BlueWallet/class/hd-legacy-p2pkh-wallet.js

import bip39 from 'bip39';
import { AbstractHDElectrumWallet } from './abstract-hd-electrum-wallet';
const bitcoin = require('bitcoinjs-lib');
const HDNode = require('bip32');
const BlueElectrum = require('../BlueElectrum');

/**
 * HD Wallet (BIP39).
 * In particular, BIP44 (P2PKH legacy addressess)
 * @see https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki
 */
export class HDLegacyP2PKHWallet extends AbstractHDElectrumWallet {
  static type = 'HDlegacyP2PKH';
  static typeReadable = 'HD Legacy (BIP44 P2PKH)';

  allowSend() {
    return true;
  }

  getXpub() {
    if (this._xpub) {
      return this._xpub; // cache hit
    }
    const mnemonic = this.secret;
    const seed = bip39.mnemonicToSeed(mnemonic);
    const root = bitcoin.bip32.fromSeed(seed);

    const path = "m/44'/0'/0'";
    const child = root.derivePath(path).neutered();
    this._xpub = child.toBase58();

    return this._xpub;
  }

  _getExternalWIFByIndex(index) {
    return this._getWIFByIndex(false, index);
  }

  _getInternalWIFByIndex(index) {
    return this._getWIFByIndex(true, index);
  }

  /**
   * Get internal/external WIF by wallet index
   * @param {Boolean} internal
   * @param {Number} index
   * @returns {*}
   * @private
   */
  _getWIFByIndex(internal, index) {
    const mnemonic = this.secret;
    const seed = bip39.mnemonicToSeed(mnemonic);

    const root = HDNode.fromSeed(seed);
    const path = `m/44'/0'/0'/${internal ? 1 : 0}/${index}`;
    const child = root.derivePath(path);

    return child.toWIF();
  }

  _getExternalAddressByIndex(index) {
    index = index * 1; // cast to int
    if (this.external_addresses_cache[index]) return this.external_addresses_cache[index]; // cache hit

    const node = bitcoin.bip32.fromBase58(this.getXpub());
    const address = bitcoin.payments.p2pkh({
      pubkey: node.derive(0).derive(index).publicKey,
    }).address;

    return (this.external_addresses_cache[index] = address);
  }

  _getInternalAddressByIndex(index) {
    index = index * 1; // cast to int
    if (this.internal_addresses_cache[index]) return this.internal_addresses_cache[index]; // cache hit

    const node = bitcoin.bip32.fromBase58(this.getXpub());
    const address = bitcoin.payments.p2pkh({
      pubkey: node.derive(1).derive(index).publicKey,
    }).address;

    return (this.internal_addresses_cache[index] = address);
  }

  async fetchUtxo() {
    await super.fetchUtxo();
    // now we need to fetch txhash for each input as required by PSBT
    let txhexes = await BlueElectrum.multiGetTransactionByTxid(
      this.getUtxo().map(x => x['txid']),
      50,
      false,
    );

    let newUtxos = [];
    for (let u of this.getUtxo()) {
      if (txhexes[u.txid]) u.txhex = txhexes[u.txid];
      newUtxos.push(u);
    }

    return newUtxos;
  }

  _addPsbtInput(psbt, input, sequence, masterFingerprintBuffer) {
    const pubkey = this._getPubkeyByAddress(input.address);
    const path = this._getDerivationPathByAddress(input.address, 44);

    if (!input.txhex) throw new Error('UTXO is missing txhex of the input, which is required by PSBT for non-segwit input');

    psbt.addInput({
      hash: input.txid,
      index: input.vout,
      sequence,
      bip32Derivation: [
        {
          masterFingerprint: masterFingerprintBuffer,
          path,
          pubkey,
        },
      ],
      // non-segwit inputs now require passing the whole previous tx as Buffer
      nonWitnessUtxo: Buffer.from(input.txhex, 'hex'),
    });

    return psbt;
  }

  allowSendMax() {
    return true;
  }
}