spaWithCsp proxies GET and HEAD only (405 otherwise, no body buffering) and forwards only accept,
if-none-match, if-modified-since and range. The internal server listens on a Unix socket in a private
0700 temp dir. Bun 1.3.14 ignores proxy: false for this hop, and over a socket with a proxy set it sends
an absolute-form target that breaks asset routing, so localhost, 127.0.0.1 and ::1 are appended to
NO_PROXY/no_proxy (existing entries kept). accept-encoding is no longer forced; fetch decompresses and
the encoding headers are dropped.
Test: in a subprocess with HTTP(S)_PROXY and ALL_PROXY set to a dead proxy, the SPA and an asset load
with the CSP, POST gets 405, and the upstream sees no Cookie, Authorization or X-Forwarded-For.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
C1: lesson HTML goes through a sanitize-html allowlist on the fully rendered output (no on* attributes, no
style, no svg/math/iframe/object/embed/form; URLs limited to http(s), mailto, relative and anchors). Raw tags
outside the allowlist are escaped as text. The SPA document is served with a CSP (script-src 'self', no inline
script) through spaWithCsp in main.ts; contract request §5 asks core to own it.
C2: exercises run in <iframe sandbox="allow-scripts"> (opaque origin, no cookies) loaded from
/api/learner/runner-frame, whose CSP allows only its own script (by hash) and blob: workers, and connect-src
'none'. postMessage only, both sides check event.source; the timeout removes the frame. The worker stubs now
also cover Worker, SharedWorker and caches.
I1: learner visibility calls core canView with per-course authorship only, like /api/media (contract request §6).
I2: Tab and Shift+Tab move focus; Enter keeps the previous line's indentation.
Tests: XSS unit cases, headless-Chrome checks for the exploit lesson and for fetch, import, Cache.add, nested
Worker, img, EventSource, WebSocket, XHR and sendBeacon from learner and test code (plus a negative control),
visibility on both dialects, SPA and runner-frame CSP headers.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
