Add docs/ (SPECIFICATION, ROADMAP, OPERATIONS, COMMAND_REFERENCE,
THREAT_MODEL) describing the current v0.7 agent and the phased path from
local HIDS to a host security platform. Reframe README, package metadata,
and CLI/module descriptions from "intrusion-detection daemon" to "Linux
host security platform", and surface the v0.7 signed-package verify
(pkgdb_pkgverify*) and anti-rootkit (rootcheck_*) knobs in the sample
config. Also wrap the pacman.conf read in pkgdb.siglevel_alert in a
context manager to avoid a leaked file handle.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Closes the tamper-evidence loop with two trust anchors the attacker can't
forge from userland:
- pkgdb Layer 2: verify on-disk files against the .MTREE in the *signed*
cache package, surviving a rewritten local checksum DB. Rotating-sample
cadence keeps it affordable; flags pkg_signature_mismatch (sid 100027)
and SigLevel downgrades (sid 100026). Fixes parse_mtree, which required
type=file on every line and so matched nothing on real pacman MTREEs
(which use a /set type=file default with bare file entries).
- rootcheck: anti-rootkit cross-view — hidden processes, modules, ports,
and promiscuous interfaces, each caught by diffing two views of the
same state (sids 100022-100025).
Wired both through config, the daemon (off-loop slow cadence), and CLI
(pkgdb-verify, rootcheck). 14 new tests (95 total). Docs + version bump.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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>
