"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); exports.bls = bls; const modular_js_1 = require("./modular.js"); const utils_js_1 = require("./utils.js"); // prettier-ignore const hash_to_curve_js_1 = require("./hash-to-curve.js"); const weierstrass_js_1 = require("./weierstrass.js"); // prettier-ignore const _2n = BigInt(2), _3n = BigInt(3); function bls(CURVE) { // Fields are specific for curve, so for now we'll need to pass them with opts const { Fp, Fr, Fp2, Fp6, Fp12 } = CURVE.fields; const BLS_X_LEN = (0, utils_js_1.bitLen)(CURVE.params.x); // Pre-compute coefficients for sparse multiplication // Point addition and point double calculations is reused for coefficients function calcPairingPrecomputes(p) { const { x, y } = p; // prettier-ignore const Qx = x, Qy = y, Qz = Fp2.ONE; // prettier-ignore let Rx = Qx, Ry = Qy, Rz = Qz; let ell_coeff = []; for (let i = BLS_X_LEN - 2; i >= 0; i--) { // Double let t0 = Fp2.sqr(Ry); // Ry² let t1 = Fp2.sqr(Rz); // Rz² let t2 = Fp2.multiplyByB(Fp2.mul(t1, _3n)); // 3 * T1 * B let t3 = Fp2.mul(t2, _3n); // 3 * T2 let t4 = Fp2.sub(Fp2.sub(Fp2.sqr(Fp2.add(Ry, Rz)), t1), t0); // (Ry + Rz)² - T1 - T0 ell_coeff.push([ Fp2.sub(t2, t0), // T2 - T0 Fp2.mul(Fp2.sqr(Rx), _3n), // 3 * Rx² Fp2.neg(t4), // -T4 ]); Rx = Fp2.div(Fp2.mul(Fp2.mul(Fp2.sub(t0, t3), Rx), Ry), _2n); // ((T0 - T3) * Rx * Ry) / 2 Ry = Fp2.sub(Fp2.sqr(Fp2.div(Fp2.add(t0, t3), _2n)), Fp2.mul(Fp2.sqr(t2), _3n)); // ((T0 + T3) / 2)² - 3 * T2² Rz = Fp2.mul(t0, t4); // T0 * T4 if ((0, utils_js_1.bitGet)(CURVE.params.x, i)) { // Addition let t0 = Fp2.sub(Ry, Fp2.mul(Qy, Rz)); // Ry - Qy * Rz let t1 = Fp2.sub(Rx, Fp2.mul(Qx, Rz)); // Rx - Qx * Rz ell_coeff.push([ Fp2.sub(Fp2.mul(t0, Qx), Fp2.mul(t1, Qy)), // T0 * Qx - T1 * Qy Fp2.neg(t0), // -T0 t1, // T1 ]); let t2 = Fp2.sqr(t1); // T1² let t3 = Fp2.mul(t2, t1); // T2 * T1 let t4 = Fp2.mul(t2, Rx); // T2 * Rx let t5 = Fp2.add(Fp2.sub(t3, Fp2.mul(t4, _2n)), Fp2.mul(Fp2.sqr(t0), Rz)); // T3 - 2 * T4 + T0² * Rz Rx = Fp2.mul(t1, t5); // T1 * T5 Ry = Fp2.sub(Fp2.mul(Fp2.sub(t4, t5), t0), Fp2.mul(t3, Ry)); // (T4 - T5) * T0 - T3 * Ry Rz = Fp2.mul(Rz, t3); // Rz * T3 } } return ell_coeff; } function millerLoop(ell, g1) { const { x } = CURVE.params; const Px = g1[0]; const Py = g1[1]; let f12 = Fp12.ONE; for (let j = 0, i = BLS_X_LEN - 2; i >= 0; i--, j++) { const E = ell[j]; f12 = Fp12.multiplyBy014(f12, E[0], Fp2.mul(E[1], Px), Fp2.mul(E[2], Py)); if ((0, utils_js_1.bitGet)(x, i)) { j += 1; const F = ell[j]; f12 = Fp12.multiplyBy014(f12, F[0], Fp2.mul(F[1], Px), Fp2.mul(F[2], Py)); } if (i !== 0) f12 = Fp12.sqr(f12); } return Fp12.conjugate(f12); } const utils = { randomPrivateKey: () => { const length = (0, modular_js_1.getMinHashLength)(Fr.ORDER); return (0, modular_js_1.mapHashToField)(CURVE.randomBytes(length), Fr.ORDER); }, calcPairingPrecomputes, }; // Point on G1 curve: (x, y) const G1_ = (0, weierstrass_js_1.weierstrassPoints)({ n: Fr.ORDER, ...CURVE.G1 }); const G1 = Object.assign(G1_, (0, hash_to_curve_js_1.createHasher)(G1_.ProjectivePoint, CURVE.G1.mapToCurve, { ...CURVE.htfDefaults, ...CURVE.G1.htfDefaults, })); function pairingPrecomputes(point) { const p = point; if (p._PPRECOMPUTES) return p._PPRECOMPUTES; p._PPRECOMPUTES = calcPairingPrecomputes(point.toAffine()); return p._PPRECOMPUTES; } // TODO: export // function clearPairingPrecomputes(point: G2) { // const p = point as G2 & withPairingPrecomputes; // p._PPRECOMPUTES = undefined; // } // Point on G2 curve (complex numbers): (x₁, x₂+i), (y₁, y₂+i) const G2_ = (0, weierstrass_js_1.weierstrassPoints)({ n: Fr.ORDER, ...CURVE.G2 }); const G2 = Object.assign(G2_, (0, hash_to_curve_js_1.createHasher)(G2_.ProjectivePoint, CURVE.G2.mapToCurve, { ...CURVE.htfDefaults, ...CURVE.G2.htfDefaults, })); const { ShortSignature } = CURVE.G1; const { Signature } = CURVE.G2; // Calculates bilinear pairing function pairing(Q, P, withFinalExponent = true) { if (Q.equals(G1.ProjectivePoint.ZERO) || P.equals(G2.ProjectivePoint.ZERO)) throw new Error('pairing is not available for ZERO point'); Q.assertValidity(); P.assertValidity(); // Performance: 9ms for millerLoop and ~14ms for exp. const Qa = Q.toAffine(); const looped = millerLoop(pairingPrecomputes(P), [Qa.x, Qa.y]); return withFinalExponent ? Fp12.finalExponentiate(looped) : looped; } function normP1(point) { return point instanceof G1.ProjectivePoint ? point : G1.ProjectivePoint.fromHex(point); } function normP1Hash(point, htfOpts) { return point instanceof G1.ProjectivePoint ? point : G1.hashToCurve((0, utils_js_1.ensureBytes)('point', point), htfOpts); } function normP2(point) { return point instanceof G2.ProjectivePoint ? point : Signature.fromHex(point); } function normP2Hash(point, htfOpts) { return point instanceof G2.ProjectivePoint ? point : G2.hashToCurve((0, utils_js_1.ensureBytes)('point', point), htfOpts); } // Multiplies generator (G1) by private key. // P = pk x G function getPublicKey(privateKey) { return G1.ProjectivePoint.fromPrivateKey(privateKey).toRawBytes(true); } // Multiplies generator (G2) by private key. // P = pk x G function getPublicKeyForShortSignatures(privateKey) { return G2.ProjectivePoint.fromPrivateKey(privateKey).toRawBytes(true); } function sign(message, privateKey, htfOpts) { const msgPoint = normP2Hash(message, htfOpts); msgPoint.assertValidity(); const sigPoint = msgPoint.multiply(G1.normPrivateKeyToScalar(privateKey)); if (message instanceof G2.ProjectivePoint) return sigPoint; return Signature.toRawBytes(sigPoint); } function signShortSignature(message, privateKey, htfOpts) { const msgPoint = normP1Hash(message, htfOpts); msgPoint.assertValidity(); const sigPoint = msgPoint.multiply(G1.normPrivateKeyToScalar(privateKey)); if (message instanceof G1.ProjectivePoint) return sigPoint; return ShortSignature.toRawBytes(sigPoint); } // Checks if pairing of public key & hash is equal to pairing of generator & signature. // e(P, H(m)) == e(G, S) function verify(signature, message, publicKey, htfOpts) { const P = normP1(publicKey); const Hm = normP2Hash(message, htfOpts); const G = G1.ProjectivePoint.BASE; const S = normP2(signature); // Instead of doing 2 exponentiations, we use property of billinear maps // and do one exp after multiplying 2 points. const ePHm = pairing(P.negate(), Hm, false); const eGS = pairing(G, S, false); const exp = Fp12.finalExponentiate(Fp12.mul(eGS, ePHm)); return Fp12.eql(exp, Fp12.ONE); } // Checks if pairing of public key & hash is equal to pairing of generator & signature. // e(S, G) == e(H(m), P) function verifyShortSignature(signature, message, publicKey, htfOpts) { const P = normP2(publicKey); const Hm = normP1Hash(message, htfOpts); const