/*! noble-ed25519 - MIT License (c) 2019 Paul Miller (paulmillr.com) */ /** * 5KB JS implementation of ed25519 EdDSA signatures. * Targets RFC8032, FIPS 186-5, and ZIP215 behavior. * @module * @example * ```js import * as ed from '@noble/ed25519'; (async () => { const secretKey = ed.utils.randomSecretKey(); const message = Uint8Array.from([0xab, 0xbc, 0xcd, 0xde]); const pubKey = await ed.getPublicKeyAsync(secretKey); // Sync methods are also present const signature = await ed.signAsync(message, secretKey); const isValid = await ed.verifyAsync(signature, message, pubKey); })(); ``` */ /** * Curve params. edwards25519 uses the RFC equation `-x² + y² = 1 + dx²y²`. * The stored `a` literal below is `p - 1`, i.e. the field-element encoding of RFC `a = -1`. * * P = `2n**255n - 19n` // field over which calculations are done * * N = `2n**252n + 27742317777372353535851937790883648493n` // prime-order subgroup order * * h = 8 // cofactor * * a = `Fp.create(BigInt(-1))` // equation param, stored here as `p - 1` * * d = -121665/121666 a.k.a. `Fp.neg(121665 * Fp.inv(121666))` // equation param * * Gx, Gy are coordinates of Generator / base point * * Mirror noble-curves: Point.CURVE() exposes shared params, but callers must not be able to mutate * that shared view and desynchronize it from the arithmetic constants captured below. */ const freeze = Object.freeze; const P = 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffedn; const N = 0x1000000000000000000000000000000014def9dea2f79cd65812631a5cf5d3edn; const _d = 0x52036cee2b6ffe738cc740797779e89800700a4d4141d8ab75eb4dca135978a3n; const Gx = 0x216936d3cd6e53fec0a4e231fdd6dc5c692cc7609525a7b2c9562d608f25d51an; const Gy = 0x6666666666666666666666666666666666666666666666666666666666666658n; const _a = P - 1n; // field-element encoding of RFC `a = -1` const ed25519_CURVE: EdwardsOpts = freeze({ p: P, n: N, h: 8n, a: _a, d: _d, Gx, Gy, }); // Shared 32-byte encoded width for Ed25519 points, scalars, signatures/2, and keys. Named LEN // rather than RFC 8032's `L`, which names the group order (stored here as `N`). const LEN = 32; /** Alias to Uint8Array. */ export type Bytes = Uint8Array; /** Edwards elliptic curve options. */ export type EdwardsOpts = Readonly<{ /** Prime field modulus. */ p: bigint; /** Group order. */ n: bigint; /** Curve cofactor. */ h: bigint; /** Edwards curve parameter `a`. */ a: bigint; /** Edwards curve parameter `d`. */ d: bigint; /** Generator x coordinate. */ Gx: bigint; /** Generator y coordinate. */ Gy: bigint; }>; // Helpers and Precomputes sections are reused between libraries // ## Helpers // ---------- /** Checks if something is Uint8Array. Be careful: nodejs Buffer will return true. */ const isBytes = (a: unknown): a is Uint8Array => { // Plain `instanceof Uint8Array` is too strict for some Buffer / proxy / cross-realm cases. // The fallback still requires a real ArrayBuffer view, so plain // JSON-deserialized `{ constructor: ... }` spoofing is rejected, and // `BYTES_PER_ELEMENT === 1` keeps the fallback on byte-oriented views. return ( a instanceof Uint8Array || (ArrayBuffer.isView(a) && a.constructor.name === 'Uint8Array' && (a as Uint8Array).BYTES_PER_ELEMENT === 1) ); }; /** Asserts something is Bytes. */ const abytes = (value: unknown, length?: number, title: string = ''): TRet => { // Success path first: this runs at the start of every update() / digestInto(), and the // common `abytes(data)` form must not pay for length handling it does not use. if (isBytes(value) && (length === undefined || value.length === length)) return value as TRet; // Error path: recompute freely to build the exact message. const bytes = isBytes(value); const ofLen = length !== undefined ? ` of length ${length}` : ''; const got = bytes ? `length=${value.length}` : `type=${typeof value}`; const message = (title ? `"${title}" ` : '') + 'expected Uint8Array' + ofLen + ', got ' + got; if (!bytes) throw new TypeError(message); throw new RangeError(message); }; // Validate, then take one owned copy, so later caller mutation cannot be observed — e.g. cannot // make sign()'s nonce derivation and challenge derivation see different messages. const snapshotBytes = (value: unknown, title: string = '', length?: number): TRet => Uint8Array.from(abytes(value, length, title)); // Callers keep values non-negative and within the requested width; padStart() won't truncate over-wide inputs. const padh = (n: number | bigint, pad: number) => n.toString(16).padStart(pad, '0'); /** Convert byte array to hex string. */ const bytesToHex = (bytes: TArg): string => { let hex = ''; for (const byte of abytes(bytes)) hex += padh(byte, 2); return hex; }; /** Convert hex string to byte array. */ const hexToBytes = (hex: string): TRet => { const e = 'hex invalid'; // Strict ASCII hex only, with one generic error for parse failures. if (typeof hex !== 'string') throw new TypeError(e); if (hex.length % 2 || !