OIDC is pansy's primary login path (Authentik the target IdP); local
auth (#4) remains the fallback and both issue the same session cookie.
- deps: github.com/coreos/go-oidc/v3 + golang.org/x/oauth2 (both pure Go;
CGO stays off).
- api/oidc.go: lazy issuer discovery (retried per-request, never crashes
a server that also serves local auth), GET /auth/oidc/login builds an
authorization-code URL with PKCE S256 + random state + nonce stashed in
a short-lived HttpOnly cookie, GET /auth/oidc/callback verifies state
(constant-time), exchanges the code with the PKCE verifier, verifies the
ID token + nonce, and starts a pansy session. Failures redirect to
/login?error=... ; success to /gardens.
- service.LoginOIDC: (issuer,subject) match -> login; else *verified*
email match -> link onto the existing account; else JIT-create (the IdP
gates access, so PANSY_REGISTRATION doesn't apply). Unverified email
colliding with an existing account is refused (takeover guard); no email
is refused (email is the account key). Reuses the atomic CreateUser.
- store: GetUserByOIDC + LinkOIDC (unique-pair backstop).
- config: OIDCReady() (needs issuer+client+BaseURL for the redirect URI);
/auth/providers now reports oidc from it and defaults the button label
to "Sign in with Authentik". OIDC routes are only registered when ready,
so an unconfigured instance 404s them.
- PANSY_LOCAL_AUTH=false rejects/hides local auth but not OIDC.
Tests: service provisioning (JIT, repeat login, link, unverified-collision
refusal, no-email, name fallback, works with local auth off); api
(routes-absent-when-unconfigured, providers reporting, login redirect with
PKCE params + tx cookie via a fake discovery server, callback state/error
paths). Smoke-tested: unreachable issuer degrades to error=oidc_unavailable
with the server still up and local auth working.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01JdQpdYYsTgtkJBxbcpAszi
