Use declarative curve field validation

src/abstract/curve.ts

@@ -1,6 +1,7 @@
 /*! noble-curves - MIT License (c) 2022 Paul Miller (paulmillr.com) */
 // Abelian group utilities
 import { Field, validateField, nLength } from './modular.js';
+import { validateObject } from './utils.js';
 const _0n = BigInt(0);
 const _1n = BigInt(1);
 
@@ -153,7 +154,7 @@ export function wNAF<T extends Group<T>>(c: GroupConstructor<T>, bits: number) {
 
 // Generic BasicCurve interface: works even for polynomial fields (BLS): P, n, h would be ok.
 // Though generator can be different (Fp2 / Fp6 for BLS).
-export type AbstractCurve<T> = {
+export type BasicCurve<T> = {
   Fp: Field<T>; // Field over which we'll do calculations (Fp)
   n: bigint; // Curve order, total count of valid points in the field
   nBitLength?: number; // bit length of curve order
@@ -165,20 +166,21 @@ export type AbstractCurve<T> = {
   allowInfinityPoint?: boolean; // bls12-381 requires it. ZERO point is valid, but invalid pubkey
 };
 
-export function validateAbsOpts<FP, T>(curve: AbstractCurve<FP> & T) {
+export function validateBasic<FP, T>(curve: BasicCurve<FP> & T) {
   validateField(curve.Fp);
-  for (const i of ['n', 'h'] as const) {
+  validateObject(
-    const val = curve[i];
+    curve,
-    if (typeof val !== 'bigint') throw new Error(`Invalid curve param ${i}=${val} (${typeof val})`);
+    {
-  }
+      n: 'bigint',
-  if (!curve.Fp.isValid(curve.Gx)) throw new Error('Invalid generator X coordinate Fp element');
+      h: 'bigint',
-  if (!curve.Fp.isValid(curve.Gy)) throw new Error('Invalid generator Y coordinate Fp element');
+      Gx: 'field',
-
+      Gy: 'field',
-  for (const i of ['nBitLength', 'nByteLength'] as const) {
+    },
-    const val = curve[i];
+    {
-    if (val === undefined) continue; // Optional
+      nBitLength: 'isSafeInteger',
-    if (!Number.isSafeInteger(val)) throw new Error(`Invalid param ${i}=${val} (${typeof val})`);
+      nByteLength: 'isSafeInteger',
     }
+  );
   // Set defaults
   return Object.freeze({ ...nLength(curve.n, curve.nBitLength), ...curve } as const);
 }

src/abstract/edwards.ts

@@ -1,23 +1,9 @@
 /*! noble-curves - MIT License (c) 2022 Paul Miller (paulmillr.com) */
 // Twisted Edwards curve. The formula is: ax² + y² = 1 + dx²y²
 import { mod } from './modular.js';
-import {
+import * as ut from './utils.js';
-  bytesToHex,
+import { ensureBytes, FHash, Hex } from './utils.js';
-  bytesToNumberLE,
+import { Group, GroupConstructor, wNAF, BasicCurve, validateBasic, AffinePoint } from './curve.js';
-  concatBytes,
-  ensureBytes,
-  FHash,
-  Hex,
-  numberToBytesLE,
-} from './utils.js';
-import {
-  Group,
-  GroupConstructor,
-  wNAF,
-  AbstractCurve,
-  validateAbsOpts,
-  AffinePoint,
-} from './curve.js';
 
 // Be friendly to bad ECMAScript parsers by not using bigint literals like 123n
 const _0n = BigInt(0);
@@ -26,7 +12,7 @@ const _2n = BigInt(2);
 const _8n = BigInt(8);
 
 // Edwards curves must declare params a & d.
-export type CurveType = AbstractCurve<bigint> & {
+export type CurveType = BasicCurve<bigint> & {
   a: bigint; // curve param a
   d: bigint; // curve param d
   hash: FHash; // Hashing
@@ -39,19 +25,22 @@ export type CurveType = AbstractCurve<bigint> & {
 };
 