/^[\da-f]*$/i.test(hex)) throw new RangeError(e); const array = new Uint8Array(hex.length / 2); for (let ai = 0, hi = 0; ai < array.length; ai++, hi += 2) { const n1 = hex.charCodeAt(hi); const n2 = hex.charCodeAt(hi + 1); // Regex guarantees ASCII. For 0..9/A..F/a..f, this maps char codes to 0..15. array[ai] = ((n1 & 15) + (n1 >> 6) * 9) * 16 + (n2 & 15) + (n2 >> 6) * 9; } return array as TRet; }; declare const globalThis: Record | undefined; // Typescript symbol present in browsers // WebCrypto is available in all modern environments /** Copies several Uint8Arrays into one. */ const concatBytes = (...arrays: TArg): TRet => { let sum = 0; for (const a of arrays) sum += abytes(a).length; const res = new Uint8Array(sum); let pad = 0; for (const a of arrays) { res.set(a, pad); pad += a.length; } return res; }; /** * WebCrypto OS-level CSPRNG (random number generator). * Will throw when not available; large-request ceilings are delegated to getRandomValues(). */ const randomBytes = (len: number = LEN): TRet => { const c = globalThis?.crypto; if (typeof c?.getRandomValues !== 'function') throw new Error('crypto.getRandomValues must be defined, consider polyfill'); return c.getRandomValues(new Uint8Array(len)) as TRet; }; /** Inclusive-lower, exclusive-upper bigint range assertion. */ const arange = (n: bigint, min: bigint, max: bigint, msg = 'bad number: out of range'): bigint => { if (typeof n !== 'bigint') throw new TypeError(msg); if (min <= n && n < max) return n; throw new RangeError(msg); }; /** Canonical modular reduction. Callers must provide a positive modulus. */ const mod = (a: bigint, b: bigint = P) => ((a %= b) >= 0n ? a : b + a); // Low-255-bit mask used by the `2^255 - 19` fast reduction in `modP(...)`. const P_MASK = (1n << 255n) - 1n; // Fast reduction for the special prime `2^255 - 19`. This path assumes nonnegative inputs; the // generic fallback would simply be `mod(num, P)`. const modP = (num: bigint): bigint => { if (num < 0n) throw new RangeError('negative coordinate'); let r = (num >> 255n) * 19n + (num & P_MASK); r = (r >> 255n) * 19n + (r & P_MASK); return r % P; }; // Reduce modulo the subgroup order stored in implementation constant `N` (RFC 8032's `L`). const modN = (a: bigint) => mod(a, N); /** Modular inversion using extended euclidean GCD. Variable-time (non-CT). */ const invert = (number: bigint, modulo: bigint): bigint => { if (number === 0n) throw new Error('invert: expected non-zero number'); // modulo = 1 is the zero ring: gcd(x, 1) = 1 makes the loop below "succeed" and return the // useless inverse 0. Reject it like pow() and invertCt() do. if (modulo <= 1n) throw new Error('invert: expected modulus > 1, got ' + modulo); // This is variable-time: the loop count depends on `number`. let a = mod(number, modulo); let b = modulo; // Only the Bézout coefficient of `number` (x/u chain) is tracked; the coefficient of `modulo` // never affects the output, so it is not computed. // prettier-ignore let x = 0n, u = 1n; while (a !== 0n) { const q = b / a; const r = b - a * q; const m = x - u * q; // prettier-ignore b = a, a = r, x = u, u = m; } const gcd = b; if (gcd !== 1n) throw new Error('invert: does not exist'); return mod(x, modulo); }; // Dynamic lookup keeps sync/async hash providers configurable at runtime. Both exported slots are // caller-owned and may be unset; wrapper helpers use this lookup first and then enforce the digest // contract instead of trusting provider output. const _hash = (name: string) => { // @ts-ignore const fn = hashes[name]; if (typeof fn !== 'function') throw new Error('hashes.' + name + ' not set'); return fn; }; // All exported provider slots are caller-configurable and may be unset or return arbitrary values, // so wrapper helpers must enforce the exact 64-byte SHA-512 digest contract instead of trusting providers. const callHash = (name: string, ...m: Uint8Array[]): TRet => abytes(_hash(name)(concatBytes(...m)), 64, 'digest'); const callHashAsync = async (name: string, ...m: Uint8Array[]): Promise> => abytes(await _hash(name)(concatBytes(...m)), 64, 'digest'); /** * SHA-512 helper used by the synchronous API. * @param msg - Message bytes to hash. * @returns 64-byte SHA-512 digest. * @example * Hash message bytes after wiring the synchronous SHA-512 implementation. * * ```ts * import * as ed from '@noble/ed25519'; * import { sha512 } from '@noble/hashes/sha2.js'; * * ed.hashes.sha512 = sha512; * const digest = ed.hash(new Uint8Array([1, 2, 3])); * ``` */ // Public helper validates the message boundary explicitly; the configured provider is still looked // up dynamically and its output is checked with `callHash(...)`. const hash = (msg: TArg): TRet => callHash('sha512', abytes(msg, undefined, 'message')); // Runtime class guard: this is `instanceof Point`, so cross-realm / duplicate-bundle Point objects // are rejected even if they are structurally identical. const apoint = (p: unknown) => { if (p instanceof Point) return p; throw new TypeError('Point expected'); }; /** Point in 2d xy affine coordinates. */ export type AffinePoint = { /** Affine x coordinate. */ x: bigint; /** Affine y coordinate. */ y: bigint; }; // ## End of Helpers // ----------------- // Exclusive upper bound `2^256` used by 32-byte decode/serialization range checks. const B256 = 2n ** 256n; /** * Point in XYZT extended coordinates. * @param X - X coordinate. * @param Y - Y coordinate. * @param Z - Projective Z coordinate. * @param T - Cached cross-product term. * @example * Do point arithmetic with the built-in base point and encode the result as hex. * * ```ts * const hex = Point.BASE.double().toHex(); * ``` */ class Point { static BASE: Point; static ZERO: Point; readonly X: bigint; readonly Y: bigint; readonly Z: bigint; readonly T: bigint; // Constructor only bounds-checks and freezes XYZT coordinates; it does not prove the point is // on-curve or that T matches X*Y/Z. constructor(X: bigint, Y: bigint, Z: bigint, T: bigint) { const max = B256; this.X = arange(X, 0n, max); this.Y = arange(Y, 0n, max); this.Z = arange(Z, 1n, max); this.T = arange(T, 0n, max); freeze(this); } static CURVE(): EdwardsOpts { return ed25519_CURVE; } static fromAffine(p: AffinePoint): Point { return new Point(p.x, p.y, 1n, modP(p.x * p.y)); } /** RFC8032 5.1.3: Uint8Array to Point. */ static fromBytes(bytes: TArg, zip215 = false): Point { const normed = snapshotBytes(bytes, 'point', LEN); // owned copy: sign-bit mask below mutates it // adjust first LE byte = last BE byte const lastByte = normed[31]; normed[31] = lastByte & ~0x80; const y = bytesToNumberLE(normed); // After clearing the sign bit, parsed `y` is always < 2^255. ZIP-215 still accepts the full // post-mask range here, while strict RFC8032 decoding further requires `y < p`. if (!zip215) arange(y, 0n, P); const y2 = modP(y * y); // y² const u = mod(y2 - 1n); // u=y²-1 const v = modP(_d * y2 + 1n); // v=dy²+1 let { isValid, value: x } = uvRatio(u, v); // (uv³)(uv⁷)^(p-5)/8; square root if (!isValid) throw new Error('bad point: y not sqrt'); // not square root: bad point const isLastByteOdd = !!(lastByte & 0x80); // x_0, last bit // ZIP-215-compatible decoding keeps the x=0 / sign-bit=1 encoding accepted; strict RFC 8032 // rejects it, but the vendored ZIP-215 compliance vectors include this form in A/R bytes. if (!zip215 && x === 0n && isLastByteOdd) throw new Error('bad point: x==0, isLastByteOdd'); // x=0, x_0=1 if (isLastByteOdd !== !!(x & 1n)) x = mod(-x); // adjust sign of x coordinate return new Point(x, y, 1n, modP(x * y)); // Z=1, T=xy } static fromHex(hex: string, zip215?: boolean): Point { return Point.fromBytes(hexToBytes(hex), zip215); } get x(): bigint { return this.toAffine().x; } get y(): bigint { return this.toAffine().y; } /** Checks if the point is valid and on-curve. */ assertValidity(): this { const a = _a; const d = _d; const p = this; // Intentional stricter-than-on-curve policy: reject ZERO by default because many protocols // require a non-zero point, and silently accepting identity points is a common caller mistake. if (p.is0()) throw new Error('bad point: ZERO'); // Equation in affine coordinates: ax² + y² = 1 + dx²y² // Equation in projective coordinates (X/Z, Y/Z, Z): (aX² + Y²)Z² = Z⁴ + dX²Y² const { X, Y, Z, T } = p; const X2 = modP(X * X); // X² const Y2 = modP(Y * Y); // Y² const Z2 = modP(Z * Z); // Z² const Z4 = modP(Z2 * Z2); // Z⁴ const aX2 = modP(X2 * a); // aX² const left = modP(Z2 * (aX2 + Y2)); // (aX² + Y²)Z² const right = mod(Z4 + modP(d * modP(X2 * Y2))); // Z⁴ + dX²Y² if (left !== right) throw new Error('bad point: equation left != right (1)'); // In Extended coordinates we also have T, which is x*y=T/Z: check X*Y == Z*T const XY = modP(X * Y); const ZT = modP(Z * T); if (XY !== ZT) throw new Error('bad point: equation left != right (2)'); return this; } /** Equality check: compare points P&Q. */ equals(other: Point): boolean { const { X: X1, Y: Y1, Z: Z1 } = this; const { X: X2, Y: Y2, Z: Z2 } = apoint(other); // checks class equality return modP(X1 * Z2) === modP(X2 * Z1) && modP(Y1 * Z2) === modP(Y2 * Z1); } is0(): boolean { return this.equals(I); } /** Flip point over y coordinate. */ negate(): Point { return new Point(mod(-this.X), this.Y, this.Z, mod(-this.T)); } /** Point doubling. Complete formula. Cost: `4M + 4S + 1*a + 6add + 1*2`. */ double(): Point { const { X: X1, Y: Y1, Z: Z1 } = this; const a = _a; // https://hyperelliptic.org/EFD/g1p/auto-twisted-extended.html#doubling-dbl-2008-hwcd const A = modP(X1 * X1); const B = modP(Y1 * Y1); const C = modP(2n * Z1 * Z1); const D = modP(a * A); const x1y1 = mod(X1 + Y1); const E = mod(modP(x1y1 * x1y1) - A - B); const G = mod(D + B); const F = mod(G - C); const H = mod(D - B); const X3 = modP(E * F); const Y3 = modP(G * H); const T3 = modP(E * H); const Z3 = modP(F * G); return new Point(X3, Y3, Z3, T3); } /** Point addition. Complete formula. Cost: `9M + 1*a + 1*d + 7add`. */ add(other: Point): Point { const { X: X1, Y: Y1, Z: Z1, T: T1 } = this; const { X: X2, Y: Y2, Z: Z2, T: T2 } = apoint(other); // doesn't check if other on-curve const a = _a; const d = _d; // https://hyperelliptic.org/EFD/g1p/auto-twisted-extended.html#addition-add-2008-hwcd const A = modP(X1 * X2); const B = modP(Y1 * Y2); const C = modP(modP(T1 * d) * T2); const D = modP(Z1 * Z2); const E = mod(modP(mod(X1 + Y1) * mod(X2 + Y2)) - A - B); const F = mod(D - C); const G = mod(D + C); const H = mod(B - modP(a * A)); const X3 = modP(E * F); const Y3 = modP(G * H); const T3 = modP(E * H); const Z3 = modP(F * G); return new Point(X3, Y3, Z3, T3); } subtract(other: Point): Point { return this.add(apoint(other).negate()); } /** * Point-by-scalar multiplication. Safe mode requires `1 <= n < CURVE.n`. * Unsafe mode additionally permits `n = 0` and returns the identity point for that case. * Uses {@link wNAF} for base point. * Uses