APPLICATION-SECURITY Contents

OIDC Internals (Discovery, JWKS, Claims)

OIDC runbook: issuer discovery, JWKS rotation, claims mapping, and safe audience/nonce handling for production apps.

On this page

What OIDC Adds

  • An identity layer on top of OAuth2.
  • Standardized id_token with claims about the user.
  • Discovery metadata + JWKS for key distribution.

Hard Requirements

  • Verify issuer (iss) exactly.
  • Verify audience (aud) per client/app.
  • Verify token expiry and clock skew policy.
  • Use nonce in browser-based flows where applicable.

JWKS Rotation (Ops)

Best practice:
- cache JWKS with TTL
- refresh on unknown kid
- keep previous keys available during rotation
- alert on sudden verify failures

Claims Mapping

  • Map stable subject (sub) to your internal user id.
  • Avoid using mutable fields (email) as primary identity key.
  • Handle email change and verification status explicitly.

Failure Modes

  • Issuer drift: accepting multiple issuers accidentally.
  • Key confusion: wrong JWKS for issuer/client.
  • Audience mismatch: token usable across services if not checked.