 function validateOpts(curve: CurveType) {
-  const opts = validateAbsOpts(curve);
+  const opts = validateBasic(curve);
-  if (typeof opts.hash !== 'function') throw new Error('Invalid hash function');
+  ut.validateObject(
-  for (const i of ['a', 'd'] as const) {
+    curve,
-    const val = opts[i];
+    {
-    if (typeof val !== 'bigint') throw new Error(`Invalid curve param ${i}=${val} (${typeof val})`);
+      hash: 'function',
-  }
+      a: 'bigint',
-  for (const fn of ['randomBytes'] as const) {
+      d: 'bigint',
-    if (typeof opts[fn] !== 'function') throw new Error(`Invalid ${fn} function`);
+      randomBytes: 'function',
-  }
+    },
-  for (const fn of ['adjustScalarBytes', 'domain', 'uvRatio', 'mapToCurve'] as const) {
+    {
-    if (opts[fn] === undefined) continue; // Optional
+      adjustScalarBytes: 'function',
-    if (typeof opts[fn] !== 'function') throw new Error(`Invalid ${fn} function`);
+      domain: 'function',
+      uvRatio: 'function',
+      mapToCurve: 'function',
     }
+  );
   // Set defaults
   return Object.freeze({ ...opts } as const);
 }
@@ -75,7 +64,7 @@ export interface ExtPointConstructor extends GroupConstructor<ExtPointType> {
   new (x: bigint, y: bigint, z: bigint, t: bigint): ExtPointType;
   fromAffine(p: AffinePoint<bigint>): ExtPointType;
   fromHex(hex: Hex): ExtPointType;
-  fromPrivateKey(privateKey: Hex): ExtPointType; // TODO: remove
+  fromPrivateKey(privateKey: Hex): ExtPointType;
 }
 
 export type CurveFn = {
@@ -340,7 +329,7 @@ export function twistedEdwards(curveDef: CurveType): CurveFn {
       const normed = hex.slice(); // copy again, we'll manipulate it
       const lastByte = hex[len - 1]; // select last byte
       normed[len - 1] = lastByte & ~0x80; // clear last bit
-      const y = bytesToNumberLE(normed);
+      const y = ut.bytesToNumberLE(normed);
       if (y === _0n) {
         // y=0 is allowed
       } else {
@@ -366,12 +355,12 @@ export function twistedEdwards(curveDef: CurveType): CurveFn {
     }
     toRawBytes(): Uint8Array {
       const { x, y } = this.toAffine();
-      const bytes = numberToBytesLE(y, Fp.BYTES); // each y has 2 x values (x, -y)
+      const bytes = ut.numberToBytesLE(y, Fp.BYTES); // each y has 2 x values (x, -y)
       bytes[bytes.length - 1] |= x & _1n ? 0x80 : 0; // when compressing, it's enough to store y
       return bytes; // and use the last byte to encode sign of x
     }
     toHex(): string {
-      return bytesToHex(this.toRawBytes()); // Same as toRawBytes, but returns string.
+      return ut.bytesToHex(this.toRawBytes()); // Same as toRawBytes, but returns string.
     }
   }
   const { BASE: G, ZERO: I } = Point;
@@ -382,7 +371,7 @@ export function twistedEdwards(curveDef: CurveType): CurveFn {
   }
   // Little-endian SHA512 with modulo n
   function modN_LE(hash: Uint8Array): bigint {
-    return modN(bytesToNumberLE(hash));
+    return modN(ut.bytesToNumberLE(hash));
   }
   function isHex(item: Hex, err: string) {
     if (typeof item !== 'string' && !(item instanceof Uint8Array))
@@ -411,7 +400,7 @@ export function twistedEdwards(curveDef: CurveType): CurveFn {
 
   // int('LE', SHA512(dom2(F, C) || msgs)) mod N
   function hashDomainToScalar(context: Hex = new Uint8Array(), ...msgs: Uint8Array[]) {
-    const msg = concatBytes(...msgs);
+    const msg = ut.concatBytes(...msgs);
     return modN_LE(cHash(domain(msg, ensureBytes(context), !!preHash)));
   }
 
@@ -426,7 +415,7 @@ export function twistedEdwards(curveDef: CurveType): CurveFn {
     const k = hashDomainToScalar(context, R, pointBytes, msg); // R || A || PH(M)
     const s = modN(r + k * scalar); // S = (r + k * s) mod L
     assertGE0(s); // 0 <= s < l
-    const res = concatBytes(R, numberToBytesLE(s, Fp.BYTES));
+    const res = ut.concatBytes(R, ut.numberToBytesLE(s, Fp.BYTES));
     return ensureBytes(res, nByteLength * 2); // 64-byte signature
   }
 
