jsonld-signatures-merkleproof2019/lib/esm/inspectors/ensureValidReceipt.js

A jsonld signature implementation to support MerkleProof2019 verification in Verifiable Credential context

import sha256 from 'sha256';
import VerifierError from '../models/VerifierError';
import { toByteArray } from '../utils/data';
import getText from '../helpers/getText';
export default function ensureValidReceipt(receipt) {
    let proofHash = receipt.targetHash;
    const merkleRoot = receipt.merkleRoot;
    try {
        const proof = receipt.path;
        if (proof && proofHash) {
            for (const index in proof) {
                const node = proof[index];
                let appendedBuffer;
                if (typeof node.left !== 'undefined') {
                    appendedBuffer = toByteArray(`${node.left}${proofHash}`);
                    proofHash = sha256(appendedBuffer);
                }
                else if (typeof node.right !== 'undefined') {
                    appendedBuffer = toByteArray(`${proofHash}${node.right}`);
                    proofHash = sha256(appendedBuffer);
                }
                else {
                    throw new VerifierError('checkReceipt', 'Trigger catch error.');
                }
            }
        }
    }
    catch (e) {
        throw new VerifierError('checkReceipt', getText('errors', 'ensureValidReceipt'));
    }
    if (proofHash !== merkleRoot) {
        throw new VerifierError('checkReceipt', getText('errors', 'invalidMerkleReceipt'));
    }
}