provenance-verify (Python)

A clean-room, zero-platform-dependency offline verifier for the TruthLayer ledger and EvidenceVault (TruthCert) certificate trust chain.

provenance-verify independently checks the cryptographic claims of both platforms from public artifacts alone — no platform endpoint, cooperation, or continued existence required. It reimplements every trust-critical primitive (RFC 8785 JSON canonicalization, RFC 6962 Merkle trees, Ed25519, ML-DSA-65, SLH-DSA-SHA2-128f, OpenTimestamps→Bitcoin, Lamport OTS) from the published format spec, depending only on audited public cryptography libraries (cryptography, dilithium-py, slh-dsa, blake3).

Why "independent" matters. The platforms ship their own verifiers, but those run identical logic to the code that produced the artifacts — a bug or tampering in that code would pass both. This package shares no code with either platform. It is a genuine second implementation whose agreement with the platform is proven, not assumed: against a byte-identical cross-implementation conformance corpus and a live field-for-field diff against the TypeScript provenance-verify over shared fixtures.

This is the Python sibling of the TypeScript provenance-verify npm package. Both verify the same artifacts and produce the same verdicts. MIT licensed. Python ≥ 3.10.

Install

Status: not yet published to PyPI. Until the first release lands, install from source:

pip install ./tools/independent-verify-py

Once published (via the gated publish.yml → pypi-provenance-verify):

pip install provenance-verify

CLI

# Verify a TruthLayer sealed agent-day (event chain → hourly sub-seals → daily
# root → Bitcoin anchor) from a local artifact bundle (or --base-url <url>):
provenance-verify ledger --tenant-id <t> --agent-id <a> --date <YYYY-MM-DD> --dir <bundle>

# Verify an EvidenceVault certificate (Ed25519 + ML-DSA-65 + SLH-DSA hybrid):
provenance-verify cert --cert-id <c> --tenant-id <t> --dir <bundle>

# Verify the full provenance→certificate chain, including the Merkle-root join:
provenance-verify chain --tenant-id <t> --agent-id <a> --date <d> \
                        --cert-id <c> --cert-tenant <t> --dir <bundle>

# Self-test the crypto core against the bundled cross-implementation corpus:
provenance-verify conformance

Exit codes: 0 ok · 1 a check failed (fail-closed) · 2 usage error.

Library

from provenance_verify import DirSource, verify_certificate_from_artifacts, verify_day

cert = verify_certificate_from_artifacts(
    DirSource("bundle"), {"certId": "cert_...", "tenantId": "tnt_..."}
)
print(cert["ok"], cert["checks"])

What it verifies

• RFC 8785 (JCS) canonicalization, byte-identical to the JavaScript signer — including the ECMAScript Number::toString number format and UTF-16 key ordering.
• RFC 6962 / RFC 9162 Merkle inclusion and consistency proofs (0x00 leaf / 0x01 node domain separation), plus the frozen Bitcoin-style v1 tree.
• Hybrid-AND signatures — a certificate/seal is valid only if every family verifies: Ed25519 (RFC 8032) + ML-DSA-65 (FIPS 204) + SLH-DSA-SHA2-128f (FIPS 205).
• The trust root — two-level tenant root → time-bounded agent subkey resolution, and SLH-DSA root certifications.
• The OpenTimestamps → Bitcoin anchor — the stored calendar proof is parsed and executed to the claimed block; an unparseable/unexecutable proof is an error, never silently "pending".
• The Lamport one-time anchor — the SHA-256-only floor beneath the hybrid stack.
• Fail-closed discipline — unknown formats, hash suites, and signature suites are rejected; missing required artifacts fail closed.

Proof of faithfulness

The port is not merely internally consistent — its agreement with the reference implementation is tested:

• tests/test_conformance.py runs the shared canon-vectors.json corpus (JCS canonical strings + SHA-256, v1/v2 Merkle roots for leaf counts 1..32) and asserts every value matches byte-for-byte.
• tests/test_cross_validation.py runs the TypeScript provenance-verify CLI and this implementation over the same fixtures and asserts they agree on ok, validity, and the entire checks map, field-for-field.
• tests/test_fixtures.py verifies real green bundles end-to-end and confirms tampered payloads/seals and missing registries fail closed.

pip install -e ".[test]" && pytest