fake point to mitigate side-channel leakage. * @param n - scalar by which point is multiplied * @param safe - safe mode guards against timing attacks; unsafe mode is faster */ multiply(n: bigint, safe = true): Point { // Mirror noble-curves: unsafe mode still validates scalar range first, but intentionally keeps // `n = 0` as the one extra accepted case used by verification-style callers. if (!safe && n === 0n) return I; arange(n, 1n, N); if (!safe && this.is0()) return I; if (n === 1n) return this; if (this.equals(G)) return wNAF(n).p; // init result point & fake point let p = I; let f = G; let d: Point = this; // Safe mode always runs 256 iterations so ladder length can't leak the scalar's // leading zero bits; unsafe mode stops at the top set bit for speed. for (let i = 0; safe ? i < 256 : n > 0n; i++) { // if bit is present, add to point // if not present, add to fake, for timing safety if (n & 1n) p = p.add(d); else if (safe) f = f.add(d); d = d.double(); n >>= 1n; } return p; } multiplyUnsafe(scalar: bigint): Point { return this.multiply(scalar, false); } /** Convert point to 2d xy affine point. (X, Y, Z) ∋ (x=X/Z, y=Y/Z) */ toAffine(): AffinePoint { const { X, Y, Z } = this; // Fast-path only for the identity point; all other inputs still go through inversion. if (this.equals(I)) return { x: 0n, y: 1n }; const iz = invert(Z, P); // (Z * Z^-1) must be 1, otherwise bad math if (modP(Z * iz) !== 1n) throw new Error('invalid inverse'); // x = X*Z^-1; y = Y*Z^-1 return { x: modP(X * iz), y: modP(Y * iz) }; } toBytes(): TRet { const { x, y } = this.toAffine(); const b = numTo32bLE(y); // store sign in first LE byte b[31] |= x & 1n ? 0x80 : 0; return b; } toHex(): string { return bytesToHex(this.toBytes()); } clearCofactor(): Point { return this.multiply(8n, false); // h = 8 } isSmallOrder(): boolean { return this.clearCofactor().is0(); } isTorsionFree(): boolean { // Multiply by big number N. We can't `mul(N)` because of checks. Instead, we `mul(N/2)*2+1`; // N is odd, so N/2 truncates and the final `add(this)` is always needed. return this.multiply(N / 2n, false) .double() .add(this) .is0(); } } /** Generator / base point */ const G: Point = new Point(Gx, Gy, 1n, mod(Gx * Gy)); /** Identity / zero point */ const I: Point = new Point(0n, 1n, 1n, 0n); // Static aliases Point.BASE = G; Point.ZERO = I; const numTo32bLE = (num: bigint): TRet => hexToBytes(padh(arange(num, 0n, B256), 64)).reverse() as TRet; // Caller-enforced width: some sites require 32-byte RFC encodings, while others intentionally feed // wider SHA-512 output chunks through the same little-endian parser. const bytesToNumberLE = (b: Uint8Array): bigint => BigInt('0x' + bytesToHex(Uint8Array.from(abytes(b)).reverse())); const pow2 = (x: bigint, power: number): bigint => { // pow2(x, 4) == x^(2^4) // Negative `power` values are not rejected here and currently leave `x` unchanged. let r = x; while (power-- > 0) { r = modP(r * r); } return r; }; // prettier-ignore const pow_2_252_3 = (x: bigint) => { // x^(2^252-3) unrolled util for square root const x2 = modP(x * x); // x^2, bits 1 const b2 = modP(x2 * x); // x^3, bits 11 const b4 = modP(pow2(b2, 2) * b2); // x^(2^4-1), bits 1111 const b5 = modP(pow2(b4, 1) * x); // x^(2^5-1), bits 11111 const b10 = modP(pow2(b5, 5) * b5); // x^(2^10-1) const b20 = modP(pow2(b10, 10) * b10); // x^(2^20-1) const b40 = modP(pow2(b20, 20) * b20); // x^(2^40-1) const b80 = modP(pow2(b40, 40) * b40); // x^(2^80-1) const b160 = modP(pow2(b80, 80) * b80); // x^(2^160-1) const b240 = modP(pow2(b160, 80) * b80); // x^(2^240-1) const b250 = modP(pow2(b240, 10) * b10); // x^(2^250-1) return modP(pow2(b250, 2) * x); // x^((p-5)/8), used by RFC8032 point decode }; const RM1 = 0x2b8324804fc1df0b2b4d00993dfbd7a72f431806ad2fe478c4ee1b274a0ea0b0n; // 2^((p-1)/4) = sqrt(-1) // RFC8032 §5.1.3 square-root helper for point decompression. `value` is only meaningful when // `isValid` is true; callers are also expected to pass canonical field elements with non-zero `v`. // prettier-ignore const uvRatio = (u: bigint, v: bigint): { isValid: boolean, value: bigint } => { const v3 = modP(v * modP(v * v)); // v³ const v7 = modP(modP(v3 * v3) * v); // v⁷ const pow = pow_2_252_3(modP(u * v7)); // (uv⁷)^(p-5)/8 let x = modP(u * modP(v3 * pow)); // (uv³)(uv⁷)^(p-5)/8 const vx2 = modP(v * modP(x * x)); // vx² const root1 = x; // First root candidate const root2 = modP(x * RM1); // Second root candidate; RM1 is √-1 const useRoot1 = vx2 === u; // If vx² = u (mod p), x is a square root const useRoot2 = vx2 === mod(-u); // If vx² = -u, set x <-- x * 2^((p-1)/4) const noRoot = vx2 === mod(-u * RM1); // There is no valid root, vx² = -u√-1 if (useRoot1) x = root1; if (useRoot2 || noRoot) x = root2; // We return root2 anyway, for const-time if ((mod(x) & 1n) === 1n) x = mod(-x); // edIsNegative return { isValid: useRoot1 || useRoot2, value: x }; }; // Reduce a little-endian byte string modulo the subgroup order `N` (RFC 8032's `L`); the `hash` // param name reflects the common caller shape, not an input restriction. const modL_LE = (hash: Uint8Array): bigint => modN(bytesToNumberLE(hash)); type ExtK = { head: Uint8Array; prefix: Uint8Array; scalar: bigint; point: Point; pointBytes: Uint8Array; }; // RFC8032 