| name | audit-verify |
| description | Verifies the tamper-evidence hash chain on audit-trail's JSONL log. Use when the developer asks to verify audit integrity, check whether the audit log has been tampered with, validate the hash chain, or investigate suspected log manipulation. Auto-triggers on: "verify audit", "check audit integrity", "tamper check", "validate hash chain", "audit log tampered", "hash chain broken".
|
| allowed-tools | ["Read","Bash"] |
Walk the audit-trail JSONL hash chain (prev_hash field per line) and report
whether the log is intact. Each entry's prev_hash must equal
base64(sha256(canonical_json(previous_line))), or "GENESIS" for line 1.
A mismatch signals an in-place edit, deletion, or insertion.
1. Read-only on audit.jsonl. Never repair or rewrite the log — a broken chain
is forensic evidence; preserve it.
2. Run verify_chain via the shared helper, not a re-implementation. The helper
is the source of truth for canonicalisation rules.
3. If openssl or jq is missing, report the missing dep — do NOT claim the
chain is intact.
<decision_tree>
IF user asks to verify the audit log:
→ Run:
bash -c 'source "${CLAUDE_PLUGIN_ROOT}/scripts/chain-helpers.sh" && verify_chain "${CLAUDE_PLUGIN_ROOT}/state/audit.jsonl"'
→ Exit 0 → report "Chain intact across N lines."
→ Exit 1 → report the offending line number and hashes verbatim from stderr.
→ Exit 2 → report "audit.jsonl not found at expected path."
IF user asks to verify a specific file (not the default audit log):
→ Substitute the path into the same one-liner.
IF user asks "what's in the chain":
→ Read the last 5 lines of audit.jsonl, show event/ts/tool/prev_hash columns.
</decision_tree>
<output_format>
Audit Chain Verification
- File:
<path>
- Lines walked: N
- Status: intact | BROKEN at line K
- Diagnostic (if broken):
expected <hash> got <hash>
If broken, recommend: capture a copy of the current audit.jsonl for forensic
review before any further writes, then investigate which event was tampered.
</output_format>
<failure_modes>
- F02 fabrication: never claim "intact" without actually running verify_chain.
- F09 parallel race: a verify run during a heavy tool burst may see a
partial last line; rerun once the workload settles.
</failure_modes>
