Understanding the Authorization Code Flow with PKCE in OAuth 2.0
OAuth 2.0 is a widely used authorization framework that allows applications to obtain limited access to user resources without handling user credentials directly. The Authorization Code Flow with PKCE (Proof Key for Code Exchange) is a security-enhanced version of the Authorization Code Flow, specifically designed to address vulnerabilities in public clients like mobile apps and single-page applications (SPAs) that cannot safely store a client secret. Why PKCE Is Needed Traditional Authorization Code Flow relies on a client_secret to authenticate the client when exchanging an authorization code for a token. In public clients (like browser apps or mobile apps), this secret cannot be safely stored. Without proper safeguards, attackers could intercept the authorization code during redirection and exchange it for tokens. ...