Commit Graph

2 Commits

Author SHA1 Message Date
Garry Tan
50d07eb234 fix(browse): apply codex adversarial findings on the new lifecycle
Codex outside-voice review caught five real production-failure modes in
the v1.28.0.0 proxy/headed lifecycle. Fixed:

1) `browse disconnect` skip-graceful for proxy-only daemons
   (browse/src/cli.ts). The graceful /command POST went out with stray
   `domains,` shorthand and (even fixed) the server's disconnect handler
   only tears down headed mode — proxy-only daemons returned 200 "Not
   in headed mode" while leaving the bridge running. Now disconnect
   short-circuits to force-cleanup for non-headed daemons, which kicks
   process.on('exit') in server.ts to close the bridge + Xvfb.

2) sendCommand crash retry preserves --proxy / --headed
   (browse/src/cli.ts). The ECONNRESET retry path called startServer()
   with no extraEnv, silently dropping the proxied flags. A daemon that
   died mid-command would silently restart in default direct/headless
   mode and bypass the SOCKS bridge. Now reapplies BROWSE_PROXY_URL,
   BROWSE_HEADED, and BROWSE_CONFIG_HASH from the resolved global flags.

3) `connect` honors --proxy (browse/src/cli.ts). The headed-mode
   `connect` command built its own serverEnv that didn't include
   BROWSE_PROXY_URL, so `browse --proxy <url> connect` launched headed
   Chromium without the proxy. Now threads proxyUrl + configHash into
   the connect serverEnv.

4) SOCKS5 bridge handles fragmented TCP frames
   (browse/src/socks-bridge.ts). Previously used once('data') and
   parsed each chunk as a complete SOCKS5 frame — TCP doesn't preserve
   message boundaries and split greetings/CONNECT requests caused
   intermittent handshake failures. Replaced with a single state
   machine that buffers chunks and uses size predicates on the SOCKS5
   header to know when a complete frame has arrived. Pauses the client
   socket during upstream connect and replays any remainder bytes
   into the upstream on success.

5) Xvfb cleanup-then-state-delete ordering
   (browse/src/server.ts). emergencyCleanup() previously deleted the
   state file BEFORE any Xvfb cleanup could read it, orphaning Xvfb
   on uncaughtException / unhandledRejection. Now reads the state
   file first, calls cleanupXvfb() (which validates cmdline +
   start-time before kill), then deletes the state file.

Adds a regression test for #4: writes the SOCKS5 greeting + CONNECT
one byte at a time with 5ms ticks, asserts a clean round trip after
the fragmented handshake.

Codex's sixth finding (bridge advertises NO_AUTH on 127.0.0.1, so any
co-located process can use the authenticated upstream) is documented
as a known limitation — gstack's threat model assumes single-user
hosts. Adding bridge-side auth is a separate change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 14:54:15 -07:00
Garry Tan
7e7530ea3f feat(browse): SOCKS5 bridge with auth + cred redaction helper
Adds browse/src/socks-bridge.ts: a 127.0.0.1-only SOCKS5 listener that
accepts unauthenticated connections from Chromium and relays them through
an authenticated upstream proxy. Chromium does not prompt for SOCKS5 auth
at launch, so this bridge is the workaround for using auth-required
residential SOCKS5 upstreams.

- startSocksBridge({ upstream, port: 0 }) → ephemeral 127.0.0.1 listener
- testUpstream({ upstream, retries: 3, backoffMs: 500, budgetMs: 5000 })
  pre-flight that connects to a known endpoint (default 1.1.1.1:443)
- Stream-error policy: kill affected client + upstream sockets on any
  error mid-stream; no transport retries (a transport-layer retry can
  corrupt browser traffic)

Adds browse/src/proxy-redact.ts: single source of truth for redacting
credentials in any logged proxy URL or upstream config. Every code path
that prints proxy config goes through this helper.

Adds the socks npm dep (~30KB) and 16 tests covering: 127.0.0.1-only
bind, byte-for-byte round trip through the bridge, auth rejection,
mid-stream upstream drop kills client conn, listener teardown,
testUpstream success + retry-exhaust paths, redaction of every
credential shape.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 13:20:35 -07:00