REF: start transition to Electrum server

2024-11-19 01:40:12 +01:00 · 2019-01-29 02:27:07 +00:00 · 2019-01-29 02:27:07 +00:00 · 240f2c35cb
commit 240f2c35cb
parent 95c98db486
15 changed files with 359 additions and 23 deletions
--- a/BlueApp.js
+++ b/BlueApp.js
@ -7,6 +7,7 @@ let EV = require('./events');
 let currency = require('./currency');
 let loc = require('./loc');
 let A = require('./analytics');
+let BlueElectrum = require('./BlueElectrum'); // eslint-disable-line

 /** @type {AppStorage} */
 let BlueApp = new AppStorage();
--- a/BlueElectrum.js
+++ b/BlueElectrum.js
@ -0,0 +1,105 @@
+import { AsyncStorage } from 'react-native';
+const ElectrumClient = require('electrum-client');
+let bitcoin = require('bitcoinjs-lib');
+let reverse = require('buffer-reverse');
+
+const defaultPeer = { host: 'electrum.coinucopia.io', ssl: 50002, tcp: 50001, pruning: null, http: null, https: null };
+console.log('begin connection:', JSON.stringify(defaultPeer));
+
+let mainClient = new ElectrumClient(defaultPeer.tcp, defaultPeer.host, 'tcp');
+
+(async () => {
+  try {
+    await mainClient.connect();
+    const ver = await mainClient.server_version('2.7.11', '1.2');
+    console.log('connected to ', ver);
+    let peers = await mainClient.serverPeers_subscribe();
+    // console.log('peers', peers);
+    if (peers && peers.length > 0) {
+      AsyncStorage.setItem('ELECTRUM_PEERS', JSON.stringify(peers));
+    }
+  } catch (e) {
+    console.log('bad connection:', JSON.stringify(defaultPeer));
+    throw new Error();
+  }
+})();
+
+/**
+ *
+ * @param address {String}
+ * @returns {Promise<Object>}
+ */
+async function getBalanceByAddress(address) {
+  let script = bitcoin.address.toOutputScript(address);
+  let hash = bitcoin.crypto.sha256(script);
+  let reversedHash = Buffer.from(reverse(hash));
+  let balance = await mainClient.blockchainScripthash_getBalance(reversedHash.toString('hex'));
+  balance.addr = address;
+  return balance;
+}
+
+/**
+ *
+ * @param address {String}
+ * @returns {Promise<Array>}
+ */
+async function getTransactionsByAddress(address) {
+  let script = bitcoin.address.toOutputScript(address);
+  let hash = bitcoin.crypto.sha256(script);
+  let reversedHash = Buffer.from(reverse(hash));
+  let history = await mainClient.blockchainScripthash_getHistory(reversedHash.toString('hex'));
+  return history;
+}
+
+/**
+ *
+ * @param addresses {Array}
+ * @returns {Promise<{balance: number, unconfirmed_balance: number}>}
+ */
+async function multiGetBalanceByAddress(addresses) {
+  let balance = 0;
+  let unconfirmedBalance = 0;
+  for (let addr of addresses) {
+    let b = await getBalanceByAddress(addr);
+
+    balance += b.confirmed;
+    unconfirmedBalance += b.unconfirmed_balance;
+  }
+
+  return { balance, unconfirmed_balance: unconfirmedBalance };
+}
+
+module.exports.getBalanceByAddress = getBalanceByAddress;
+module.exports.getTransactionsByAddress = getTransactionsByAddress;
+module.exports.multiGetBalanceByAddress = multiGetBalanceByAddress;
+
+module.exports.forceDisconnect = () => {
+  mainClient.keepAlive = () => {}; // dirty hack to make it stop reconnecting
+  mainClient.reconnect = () => {}; // dirty hack to make it stop reconnecting
+  mainClient.close();
+};
+
+/*
+
+
+
+let addr4elect = 'bc1qwqdg6squsna38e46795at95yu9atm8azzmyvckulcc7kytlcckxswvvzej';
+let script = bitcoin.address.toOutputScript(addr4elect);
+let hash = bitcoin.crypto.sha256(script);
+let reversedHash = Buffer.from(hash.reverse());
+console.log(addr4elect, ' maps to ', reversedHash.toString('hex'));
+console.log(await mainClient.blockchainScripthash_getBalance(reversedHash.toString('hex')));
+
+addr4elect = '1BWwXJH3q6PRsizBkSGm2Uw4Sz1urZ5sCj';
+script = bitcoin.address.toOutputScript(addr4elect);
+hash = bitcoin.crypto.sha256(script);
+reversedHash = Buffer.from(hash.reverse());
+console.log(addr4elect, ' maps to ', reversedHash.toString('hex'));
+console.log(await mainClient.blockchainScripthash_getBalance(reversedHash.toString('hex')));