@@ -439,7 +428,7 @@ export function twistedEdwards(curveDef: CurveType): CurveFn {
     if (preHash) msg = preHash(msg); // for ed25519ph, etc
     const A = Point.fromHex(publicKey, false); // Check for s bounds, hex validity
     const R = Point.fromHex(sig.slice(0, len), false); // 0 <= R < 2^256: ZIP215 R can be >= P
-    const s = bytesToNumberLE(sig.slice(len, 2 * len)); // 0 <= s < l
+    const s = ut.bytesToNumberLE(sig.slice(len, 2 * len)); // 0 <= s < l
     const SB = G.multiplyUnsafe(s);
     const k = hashDomainToScalar(context, R.toRawBytes(), A.toRawBytes(), msg);
     const RkA = R.add(A.multiplyUnsafe(k));

src/abstract/hash-to-curve.ts

@@ -45,7 +45,7 @@ declare const TextDecoder: any;
 
 export function stringToBytes(str: string): Uint8Array {
   if (typeof str !== 'string') {
-    throw new TypeError(`utf8ToBytes expected string, got ${typeof str}`);
+    throw new Error(`utf8ToBytes expected string, got ${typeof str}`);
   }
   return new TextEncoder().encode(str);
 }

src/abstract/modular.ts

@@ -7,6 +7,7 @@ import {
   bytesToNumberBE,
   bytesToNumberLE,
   ensureBytes,
+  validateObject,
 } from './utils.js';
 // prettier-ignore
 const _0n = BigInt(0), _1n = BigInt(1), _2n = BigInt(2), _3n = BigInt(3);
@@ -40,7 +41,6 @@ export function pow(num: bigint, power: bigint, modulo: bigint): bigint {
 }
 
 // Does x ^ (2 ^ power) mod p. pow2(30, 4) == 30 ^ (2 ^ 4)
-// TODO: Fp version?
 export function pow2(x: bigint, power: bigint, modulo: bigint): bigint {
   let res = x;
   while (power-- > _0n) {
@@ -249,18 +249,17 @@ const FIELD_FIELDS = [
   'addN', 'subN', 'mulN', 'sqrN'
 ] as const;
 export function validateField<T>(field: Field<T>) {
-  for (const i of ['ORDER', 'MASK'] as const) {
+  const initial = {
-    if (typeof field[i] !== 'bigint')
+    ORDER: 'bigint',
-      throw new Error(`Invalid field param ${i}=${field[i]} (${typeof field[i]})`);
+    MASK: 'bigint',
-  }
+    BYTES: 'isSafeInteger',
-  for (const i of ['BYTES', 'BITS'] as const) {
+    BITS: 'isSafeInteger',
-    if (typeof field[i] !== 'number')
+  } as Record<string, string>;
-      throw new Error(`Invalid field param ${i}=${field[i]} (${typeof field[i]})`);
+  const opts = FIELD_FIELDS.reduce((map, val: string) => {
-  }
+    map[val] = 'function';
-  for (const i of FIELD_FIELDS) {
+    return map;
-    if (typeof field[i] !== 'function')
+  }, initial);
-      throw new Error(`Invalid field param ${i}=${field[i]} (${typeof field[i]})`);
+  return validateObject(field, opts);
-  }
 }
 
 // Generic field functions

src/abstract/montgomery.ts

@@ -1,14 +1,13 @@
 /*! noble-curves - MIT License (c) 2022 Paul Miller (paulmillr.com) */
 import { mod, pow } from './modular.js';
-import { ensureBytes, numberToBytesLE, bytesToNumberLE } from './utils.js';
+import { bytesToNumberLE, ensureBytes, numberToBytesLE, validateObject } from './utils.js';
 
 const _0n = BigInt(0);
 const _1n = BigInt(1);
 type Hex = string | Uint8Array;
 
 export type CurveType = {
-  // Field over which we'll do calculations. Verify with:
+  P: bigint; // finite field prime
-  P: bigint;
   nByteLength: number;
   adjustScalarBytes?: (bytes: Uint8Array) => Uint8Array;
   domain?: (data: Uint8Array, ctx: Uint8Array, phflag: boolean) => Uint8Array;
@@ -27,24 +26,20 @@ export type CurveFn = {
 };
 
