from stealing authorization codes and exchanging them for access tokens because the authorization code is bound to a one-time generated secret known only to the client. ...