2 Commits

Author SHA1 Message Date
shankar0123 c4ed3da30b fix(ci): Sprint 6 CI follow-up — staticcheck ST1021 + tenant-query baseline + skip inventory
Sprint 6 push (commits 43836ac + 663b14b) tripped three CI guards.
Fixing all three in this single follow-up — each is a small,
mechanical correction that doesn't change behavior:

1. staticcheck ST1021: AuditChainSnapshot doc comment was on the
   wrong type.

   internal/service/audit_chain_metric.go:91 had:
     // Snapshot returns the current counter state for the Prometheus
     // exposer. Reads use atomic loads — no mutex.
     type AuditChainSnapshot struct { ... }

   The comment described Snapshot() (the method on AuditChainCounter)
   but sat directly above the AuditChainSnapshot struct. staticcheck
   ST1021 requires exported-type comments to start with the type's
   name + optional leading article. Rewrote to lead with
   "AuditChainSnapshot is the point-in-time view ...".

2. multi-tenant-query-coverage: baseline drifted 31 → 32 because
   Sprint 6 COMP-002-RETENTION added UserRepository.ListDeactivatedBefore
   at internal/repository/postgres/user.go:191 — legitimately
   tenant-spanning by design.

   The retention policy is control-plane-wide (one
   CERTCTL_USER_RETENTION_WINDOW for the whole deployment, not
   per-tenant). The scheduler's userRetentionLoop walks every
   tenant's deactivated users on the same tick. A per-tenant
   tenant_id filter would require the scheduler to iterate every
   tenant — more code for equivalent semantics.

   Per the guard's own documentation (option b), legitimately
   tenant-spanning queries get an inline rationale comment + a
   baseline lift. Both delivered:
     - Inline comment block on the SELECT in user.go::ListDeactivatedBefore.
     - BASELINE_COUNT 31 → 32 in
       scripts/ci-guards/multi-tenant-query-coverage.sh, with the
       Sprint 6 rebase entry added to the rebase-history comment.

3. skip-inventory-drift: docs/testing/skip-inventory.md was stale.
   COMP-001-HASH added three new t.Skip sites in
   internal/repository/postgres/audit_chain_test.go (the three
   testing.Short() gates on the testcontainers integration tests).
   Re-ran ./scripts/skip-inventory.sh to regenerate the doc —
   totals went from 144 → 147 sites + 78 → 82 short-mode guards.

Verified locally:
  bash scripts/ci-guards/multi-tenant-query-coverage.sh      (clean)
  bash scripts/ci-guards/skip-inventory-drift.sh              (clean)
  go vet ./...                                                (clean)
  staticcheck ./internal/service/...                          (clean)

Closes the three Sprint 6 CI failures. The next CI run should
green out.
2026-05-16 06:24:09 +00:00
shankar0123 43836aca7c feat(audit): COMP-001-HASH — per-row hash chain on audit_events (tamper-evidence)
Sprint 6 closure of the audit's HIGH-severity COMP-001-HASH finding.

Pre-fix posture: migration 000018 installs a WORM trigger on
audit_events that blocks UPDATE / DELETE for the application role.
But the trigger header itself documents a compliance-superuser
bypass (backup restore, retention purges, breach recovery). Without
a hash chain, that role can rewrite any row's actor / action /
details / timestamp / event_category with no on-disk trace.

HIPAA §164.312(b), FedRAMP AU-9, NIST 800-53 AU-10 want tamper-
EVIDENCE, not just tamper-prevention. This commit ships the
evidence layer.

Wire shape:

