Hermes Attestation Guardian

Hermes Attestation Guardian

IMPORTANT SCOPE:

• This skill targets Hermes infrastructure only (CLI/Gateway/profile-managed deployments).
• This skill is not an OpenClaw runtime hook package.

Release Artifact Verification

For standalone installs, verify the signed release manifest before trusting SKILL.md, skill.json, or the archive. The skill.json file is the package metadata/SBOM source, and the release pipeline signs checksums.json with the ClawSec release key.

set -euo pipefail

SKILL_NAME="hermes-attestation-guardian"
VERSION="0.1.2"
REPO="prompt-security/clawsec"
TAG="${SKILL_NAME}-v${VERSION}"
BASE="https://github.com/${REPO}/releases/download/${TAG}"
ZIP_NAME="${SKILL_NAME}-v${VERSION}.zip"
TMP_DIR="$(mktemp -d)"
trap 'rm -rf "$TMP_DIR"' EXIT

RELEASE_PUBKEY_SHA256="711424e4535f84093fefb024cd1ca4ec87439e53907b305b79a631d5befba9c8"

curl -fsSL "$BASE/checksums.json" -o "$TMP_DIR/checksums.json"
curl -fsSL "$BASE/checksums.sig" -o "$TMP_DIR/checksums.sig"
curl -fsSL "$BASE/signing-public.pem" -o "$TMP_DIR/signing-public.pem"
curl -fsSL "$BASE/$ZIP_NAME" -o "$TMP_DIR/$ZIP_NAME"
curl -fsSL "$BASE/SKILL.md" -o "$TMP_DIR/SKILL.md"
curl -fsSL "$BASE/skill.json" -o "$TMP_DIR/skill.json"

ACTUAL_PUBKEY_SHA256="$(openssl pkey -pubin -in "$TMP_DIR/signing-public.pem" -outform DER | shasum -a 256 | awk '{print $1}')"
if [ "$ACTUAL_PUBKEY_SHA256" != "$RELEASE_PUBKEY_SHA256" ]; then
  echo "ERROR: signing-public.pem fingerprint mismatch" >&2
  exit 1
fi

openssl base64 -d -A -in "$TMP_DIR/checksums.sig" -out "$TMP_DIR/checksums.sig.bin"
openssl pkeyutl -verify -rawin -pubin \
  -inkey "$TMP_DIR/signing-public.pem" \
  -sigfile "$TMP_DIR/checksums.sig.bin" \
  -in "$TMP_DIR/checksums.json" >/dev/null

hash_file() {
  if command -v shasum >/dev/null 2>&1; then
    shasum -a 256 "$1" | awk '{print $1}'
  else
    sha256sum "$1" | awk '{print $1}'
  fi
}

verify_manifest_file() {
  asset="$1"
  path="$2"
  expected="$(jq -r --arg asset "$asset" '.files[$asset].sha256 // empty' "$TMP_DIR/checksums.json")"
  if [ -z "$expected" ]; then
    echo "ERROR: checksums.json missing $asset" >&2
    exit 1
  fi
  actual="$(hash_file "$path")"
  if [ "$actual" != "$expected" ]; then
    echo "ERROR: checksum mismatch for $asset" >&2
    exit 1
  fi
}

expected_archive="$(jq -r '.archive.sha256 // empty' "$TMP_DIR/checksums.json")"
if [ -z "$expected_archive" ]; then
  echo "ERROR: checksums.json missing archive.sha256" >&2
  exit 1
fi
actual_archive="$(hash_file "$TMP_DIR/$ZIP_NAME")"
if [ "$actual_archive" != "$expected_archive" ]; then
  echo "ERROR: archive checksum mismatch" >&2
  exit 1
fi

verify_manifest_file "SKILL.md" "$TMP_DIR/SKILL.md"
verify_manifest_file "skill.json" "$TMP_DIR/skill.json"

echo "Signed release manifest, archive, SKILL.md, and skill.json verified."

Only install or extract the archive after this verification succeeds.

Goal

Generate deterministic Hermes posture attestations, verify them with fail-closed integrity checks, and compare baseline drift using stable severity mapping.

Hermes guard trust policy note

When installing from community sources, configure Hermes guard to use signature-aware trust (trusted signer fingerprint allowlist) rather than source-name-only trust. Unknown signer fingerprints should stay on community policy, and invalid signatures must remain blocked.

Commands

# Generate attestation (default output: ~/.hermes/security/attestations/current.json)
node scripts/generate_attestation.mjs

# Generate with explicit policy + deterministic timestamp
node scripts/generate_attestation.mjs \
  --policy ~/.hermes/security/attestation-policy.json \
  --generated-at 2026-04-15T18:00:00.000Z \
  --write-sha256

# Verify schema + canonical digest
node scripts/verify_attestation.mjs --input ~/.hermes/security/attestations/current.json

# Verify with baseline diff (baseline must be authenticated)
node scripts/verify_attestation.mjs \
  --input ~/.hermes/security/attestations/current.json \
  --baseline ~/.hermes/security/attestations/baseline.json \
  --baseline-expected-sha256 <trusted-baseline-sha256> \
  --fail-on-severity high

# Optional detached signature verification
node scripts/verify_attestation.mjs \
  --input ~/.hermes/security/attestations/current.json \
  --signature ~/.hermes/security/attestations/current.json.sig \
  --public-key ~/.hermes/security/keys/attestation-public.pem

