fix(connection): hold markerless requests to the Host fence — plain-HTTP browser reads carry no markers

Fetch-Metadata and Origin are only attached to trustworthy destinations, so
over plain HTTP a rebound page's same-origin GET (EventSource, images,
navigations) arrives with no browser markers and a readable response. Remove
the marker shortcut; non-browser clients pass the same fence via loopback,
the CLI-derived LAN IP literals, or a declared authority.
This commit is contained in:
creatixchu
2026-07-28 17:02:39 +08:00
parent 7ff8da56df
commit 772653464d
11 changed files with 45 additions and 41 deletions

View File

@@ -6,7 +6,7 @@ Wire consumer layer: the client plugin's apply mounts `ctx.connection` (shared a
## /api browser-trust fence
The node half guards every request under `/api` before bridging (`src/api-request-trust.ts`). Requests without browser markers (no `Origin`, no `sec-fetch-site` — curl, tests, native clients) pass on any Host: without a browser there is no confused deputy, and such a sender forges every header anyway. For browser requests, the `Host` header must be a loopback authority or match a `trustedHosts` entry — exact on `host:port` entries, any port on port-less entries, both sides compared through WHATWG normalization (DNS-rebinding defense); an attached `Origin` must equal that authority, and an explicit `sec-fetch-site: cross-site` marker is refused. A `trustedHosts` entry that is not a bare, canonical `host[:port]` authority — one WHATWG parsing reads back exactly as written — fails the plugin load loudly: parsing would otherwise quietly authorize the hostname inside `harness.internal/path`, or broaden a dangling-colon or zero-padded port to an any-port grant. Failures answer plain 403 before any RPC dispatch. A non-loopback (`--host 0.0.0.0`) deployment therefore needs its serving authorities trusted: the dsh CLI derives the machine's LAN IP literals itself and its `--trusted-host` flag declares named ones, so `trustedHosts` in cordis.yml is for compositions the CLI does not boot. The fence is deliberately not an authentication layer — reachability policy stays with the webserver binding, and auth remains deferred work. Decision record: [the api browser-trust boundary Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-api-browser-trust-boundary.md).
The node half guards every request under `/api` before bridging (`src/api-request-trust.ts`). Every request — browser-marked or not — must present a `Host` that is a loopback authority or matches a `trustedHosts` entry: exact on `host:port` entries, any port on port-less entries, both sides compared through WHATWG normalization (DNS-rebinding defense). There is deliberately no shortcut for requests without browser markers: over plain HTTP a browser attaches neither `Origin` nor Fetch-Metadata to reads (EventSource, images, navigations — those headers go only to trustworthy destinations), so an unmarked request may still be a rebound browser read with a readable response, and Host is the one header rebinding cannot forge; non-browser clients pass the same fence via loopback, the CLI-derived LAN IP literals, or a declared authority. When markers are present, an attached `Origin` must equal the Host authority, and an explicit `sec-fetch-site: cross-site` marker is refused. A `trustedHosts` entry that is not a bare, canonical `host[:port]` authority — one WHATWG parsing reads back exactly as written — fails the plugin load loudly: parsing would otherwise quietly authorize the hostname inside `harness.internal/path`, or broaden a dangling-colon or zero-padded port to an any-port grant. Failures answer plain 403 before any RPC dispatch. A non-loopback (`--host 0.0.0.0`) deployment therefore needs its serving authorities trusted: the dsh CLI derives the machine's LAN IP literals itself and its `--trusted-host` flag declares named ones, so `trustedHosts` in cordis.yml is for compositions the CLI does not boot. The fence is deliberately not an authentication layer — reachability policy stays with the webserver binding, and auth remains deferred work. Decision record: [the api browser-trust boundary Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-api-browser-trust-boundary.md).
## Keyless fixture