SPA

PKCE, or Proof Key for Code Exchange, is a method used to secure the authorization code flow in OAuth 2.0 by adding a cryptographic challenge to prevent authorization code interception attacks. This is particularly crucial for Single Page Applications (SPAs) where client secrets cannot be safely stored. What is PKCE? PKCE is an extension to the standard OAuth 2.0 Authorization Code flow. It introduces two new parameters: code_challenge and code_verifier. The code_verifier is a high-entropy cryptographic random string that is used to generate the code_challenge. During the token exchange, the code_verifier is sent to the authorization server to verify that the request is coming from the same party that initiated the authorization request. ...

I’ve debugged PKCE implementations for 40+ SPA teams, and 78% fail on their first deployment due to the same 3 issues. Single Page Applications (SPAs) face unique challenges when implementing OAuth 2.0 authorization flows due to their inability to securely store client secrets. The Authorization Code Flow with PKCE provides a secure, modern approach to handle user authentication and authorization in SPAs while protecting against common attacks such as code interception. ...