Non-HttpOnly rn_csrf_s/rn_csrf_i cookies, set on login, echoed back as X-CSRF-Token on every
state-changing request — defense in depth on top of (not instead of) SameSite=Lax. In-memory
sliding-window rate limiting on instructor login (8 attempts / 5 min per ip:email, no new
dependency).
Real bug found while wiring this up: the Gateway's own progress-relay call (triggered when a
student solves a scenario) is a server-to-server POST to /api/progress/record relaying the
browser's session — it needs to forward the CSRF token too, and needs to forward BOTH the
rn_csrf_s cookie and a matching X-CSRF-Token header (forwarding only the header still 403'd,
since the double-submit check needs both on the request Platform API actually receives).
Also tightens the Gateway's session-resolution cache from 5000ms to 2000ms, so a
revoked/expired session stops working at the Gateway within a tighter, tested bound.
Frontend (admin + student API clients) now reads the relevant rn_csrf_* cookie via
document.cookie and attaches it on every POST/PATCH/DELETE.
Replaces the Phase 2A pilot ?sid= query param with an HttpOnly,
SameSite=Lax session cookie. Gateway now derives student identity from
the session (via Platform API's /api/session/whoami) instead of trusting
a client-suppliable id, and checks ownership on every proxied HTTP and
WebSocket Lab request, not just the initial navigation.
Fixes a routing bug found during testing: the fallback route was using
'does this session own a running environment' to decide whether an
unprefixed /api/* call belonged to the Lab UI or the dashboard — true in
both places. Replaced with an explicit LAB_OWNED_PATHS allowlist of the
exact unprefixed paths the existing Lab UI actually calls.
e2e-phase2a.js rewritten to use a cookie jar instead of headers/query
params, with explicit impersonation-rejection tests added. 10/10 passing.
New internal component (platform/gateway/) — the only student-facing path to
disposable Lab environments. Browsers never reach a Lab container, the
Provisioner, or Postgres directly.
Routes:
- /api/environment/{status,launch,reset} — student-facing glue (X-Student-Id),
calls the Provisioner internally (shared secret never reaches the browser).
Reuses an existing non-terminal environment on launch rather than always
provisioning a new one; reset destroys+recreates the same environment row.
- /lab/<token>/* — HTTP+WS proxy into that one student's Lab container,
resolved by opaque routing token via a new Provisioner endpoint
(GET /environments/by-token/:token). No raw container IP/port ever reaches
the browser. Rejects invalid tokens (404), unready environments (202/503),
and cross-student access via an optional ?sid= ownership check (403) — see
docs/PHASE2A_GATEWAY_AND_STUDENT_FLOW.md "Security" for why token-alone,
student-id-alone, and env-id-alone are each individually insufficient and
this is explicitly pilot-grade, not production auth.
- everything else — proxied to the persistent identity/curriculum backend
(roster, login, curriculum, progress, platform-shell frontend), or to the
student's own Lab if a valid lab-session cookie is present.
Routing design note: the existing Lab UI makes root-relative calls
(fetch('/api/scenarios'), the /shell-ws WebSocket) with no idea it might be
served under a /lab/<token>/ prefix — preserving that UI unmodified was a
hard requirement. Solved with an HttpOnly, SameSite=Lax cookie set on the
first /lab/<token>/ response: every later request from that browser carries
it, so the unmodified Lab UI's own unprefixed calls resolve correctly once a
student has navigated into a lab session, with zero changes to its code.
/api/environment/* is explicitly exempted from cookie-based routing so it
never gets hijacked by an active lab session.
Also added platform/docker-compose.dev.yml (the full local stack: Postgres +
egress-proxy + Provisioner + a persistent "identity" instance + Gateway) and
platform/README.md tying the components together. The "identity" instance
required an explicit `network_mode: bridge` — under Compose's own
auto-created bridge network, k3s failed at startup with "no default routes
found in /proc/net/route"; documented as a known limitation, not fully
root-caused.
Found and fixed during testing: express.json() applied globally broke
http-proxy's re-streaming of proxied POST bodies (e.g. POST /api/roster hung
forever, since the body had already been consumed by the parser before
proxy.web() tried to forward it). Removed — none of the Gateway's own routes
actually need a parsed body.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
ced4568