5.1.5. Split the 64-byte hashed seed into the clamped scalar half and nonce prefix. const hashedToExtK = (hashed: Uint8Array): TRet => { // slice creates a copy, unlike subarray const copy = snapshotBytes(hashed); const head = copy.slice(0, 32); head[0] &= 248; // Clamp bits: 0b1111_1000 head[31] &= 127; // 0b0111_1111 head[31] |= 64; // 0b0100_0000 const prefix = copy.slice(32); // secret key "prefix" // RFC words this as `[s]B`; reducing the clamped little-endian scalar modulo `N` is equivalent // for base-point multiplication because `G` already has subgroup order `N`. const scalar = modL_LE(head); const point = G.multiply(scalar); // public key point const pointBytes = point.toBytes(); // point serialized to Uint8Array return { head, prefix, scalar, point, pointBytes } as TRet; }; // RFC8032 5.1.5; getPublicKey async, sync. Hash secret key and extract point. const getExtendedPublicKeyAsync = (secretKey: TArg): Promise> => callHashAsync('sha512Async', abytes(secretKey, LEN, 'secretKey')).then(hashedToExtK); const getExtendedPublicKey = (secretKey: TArg): TRet => hashedToExtK(callHash('sha512', abytes(secretKey, LEN, 'secretKey'))); /** * Creates a 32-byte Ed25519 public key from the RFC 8032 32-byte secret-key seed. Async. * @param secretKey - 32-byte RFC 8032 secret-key seed, not a 64-byte expanded secret key. * @returns 32-byte public key. * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Derive the public key bytes for a newly generated signer secret. * * ```ts * import * as ed from '@noble/ed25519'; * * const secretKey = ed.utils.randomSecretKey(); * const publicKey = await ed.getPublicKeyAsync(secretKey); * ``` */ const getPublicKeyAsync = (secretKey: TArg): Promise> => getExtendedPublicKeyAsync(secretKey).then((p) => p.pointBytes as TRet); /** * Creates a 32-byte Ed25519 public key from the RFC 8032 32-byte secret-key seed. * To use, set `hashes.sha512` first. * @param secretKey - 32-byte RFC 8032 secret-key seed, not a 64-byte expanded secret key. * @returns 32-byte public key. * @throws If synchronous SHA-512 has not been configured in `hashes`. {@link Error} * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Derive the public key entirely through the synchronous API. * * ```ts * import * as ed from '@noble/ed25519'; * import { sha512 } from '@noble/hashes/sha2.js'; * * ed.hashes.sha512 = sha512; * const secretKey = ed.utils.randomSecretKey(); * const publicKey = ed.getPublicKey(secretKey); * ``` */ const getPublicKey = (secretKey: TArg): TRet => getExtendedPublicKey(secretKey).pointBytes; type Finishable = readonly [ // Shared between sync/async sign() and verify(): hash `hashable` with SHA-512, then hand the // resulting 64-byte digest to `finish(...)`. Uint8Array, (hashed: Uint8Array) => T, ]; const hashFinishAsync = async (res: Finishable): Promise => res[1](await callHashAsync('sha512Async', res[0])); const hashFinishSync = (res: Finishable): T => res[1](callHash('sha512', res[0])); // Code, shared between sync & async sign const _sign = ( e: { pointBytes: Uint8Array; scalar: bigint }, rBytes: Uint8Array, msg: Uint8Array ): Finishable> => { const { pointBytes: A, scalar: s } = e; const r = modL_LE(rBytes); // r was created outside, reduce it modulo L // RFC 8032 5.1.6 allows r mod L = 0, and SUPERCOP ref10 accepts the resulting identity-point // signature. // We intentionally keep the safe multiply() rejection here so a miswired all-zero SHA-512 provider // fails loudly instead of silently producing a degenerate signature. const R = G.multiply(r).toBytes(); // R = [r]B const hashable = concatBytes(R, A, msg); // dom2(F, C) || R || A || PH(M) const finish = (hashed: Uint8Array): TRet => { // k = SHA512(dom2(F, C) || R || A || PH(M)) const S = modN(r + modL_LE(hashed) * s); // S = (r + k * s) mod L; 0 <= s < l return abytes(concatBytes(R, numTo32bLE(S)), 64); // 64-byte sig: 32-byte encoded R point || 32-byte LE(S) }; return [hashable, finish]; }; /** * Signs message using secret key. Async. * Follows RFC8032 5.1.6. * @param message - Message bytes to sign. * @param secretKey - 32-byte RFC 8032 secret-key seed, not a 64-byte expanded secret key. * @returns 64-byte Ed25519 signature. * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Sign an arbitrary message with a fresh Ed25519 secret key. * * ```ts * import * as ed from '@noble/ed25519'; * * const secretKey = ed.utils.randomSecretKey(); * const message = new Uint8Array([1, 2, 3]); * const signature = await ed.signAsync(message, secretKey); * ``` */ const signAsync = async ( message: TArg, secretKey: TArg ): Promise> => { const m = snapshotBytes(message, 'message'); const e = await getExtendedPublicKeyAsync(secretKey); // r = SHA512(dom2(F, C) || prefix || PH(M)); then generate R, k, S and the signature. return hashFinishAsync(_sign(e, await callHashAsync('sha512Async', e.prefix, m), m)); }; /** * Signs message using secret key. To use, set `hashes.sha512` first. * Follows RFC8032 5.1.6. * @param message - Message bytes to sign. * @param secretKey - 32-byte RFC 8032 secret-key seed, not a 64-byte expanded secret key. * @returns 64-byte Ed25519 signature. * @throws If synchronous SHA-512 has not been configured in `hashes`. {@link Error} * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Use