# Refresh advisory feed verification state (fail-closed by default)
node scripts/refresh_advisory_feed.mjs

# Check advisory feed verification + feed summary
node scripts/check_advisories.mjs

# Guarded advisory-aware skill verification gate (returns 42 on advisory match without explicit confirm)
node scripts/guarded_skill_verify.mjs --skill some-skill --version 1.2.3

# Explicit operator acknowledgement path for advisory matches
node scripts/guarded_skill_verify.mjs --skill some-skill --version 1.2.3 --confirm-advisory

# Optional temporary unsigned bypass (dangerous; emergency-only)
HERMES_ADVISORY_ALLOW_UNSIGNED_FEED=1 node scripts/refresh_advisory_feed.mjs --allow-unsigned

# Preview scheduler config without mutating user schedule state
node scripts/setup_attestation_cron.mjs --every 6h --print-only

# Apply managed scheduler block
node scripts/setup_attestation_cron.mjs --every 6h --apply

# Preview advisory check scheduler config (guarded flow, print-only default)
node scripts/setup_advisory_check_cron.mjs --every 6h --skill some-skill --print-only

# Apply advisory check scheduler block (uses guarded_skill_verify flow)
node scripts/setup_advisory_check_cron.mjs --every 6h --skill some-skill --version 1.2.3 --apply

# Emergency-only: unsigned bypass for scheduled advisory checks (do not keep enabled)
node scripts/setup_advisory_check_cron.mjs --every 6h --skill some-skill --allow-unsigned --apply

WARNING: --allow-unsigned in scheduled commands is incident-response only. Remove it immediately after recovery and restore signed advisory verification.

Attestation payload (implemented)

The generator emits:

• schema_version, platform, generated_at
• generator metadata (skill + node version)
• host metadata (hostname/platform/arch)
• posture.runtime (gateway enabled flags + risky toggles)
• posture.feed_verification status (verified|unverified|unknown) sourced from $HERMES_HOME/security/advisories/feed-verification-state.json
• posture.integrity watched_files and trust_anchors (existence + sha256)
• digests.canonical_sha256 over a stable canonical JSON representation

Fail-closed behavior

Verifier exits non-zero when:

• schema validation fails
• canonical digest algorithm is unsupported or digest binding mismatches
• expected file sha256 mismatches (if configured)
• detached signature verification fails (if configured)
• baseline is provided without authenticated trust binding (--baseline-expected-sha256 and/or baseline signature + public key)
• baseline authenticity or baseline schema/digest validation fails
• baseline diff highest severity is at/above --fail-on-severity (default: critical)

Severity messages are emitted as INFO / WARNING / CRITICAL style lines.

Side effects

• generate_attestation.mjs writes one JSON file (and optional .sha256) under $HERMES_HOME/security/attestations.
• verify_attestation.mjs is read-only.
• refresh_advisory_feed.mjs writes verified feed cache + verification state under $HERMES_HOME/security/advisories.
• check_advisories.mjs is read-only.
• guarded_skill_verify.mjs re-runs feed refresh/verification (same advisory cache + state side effects) and then performs advisory-aware gate checks.
• setup_attestation_cron.mjs is read-only unless --apply is provided.
• setup_attestation_cron.mjs --apply rewrites only the current user managed schedule block delimited by:
  • # >>> hermes-attestation-guardian >>>
  • # <<< hermes-attestation-guardian <<<
• setup_advisory_check_cron.mjs is read-only unless --apply is provided.
• setup_advisory_check_cron.mjs --apply rewrites only the current user advisory-check managed schedule block delimited by:
  • # >>> hermes-attestation-guardian-advisory-check >>>
  • # <<< hermes-attestation-guardian-advisory-check <<<
  • generated command path uses guarded_skill_verify.mjs (advisory-aware gate), not raw check_advisories.mjs

Advisory feed override knobs

• Source selection: HERMES_ADVISORY_FEED_SOURCE=auto|remote|local
• Remote artifacts: HERMES_ADVISORY_FEED_URL, HERMES_ADVISORY_FEED_SIG_URL, HERMES_ADVISORY_FEED_CHECKSUMS_URL, HERMES_ADVISORY_FEED_CHECKSUMS_SIG_URL
• Local artifacts: HERMES_LOCAL_ADVISORY_FEED, HERMES_LOCAL_ADVISORY_FEED_SIG, HERMES_LOCAL_ADVISORY_FEED_CHECKSUMS, HERMES_LOCAL_ADVISORY_FEED_CHECKSUMS_SIG
• Pinned key override: HERMES_ADVISORY_FEED_PUBLIC_KEY (default is built-in pinned key)
• Optional checksum toggle: HERMES_ADVISORY_VERIFY_CHECKSUM_MANIFEST (default: enabled)
• UNSAFE emergency bypass only: HERMES_ADVISORY_ALLOW_UNSIGNED_FEED=1

Notes

• Hermes scan + test context is .mjs-based by design:
  • runtime scripts: scripts/*.mjs
  • shared libraries: lib/*.mjs
  • regression tests: test/*.test.mjs
• Keep .mjs paths/extensions stable so scanner scope, SBOM wiring, and test harness references stay valid.
• Default output root is ~/.hermes/security/attestations/.
• No destructive remediation actions (delete/restore/quarantine) are implemented.
• Advisory feed remote URL allowlisting is not implemented in v0.0.2; operators must explicitly trust configured feed/checksum endpoints.
• Guarded advisory version matching currently uses a lightweight comparator parser (>=, <=, >, <, =, ^, ~, wildcard *) and does not implement full npm semver range grammar (for example, OR ranges and complex comparator sets).
• Operator policy file is optional JSON with:
  • watch_files: list of file paths
  • trust_anchor_files: list of file paths