## Summary
Closes the wide-open `/ws` WebSocket upgrader (`CheckOrigin: return
true`) that lets any browser origin scrape live packet data. Replaces it
with an explicit allowlist consulted from `cfg.CORSAllowedOrigins`, plus
an implicit same-origin allowance and an empty-Origin (non-browser
client) allowance.
Fixes#1793.
## Rules (`Hub.checkOrigin`)
- Empty `Origin` header → **allow** (non-browser clients; per-IP
rate/deny gating tracked separately in #1794).
- `Origin` host == request `Host` (case-insensitive) → **allow**
(same-origin).
- `Origin` matches an entry in `cfg.CORSAllowedOrigins` by exact
case-insensitive match → **allow**.
- `"*"` in `cfg.CORSAllowedOrigins` is **deliberately ignored** for
`/ws`. A startup `[ws] WARNING:` is logged once when present.
- Anything else → **reject** (gorilla returns 403).
### Deliberate divergence from CORS XHR
CORS XHR (`corsMiddleware`) still honors `"*"` for read-only
cross-origin GETs. The `/ws` upgrade does NOT, per OWASP's WebSocket
Security Cheat Sheet:
> Use an allowlist, not a denylist. Avoid wildcards or substring
matching.
—
https://cheatsheetseries.owasp.org/cheatsheets/WebSocket_Security_Cheat_Sheet.html
`"*"` on the WS path would re-open the exact CSWSH/scraping vector this
PR closes, so it is rejected with a startup warning rather than silently
honored. This intentional asymmetry is documented in the updated
`_comment_corsAllowedOrigins` in `config.example.json`.
## TDD red → green
- `e5974c6a` **RED** — adds `cmd/server/websocket_checkorigin_test.go`
with five cases; `SetAllowedOrigins` introduced as an enforcement stub
so the test compiles and fails on the assertion (CI fails on this commit
by design).
- `a4791dc3` **GREEN** — implements `Hub.checkOrigin`, wires
`SetAllowedOrigins` from `main.go`, updates the config example. All
tests pass.
## Tests added (`cmd/server/websocket_checkorigin_test.go`)
- `TestCheckOriginRejectsForeignOrigin` — foreign Origin → 403
- `TestCheckOriginAllowsEmptyOrigin` — non-browser client → 101
- `TestCheckOriginAllowsSameHost` — same-origin → 101
- `TestCheckOriginAllowsAllowlistedOrigin` — exact allowlist match → 101
- `TestCheckOriginWildcardDoesNotAllowForeignOrigin` — `"*"` in
allowlist still rejects foreign origin → 403
## Files changed
- `cmd/server/websocket.go` — `Hub.allowedOrigins`, `SetAllowedOrigins`,
`checkOrigin`, wired into `Upgrader.CheckOrigin`.
- `cmd/server/main.go` — `hub.SetAllowedOrigins(cfg.CORSAllowedOrigins)`
at the single call site.
- `cmd/server/websocket_checkorigin_test.go` — new test file.
- `config.example.json` — updated `_comment_corsAllowedOrigins` to
document `/ws` gating and the `"*"` divergence.
## Out of scope (follow-up)
- **#1794** — per-IP rate limit / deny list / connection cap for
non-browser clients (which still bypass Origin because they don't send
one). Layered defense; not in this PR.
## Verification
- `go test ./cmd/server/...` — all server tests pass locally (574s).
- Preflight clean (`bash
~/.openclaw/skills/pr-preflight/scripts/run-all.sh origin/master`).
---------
Co-authored-by: openclaw-bot <bot@openclaw.local>
Kpa-clawbot