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Merged
metalurgical merged 1 commit into from
Feb 8, 2024
Merged

Feat ed/update lagrange #247

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22 changes: 11 additions & 11 deletions packages/core/src/core.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -438,7 +438,7 @@ class ThresholdKey implements ITKey {
shareArr.push(this.shares[pubPolyID][polyShares[i]].share.share);
shareIndexArr.push(this.shares[pubPolyID][polyShares[i]].share.shareIndex);
}
const privKey = lagrangeInterpolation(shareArr, shareIndexArr);
const privKey = lagrangeInterpolation(shareArr, shareIndexArr, this.ecCurve);
// check that priv key regenerated is correct
const reconstructedPubKey = getPubKeyPoint(privKey, this.keyType);
if (this.metadata.pubKey.x.cmp(reconstructedPubKey.x) !== 0) {
Expand Down Expand Up @@ -484,7 +484,7 @@ class ThresholdKey implements ITKey {
for (let i = 0; i < threshold; i += 1) {
pointsArr.push(new Point(new BN(sharesForExistingPoly[i], "hex"), this.shares[pubPolyID][sharesForExistingPoly[i]].share.share, this.keyType));
}
return lagrangeInterpolatePolynomial(pointsArr);
return lagrangeInterpolatePolynomial(pointsArr, this.ecCurve);
}

async deleteShare(shareIndex: BNString): Promise<DeleteShareResult> {
Expand Down Expand Up @@ -571,7 +571,7 @@ class ThresholdKey implements ITKey {
new Point(new BN(sharesForExistingPoly[i], "hex"), this.shares[previousPolyID][sharesForExistingPoly[i]].share.share, this.keyType)
);
}
const oldPoly = lagrangeInterpolatePolynomial(pointsArr);
const oldPoly = lagrangeInterpolatePolynomial(pointsArr, this.ecCurve);

const shareIndexesNeedingEncryption: string[] = [];
for (let index = 0; index < existingShareIndexes.length; index += 1) {
Expand Down Expand Up @@ -659,7 +659,7 @@ class ThresholdKey implements ITKey {
delete1OutOf1?: boolean;
} = {}): Promise<InitializeNewKeyResult> {
if (this.keyType === KeyType.secp256k1) {
const tmpPriv = importedKey ? importedKey : generatePrivate(this.ecCurve);
const tmpPriv = importedKey || generatePrivate(this.ecCurve);
this._setKey(new BN(tmpPriv));
} else {
const seed = importedKey ? importedKey.toBuffer() : nacl.randomBytes(32);
Expand All @@ -668,11 +668,11 @@ class ThresholdKey implements ITKey {
// need to decode from le ??
const tempPriv = new BN(keyPair.secretKey);
this._setKey(tempPriv);

// encrypt and add to local metadata transitions
const encMsg = await this.encrypt(Buffer.from(seed));
await this.addLocalMetadataTransitions({ input: [{ message: JSON.stringify(encMsg), dateAdded: Date.now() }], privKey: [tempPriv] });

// testing and checking code - to remove
// const decMsg = await this.decrypt(encMsg);
// const decSeed = Buffer.from(decMsg).toString("hex");
Expand Down Expand Up @@ -1298,8 +1298,8 @@ class ThresholdKey implements ITKey {
await this.inputShareStoreSafe(shareStore);
}

// Export Tkey
async exportFinalKey(): Promise<String> {
// Export Tkey
async exportFinalKey(): Promise<string> {
if (!this.metadata) {
throw CoreError.metadataUndefined();
}
Expand All @@ -1310,8 +1310,8 @@ class ThresholdKey implements ITKey {
if (this.keyType === KeyType.secp256k1) {
return this.privKey.toString("hex");
} else if (this.keyType === KeyType.ed25519) {
let result: EncryptedMessage = await this.storageLayer.getMetadata({privKey: this.privKey});
let seed = await this.decrypt(result);
const result: EncryptedMessage = await this.storageLayer.getMetadata({ privKey: this.privKey });
const seed = await this.decrypt(result);
return seed.toString("hex");
}
throw CoreError.default("Invalid KeyType");
Expand Down Expand Up @@ -1345,7 +1345,7 @@ class ThresholdKey implements ITKey {
for (let i = 0; i < threshold; i += 1) {
pointsArr.push(new Point(new BN(sharesForExistingPoly[i], "hex"), this.shares[pubPolyID][sharesForExistingPoly[i]].share.share, this.keyType));
}
const currentPoly = lagrangeInterpolatePolynomial(pointsArr);
const currentPoly = lagrangeInterpolatePolynomial(pointsArr, this.ecCurve);
const allExistingShares = currentPoly.generateShares(existingShareIndexes);
const shareArray = existingShareIndexes.map((shareIndex) => {
return this.metadata.shareToShareStore(allExistingShares[shareIndex].share);
Expand Down
31 changes: 16 additions & 15 deletions packages/core/src/lagrangeInterpolatePolynomial.ts
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
import { ecCurve, generatePrivateExcludingIndexes, KeyType, Point, Polynomial, Share } from "@tkey/common-types";
import { generatePrivateExcludingIndexes, KeyType, keyTypeToCurve, Point, Polynomial, Share } from "@tkey/common-types";
import { generatePrivate } from "@toruslabs/eccrypto";
import BN from "bn.js";
import { curve, ec as EllipticCurve } from "elliptic";
Expand All @@ -7,7 +7,7 @@ import CoreError from "./errors";

