Merge pull request #1 from brickpop/master

Adding Typescript support

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 blindsecp256k1-browser.js
+dist

package.json

@@ -2,21 +2,34 @@
   "name": "blindsecp256k1",
   "version": "0.0.1",
   "description": "Blind signatures over secp256k1, compatible with https://github.com/arnaucube/go-blindsecp256k1",
-  "main": "src/index.js",
+  "main": "dist/index",
+  "types": "dist/index",
   "scripts": {
-    "browserify": "browserify src/index.js --standalone blindsecp256k1 > blindsecp256k1-browser.js",
-    "test": "mocha"
+    "prepublishOnly": "npm run build",
+    "clean": "rimraf dist",
+    "build": "npm run clean && ./node_modules/.bin/tsc",
+    "watch": "./node_modules/.bin/tsc -w -p .",
+    "ts-node": "./node_modules/.bin/ts-node",
+    "test": "npm run build && ./node_modules/.bin/mocha -r ts-node/register test/**/*.ts"
   },
   "author": "arnaucube",
   "license": "GPL-3.0",
   "dependencies": {
-    "bigi": "^1.1.0",
-    "bignumber.js": "7.0.2",
-    "ecurve": "1.0.0",
-    "@ethersproject/keccak256": "5.0.7"
+    "@ethersproject/keccak256": "5.0.7",
+    "bn.js": "^5.1.3",
+    "elliptic": "^6.5.4"
   },
   "devDependencies": {
-    "browserify": "^16.5.0",
-    "mocha": "^5.2.0"
+    "@types/bn.js": "^5.1.0",
+    "@types/chai": "^4.2.14",
+    "@types/elliptic": "^6.4.12",
+    "@types/mocha": "^8.2.0",
+    "@types/node": "^14.14.25",
+    "chai": "^4.2.0",
+    "mocha": "^8.2.1",
+    "rimraf": "^3.0.2",
+    "ts-node": "^9.1.1",
+    "tslint": "^6.1.3",
+    "typescript": "^4.1.3"
   }
 }

src/index.js

@@ -1,109 +0,0 @@
-var crypto = require('crypto');
-var BigInteger = require('bigi')
-var ecurve = require('ecurve')
-const {keccak256} = require("@ethersproject/keccak256");
-
-const ecparams = ecurve.getCurveByName('secp256k1');
-const G = ecparams.G;
-const n = ecparams.n;
-
-function newBigFromString(s) {
-    var a = new BigInteger()
-    a.fromString(s)
-    return a;
-}
-
-function random(bytes){
-    do {
-	var k = BigInteger.fromByteArrayUnsigned(crypto.randomBytes(bytes));
-    } while (k.toString() == "0" && k.gcd(n).toString() != "1")
-    return k;
-}
-
-function newKeyPair() {
-    const sk = random(32);
-    return {sk: sk, pk: G.multiply(sk)};
-}
-
-function newRequestParameters() {
-    const k = random(32);
-    return {k: k, signerR: G.multiply(k)};
-}
-
-/**
- * Blinds the message for the signer R.
- * @param {BigInteger} m
- * @param {Point} signerR
- * @returns {struct} {mBlinded: BigInteger, userSecretData: {a: BigInteger, b: BigInteger, f: Point}}
- */
-function blind(m, signerR) {
-    let u = {a: BigInteger.ZERO, b: BigInteger.ZERO, f: G};
-    u.a = random(32);
-    u.b = random(32);
-
-    const aR = signerR.multiply(u.a);
-    const bG = G.multiply(u.b);
-    u.f = aR.add(bG);
-
-    const rx = u.f.affineX.mod(n);
-
-    const ainv = u.a.modInverse(n);
-    const ainvrx = ainv.multiply(rx);
-
-    const mHex = m.toString(16);
-    const hHex = keccak256('0x' + mHex);
-    const h = BigInteger.fromHex(hHex.slice(2));
-    const mBlinded = ainvrx.multiply(h);
-
-    return {mBlinded: mBlinded.mod(n), userSecretData: u};
-}
-
-function blindSign(sk, mBlinded, k) {
-    let sBlind = sk.multiply(mBlinded);
-    sBlind = sBlind.add(k);
-    return sBlind.mod(n);
-}
-
-/**
- * Unblinds the blinded signature.
- * @param {BigInteger} sBlind - blinded signature
- * @param {a: BigInteger, b: BigInteger, f: Point} - userSecretData
- * @returns {s: BigInteger, f: Point} - unblinded signature
- */
-function unblind(sBlind, userSecretData) {
-    const s = userSecretData.a.multiply(sBlind).add(userSecretData.b);
-    return {s: s.mod(n), f: userSecretData.f};
-}
-
-function verify(m, s, q) {
-    const sG = G.multiply(s.s);
-
-    const mHex = m.toString(16);
-    const hHex = keccak256('0x' + mHex);
-    const h = BigInteger.fromHex(hHex.slice(2));
-
-    const rx = s.f.affineX.mod(n);
-    const right = s.f.add(
-	q.multiply(
-	    rx.multiply(h)
-	)
-    );
-
-    if ((sG.affineX.toString() == right.affineX.toString())
-	&& (sG.affineY.toString() == right.affineY.toString())) {
-	return true;
-    }
-    return false;
-}
-
-
-module.exports = {
-    newBigFromString: newBigFromString,
-    ecparams: ecparams,
-    newKeyPair: newKeyPair,
-    newRequestParameters: newRequestParameters,
-    blind: blind,
-    blindSign: blindSign,
-    unblind: unblind,
-    verify: verify
-}