G = G2.ProjectivePoint.BASE; const S = normP1(signature); // Instead of doing 2 exponentiations, we use property of billinear maps // and do one exp after multiplying 2 points. const eHmP = pairing(Hm, P, false); const eSG = pairing(S, G.negate(), false); const exp = Fp12.finalExponentiate(Fp12.mul(eSG, eHmP)); return Fp12.eql(exp, Fp12.ONE); } function aggregatePublicKeys(publicKeys) { if (!publicKeys.length) throw new Error('Expected non-empty array'); const agg = publicKeys.map(normP1).reduce((sum, p) => sum.add(p), G1.ProjectivePoint.ZERO); const aggAffine = agg; //.toAffine(); if (publicKeys[0] instanceof G1.ProjectivePoint) { aggAffine.assertValidity(); return aggAffine; } // toRawBytes ensures point validity return aggAffine.toRawBytes(true); } function aggregateSignatures(signatures) { if (!signatures.length) throw new Error('Expected non-empty array'); const agg = signatures.map(normP2).reduce((sum, s) => sum.add(s), G2.ProjectivePoint.ZERO); const aggAffine = agg; //.toAffine(); if (signatures[0] instanceof G2.ProjectivePoint) { aggAffine.assertValidity(); return aggAffine; } return Signature.toRawBytes(aggAffine); } function aggregateShortSignatures(signatures) { if (!signatures.length) throw new Error('Expected non-empty array'); const agg = signatures.map(normP1).reduce((sum, s) => sum.add(s), G1.ProjectivePoint.ZERO); const aggAffine = agg; //.toAffine(); if (signatures[0] instanceof G1.ProjectivePoint) { aggAffine.assertValidity(); return aggAffine; } return ShortSignature.toRawBytes(aggAffine); } // https://ethresear.ch/t/fast-verification-of-multiple-bls-signatures/5407 // e(G, S) = e(G, SUM(n)(Si)) = MUL(n)(e(G, Si)) function verifyBatch(signature, messages, publicKeys, htfOpts) { // @ts-ignore // console.log('verifyBatch', bytesToHex(signature as any), messages, publicKeys.map(bytesToHex)); if (!messages.length) throw new Error('Expected non-empty messages array'); if (publicKeys.length !== messages.length) throw new Error('Pubkey count should equal msg count'); const sig = normP2(signature); const nMessages = messages.map((i) => normP2Hash(i, htfOpts)); const nPublicKeys = publicKeys.map(normP1); try { const paired = []; for (const message of new Set(nMessages)) { const groupPublicKey = nMessages.reduce((groupPublicKey, subMessage, i) => subMessage === message ? groupPublicKey.add(nPublicKeys[i]) : groupPublicKey, G1.ProjectivePoint.ZERO); // const msg = message instanceof PointG2 ? message : await PointG2.hashToCurve(message); // Possible to batch pairing for same msg with different groupPublicKey here paired.push(pairing(groupPublicKey, message, false)); } paired.push(pairing(G1.ProjectivePoint.BASE.negate(), sig, false)); const product = paired.reduce((a, b) => Fp12.mul(a, b), Fp12.ONE); const exp = Fp12.finalExponentiate(product); return Fp12.eql(exp, Fp12.ONE); } catch { return false; } } G1.ProjectivePoint.BASE._setWindowSize(4); return { getPublicKey, getPublicKeyForShortSignatures, sign, signShortSignature, verify, verifyBatch, verifyShortSignature, aggregatePublicKeys, aggregateSignatures, aggregateShortSignatures, millerLoop, pairing, G1, G2, Signature, ShortSignature, fields: { Fr, Fp, Fp2, Fp6, Fp12, }, params: { x: CURVE.params.x, r: CURVE.params.r, G1b: CURVE.G1.b, G2b: CURVE.G2.b, }, utils, }; } //# sourceMappingURL=bls.js.map