Addresses PR #793 re-review #3 (F1/F3 already confirmed closed). Both fixes TDD
red-first on this branch (7 tests red against the prior head, then green).
F2a (BLOCKER) — verifyListenerIdentity no longer accepts a listener by BASENAME.
The old code ran `if (basename(exePath) === CLAUDEX_PROXY_BINARY) return 'ok'`
unconditionally, so a same-uid process running `/tmp/claude-code-proxy` (right
name, wrong path) was trusted. On a shared-uid host that is the squatter vector,
not hypothetical — uid is NOT a trust boundary there, the executable path is.
Now: when the expected proxy path resolves we require an EXACT canonical-path
match (both sides canonicalized via realpath for symlinks); there is NO basename
fallback. If the expected path can't be resolved, or either path can't be
canonicalized, we fail closed (`unknown`). New tests: wrong-path/right-basename →
wrong-exe; unresolved expected → unknown; uncanonicalizable → unknown; and a
symlink-resolution case that canonically matches → ok.
F2b (BLOCKER) — runProxyPreflight now verifies listener identity too. Previously
`ok` was `bin.present && auth==='valid' && live` where `live` is /healthz-2xx
only, so a squatter answering 2xx yielded `ok:true` and any consumer of the
report (the phase-2 launch path) would route Claude traffic to it. Added
`verifyListener` to PreflightDeps + a `listenerVerdict` field; `ok` now requires
a trusted verdict; a live-but-unverified responder emits a non-sensitive problem
(port + verdict only — no listener command line or token). Identity is not
checked when the port is dead (no listener to trust). New tests: each non-ok
verdict fails preflight and leaks no token material; dead proxy skips verify.
Gates green: typecheck, lint, format:check; full mosaic suite 1115 passing;
claudex-proxy.ts coverage 90.57% stmts/lines, 89.06% branch (>= 85%).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Addresses the three items from PR #793 re-review #2, all TDD red-first on this
branch:
F1 (BLOCKER, dup-proxy race) — ensureProxyRunning no longer falls back to nohup
after `systemctl start` is ACCEPTED. An accepted-but-not-yet-healthy systemd
unit may bind late or be restarted; spawning nohup then would create a second
proxy contending for :18765. Once systemd accepts the job we poll to the startup
deadline and, on a miss, report a managed-service startup failure. nohup is now
reachable only when systemd never accepted the job. New test: "does NOT fall back
to nohup after systemd accepts but never binds".
F2 (BLOCKER, CWE-345) — a 2xx on /healthz is liveness, not identity. Added
verifyListenerIdentity(): an OS-level check (via `ss` + /proc) that the process
owning :18765 is the current uid running the expected proxy executable, failing
CLOSED (`unknown`) when identity can't be established — needs no upstream
shared-secret/unix-socket support. ensureProxyRunning now gates EVERY trust point
on it: an already-present responder that fails identity returns `untrusted`
without starting anything; a started proxy is trusted only once it is both live
AND identity-verified. probeLiveness doc-comment updated to record the residual
CWE-345 risk and point at the identity check (multi-user warning deferred).
F3 (SHOULD-FIX) — parseAuthStatus no longer treats a signal-terminated check
(status null) with an auth-looking line as valid; a clean exit 0 is required.
Regression test: { status: null, stdout: 'Authenticated' } → unknown.
Gates green: typecheck, lint, format:check; full mosaic suite 1110 passing;
claudex-proxy.ts coverage 92.3% stmts/lines, 88.13% branch (>= 85%).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Addresses the four findings from the independent review of #793 (exact head
0e41a5c2). TDD: each fix's failing test was added first (18 new tests), then
the implementation; full mosaic suite 1098 green, three gates green.
1. nohup fallback async spawn error (correctness): spawn() reports ENOENT/EACCES
asynchronously via the child 'error' event, which the old try/catch could not
see -> an unhandled 'error' would crash the launcher, and it returned status 0
before the child had started. Extract startNohupProxy(): attach the 'error'
listener BEFORE unref(), resolve non-zero on async error/sync throw, and
resolve success only after a confirmed 'spawn'. startNohup dep is now async.
2. systemd start not socket-bound (correctness): `systemctl --user start` exit 0
means the job was accepted, not bound within one probe. ensureProxyRunning now
polls liveness to a bounded startupDeadlineMs after a start before falling
back, so a slow systemd bind can't trigger a second, contending proxy.
3. liveness trust (security, CWE-345): probeLiveness hit the root and trusted ANY
HTTP response, so a local port-squatter could be taken for the proxy and MITM
Claude traffic. Now probe the proxy-specific GET /healthz and require a 2xx.
This also resolves gotcha #1 (root returns non-2xx): /healthz returns 2xx when
healthy, so a live proxy is never mistaken for dead. (Upstream offers no unix
socket or shared-secret handshake; /healthz is the in-scope identity ceiling.)
4. systemd ExecStart injection (security, CWE-74): buildSystemdUnitContent
interpolated binaryPath raw, so a CR/LF could inject unit directives. Validate
the path (absolute, reject control chars) and systemd-quote it when it carries
whitespace/quotes; installSystemdUnit now refuses to write a poisoned unit.
Coverage on claudex-proxy.ts: 96.3% stmts/lines, 87.1% branch.
Refs #790
P1 of the `mosaic yolo claudex` launcher (#790): pure, dependency-injected
preflight and lifecycle helpers for `raine/claude-code-proxy` (the local
Anthropic->Codex translation proxy on 127.0.0.1:18765). No session launch yet;
the isolated CLAUDE_CONFIG_DIR composition + env-injection land in PR-2.
Authored test-first (spec written and run red before implementation, then
green). 39 unit tests, 89.6% statement/line coverage on the new module; the
only uncovered lines are the process-spawning system wrappers
(systemd/nohup/wait), which are integration glue unsuitable for unit spawning.
Helpers:
- checkProxyBinary — binary presence via an injectable `which` resolver.
- parseAuthStatus / checkAuthStatus — coarse OAuth state from
`codex auth status`. Carries NO token material (state + optional expiry only)
so token-shaped output can never leak downstream.
- runDeviceReauth — `codex auth device` with stdio:'inherit' so the device code
streams to the user's TTY; the launcher never captures/logs it or sees the
resulting token.
- probeLiveness — gotcha #1: ANY HTTP response (incl. non-2xx) = alive; only a
transport failure/timeout = dead. NEVER `curl -f` (that spawned duplicate
proxies). Bounded by an explicit timeout race so a hung socket can't wedge.
- buildSystemdUnitContent / systemdUnitPath / installSystemdUnit — systemd
--user unit management; unit carries no credential material.
- runProxyPreflight — structured binary+auth+liveness report.
- ensureProxyRunning — no-op when live, else systemd-preferred with nohup
fallback, re-probing after each attempt so it never spawns a duplicate.
Refs #790. Not part of the #758 fleet DAG.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