const generateEmptyBNArray = (length: number): BN[] => Array.from({ length }, () => new BN(0));

const denominator = (i: number, innerPoints: Array<Point>) => {
const denominator = (i: number, innerPoints: Array<Point>, ecCurve: EllipticCurve) => {
let result = new BN(1);
const xi = innerPoints[i].x;
for (let j = innerPoints.length - 1; j >= 0; j -= 1) {
Expand All @@ -22,9 +22,9 @@ const denominator = (i: number, innerPoints: Array<Point>) => {
return result;
};

const interpolationPoly = (i: number, innerPoints: Array<Point>): BN[] => {
const interpolationPoly = (i: number, innerPoints: Array<Point>, ecCurve: EllipticCurve): BN[] => {
let coefficients = generateEmptyBNArray(innerPoints.length);
const d = denominator(i, innerPoints);
const d = denominator(i, innerPoints, ecCurve);
if (d.cmp(new BN(0)) === 0) {
throw CoreError.default("Denominator for interpolationPoly is 0");
}
Expand Down Expand Up @@ -60,11 +60,11 @@ const pointSort = (innerPoints: Point[]): Point[] => {
return pointArrClone;
};

const lagrange = (unsortedPoints: Point[]) => {
const lagrange = (unsortedPoints: Point[], ecCurve: EllipticCurve) => {
const sortedPoints = pointSort(unsortedPoints);
const polynomial = generateEmptyBNArray(sortedPoints.length);
for (let i = 0; i < sortedPoints.length; i += 1) {
const coefficients = interpolationPoly(i, sortedPoints);
const coefficients = interpolationPoly(i, sortedPoints, ecCurve);
for (let k = 0; k < sortedPoints.length; k += 1) {
let tmp = new BN(sortedPoints[i].y);
tmp = tmp.mul(coefficients[k]);
Expand All @@ -75,11 +75,11 @@ const lagrange = (unsortedPoints: Point[]) => {
return new Polynomial(polynomial);
};

export function lagrangeInterpolatePolynomial(points: Array<Point>): Polynomial {
return lagrange(points);
export function lagrangeInterpolatePolynomial(points: Array<Point>, ecCurve: EllipticCurve): Polynomial {
return lagrange(points, ecCurve);
}

export function lagrangeInterpolation(shares: BN[], nodeIndex: BN[]): BN {
export function lagrangeInterpolation(shares: BN[], nodeIndex: BN[], ecCurve: EllipticCurve): BN {
if (shares.length !== nodeIndex.length) {
throw CoreError.default("shares not equal to nodeIndex length in lagrangeInterpolation");
}
Expand All @@ -106,19 +106,19 @@ export function lagrangeInterpolation(shares: BN[], nodeIndex: BN[]): BN {
// generateRandomPolynomial - determinisiticShares are assumed random
export function generateRandomPolynomial(
degree: number,
eCurve: EllipticCurve,
ecCurve: EllipticCurve,
secret?: BN,
deterministicShares?: Array<Share>,
keyType?: KeyType
): Polynomial {
let actualS = secret;
if (!secret) {
actualS = generatePrivateExcludingIndexes([new BN(0)], eCurve);
actualS = generatePrivateExcludingIndexes([new BN(0)], ecCurve);
}
if (!deterministicShares) {
const poly = [actualS];
for (let i = 0; i < degree; i += 1) {
const share = generatePrivateExcludingIndexes(poly, eCurve);
const share = generatePrivateExcludingIndexes(poly, ecCurve);
poly.push(share);
}
return new Polynomial(poly);
Expand All @@ -135,18 +135,19 @@ export function generateRandomPolynomial(
points[share.shareIndex.toString("hex") as string] = new Point(share.shareIndex, share.share, keyType);
});
for (let i = 0; i < degree - deterministicShares.length; i += 1) {
let shareIndex = generatePrivateExcludingIndexes([new BN(0)], eCurve);
let shareIndex = generatePrivateExcludingIndexes([new BN(0)], ecCurve);
while (points[shareIndex.toString("hex")] !== undefined) {
shareIndex = generatePrivateExcludingIndexes([new BN(0)], eCurve);
shareIndex = generatePrivateExcludingIndexes([new BN(0)], ecCurve);
}
points[shareIndex.toString("hex")] = new Point(shareIndex, new BN(generatePrivate()), keyType);
}
points["0"] = new Point(new BN(0), actualS, keyType);
return lagrangeInterpolatePolynomial(Object.values(points));
return lagrangeInterpolatePolynomial(Object.values(points), ecCurve);
}

// 2 + 3x = y | secret for index 1 is 5 >>> g^5 is the commitment | now we have g^2, g^3 and 1, |
export function polyCommitmentEval(polyCommitments: Array<Point>, index: BN, keyType?: KeyType): Point {
const ecCurve = keyTypeToCurve(keyType);
// convert to base points, this is badly written, its the only way to access the point rn zzz TODO: refactor
const basePtPolyCommitments: Array<curve.base.BasePoint> = [];
for (let i = 0; i < polyCommitments.length; i += 1) {
Expand Down