the sync API when you've wired a SHA-512 implementation yourself. * * ```ts * import * as ed from '@noble/ed25519'; * import { sha512 } from '@noble/hashes/sha2.js'; * * ed.hashes.sha512 = sha512; * const secretKey = ed.utils.randomSecretKey(); * const signature = ed.sign(new Uint8Array([1, 2, 3]), secretKey); * ``` */ const sign = (message: TArg, secretKey: TArg): TRet => { const m = snapshotBytes(message, 'message'); const e = getExtendedPublicKey(secretKey); // r = SHA512(dom2(F, C) || prefix || PH(M)); then generate R, k, S and the signature. return hashFinishSync(_sign(e, callHash('sha512', e.prefix, m), m)); }; /** * Verification options. zip215: true (default) follows ZIP215 spec. false would follow RFC8032. * * Any message with pubkey from `ED25519_TORSION_SUBGROUP` would be valid in sigs under ZIP215. */ export type EdDSAVerifyOpts = { /** Whether to use ZIP215 verification semantics instead of the library's stricter branch. */ zip215?: boolean; }; // Exported defaults favor ZIP-215 interoperability semantics; callers must opt into the stricter // branch with `{ zip215: false }`. // Preserves the exported ZIP-215 default for `{}` / `{ zip215: undefined }`, not just omitted opts. const getZip215 = (options: TArg): boolean => { if (options === null || typeof options !== 'object') throw new TypeError('expected valid options object'); return options.zip215 ?? true; }; const _verify = ( sig: Uint8Array, msg: Uint8Array, publicKey: Uint8Array, options: TArg ): Finishable => { sig = abytes(sig, 64, 'signature'); // Signature hex str/Bytes, must be 64 bytes msg = abytes(msg, undefined, 'message'); // Message hex str/Bytes publicKey = abytes(publicKey, LEN, 'publicKey'); const zip215 = getZip215(options); // zip215=false keeps the library's stricter branch, which still canonicalizes `R` / `A` before // hashing and rejects small-order public keys earlier than pure RFC8032 text would require. const r = sig.subarray(0, LEN); const s = bytesToNumberLE(sig.subarray(LEN, 64)); // Decode second half as an integer S; let A: Point, R: Point, SB: Point; let hashable: Uint8Array = Uint8Array.of(); let finished = false; try { // zip215=true is good for consensus-critical apps. =false follows RFC8032 / NIST186-5. // zip215=true: 0 <= y < MASK (2^256 for ed25519) // zip215=false: 0 <= y < P (2^255-19 for ed25519) A = Point.fromBytes(publicKey, zip215); R = Point.fromBytes(r, zip215); SB = G.multiply(s, false); // 0 <= s < l is done inside // ZIP-215 accepts noncanonical / unreduced point encodings, so the challenge hash must use the // exact signature/public-key bytes rather than canonicalized re-encodings of the decoded points. hashable = concatBytes(r, publicKey, msg); // dom2(F, C) || R || A || PH(M) finished = true; } catch (error) {} const finish = (hashed: Uint8Array): boolean => { if (!finished) return false; // Policy: strict mode intentionally rejects all small-order public keys, even though the raw RFC // equation text is looser here. This matches libsodium and avoids weak / ambiguous verification // outcomes where unusual low-order public keys can make distinct key/signature combinations verify. if (!zip215 && A.isSmallOrder()) return false; // k = SHA512(dom2(F, C) || R || A || PH(M)) const k = modL_LE(hashed); const RkA = R.add(A.multiply(k, false)); // Extended group equation // [8][S]B = [8]R + [8][k]A' return RkA.subtract(SB).clearCofactor().is0(); }; return [hashable, finish]; }; /** * Verifies a signature on message and public key. Async. * The implementation is based on RFC8032 5.1.7, but default opts use ZIP-215 semantics; pass * `{ zip215: false }` for the library's stricter branch. * @param signature - 64-byte signature. * @param message - Signed message bytes. * @param publicKey - 32-byte public key. * @param opts - Verification options. Defaults to ZIP-215 semantics. See {@link EdDSAVerifyOpts}. * @returns `true` when the signature is valid. * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Verify the signature against the same message and derived public key. * * ```ts * import * as ed from '@noble/ed25519'; * * const secretKey = ed.utils.randomSecretKey(); * const message = new Uint8Array([1, 2, 3]); * const publicKey = await ed.getPublicKeyAsync(secretKey); * const signature = await ed.signAsync(message, secretKey); * const isValid = await ed.verifyAsync(signature, message, publicKey); * ``` */ const verifyAsync = async ( signature: TArg, message: TArg, publicKey: TArg, opts: TArg = {} ): Promise => hashFinishAsync(_verify(signature, message, publicKey, opts)); /** * Verifies a signature on message and public key using the synchronous hash path. * The implementation is based on RFC8032 5.1.7, but default opts use ZIP-215 semantics; pass * `{ zip215: false }` for the library's stricter branch. * @param signature - 64-byte signature. * @param message - Signed message bytes. * @param publicKey - 32-byte public key. * @param opts - Verification options. Defaults to ZIP-215 semantics. See {@link EdDSAVerifyOpts}. * @returns `true` when the signature is valid. * @throws If synchronous SHA-512 has not been configured in `hashes`. {@link Error} * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Verify a signature entirely through the synchronous