Enterprise Immutable Append Only Audit Log

Enterprise Immutable Append-Only Audit Log

CAVRA R3.2 defines a public-safe immutable append-only audit log contract for Enterprise and Managed deployments.

The audit log is separate from evidence bundles. Evidence bundles package reviewer and auditor artifacts for a session. The audit log is the continuous operating record of decisions, approvals, exports, failures, recovery actions, and administrative changes.

Implemented Foundation

Component	Purpose
append_audit_event	Appends JSONL audit records with sequence numbers, previous hash, record hash, and optional HMAC signature.
verify_append_only_audit_log	Verifies sequence order, hash-chain continuity, record hashes, and optional signatures.
validate_enterprise_audit_log_packet	Validates sample or live Enterprise immutable audit-log readiness packets.
scripts/validate_enterprise_audit_log.py	Verifies local JSONL audit logs and validates public sample or private live readiness packets.
examples/audit/enterprise-audit-log.sample.json	Public-safe packet showing the expected readiness evidence shape.
examples/audit/enterprise-audit-log.live.sanitized.example.json	Sanitized live-mode example that passes --require-live without exposing real customer infrastructure.
.github/workflows/enterprise-audit-log.yml	CI workflow for sample validation and manual strict live validation.
tests/test_audit_log.py	Hash-chain, tamper detection, sample, live-mode, blocker, and workflow tests.

Required Evidence

• Audit log is separate from evidence bundles.
• Records are append-only and hash chained.
• Tamper detection is tested.
• Retention is at least 2555 days for regulated evidence.
• Legal hold and delete protection are enabled.
• JSONL, SIEM, and auditor-package exports are supported.
• Alerts cover audit write, integrity, retention, and export failures.
• Tamper drill, recovery drill, and auditor handoff evidence are present.

Validation

Local hash-chain validation:

python3 scripts/validate_enterprise_audit_log.py \
  --log .cavra/audit/audit.jsonl \
  --key "$CAVRA_AUDIT_LOG_HMAC_KEY" \
  --key-id audit-prod-2026-q3

Private live readiness validation:

python3 scripts/validate_enterprise_audit_log.py \
  --packet .cavra/enterprise/enterprise-audit-log-live.json \
  --require-live \
  --output dist/enterprise/enterprise-audit-log-result.json

Sanitized live-mode template validation:

python3 scripts/validate_enterprise_audit_log.py \
  --packet examples/audit/enterprise-audit-log.live.sanitized.example.json \
  --require-live

R3.2 is production-complete only when the live packet returns ready_for_enterprise_live_audit_log: true, blocker_count: 0, and warning_count: 0.

Detailed repo document: Enterprise Immutable Append-Only Audit Log.