src/index.ts

@@ -0,0 +1,124 @@
+import { randomBytes } from 'crypto'
+import * as BigNumber from 'bn.js'
+import { ec, curve } from 'elliptic'
+import { keccak256 } from "@ethersproject/keccak256"
+
+export type Point = curve.base.BasePoint
+export { BigNumber }
+
+const secp256k1 = new ec("secp256k1")
+const G: Point = secp256k1.g
+const n = secp256k1.n // as BigNumber
+
+export const ecParams = { G, n }
+
+export type UserSecretData = { a: BigNumber, b: BigNumber, f: Point }
+export type UnblindedSignature = { s: BigNumber, f: Point }
+
+export function messageToBigNumber(message: string) {
+    const msg = Buffer.from(message, 'utf8')
+    return new BigNumber(msg)
+}
+
+export function hashBigNumber(m: BigNumber) {
+    const mHex = m.toString(16)
+
+    if (mHex.length % 2 == 0)
+        return keccak256('0x' + mHex).slice(2) // Trim 0x
+    else
+        return keccak256('0x0' + mHex).slice(2) // Trim 0x
+}
+
+export function stringToBigNumber(s: string) {
+    return new BigNumber(s)
+}
+
+export function decodePoint(hexPoint: string): Point {
+    return secp256k1.keyFromPublic(Buffer.from(hexPoint, "hex")).getPublic()
+}
+
+function random(bytes: number) {
+    let k: BigNumber
+    do {
+        k = new BigNumber(randomBytes(bytes))
+    } while (k.toString() == "0" && k.gcd(n).toString() != "1")
+    return k
+}
+
+export function newKeyPair() {
+    const sk = random(32)
+    return { sk: sk, pk: G.mul(sk) }
+}
+
+export function newRequestParameters() {
+    const k = random(32)
+    return { k: k, signerR: G.mul(k) }
+}
+
+/**
+ * Blinds the message for the signer R.
+ * @param m The message to blind
+ * @param signerR
+ * @returns The blinded signature and the user secret data
+ */
+export function blind(m: BigNumber, signerR: Point): { mBlinded: BigNumber, userSecretData: UserSecretData } {
+    const u: UserSecretData = { a: new BigNumber(0), b: new BigNumber(0), f: G }
+    u.a = random(32)
+    u.b = random(32)
+
+    const aR = signerR.mul(u.a)
+    const bG = G.mul(u.b)
+    u.f = aR.add(bG)
+
+    const rx = u.f.getX().mod(n)
+
+    const ainv = u.a.invm(n)
+    const ainvrx = ainv.mul(rx)
+
+    // const mHex = m.toString(16)
+    const hHex = hashBigNumber(m)
+
+    const h = new BigNumber(Buffer.from(hHex, "hex"))
+    const mBlinded = ainvrx.mul(h)
+
+    return { mBlinded: mBlinded.mod(n), userSecretData: u }
+}
+
+/** Performs a signature on a blinded message */
+export function blindSign(sk: BigNumber, mBlinded: BigNumber, k: BigNumber): BigNumber {
+    let sBlind = sk.mul(mBlinded)
+    sBlind = sBlind.add(k)
+    return sBlind.mod(n)
+}
+
+/**
+ * Unblinds the blinded signature.
+ * @param blinded signature
+ * @param userSecretData
+ * @returns unblinded signature
+ */
+export function unblind(sBlind: BigNumber, userSecretData: UserSecretData): UnblindedSignature {
+    const s = userSecretData.a.mul(sBlind).add(userSecretData.b)
+    return { s: s.mod(n), f: userSecretData.f }
+}
+
+export function verify(m: BigNumber, s: UnblindedSignature, q: Point) {
+    const sG = G.mul(s.s)
+
+    const hHex = hashBigNumber(m)
+
+    const h = new BigNumber(Buffer.from(hHex, "hex"))
+
+    const rx = s.f.getX().mod(n)
+    const right = s.f.add(
+        q.mul(
+            rx.mul(h)
+        )
+    )
+
+    if ((sG.getX().toString() == right.getX().toString())
+        && (sG.getY().toString() == right.getY().toString())) {
+        return true
+    }
+    return false
+}