API. * * ```ts * import * as ed from '@noble/ed25519'; * import { sha512 } from '@noble/hashes/sha2.js'; * * ed.hashes.sha512 = sha512; * const secretKey = ed.utils.randomSecretKey(); * const message = new Uint8Array([1, 2, 3]); * const publicKey = ed.getPublicKey(secretKey); * const signature = ed.sign(message, secretKey); * const isValid = ed.verify(signature, message, publicKey); * ``` */ const verify = ( signature: TArg, message: TArg, publicKey: TArg, opts: TArg = {} ): boolean => hashFinishSync(_verify(signature, message, publicKey, opts)); /** * Math, hex, byte helpers. Not in `utils` because utils share API with noble-curves. * Exposes the same low-level field-default `mod` reducer and non-CT `invert` helper used * internally. * @example * Convert bytes to a hex string with the low-level helper namespace. * * ```ts * const hex = etc.bytesToHex(new Uint8Array([1, 2, 3])); * ``` */ const etc: { bytesToHex: (bytes: TArg) => string; hexToBytes: (hex: string) => TRet; concatBytes: (...arrs: TArg) => TRet; mod: (a: bigint, md?: bigint) => bigint; invert: typeof invert; randomBytes: (len?: number) => TRet; } = /* @__PURE__ */ freeze({ bytesToHex, hexToBytes, concatBytes, mod, invert, randomBytes, }); /** * Hash implementations used by the synchronous API plus the default async WebCrypto provider. * Both slots are configurable API surface; wrapper helpers revalidate that providers still return * 64-byte SHA-512 digests. * @example * Provide a SHA-512 implementation before calling synchronous helpers. * * ```ts * import * as ed from '@noble/ed25519'; * import { sha512 } from '@noble/hashes/sha2.js'; * * ed.hashes.sha512 = sha512; * const { publicKey } = ed.keygen(); * ``` */ const hashes = { sha512Async: async (message: TArg): Promise> => { const s = globalThis?.crypto?.subtle; if (!s) throw new Error('crypto.subtle must be defined, consider polyfill'); return new Uint8Array(await s.digest('SHA-512', concatBytes(message))) as TRet; }, sha512: undefined as undefined | ((message: TArg) => TRet), }; // Returns the final 32-byte Ed25519 secret-key seed verbatim, generating fresh random bytes only // when omitted. const randomSecretKey = (seed?: TArg): TRet => { return abytes(seed === undefined ? randomBytes() : seed, LEN, 'seed'); }; type KeysSecPub = { secretKey: Uint8Array; publicKey: Uint8Array }; /** * Generates a secret/public keypair. * @param seed - Optional 32-byte Ed25519 secret-key seed, returned verbatim as `secretKey`. * @returns Keypair with `secretKey` and `publicKey`. * @throws If synchronous SHA-512 has not been configured in `hashes`. {@link Error} * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Generate a new keypair through the synchronous API after wiring SHA-512. * * ```ts * import * as ed from '@noble/ed25519'; * import { sha512 } from '@noble/hashes/sha2.js'; * * ed.hashes.sha512 = sha512; * const { secretKey, publicKey } = ed.keygen(); * ``` */ const keygen = (seed?: TArg): TRet => { const secretKey = randomSecretKey(seed); const publicKey = getPublicKey(secretKey); return { secretKey, publicKey } as TRet; }; /** * Generates a secret/public keypair asynchronously. * @param seed - Optional 32-byte Ed25519 secret-key seed, returned verbatim as `secretKey`. * @returns Keypair with `secretKey` and `publicKey`. * @throws On wrong argument types. {@link TypeError} * @throws On wrong argument ranges or values. {@link RangeError} * @example * Generate a new keypair through the asynchronous WebCrypto-backed path. * * ```ts * import * as ed from '@noble/ed25519'; * * const { secretKey, publicKey } = await ed.keygenAsync(); * ``` */ const keygenAsync = async (seed?: TArg): Promise> => { const secretKey = randomSecretKey(seed); const publicKey = await getPublicKeyAsync(secretKey); return { secretKey, publicKey } as TRet; }; /** * Ed25519-specific key utilities. * `utils.getExtendedPublicKey*` expose secret-derived internals (`head`, `prefix`, `scalar`, and * point objects), not just public-key bytes. * @example * Generate a new Ed25519 secret key and derive the matching public key. * * ```ts * import * as ed from '@noble/ed25519'; * * const secretKey = ed.utils.randomSecretKey(); * const publicKey = await ed.getPublicKeyAsync(secretKey); * ``` */ const utils: { getExtendedPublicKeyAsync: typeof getExtendedPublicKeyAsync; getExtendedPublicKey: typeof getExtendedPublicKey; randomSecretKey: typeof randomSecretKey; } = /* @__PURE__ */ freeze({ getExtendedPublicKeyAsync, getExtendedPublicKey, randomSecretKey, }); // ## Precomputes // -------------- // Fixed W=8 window: 33 windows (ceil(256/8) + 1, NOT 32 - see wNAF loop), 128 points per window. // Layout is grouped by window: each block stores the positive multiples `1*base .. 