Answers two hard questions: "what guards the hashes FIM trusts?" and "how do we
make the sensor itself hard to silently disable?" — within the honest limit that
a root attacker who shares your privileges can't be fully stopped on-box, only
made loud.
- pkgdb.py: guards the package DB that `pacman -Qkk` trusts. Anchors a
fingerprint of /var/lib/pacman/local (refreshed ONLY by the pacman hook) and
cross-checks pacman.log; a DB change with no logged transaction is flagged
pkgdb_tamper (CRITICAL, sid 100021) — catches an attacker rewriting a stored
checksum to mask a modified binary. Verified end-to-end against a simulated
hash-overwrite.
- selfprotect.py: Sentinel's own binaries/config/units/hook are always in the
FIM watch set (self-integrity); a heartbeat is written each loop; an external
`watchdog` command polls a remote dashboard and pushes if the sensor goes
silent or unreachable — silence becomes the alarm.
- daemon: heartbeat + slow-cadence pkgdb check; DB anchor re-anchored in
build_fim_baseline so the pacman hook refreshes it after each transaction
- web: /api/status now reports heartbeat_age/stale; dashboard shows it
- cli: pkgdb-check, watchdog (--url/--token/--max-age, bypasses min-severity)
- config: pkgdb_verify/_interval, heartbeat_max_age
- README: threat model (trust-anchor problem) + hardening layers (immutability,
signed-package + external anchor); reframes "anti-rootkit" as tamper-evidence
- tests: +8 (DB fingerprint, anchor/transaction logic, pacman.log parse,
heartbeat + watchdog verdicts). 80/80 pass
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Both zero-dependency (stdlib http.server + urllib), consistent with the
project's no-dependency-tree stance for a security daemon.
Web dashboard (enodia_sentinel/web.py + static/dashboard.html):
- read-only JSON API over the log dir: /api/status, /api/alerts,
/api/alerts/<id>, /api/events
- bearer-token auth (constant-time; header or ?token=), required on non-
loopback binds, auto-generated + persisted (0600) when unset
- binds the host's Tailscale IP by default (auto-detected), reachable from the
tailnet but not the LAN/internet
- self-contained dark SPA: severity cards, live alert list, full snapshot
viewer; 10s auto-refresh
- path-traversal-safe alert lookup; `enodia-sentinel web` subcommand; daemon
now writes a pidfile so the dashboard can show live status
- hardened enodia-sentinel-web.service (read-only, no caps)
Phone push (enodia_sentinel/notify/):
- pluggable backends — ntfy, Pushover, generic webhook — each separating a pure
build() (unit-tested, no network) from send()
- a backend turns on when its config keys are set; pushes gated by
notify_min_severity; severity → per-service priority/tags
- fired from snapshot.capture on worker threads, errors swallowed
- desktop notify-send retained
Tests: +16 (9 web incl. a real-server 401/200 auth test, 7 notify request-build
cases). 55/55 pass. Live end-to-end verified: daemon → alert → API → page.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