 function validateOpts(curve: CurveType) {
-  for (const i of ['a24'] as const) {
+  validateObject(
-    if (typeof curve[i] !== 'bigint')
+    curve,
-      throw new Error(`Invalid curve param ${i}=${curve[i]} (${typeof curve[i]})`);
+    {
-  }
+      a24: 'bigint',
-  for (const i of ['montgomeryBits', 'nByteLength'] as const) {
+    },
-    if (curve[i] === undefined) continue; // Optional
+    {
-    if (!Number.isSafeInteger(curve[i]))
+      montgomeryBits: 'isSafeInteger',
-      throw new Error(`Invalid curve param ${i}=${curve[i]} (${typeof curve[i]})`);
+      nByteLength: 'isSafeInteger',
-  }
+      adjustScalarBytes: 'function',
-  for (const fn of ['adjustScalarBytes', 'domain', 'powPminus2'] as const) {
+      domain: 'function',
-    if (curve[fn] === undefined) continue; // Optional
+      powPminus2: 'function',
-    if (typeof curve[fn] !== 'function') throw new Error(`Invalid ${fn} function`);
+      Gu: 'string',
-  }
-  for (const i of ['Gu'] as const) {
-    if (curve[i] === undefined) continue; // Optional
-    if (typeof curve[i] !== 'string')
-      throw new Error(`Invalid curve param ${i}=${curve[i]} (${typeof curve[i]})`);
     }
+  );
   // Set defaults
   return Object.freeze({ ...curve } as const);
 }
@@ -61,27 +56,7 @@ export function montgomery(curveDef: CurveType): CurveFn {
   const adjustScalarBytes = CURVE.adjustScalarBytes || ((bytes: Uint8Array) => bytes);
   const powPminus2 = CURVE.powPminus2 || ((x: bigint) => pow(x, P - BigInt(2), P));
 
-  /**
+  // cswap from RFC7748. But it is not from RFC7748!
-   * Checks for num to be in range:
-   * For strict == true:  `0 <  num < max`.
-   * For strict == false: `0 <= num < max`.
-   * Converts non-float safe numbers to bigints.
-   */
-  function normalizeScalar(num: bigint, max: bigint, strict = true): bigint {
-    if (!max) throw new TypeError('Specify max value');
-    if (typeof num === 'number' && Number.isSafeInteger(num)) num = BigInt(num);
-    if (typeof num === 'bigint' && num < max) {
-      if (strict) {
-        if (_0n < num) return num;
-      } else {
-        if (_0n <= num) return num;
-      }
-    }
-    throw new TypeError('Expected valid scalar: 0 < scalar < max');
-  }
-
-  // cswap from RFC7748
-  // NOTE: cswap is not from RFC7748!
   /*
     cswap(swap, x_2, x_3):
          dummy = mask(swap) AND (x_2 XOR x_3)
@@ -98,6 +73,11 @@ export function montgomery(curveDef: CurveType): CurveFn {
     return [x_2, x_3];
   }
 
+  function assertFieldElement(n: bigint): bigint {
+    if (typeof n === 'bigint' && _0n <= n && n < P) return n;
+    throw new Error('Expected valid scalar 0 < scalar < CURVE.P');
+  }
+
   // x25519 from 4
   /**
    *
@@ -106,11 +86,10 @@ export function montgomery(curveDef: CurveType): CurveFn {
    * @returns new Point on Montgomery curve
    */
   function montgomeryLadder(pointU: bigint, scalar: bigint): bigint {
-    const { P } = CURVE;
+    const u = assertFieldElement(pointU);
-    const u = normalizeScalar(pointU, P);
     // Section 5: Implementations MUST accept non-canonical values and process them as
     // if they had been reduced modulo the field prime.
-    const k = normalizeScalar(scalar, P);
+    const k = assertFieldElement(scalar);
     // The constant a24 is (486662 - 2) / 4 = 121665 for curve25519/X25519
     const a24 = CURVE.a24;
     const x_1 = u;
@@ -166,28 +145,20 @@ export function montgomery(curveDef: CurveType): CurveFn {
   }
 
   function decodeUCoordinate(uEnc: Hex): bigint {
-    const u = ensureBytes(uEnc, montgomeryBytes);
     // Section 5: When receiving such an array, implementations of X25519
     // MUST mask the most significant bit in the final byte.
     // This is very ugly way, but it works because fieldLen-1 is outside of bounds for X448, so this becomes NOOP
     // fieldLen - scalaryBytes = 1 for X448 and = 0 for X25519
+    const u = ensureBytes(uEnc, montgomeryBytes);
     u[fieldLen - 1] &= 127; // 0b0111_1111
     return bytesToNumberLE(u);
   }
-
   function decodeScalar(n: Hex): bigint {
     const bytes = ensureBytes(n);
     if (bytes.length !== montgomeryBytes && bytes.length !== fieldLen)
       throw new Error(`Expected ${montgomeryBytes} or ${fieldLen} bytes, got ${bytes.length}`);
     return bytesToNumberLE(adjustScalarBytes(bytes));
   }
-  /**
-   * Computes shared secret between private key "scalar" and public key's "u" (x) coordinate.
-   * We can get 'y' coordinate from 'u',
-   * but Point.fromHex also wants 'x' coordinate oddity flag,
-   * and we cannot get 'x' without knowing 'v'.
-   * Need to add generic conversion between twisted edwards and complimentary curve for JubJub.
-   */
   function scalarMult(scalar: Hex, u: Hex): Uint8Array {
     const pointU = decodeUCoordinate(u);
     const _scalar = decodeScalar(scalar);
@@ -197,12 +168,7 @@ export function montgomery(curveDef: CurveType): CurveFn {
     if (pu === _0n) throw new Error('Invalid private or public key received');
     return encodeUCoordinate(pu);
   }
-  /**
+  // Computes public key from private. By doing scalar multiplication of base point.
-   * Computes public key from private.
-   * Executes scalar multiplication of curve's base point by scalar.
-   * @param scalar private key
-   * @returns new public key
-   */
   function scalarMultBase(scalar: Hex): Uint8Array {
     return scalarMult(scalar, CURVE.Gu);
   }