  migrations/000047_audit_events_hash_chain.up.sql
    + pgcrypto extension (digest function)
    + audit_chain_head: single-row sentinel table holding the most
      recent row_hash; FOR UPDATE row-lock serialises chain writes
      under concurrent INSERTs so two parallel writers can't read
      the same prev_hash and produce a forked chain
    + audit_events: prev_hash + row_hash columns
    + audit_events_canonical_payload(): centralised hash input
      builder. UTC + microsecond ISO-8601 keeps the hash session-
      timezone-independent. All columns separated by '|' so a
      concatenation-ambiguity exploit can't fabricate a collision
    + audit_events_compute_hash_chain(): BEFORE-INSERT trigger
      function. Reads sentinel FOR UPDATE → computes
      sha256(prev_hash || id || actor || actor_type || action ||
      resource_type || resource_id || details::text ||
      timestamp_utc_iso || event_category) → writes both columns +
      advances the sentinel
    + backfill loop walks every existing row in (timestamp ASC, id
      ASC) order; WORM trigger temporarily DISABLEd inside this
      migration's transaction so backfill UPDATEs land cleanly,
      ENABLEd before COMMIT
    + audit_events_verify_chain(): STABLE plpgsql verifier. Walks
      the chain end-to-end and returns the first break:
        (first_break_id TEXT, first_break_pos INT, row_count INT)

  internal/repository/postgres/audit.go
    + AuditRepository.VerifyHashChain — calls the SQL function and
      maps the OUT parameters to Go return values

  internal/repository/interfaces.go
    + AuditRepository.VerifyHashChain in the contract; every
      in-memory mock + stub picks up the no-op implementation

  internal/scheduler/scheduler.go
    + AuditChainVerifier + AuditChainBreakRecorder interfaces
    + auditChainVerifyInterval (default 6h)
    + auditChainVerifyLoop: runs once on start + every tick;
      atomic.Bool guard + 5-min per-tick context timeout match every
      other GC loop's pattern

  internal/service/audit_chain_metric.go
    + AuditChainCounter type with atomic counters. Sticky-first-
      detection on (BrokenAtID, BrokenAtPos) so the actionable
      alarm doesn't drift across walks. Snapshot() returns the
      full state for the metrics handler

  internal/api/handler/metrics.go
    + AuditChainCounterSnapshotter interface + Prometheus
      exposition for four series:
        certctl_audit_chain_break_detected_total counter (the alarm)
        certctl_audit_chain_verify_total          counter (walks done)
        certctl_audit_chain_rows                  gauge (last walk size)
        certctl_audit_chain_last_verified_at      gauge (unix seconds)

  internal/config/config.go
    + AuditChainConfig{ VerifyInterval } + CERTCTL_AUDIT_CHAIN_VERIFY_INTERVAL

  cmd/server/main.go
    + wires AuditChainCounter into both the scheduler (recorder) +
      metrics handler (snapshotter) — single instance shared so the
      writer + reader are guaranteed to converge

  internal/repository/postgres/audit_chain_test.go (NEW)
    + TestAuditEventsHashChain_FreshTable: empty walk → clean
    + TestAuditEventsHashChain_AppendLinksRows: three INSERTs
      produce a strictly-linked chain; prev_hash on row 0 is NULL;
      verifier walks clean over the 3 rows
    + TestAuditEventsHashChain_VerifierDetectsTampering: simulate
      the compliance-superuser threat model (DISABLE WORM, UPDATE
      a middle row, ENABLE WORM); verifier returns the tampered
      row's id at position 1

  docs/operator/audit-chain.md (NEW)
    + Layered-defenses explainer (WORM + hash chain). Verifier
      function reference. Recommended Prometheus alert rule.
      Performance scaling table (10k to 10M rows). Step-by-step
      runbook for what to do when a break is detected. Operator
      configuration table.

  Test-stub additions for AuditRepository.VerifyHashChain:
    internal/service/testutil_test.go  — mockAuditRepo
    internal/service/acme_test.go      — fakeAuditRepo
    internal/integration/lifecycle_test.go — mockAuditRepository
    internal/api/handler/scep_intune_e2e_test.go — intuneE2EAuditRepo

Verified locally:
  go vet ./...                                          (clean)
  gofmt -l internal/ cmd/                               (clean)
  go test -short -count=1 ./internal/scheduler/... ./internal/config/...
    ./internal/service/... ./internal/api/handler/... ./internal/repository/...
    (all green)

Verified with testcontainers + postgres:16-alpine + the migration
runner (not gated under -short — requires docker):
  go test -count=1 -run TestAuditEventsHashChain ./internal/repository/postgres/...

Closes COMP-001-HASH leg of Sprint 6. COMP-002-RETENTION lands in
the next commit (separate concern: federated-user PII retention).
2026-05-16 06:17:15 +00:00