@openvtc/trust-tasks-proof

W3C Data Integrity proofs for Trust Tasks: a ProofVerifier for @openvtc/trust-tasks, and the signer that produces what it verifies.

Verifies eddsa-jcs-2022 and ecdsa-jcs-2019 on @noble — no JSON-LD, no WASM, runs in browsers, Node and React Native. Byte-compatible with the Rust trust-tasks-proof crate and the Dart trust_tasks_proof package: for the same Ed25519 key, document and created it reproduces the Rust proofValue exactly.

npm install @openvtc/trust-tasks @openvtc/trust-tasks-proof

Verifying

import { consumeInbound } from "@openvtc/trust-tasks";
import { DataIntegrityProofVerifier } from "@openvtc/trust-tasks-proof";

const outcome = await consumeInbound({
  proofPolicy: { kind: "verify", verify: new DataIntegrityProofVerifier() },
  // transport, spec, doc, handler, ... as usual
});

A document whose proof fails is rejected with proofInvalid, and nothing about why reaches the peer (SPEC §10.4). To log the reason, call verifyDetailed, which returns a ProofVerification whose failure is one of malformedProof, issuerMismatch, unsupportedCryptosuite or signatureInvalid — the same taxonomy as the Rust and Dart libraries.

What is checked

1. The proof is a DataIntegrityProof with a non-empty cryptosuite, verificationMethod, proofPurpose and proofValue.
2. The cryptosuite is one this verifier accepts.
3. created, when present, is a dateTimeStamp (ending in Z or an explicit offset) and no more than clockSkewMs (60s default) in the future. An offset-less timestamp is refused rather than read as local time.
4. The proof is bound to the document's issuer. The DID part of verificationMethod must equal issuer exactly, with no normalization (SPEC §4.8), or the document is issuerMismatch. A valid signature proves only that some key signed.
5. The signature verifies over the document minus its proof.

Keys travel in the did:key verification method — no resolver, no network.

Signing

import { signerFromPrivateKey, signTrustTask } from "@openvtc/trust-tasks-proof";

const signer = signerFromPrivateKey("ed25519", privateKey); // or "p256" / "p384"
const signed = signTrustTask(doc, signer);

signTrustTask refuses to sign a document with no issuer, or one whose issuer is not the signer's did:key — such a document could never verify. It replaces any existing proof.

Cryptosuites

| Cryptosuite | | |---|---| | eddsa-jcs-2022 | ✓ Ed25519 | | ecdsa-jcs-2019 | ✓ P-256, P-384 | | eddsa-rdfc-2022, ecdsa-rdfc-2019 | — a Trust Task document has no JSON-LD @context for RDF canonicalization to expand |

ML-DSA (post-quantum) suites will follow; the @noble foundation is chosen so they can be added without a JSON-LD toolchain.

License

Apache-2.0.