WebAuthn

WebAuthn Overview

At its core, webauthn is about doing one thing well inside your authentication project. Once you understand the pattern, you can apply it consistently across features and teams.

Good webauthn pays off across the whole codebase: fewer surprises, easier testing, and smoother onboarding. The snippet below is a solid starting point.

import { generateAuthenticationOptions, verifyAuthenticationResponse }
  from '@simplewebauthn/server';

const options = await generateAuthenticationOptions({ rpID: 'example.com' });
// browser calls navigator.credentials.get(...)
const verification = await verifyAuthenticationResponse({
  response, expectedChallenge, expectedRPID: 'example.com', authenticator,
});

WebAuthn and passkeys replace passwords with device-bound public-key credentials.

WebAuthn Example

// verify the caller on every protected request
function authenticate(req, res, next) {
  const token = req.headers.authorization?.replace('Bearer ', '');
  req.user = verifyToken(token); // throws if invalid
  next();
}

• Start from a minimal WebAuthn example and grow it only as needed.
• Keep configuration explicit so WebAuthn behaves the same in every environment.
• Name things clearly so teammates understand your WebAuthn at a glance.
• Add tests around WebAuthn early to lock in expected behaviour.

Authentication Cheatsheet

Quick authentication reference related to webauthn.

How WebAuthn Works

WebAuthn is part of proving who a user is and what they are allowed to do. Authentication verifies identity, while authorization decides access — and webauthn plays a specific role in that flow.

WebAuthn and passkeys replace passwords with device-bound public-key credentials.

• Never store or log plain-text passwords or secrets.
• Prefer short-lived tokens with refresh over long-lived ones.
• Always send credentials over HTTPS.
• Fail closed: deny access when anything is uncertain.

Security Guidance for WebAuthn

Security is the whole point of webauthn. Small mistakes — weak hashing, tokens in localStorage, missing rate limits — are exactly what attackers look for, so follow proven defaults.

Common Mistakes

• Copying webauthn snippets without understanding what each line does.
• Skipping error handling and edge cases when wiring up webauthn.
• Leaving webauthn untested, so regressions slip into production.
• Over-engineering webauthn before you actually need the extra flexibility.

Key Takeaways

• WebAuthn is a core part of working effectively with authentication.
• Start small and keep webauthn focused on a single responsibility.
• Apply consistent patterns so webauthn scales across your project.
• Test and document webauthn to keep it maintainable over time.