micro-bip32 v0.1.0

micro-bip32

Create BIP32 hierarchical deterministic (HD) wallets with minimum dependencies.

Developed for, and then extracted from js-ethereum-cryptography. The source code is the same, the files have been copied for convenience.

Check out micro-bip39 if you need mnemonic phrases.

Usage

npm install micro-bip32

Or, yarn add micro-bip32

API

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

const { HDKey } = require("micro-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.

License

MIT License

Copyright (c) 2021 Patricio Palladino, Paul Miller, ethereum-cryptography contributors