scure-bip32

Secure, audited & minimal implementation of BIP32 hierarchical deterministic (HD) wallets.

Compared to popular hdkey package, scure-bip32:

• Is 418KB all-bundled instead of 5.9MB
• Uses 3 dependencies instead of 24
• Had an external security audit by Cure53 on Jan 5, 2022

Check out scure-bip39 if you need mnemonic phrases. See micro-ed25519-hdkey if you need SLIP-0010/BIP32 HDKey implementation.

This library belongs to scure

scure — secure audited packages for every use case.

• Independent security audits
• All releases are signed with PGP keys
• Check out all libraries: base, bip32, bip39

Usage

npm install @scure/bip32

Or

yarn add @scure/bip32

This module exports a single class HDKey, which should be used like this:

const { HDKey } = require("@scure/bip32");
const hdkey1 = HDKey.fromMasterSeed(seed);
const hdkey2 = HDKey.fromExtendedKey(base58key);
const hdkey3 = HDKey.fromJSON({ xpriv: string });

// props
[hdkey1.depth, hdkey1.index, hdkey1.chainCode];
console.log(hdkey2.privateKey, hdkey2.publicKey);
console.log(hdkey3.derive("m/0/2147483647'/1"));
const sig = hdkey3.sign(hash);
hdkey3.verify(hash, sig);

Note: chainCode property is essentially a private part of a secret "master" key, it should be guarded from unauthorized access.

The full API is:

class HDKey {
  public static HARDENED_OFFSET: number;
  public static fromMasterSeed(seed: Uint8Array, versions: Versions): HDKey;
  public static fromExtendedKey(base58key: string, versions: Versions): HDKey;
  public static fromJSON(json: { xpriv: string }): HDKey;

  readonly versions: Versions;
  readonly depth: number = 0;
  readonly index: number = 0;
  readonly chainCode: Uint8Array | null = null;
  readonly parentFingerprint: number = 0;

  get fingerprint(): number;
  get identifier(): Uint8Array | undefined;
  get pubKeyHash(): Uint8Array | undefined;
  get privateKey(): Uint8Array | null;
  get publicKey(): Uint8Array | null;
  get privateExtendedKey(): string;
  get publicExtendedKey(): string;

  derive(path: string): HDKey;
  deriveChild(index: number): HDKey;
  sign(hash: Uint8Array): Uint8Array;
  verify(hash: Uint8Array, signature: Uint8Array): boolean;
  wipePrivateData(): this;
}

interface Versions {
  private: number;
  public: number;
}

The hdkey submodule provides a library for keys derivation according to BIP32.

It has almost the exact same API than the version 1.x of hdkey from cryptocoinjs, but it's backed by this package's primitives, and has built-in TypeScript types. Its only difference is that it has to be be used with a named import. The implementation is loosely based on hdkey, which has MIT License.

Security

The library has been audited by Cure53 on Jan 5, 2022. Check out the audit PDF & URL. See changes since audit.

1. The library was initially developed for js-ethereum-cryptography
2. At commit ae00e6d7, it was extracted to a separate package called micro-bip32
3. After the audit we've decided to use NPM namespace for security. Since @micro namespace was taken, we've renamed the package to @scure/bip32

License

MIT License

Copyright (c) 2022 Patricio Palladino, Paul Miller (paulmillr.com)