Building Secure Web Apps: OAuth, JWT, and Beyond

Secure web apps hinge on clear identity and careful token use. OAuth 2.0 lets apps access user data without passwords, while OpenID Connect adds login. JWTs carry information in a compact token, but they must be validated and kept short-lived.

In practice, combine OAuth with OpenID Connect for sign-in and use PKCE for public clients like mobile apps or browser SPAs. Treat access tokens as keys to APIs. Protect them in transit with TLS and store them securely; httpOnly cookies are a safe default for web apps. Request only the permissions you need with scopes.

Practical guidance:

  • Choose providers that support OpenID Connect and PKCE.
  • Validate every token: signature, issuer (iss), audience (aud), and expiry (exp).
  • Use HTTPS, same-site cookies, and anti-CSRF protections for web apps.
  • Rotate keys regularly and plan token revocation where possible.
  • Log sign-ins and monitor for unusual activity.

Notes on token types: JWTs are fast and self-contained, but they expose data and are hard to revoke. If you need better revocation signals, consider opaque or reference tokens and enforce checks at the server.

Why PKCE matters: Public clients cannot safely keep a secret. PKCE adds a code challenge to the authorization flow, making code interception harder. For server-side apps, confidential clients can store secrets, but PKCE remains useful for extra protection.

Storage and server-side considerations: Server-side apps should store tokens on the server, not in user devices, and use user sessions tied to tokens. Use secure cookies with HttpOnly and SameSite, and set reasonable session timeouts.

A quick example workflow:

  • User signs in and is redirected to the auth server.
  • After login, the app receives an access token and a refresh token.
  • The app calls APIs with the access token and refreshes before expiry.

Conclusion: Starting with OAuth and OpenID Connect, design for short token lifetimes, careful storage, and clear revocation plans. This keeps security solid across devices and networks.

Key Takeaways

  • OpenID Connect adds user login to OAuth.
  • Short-lived tokens plus secure storage reduce risk.
  • Validate tokens and monitor sign-ins for safety.