vwh-core 4.0.2

Cryptographic accountability tool for verifying digital presence.
Documentation

vwh-core

Core library for the VWH artifact format. This crate provides:

  • Binary format parsing/serialization for V1 (128 bytes) and V2 (256 bytes) artifacts
  • Ed25519 signing and verification with domain separation
  • Dual-signature model: separate author and seal keys (V2)
  • Artifact lifecycle state machine: Draft → Signed → Sealed
  • Key fingerprinting (BLAKE3)

The vwh CLI, a single binary that both inspects and authors artifacts, depends on this crate. (Through 3.x, authoring lived in a separate unpublished vwh-author tool; 4.0 unified the two.)

Windows prerequisite (when building from source or installing tools that depend on this crate):

  • The MSVC linker (link.exe) is required. Install "Build Tools for Visual Studio" with the "Desktop development with C++" workload, then reopen your terminal.

Format Summary

V2 (current, default — 256 bytes)

  • Magic: VWH\0
  • Fields: version, reserved, artifact id, timestamp, intent, author public key, note hash, author signature, seal public key, seal signature
  • Author signature: Ed25519 over the first 103 bytes (through note hash)
  • Seal signature: Ed25519 over the first 192 bytes (through seal public key — binds the author signature)
  • Note hash: BLAKE3 of a detached .vwh.note sidecar file
  • All Ed25519 operations prepend b"vwh-v2\x00" (domain separation)

V1 (legacy — 128 bytes)

  • Magic: VWH\0
  • Fields: version, flags, artifact id, timestamp, intent, author public key, signature
  • The flags byte is excluded from signing bytes — sealing is a state transition that does not invalidate the signature
  • V1 artifacts are fully supported; Artifact::from_bytes auto-detects format by version field

API Highlights

  • Artifact::from_bytes / Artifact::to_bytes — parse and serialize (auto-detects V1/V2)
  • ArtifactBuilder::new_v2 / ArtifactBuilder::new_v1 — construct unsigned artifacts
  • UnsignedArtifact::author_signing_bytes + UnsignedArtifact::with_author_signature
  • Artifact::seal_signing_bytes — bytes covered by the seal signature (V2 only)
  • verify::verify_artifact — author signature verification
  • verify::verify_seal — seal signature verification (V2 only)
  • crypto::sign / crypto::verify — raw Ed25519 helpers (domain separation applied internally)
  • TypedArtifact<S> — zero-cost phantom wrapper encoding state (Draft, Signed, Sealed) in the type system
  • KeyFingerprint — BLAKE3 fingerprint of an Ed25519 public key

Example

use vwh_core::{
    crypto, verify,
    format::{ArtifactBuilder},
    Intent,
};
use ed25519_dalek::SigningKey;
use rand::rngs::OsRng;

let author_key = SigningKey::generate(&mut OsRng);
let seal_key = SigningKey::generate(&mut OsRng);
let author_pubkey = author_key.verifying_key().to_bytes();
let seal_pubkey = seal_key.verifying_key().to_bytes();

let note = b"human-readable context for this artifact";
let note_hash = *blake3::hash(note).as_bytes();

// Build and author-sign a V2 artifact
let unsigned = ArtifactBuilder::new_v2(Intent::Lab, author_pubkey, note_hash).build_unsigned();
let author_sig = crypto::sign(&author_key, &unsigned.author_signing_bytes());
let signed = unsigned.with_author_signature(author_sig);

// Seal it (dual-sign)
let pre_seal = signed.with_seal(seal_pubkey, [0u8; 64]);
let seal_sig = crypto::sign(&seal_key, &pre_seal.seal_signing_bytes()?);
let sealed = pre_seal.with_seal(seal_pubkey, seal_sig);

// Verify both signatures
verify::verify_artifact(&sealed)?;
verify::verify_seal(&sealed)?;

Notes

  • Artifacts are immutable once sealed.
  • Signatures are always verified locally — network is never required for cryptographic checks.
  • This crate is format- and crypto-focused; registry logic lives in the vwh CLI.