src/abstract/poseidon.ts

@@ -1,6 +1,6 @@
 /*! noble-curves - MIT License (c) 2022 Paul Miller (paulmillr.com) */
 // Poseidon Hash: https://eprint.iacr.org/2019/458.pdf, https://www.poseidon-hash.info
-import { Field, validateField, FpPow } from './modular.js';
+import { Field, FpPow, validateField } from './modular.js';
 // We don't provide any constants, since different implementations use different constants.
 // For reference constants see './test/poseidon.test.js'.
 export type PoseidonOpts = {

src/abstract/utils.ts

@@ -18,7 +18,7 @@ export type FHash = (message: Uint8Array | string) => Uint8Array;
 
 const hexes = Array.from({ length: 256 }, (v, i) => i.toString(16).padStart(2, '0'));
 export function bytesToHex(bytes: Uint8Array): string {
-  if (!u8a(bytes)) throw new Error('Expected Uint8Array');
+  if (!u8a(bytes)) throw new Error('Uint8Array expected');
   // pre-caching improves the speed 6x
   let hex = '';
   for (let i = 0; i < bytes.length; i++) {
@@ -33,21 +33,21 @@ export function numberToHexUnpadded(num: number | bigint): string {
 }
 
 export function hexToNumber(hex: string): bigint {
-  if (typeof hex !== 'string') throw new Error('hexToNumber: expected string, got ' + typeof hex);
+  if (typeof hex !== 'string') throw new Error('string expected, got ' + typeof hex);
   // Big Endian
   return BigInt(`0x${hex}`);
 }
 
 // Caching slows it down 2-3x
 export function hexToBytes(hex: string): Uint8Array {
-  if (typeof hex !== 'string') throw new Error('hexToBytes: expected string, got ' + typeof hex);
+  if (typeof hex !== 'string') throw new Error('string expected, got ' + typeof hex);
-  if (hex.length % 2) throw new Error('hexToBytes: received invalid unpadded hex ' + hex.length);
+  if (hex.length % 2) throw new Error('hex string is invalid: unpadded ' + hex.length);
   const array = new Uint8Array(hex.length / 2);
   for (let i = 0; i < array.length; i++) {
     const j = i * 2;
     const hexByte = hex.slice(j, j + 2);
     const byte = Number.parseInt(hexByte, 16);
-    if (Number.isNaN(byte) || byte < 0) throw new Error('Invalid byte sequence');
+    if (Number.isNaN(byte) || byte < 0) throw new Error('invalid byte sequence');
     array[i] = byte;
   }
   return array;
@@ -58,7 +58,7 @@ export function bytesToNumberBE(bytes: Uint8Array): bigint {
   return hexToNumber(bytesToHex(bytes));
 }
 export function bytesToNumberLE(bytes: Uint8Array): bigint {
-  if (!u8a(bytes)) throw new Error('Expected Uint8Array');
+  if (!u8a(bytes)) throw new Error('Uint8Array expected');
   return hexToNumber(bytesToHex(Uint8Array.from(bytes).reverse()));
 }
 
@@ -66,11 +66,7 @@ export const numberToBytesBE = (n: bigint, len: number) =>
   hexToBytes(n.toString(16).padStart(len * 2, '0'));
 export const numberToBytesLE = (n: bigint, len: number) => numberToBytesBE(n, len).reverse();
 // Returns variable number bytes (minimal bigint encoding?)
-export const numberToVarBytesBE = (n: bigint) => {
+export const numberToVarBytesBE = (n: bigint) => hexToBytes(numberToHexUnpadded(n));
-  let hex = n.toString(16);
-  if (hex.length & 1) hex = '0' + hex;
-  return hexToBytes(hex);
-};
 
 export function ensureBytes(hex: Hex, expectedLength?: number): Uint8Array {
   // Uint8Array.from() instead of hash.slice() because node.js Buffer
@@ -82,17 +78,15 @@ export function ensureBytes(hex: Hex, expectedLength?: number): Uint8Array {
 }
 