test/index.test.js

@@ -1,39 +0,0 @@
-const assert = require('assert');
-const BigInteger = require('bigi');
-var {Point} = require('ecurve')
-const {keccak256} = require("@ethersproject/keccak256");
-
-const {newBigFromString, ecparams, newKeyPair, newRequestParameters, blind, blindSign, unblind, verify} = require("../src/index.js");
-
-describe("keccak256", function () {
-    it("keccak256", async () => {
-	const m = BigInteger.fromBuffer(Buffer.from("test", 'utf8'));
-	const mHex = m.toString(16);
-	const hHex = keccak256('0x' + mHex);
-	assert.equal('0x9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658', hHex);
-	const h = BigInteger.fromHex(hHex.slice(2));
-	assert.equal('70622639689279718371527342103894932928233838121221666359043189029713682937432', h.toString());
-    });
-});
-
-describe("test blind", function () {
-    it("blind", async () => {
-	    const {sk, pk} = newKeyPair();
-
-	    const {k, signerR} = newRequestParameters();
-
-	    const msg = BigInteger.fromBuffer(
-		    Buffer.from("test", 'utf8')
-	    );
-	    assert.equal('1952805748', msg.toString());
-
-	    const {mBlinded, userSecretData} = blind(msg, signerR);
-
-	    const sBlind = blindSign(sk, mBlinded, k);
-
-	    const sig = unblind(sBlind, userSecretData);
-
-	    const verified = verify(msg, sig, pk);
-	    assert.equal(true, verified);
-    });
-});

test/index.test.ts

@@ -0,0 +1,55 @@
+import * as assert from 'assert'
+
+import {
+	stringToBigNumber,
+	messageToBigNumber,
+	decodePoint,
+	ecParams,
+	newKeyPair,
+	newRequestParameters,
+	blind,
+	blindSign,
+	unblind,
+	verify,
+	hashBigNumber,
+	Point,
+	BigNumber
+} from "../src/index"
+
+describe("keccak256", function () {
+	it("should hash strings and big numbers", async () => {
+		const m = messageToBigNumber("test")
+		assert.strictEqual('1952805748', m.toString())
+
+		const hHex = hashBigNumber(m)
+		assert.strictEqual(hHex, '9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658')
+		const h = new BigNumber(Buffer.from(hHex, "hex"))
+		assert.strictEqual(h.toString(), '70622639689279718371527342103894932928233838121221666359043189029713682937432')
+	})
+
+	it("should decode points in the secp256k1 curve", () => {
+		const tokenR = "7cfe4af054e13b4e7231d876d23205fb5f939ac8185271ca6b64c635a365faae259fb8cabdb06dde39d1ebeada3cb75cb9739621a79c61a8cf1e9a38abaf782a"
+		const point = decodePoint("04" + tokenR)
+		assert.strictEqual(point.getX().toString(16), tokenR.substr(0, 64))
+		assert.strictEqual(point.getY().toString(16), tokenR.substr(64))
+	})
+})
+
+describe("blind signatures", function () {
+	it("should blind, unblind and verify", async () => {
+		const { sk, pk } = newKeyPair()
+
+		const { k, signerR } = newRequestParameters()
+
+		const msg = messageToBigNumber("test")
+
+		const { mBlinded, userSecretData } = blind(msg, signerR)
+
+		const sBlind = blindSign(sk, mBlinded, k)
+
+		const sig = unblind(sBlind, userSecretData)
+
+		const verified = verify(msg, sig, pk)
+		assert(verified)
+	})
+})

tsconfig.json

@@ -0,0 +1,19 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "moduleResolution": "node",
+        "resolveJsonModule": true,
+        "pretty": true,
+        "declaration": true,
+        "sourceMap": true,
+        "target": "es2017",
+        "outDir": "dist",
+        "baseUrl": "src"
+    },
+    "include": [
+        "src/**/*.ts"
+    ],
+    "exclude": [
+        "node_modules"
+    ]
+}

tslint.json

@@ -0,0 +1,24 @@
+{
+    "defaultSeverity": "error",
+    "extends": [
+        "tslint:recommended"
+    ],
+    "jsRules": {},
+    "rules": {
+        "indent": [
+            true,
+            "spaces",
+            4
+        ],
+        "semicolon": [
+            false,
+            "always"
+        ]
+    },
+    "rulesDirectory": [],
+    "linterOptions": {
+        "exclude": [
+            "node_modules/**"
+        ]
+    }
+}