Firmware Attestation

The RCAN protocol requires all robots to publish a signed firmware manifest and CycloneDX SBOM to the Robot Registry Foundation (RRF). Signatures use ML-DSA-65 (NIST FIPS 204) — Ed25519 is deprecated and removed. See the live compatibility matrix for the protocol revision currently in force.

1. Generate ML-DSA-65 Key Pair

Every robot needs an ML-DSA-65 key pair. Generate it once — it lives at ~/.opencastor/pq_signing.key and is auto-loaded at boot.

# Generate ML-DSA-65 key pair (FIPS 204)
castor keygen --pq

# Output:
# ✓ ML-DSA-65 key generated (FIPS 204)
#   private: ~/.opencastor/pq_signing.key  (4032 bytes)
#   public:  ~/.opencastor/pq_signing.pub  (1952 bytes)
#   key_id:  7c21bf58

2. Attest + Sign

Run castor attest generate to build the firmware manifest from installed packages, then castor attest sign to apply the ML-DSA-65 signature.

# 1. Generate firmware manifest
castor attest generate --config ~/opencastor/bob.rcan.yaml

# 2. Sign with ML-DSA-65
castor attest sign

# 3. Verify
castor attest verify

# Output:
# ✓ Firmware manifest signature (ML-DSA-65): VALID
#   RRN:      RRN-000000000001
#   Version:  2026.3.26.1
#   Signed:   2026-03-27T00:49:05Z

3. Manifest Schema

The signed manifest is stored at /tmp/opencastor-firmware-manifest.json (or /run/opencastor/rcan-firmware-manifest.json in production).

{
  "rrn":              "RRN-000000000001",
  "firmware_version": "2026.3.26.1",
  "build_hash":       "sha256:f072093b...",
  "signed_at":        "2026-03-27T00:49:05Z",
  "pq_alg":           "ml-dsa-65",
  "signature":        "6fMv7aDw0f3HPqrbit3VC5...",
  "components": [
    { "name": "opencastor", "version": "2026.3.27.0", "hash": "sha256:..." },
    { "name": "rcan",       "version": "1.2.1",       "hash": "sha256:..." }
  ]
}

4. Gateway API Endpoints

All attestation data is accessible via the gateway REST API (authenticated with a JWT):

# Gateway endpoints
GET  /api/attest          → manifest metadata + signature prefix
POST /api/attest/verify   → live ML-DSA-65 signature verification
GET  /api/sbom            → SBOM metadata (serial, components, ref)
GET  /api/sbom/download   → full CycloneDX JSON
GET  /api/conformance     → self-run conformance report (v2.1/v2.2 checks)

5. Conformance

Run castor conformance to see a self-run RCAN protocol conformance report inline. The report passes when all 7 checks below pass. It is a conformance check you run on your own robot, not legal compliance and not a certification:

• rcan_v21.firmware_manifest — signed manifest present
• rcan_v21.sbom_attestation — SBOM published to RRF
• rcan_v21.authority_handler — EU AI Act Art. 16(j)
• rcan_v21.audit_chain_retention — ≥ 3650 days
• rcan_v21.rcan_version — RCAN protocol version required (see the live compatibility matrix)
• rcan_v22.pq_signing_key — ML-DSA-65 key present
• rcan_v22.firmware_pq_sig — manifest has ML-DSA-65 signature

Reference

• RCAN spec §11 — Firmware Attestation
• SBOM Guide
• NIST FIPS 204 (ML-DSA)