 // Copies several Uint8Arrays into one.
-export function concatBytes(...arrays: Uint8Array[]): Uint8Array {
+export function concatBytes(...arrs: Uint8Array[]): Uint8Array {
-  if (!arrays.every((b) => u8a(b))) throw new Error('Uint8Array list expected');
+  const r = new Uint8Array(arrs.reduce((sum, a) => sum + a.length, 0));
-  if (arrays.length === 1) return arrays[0];
+  let pad = 0; // walk through each item, ensure they have proper type
-  const length = arrays.reduce((a, arr) => a + arr.length, 0);
+  arrs.forEach((a) => {
-  const result = new Uint8Array(length);
+    if (!u8a(a)) throw new Error('Uint8Array expected');
-  for (let i = 0, pad = 0; i < arrays.length; i++) {
+    r.set(a, pad);
-    const arr = arrays[i];
+    pad += a.length;
-    result.set(arr, pad);
+  });
-    pad += arr.length;
+  return r;
-  }
-  return result;
 }
 
 export function equalBytes(b1: Uint8Array, b2: Uint8Array) {
@@ -119,3 +113,32 @@ export const bitSet = (n: bigint, pos: number, value: boolean) =>
 // Return mask for N bits (Same as BigInt(`0b${Array(i).fill('1').join('')}`))
 // Not using ** operator with bigints for old engines.
 export const bitMask = (n: number) => (_2n << BigInt(n - 1)) - _1n;
+
+type ValMap = Record<string, string>;
+export function validateObject(object: object, validators: ValMap, optValidators: ValMap = {}) {
+  const validatorFns: Record<string, (val: any) => boolean> = {
+    bigint: (val) => typeof val === 'bigint',
+    function: (val) => typeof val === 'function',
+    boolean: (val) => typeof val === 'boolean',
+    string: (val) => typeof val === 'string',
+    isSafeInteger: (val) => Number.isSafeInteger(val),
+    array: (val) => Array.isArray(val),
+    field: (val) => (object as any).Fp.isValid(val),
+    hash: (val) => typeof val === 'function' && Number.isSafeInteger(val.outputLen),
+  };
+  // type Key = keyof typeof validators;
+  const checkField = (fieldName: string, type: string, isOptional: boolean) => {
+    const checkVal = validatorFns[type];
+    if (typeof checkVal !== 'function')
+      throw new Error(`Invalid validator "${type}", expected function`);
+
+    const val = object[fieldName as keyof typeof object];
+    if (isOptional && val === undefined) return;
+    if (!checkVal(val)) {
+      throw new Error(`Invalid param ${fieldName}=${val} (${typeof val}), expected ${type}`);
+    }
+  };
+  for (let [fieldName, type] of Object.entries(validators)) checkField(fieldName, type, false);
+  for (let [fieldName, type] of Object.entries(optValidators)) checkField(fieldName, type, true);
+  return object;
+}

src/abstract/weierstrass.ts

@@ -2,15 +2,8 @@
 // Short Weierstrass curve. The formula is: y² = x³ + ax + b
 import * as mod from './modular.js';
 import * as ut from './utils.js';
-import { Hex, PrivKey, ensureBytes, CHash } from './utils.js';
+import { CHash, Hex, PrivKey, ensureBytes } from './utils.js';
-import {
+import { Group, GroupConstructor, wNAF, BasicCurve, validateBasic, AffinePoint } from './curve.js';
-  Group,
-  GroupConstructor,
-  wNAF,
-  AbstractCurve,
-  validateAbsOpts,
-  AffinePoint,
-} from './curve.js';
 
 export type { AffinePoint };
 type HmacFnSync = (key: Uint8Array, ...messages: Uint8Array[]) => Uint8Array;
@@ -18,7 +11,7 @@ type EndomorphismOpts = {
   beta: bigint;
   splitScalar: (k: bigint) => { k1neg: boolean; k1: bigint; k2neg: boolean; k2: bigint };
 };
-export type BasicCurve<T> = AbstractCurve<T> & {
+export type BasicWCurve<T> = BasicCurve<T> & {
   // Params: a, b
   a: T;
   b: T;
@@ -86,34 +79,32 @@ export interface ProjConstructor<T> extends GroupConstructor<ProjPointType<T>> {
   normalizeZ(points: ProjPointType<T>[]): ProjPointType<T>[];
 }
 
