@covenance/dlc/dist/crypto/oracle.js

Crypto and Bitcoin functions for Covenance DLC implementation

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.commitToEvent = commitToEvent;
exports.attestEventOutcome = attestEventOutcome;
exports.extractOraclePrivKey = extractOraclePrivKey;
const secp256k1_1 = require("./secp256k1");
const utils_1 = require("../utils");
const general_1 = require("./general");
/**
 * Oracle function to create a commitment for an event in the future.
 * @param eventOutcomeHashes - Array of event outcome hashes for each potential event outcome
 * @param oraclePubKey - Oracle's public key
 * @returns Object containing array of event signature points and event nonce
 */
async function commitToEvent(eventOutcomeHashes, oraclePubKey) {
    // Generate random nonce
    const nonce = secp256k1_1.utils.randomPrivateKey();
    const nonceBigInt = BigInt('0x' + (0, utils_1.bytesToHex)(nonce));
    // Compute R = kG
    const R = secp256k1_1.Point.fromPrivateKey(nonce);
    // Compute signature points for each outcome
    const signaturePoints = await Promise.all(eventOutcomeHashes.map(async (m_i) => {
        // Compute H(R||V||m_i)
        const hashInput = new Uint8Array([
            ...R.toRawBytes(true).slice(1),
            ...oraclePubKey.toRawBytes(true).slice(1),
            ...m_i
        ]);
        const hash = await (0, utils_1.sha256)(hashInput);
        const e = (0, general_1.mod)(BigInt('0x' + (0, utils_1.bytesToHex)(hash)), secp256k1_1.CURVE.n);
        // Compute S_i = R + H(R||V||m_i)V
        return R.add(oraclePubKey.multiply(e));
    }));
    return { signaturePoints, nonce: nonceBigInt };
}
/**
 * Oracle function to attest to an event outcome.
 * @param oraclePrivKey - Oracle's private key
 * @param nonce - Event nonce
 * @param eventOutcomeHash - Hash of the event outcome
 * @returns Oracle's signature for the event outcome
 */
async function attestEventOutcome(oraclePrivKey, nonce, eventOutcomeHash) {
    // Compute R = kG
    const nonceBytes = new Uint8Array(32);
    const nonceHex = nonce.toString(16).padStart(64, '0');
    for (let i = 0; i < 32; i++) {
        nonceBytes[i] = parseInt(nonceHex.slice(i * 2, i * 2 + 2), 16);
    }
    const R = secp256k1_1.Point.fromPrivateKey(nonceBytes);
    // Get oracle's public key
    const V = secp256k1_1.Point.fromPrivateKey(oraclePrivKey);
    // Compute H(R||V||m_i)
    const hashInput = new Uint8Array([
        ...R.toRawBytes(true).slice(1),
        ...V.toRawBytes(true).slice(1),
        ...eventOutcomeHash
    ]);
    const hash = await (0, utils_1.sha256)(hashInput);
    const e = (0, general_1.mod)(BigInt('0x' + (0, utils_1.bytesToHex)(hash)), secp256k1_1.CURVE.n);
    // Compute s_i = k + H(R||V||m_i)v
    const v = BigInt('0x' + (0, utils_1.bytesToHex)(oraclePrivKey));
    const s_i = (0, general_1.mod)(nonce + e * v, secp256k1_1.CURVE.n);
    return { R, s: s_i };
}
/**
 * Function to extract the oracle's private key from two oracle outcome attestations.
 * This is to keep the oracle from cheating.
 */
/* c8 ignore start */
function extractOraclePrivKey() {
    throw new Error('Not implemented');
}
/* c8 ignore stop */ 
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