128*base` for // that window, and the extra `+1` window absorbs carries from signed-digit recoding. const precompute = () => { const points: Point[] = []; let p = G; let b: Point; for (let w = 0; w < 33; w++) { b = p; points.push(b); for (let i = 1; i < 128; i++) { b = b.add(p); points.push(b); } // i=1, bc we skip 0 p = b.double(); } return points; }; let Gpows: Point[] | undefined = undefined; // shared process-wide cache of base-point precomputes // Branch-based negate helper used for JS/JIT mitigation symmetry, not a strict constant-time claim. const ctneg = (cnd: boolean, p: Point): Point => { const n = p.negate(); return cnd ? n : p; }; /** * Precomputes give 12x faster getPublicKey(), 10x sign(), 2x verify() by * caching multiples of G (base point). Cache is stored in 32MB of RAM. * Any time `G.multiply` is done, precomputes are used. * Not used for getSharedSecret, which instead multiplies random pubkey `P.multiply`. * * w-ary non-adjacent form (wNAF) precomputation method is 10% slower than windowed method, * but takes 2x less RAM. RAM reduction is possible by utilizing `.subtract`. * Returns the real accumulator `p` plus a fake accumulator `f`; callers only care about `p`, while * `f` exists to keep similar work in zero-digit branches as a JS/JIT side-channel mitigation. * * !! Precomputes can be disabled by commenting-out call of the wNAF() inside Point#multiply(). */ const wNAF = (n: bigint): { p: Point; f: Point } => { const comp = Gpows || (Gpows = precompute()); let p = I; let f = G; // f must be G, or could become I in the end for (let w = 0; w < 33; w++) { let wbits = Number(n & 255n); // extract W=8 bits. n >>= 8n; // shift number by W=8 bits. // We use negative indexes to reduce size of precomputed table by 2x. // Instead of needing precomputes 0..256, we only calculate them for 0..128. // If an index > 128 is found, we do (256-index) - where 256 is next window. // Naive: index +127 => 127, +224 => 224 // Optimized: index +127 => 127, +224 => 256-32 if (wbits > 128) { wbits -= 256; n += 1n; } const off = w * 128; // offset of this window's block; also the fake-add index const offP = off + Math.abs(wbits) - 1; // real-add index; both offsets always evaluated const isOddW = w % 2 !== 0; // conditions, evaluate both; alternates fake-add sign per window const isNeg = wbits < 0; if (wbits === 0) { // wbits == 0 means the real index would be I: can't add it. Add window offset `off` instead. f = f.add(ctneg(isOddW, comp[off])); // bits are 0: add garbage to fake point } else { p = p.add(ctneg(isNeg, comp[offP])); // bits are 1: add to result point } } if (n !== 0n) throw new Error('invalid wnaf'); return { p, f }; // return both real and fake points for JIT/leakage-shape symmetry }; // !! Remove the export to easily use in REPL / browser console export { etc, getPublicKey, getPublicKeyAsync, hash, hashes, keygen, keygenAsync, Point, sign, signAsync, utils, verify, verifyAsync, }; // ## TypeScript Uint8Array compat types // ------------------------------------- /** * Bytes API type helpers for old + new TypeScript. * * TS 5.6 has `Uint8Array`, while TS 5.9+ made it generic `Uint8Array`. * We can't use specific return type, because TS 5.6 will error. * We can't use generic return type, because most TS 5.9 software will expect specific type. * * Maps typed-array input leaves to broad forms. * These are compatibility adapters, not ownership guarantees. * * - `TArg` keeps byte inputs broad. * - `TRet` marks byte outputs for TS 5.6 and TS 5.9+ compatibility. */ export type TypedArg = T extends BigInt64Array ? BigInt64Array : T extends BigUint64Array ? BigUint64Array : T extends Float32Array ? Float32Array : T extends Float64Array ? Float64Array : T extends Int16Array ? Int16Array : T extends Int32Array ? Int32Array : T extends Int8Array ? Int8Array : T extends Uint16Array ? Uint16Array : T extends Uint32Array ? Uint32Array : T extends Uint8ClampedArray ? Uint8ClampedArray : T extends Uint8Array ? Uint8Array : never; /** Maps typed-array output leaves to narrow TS-compatible forms. */ export type TypedRet = T extends BigInt64Array ? ReturnType : T extends BigUint64Array ? ReturnType : T extends Float32Array ? ReturnType : T extends Float64Array ? ReturnType : T extends Int16Array ? ReturnType : T extends Int32Array ? ReturnType : T extends Int8Array ? ReturnType : T extends Uint16Array ? ReturnType : T extends Uint32Array ? ReturnType : T extends Uint8ClampedArray ? ReturnType : T extends Uint8Array ? ReturnType : never; /** Recursively adapts byte-carrying API input types. See {@link TypedArg}. */ export type TArg = | T | ([TypedArg] extends [never] ? T extends (...args: infer A) => infer R ? ((...args: { [K in keyof A]: TRet }) => TArg) & { [K in keyof T]: T[K] extends (...args: any) => any ? T[K] : TArg; } : T extends [infer A, ...infer R] ? [TArg, ...{ [K in keyof R]: TArg }] : T extends readonly [infer A, ...infer R] ? readonly [TArg, ...{ [K in keyof R]: TArg }] : T extends (infer A)[] ? TArg[] : T extends readonly (infer A)[] ? readonly TArg[] : T extends Promise ? Promise> : T extends object ? { [K in keyof T]: TArg } : T : TypedArg); /** Recursively adapts byte-carrying API output types. See {@link TypedArg}. */ export type TRet = T extends unknown ? T & ([TypedRet] extends [never] ? T extends (...args: infer A) => infer R ? ((...args: { [K in keyof A]: TArg }) => TRet) & { [K in keyof T]: T[K] extends (...args: any) => any ? T[K] : TRet; } : T extends [infer A, ...infer R] ? [TRet, ...{ [K in keyof R]: TRet }] : T extends readonly [infer A, ...infer R] ? readonly [TRet, ...{ [K in keyof R]: TRet }] : T extends (infer A)[] ? TRet[] : T extends readonly (infer A)[] ? readonly TRet[] : T extends Promise ? Promise> : T extends object ? { [K in keyof T]: TRet } : T : TypedRet) : never;