Merge pull request #2896 from BlueWallet/fix-2886

FIX: aezeed onchain wallet produces correct zpub (closes #2886)

class/wallets/hd-aezeed-wallet.js

@@ -1,4 +1,5 @@
 import { AbstractHDElectrumWallet } from './abstract-hd-electrum-wallet';
+import b58 from 'bs58check';
 const bitcoin = require('bitcoinjs-lib');
 const { CipherSeed } = require('aezeed');
 
@@ -33,6 +34,23 @@ export class HDAezeedWallet extends AbstractHDElectrumWallet {
     }
   }
 
+  getXpub() {
+    // first, getting xpub
+    const root = bitcoin.bip32.fromSeed(this._getEntropyCached());
+
+    const path = "m/84'/0'/0'";
+    const child = root.derivePath(path).neutered();
+    const xpub = child.toBase58();
+
+    // bitcoinjs does not support zpub yet, so we just convert it from xpub
+    let data = b58.decode(xpub);
+    data = data.slice(4);
+    data = Buffer.concat([Buffer.from('04b24746', 'hex'), data]);
+    this._xpub = b58.encode(data);
+
+    return this._xpub;
+  }
+
   validateMnemonic(): boolean {
     throw new Error('Use validateMnemonicAsync()');
   }

tests/unit/hd-aezeed.test.js

@@ -1,4 +1,4 @@
-import { HDAezeedWallet } from '../../class';
+import { HDAezeedWallet, WatchOnlyWallet } from '../../class';
 const assert = require('assert');
 
 describe('HDAezeedWallet', () => {
@@ -50,7 +50,7 @@ describe('HDAezeedWallet', () => {
 
     assert.strictEqual(
       aezeed.getXpub(),
-      'zpub6rrqwqM3aF1Jdz6y5Zw18RTppHbZQeQpsrSyf3E2uibcrsEeZAbm5MX41Nq4XBF7HbCvRVASHLzRkFsg6sMgakcceWzJazZH7SaVPBoXzDQ',
+      'zpub6rkAmx9z6PmK7tBpGQatqpRweZvRw7uqiEMRS9KuZA9VFKUSoz3GQeJFtRQsQwduWugh5mGHro1tGnt78ci9AiB8qEH4hCRBWxdMaxadGVy',
     );
 
     let address = aezeed._getExternalAddressByIndex(0);
@@ -91,6 +91,30 @@ describe('HDAezeedWallet', () => {
     );
   });
 
+  it('watch-only from zpub produces correct addresses', async () => {
+    const aezeed = new HDAezeedWallet();
+    aezeed.setSecret(
+      'abstract rhythm weird food attract treat mosquito sight royal actor surround ride strike remove guilt catch filter summer mushroom protect poverty cruel chaos pattern',
+    );
+    assert.ok(await aezeed.validateMnemonicAsync());
+    assert.ok(!(await aezeed.mnemonicInvalidPassword()));
+
+    assert.strictEqual(
+      aezeed.getXpub(),
+      'zpub6rkAmx9z6PmK7tBpGQatqpRweZvRw7uqiEMRS9KuZA9VFKUSoz3GQeJFtRQsQwduWugh5mGHro1tGnt78ci9AiB8qEH4hCRBWxdMaxadGVy',
+    );
+
+    const address = aezeed._getExternalAddressByIndex(0);
+    assert.strictEqual(address, 'bc1qdjj7lhj9lnjye7xq3dzv3r4z0cta294xy78txn');
+    assert.ok(aezeed.getAllExternalAddresses().includes('bc1qdjj7lhj9lnjye7xq3dzv3r4z0cta294xy78txn'));
+
+    const watchOnly = new WatchOnlyWallet();
+    watchOnly.setSecret(aezeed.getXpub());
+    watchOnly.init();
+    assert.strictEqual(watchOnly._getExternalAddressByIndex(0), aezeed._getExternalAddressByIndex(0));
+    assert.ok(watchOnly.weOwnAddress('bc1qdjj7lhj9lnjye7xq3dzv3r4z0cta294xy78txn'));
+  });
+
   it('can sign and verify messages', async () => {
     const aezeed = new HDAezeedWallet();
     aezeed.setSecret(