-export type CurvePointsType<T> = BasicCurve<T> & {
+export type CurvePointsType<T> = BasicWCurve<T> & {
   // Bytes
   fromBytes: (bytes: Uint8Array) => AffinePoint<T>;
   toBytes: (c: ProjConstructor<T>, point: ProjPointType<T>, compressed: boolean) => Uint8Array;
 };
 
 function validatePointOpts<T>(curve: CurvePointsType<T>) {
-  const opts = validateAbsOpts(curve);
+  const opts = validateBasic(curve);
-  const Fp = opts.Fp;
+  ut.validateObject(
-  for (const i of ['a', 'b'] as const) {
+    opts,
-    if (!Fp.isValid(curve[i]))
+    {
-      throw new Error(`Invalid curve param ${i}=${opts[i]} (${typeof opts[i]})`);
+      a: 'field',
+      b: 'field',
+      fromBytes: 'function',
+      toBytes: 'function',
+    },
+    {
+      allowedPrivateKeyLengths: 'array',
+      wrapPrivateKey: 'boolean',
+      isTorsionFree: 'function',
+      clearCofactor: 'function',
     }
-  for (const i of ['allowedPrivateKeyLengths'] as const) {
+  );
-    if (curve[i] === undefined) continue; // Optional
+  const { endo, Fp, a } = opts;
-    if (!Array.isArray(curve[i])) throw new Error(`Invalid ${i} array`);
-  }
-  for (const i of ['wrapPrivateKey'] as const) {
-    if (curve[i] === undefined) continue; // Optional
-    if (typeof curve[i] !== 'boolean') throw new Error(`Invalid ${i} boolean`);
-  }
-  for (const i of ['isTorsionFree', 'clearCofactor'] as const) {
-    if (curve[i] === undefined) continue; // Optional
-    if (typeof curve[i] !== 'function') throw new Error(`Invalid ${i} function`);
-  }
-  const endo = opts.endo;
   if (endo) {
-    if (!Fp.eql(opts.a, Fp.ZERO)) {
+    if (!Fp.eql(a, Fp.ZERO)) {
       throw new Error('Endomorphism can only be defined for Koblitz curves that have a=0');
     }
     if (
@@ -124,9 +115,6 @@ function validatePointOpts<T>(curve: CurvePointsType<T>) {
       throw new Error('Expected endomorphism with beta: bigint and splitScalar: function');
     }
   }
-  if (typeof opts.fromBytes !== 'function') throw new Error('Invalid fromBytes function');
-  if (typeof opts.toBytes !== 'function') throw new Error('Invalid fromBytes function');
-  // Set defaults
   return Object.freeze({ ...opts } as const);
 }
 
@@ -609,25 +597,30 @@ type SignatureLike = { r: bigint; s: bigint };
 
 export type PubKey = Hex | ProjPointType<bigint>;
 
-export type CurveType = BasicCurve<bigint> & {
+export type CurveType = BasicWCurve<bigint> & {
-  // Default options
+  hash: CHash; // CHash not FHash because we need outputLen for DRBG
-  lowS?: boolean;
-  // Hashes
-  hash: CHash; // Because we need outputLen for DRBG
   hmac: HmacFnSync;
   randomBytes: (bytesLength?: number) => Uint8Array;
-  // truncateHash?: (hash: Uint8Array, truncateOnly?: boolean) => Uint8Array;
+  lowS?: boolean;
   bits2int?: (bytes: Uint8Array) => bigint;
   bits2int_modN?: (bytes: Uint8Array) => bigint;
 };
 
 function validateOpts(curve: CurveType) {
-  const opts = validateAbsOpts(curve);
+  const opts = validateBasic(curve);
-  if (typeof opts.hash !== 'function' || !Number.isSafeInteger(opts.hash.outputLen))
+  ut.validateObject(
-    throw new Error('Invalid hash function');
+    opts,
-  if (typeof opts.hmac !== 'function') throw new Error('Invalid hmac function');
+    {
-  if (typeof opts.randomBytes !== 'function') throw new Error('Invalid randomBytes function');
+      hash: 'hash',
-  // Set defaults
+      hmac: 'function',
+      randomBytes: 'function',
+    },
+    {
+      bits2int: 'function',
+      bits2int_modN: 'function',
+      lowS: 'boolean',
+    }
+  );
   return Object.freeze({ lowS: true, ...opts } as const);
 }
 
@@ -756,7 +749,7 @@ export function weierstrass(curveDef: CurveType): CurveFn {
         return { x, y };
       } else {
         throw new Error(
-          `Point.fromHex: received invalid point. Expected ${compressedLen} compressed bytes or ${uncompressedLen} uncompressed bytes, not ${len}`
+          `Point of length ${len} was invalid. Expected ${compressedLen} compressed bytes or ${uncompressedLen} uncompressed bytes`
         );
       }
     },
@@ -951,9 +944,10 @@ export function weierstrass(curveDef: CurveType): CurveFn {
   // NOTE: pads output with zero as per spec
   const ORDER_MASK = ut.bitMask(CURVE.nBitLength);
   function int2octets(num: bigint): Uint8Array {
-    if (typeof num !== 'bigint') throw new Error('Expected bigint');
+    if (typeof num !== 'bigint') throw new Error('bigint expected');
     if (!(_0n <= num && num < ORDER_MASK))
-      throw new Error(`Expected number < 2^${CURVE.nBitLength}`);
+      // n in [0..ORDER_MASK-1]
+      throw new Error(`bigint expected < 2^${CURVE.nBitLength}`);
     // works with order, can have different size than numToField!
     return ut.numberToBytesBE(num, CURVE.nByteLength);
   }
@@ -1045,7 +1039,7 @@ export function weierstrass(curveDef: CurveType): CurveFn {
    * ```
    */
   function verify(
-    signature: Hex | { r: bigint; s: bigint },
+    signature: Hex | SignatureLike,
     msgHash: Hex,
     publicKey: Hex,
     opts = defaultVerOpts
@@ -1090,7 +1084,6 @@ export function weierstrass(curveDef: CurveType): CurveFn {
     getSharedSecret,
     sign,
     verify,
-    // Point,
     ProjectivePoint: Point,
     Signature,
     utils,

src/p224.ts

@@ -10,7 +10,7 @@ export const P224 = createCurve(
     // Params: a, b
     a: BigInt('0xfffffffffffffffffffffffffffffffefffffffffffffffffffffffe'),
     b: BigInt('0xb4050a850c04b3abf54132565044b0b7d7bfd8ba270b39432355ffb4'),
-    // Field over which we'll do calculations; 2n**224n - 2n**96n + 1n
+    // Field over which we'll do calculations;
     Fp: Fp(BigInt('0xffffffffffffffffffffffffffffffff000000000000000000000001')),
     // Curve order, total count of valid points in the field
     n: BigInt('0xffffffffffffffffffffffffffff16a2e0b8f03e13dd29455c5c2a3d'),

src/secp256k1.ts

@@ -175,7 +175,6 @@ function schnorrSign(message: Hex, privateKey: Hex, auxRand: Hex = randomBytes(3
 
   const { x: px, scalar: d } = schnorrGetScalar(bytesToNum(ensureBytes(privateKey, 32)));
   const a = ensureBytes(auxRand, 32); // Auxiliary random data a: a 32-byte array
-  // TODO: replace with proper xor?
   const t = numTo32b(d ^ bytesToNum(taggedHash(TAGS.aux, a))); // Let t be the byte-wise xor of bytes(d) and hash/aux(a)
   const rand = taggedHash(TAGS.nonce, t, px, m); // Let rand = hash/nonce(t || bytes(P) || m)
   const k_ = modN(bytesToNum(rand)); // Let k' = int(rand) mod n

test/nist.test.js

@@ -86,7 +86,8 @@ describe('wycheproof ECDH', () => {
           try {
             const pub = CURVE.ProjectivePoint.fromHex(test.public);
           } catch (e) {
-            if (e.message.includes('Point.fromHex: received invalid point.')) continue;
+            // Our strict validation filter doesn't let weird-length DER vectors
+            if (e.message.startsWith('Point of length')) continue;
             throw e;
           }
           const shared = CURVE.getSharedSecret(test.private, test.public);
@@ -140,7 +141,8 @@ describe('wycheproof ECDH', () => {
               try {
                 const pub = curve.ProjectivePoint.fromHex(test.public);
               } catch (e) {
-                if (e.message.includes('Point.fromHex: received invalid point.')) continue;
+                // Our strict validation filter doesn't let weird-length DER vectors
+                if (e.message.includes('Point of length')) continue;
                 throw e;
               }
               const shared = curve.getSharedSecret(test.private, test.public);
@@ -194,7 +196,6 @@ const WYCHEPROOF_ECDSA = {
   secp256k1: {
     curve: secp256k1,
     hashes: {
-      // TODO: debug why fails, can be bug
       sha256: {
         hash: sha256,
         tests: [secp256k1_sha256_test],