+
+// let peers = await mainClient.serverPeers_subscribe();
+// console.log(peers);
+mainClient.keepAlive = () => {}; // dirty hack to make it stop reconnecting
+mainClient.reconnect = () => {}; // dirty hack to make it stop reconnecting
+mainClient.close();
+// setTimeout(()=>process.exit(), 3000); */
--- a/Electrum.test.js
+++ b/Electrum.test.js
@ -0,0 +1,64 @@
+/* global it, describe, jasmine */
+global.net = require('net');
+let BlueElectrum = require('./BlueElectrum');
+let assert = require('assert');
+
+describe('Electrum', () => {
+  it('ElectrumClient can connect and query', async () => {
+    jasmine.DEFAULT_TIMEOUT_INTERVAL = 100 * 1000;
+    const ElectrumClient = require('electrum-client');
+    let bitcoin = require('bitcoinjs-lib');
+    // let bitcoin = require('bitcoinjs-lib');
+
+    const peer = { host: 'electrum.coinucopia.io', ssl: 50002, tcp: 50001, pruning: null, http: null, https: null };
+    console.log('begin connection:', JSON.stringify(peer));
+    let mainClient = new ElectrumClient(peer.tcp, peer.host, 'tcp');
+
+    try {
+      await mainClient.connect();
+      const ver = await mainClient.server_version('2.7.11', '1.2');
+      console.log('connected to ', ver);
+    } catch (e) {
+      console.log('bad connection:', JSON.stringify(peer));
+      throw new Error();
+    }
+
+    let addr4elect = 'bc1qwqdg6squsna38e46795at95yu9atm8azzmyvckulcc7kytlcckxswvvzej';
+    let script = bitcoin.address.toOutputScript(addr4elect);
+    let hash = bitcoin.crypto.sha256(script);
+    let reversedHash = Buffer.from(hash.reverse());
+    let balance = await mainClient.blockchainScripthash_getBalance(reversedHash.toString('hex'));
+    assert.ok(balance.confirmed > 0);
+
+    addr4elect = '3GCvDBAktgQQtsbN6x5DYiQCMmgZ9Yk8BK';
+    script = bitcoin.address.toOutputScript(addr4elect);
+    hash = bitcoin.crypto.sha256(script);
+    reversedHash = Buffer.from(hash.reverse());
+    balance = await mainClient.blockchainScripthash_getBalance(reversedHash.toString('hex'));
+    assert.ok(balance.confirmed === 51432);
+
+    // let peers = await mainClient.serverPeers_subscribe();
+    // console.log(peers);
+    mainClient.keepAlive = () => {}; // dirty hack to make it stop reconnecting
+    mainClient.reconnect = () => {}; // dirty hack to make it stop reconnecting
+    mainClient.close();
+    // setTimeout(()=>process.exit(), 3000);
+  });
+
+  it('BlueElectrum works', async function() {
+    let address = '3GCvDBAktgQQtsbN6x5DYiQCMmgZ9Yk8BK';
+    let balance = await BlueElectrum.getBalanceByAddress(address);
+    assert.strictEqual(balance.confirmed, 51432);
+    assert.strictEqual(balance.unconfirmed, 0);
+    assert.strictEqual(balance.addr, address);
+
+    let txs = await BlueElectrum.getTransactionsByAddress(address);
+    assert.strictEqual(txs.length, 1);
+    for (let tx of txs) {
+      assert.ok(tx.tx_hash);
+      assert.ok(tx.height);
+    }
+
+    BlueElectrum.forceDisconnect();
+  });
+});
--- a/HDWallet.test.js
+++ b/HDWallet.test.js
@ -1,8 +1,15 @@
-/* global it, jasmine */
+/* global it, jasmine, afterAll */
 import { SegwitP2SHWallet, SegwitBech32Wallet, HDSegwitP2SHWallet, HDLegacyBreadwalletWallet, HDLegacyP2PKHWallet } from './class';
 global.crypto = require('crypto'); // shall be used by tests under nodejs CLI, but not in RN environment
 let assert = require('assert');
 let bitcoin = require('bitcoinjs-lib');
+global.net = require('net'); // needed by Electrum client. For RN it is proviced in shim.js
+let BlueElectrum = require('./BlueElectrum'); // so it connects ASAP
+
+afterAll(() => {
+  // after all tests we close socket so the test suite can actually terminate
+  return BlueElectrum.forceDisconnect();
+});

 it('can convert witness to address', () => {
  let address = SegwitP2SHWallet.witnessToAddress('035c618df829af694cb99e664ce1b34f80ad2c3b49bcd0d9c0b1836c66b2d25fd8');
@ -148,6 +155,30 @@ it('Segwit HD (BIP49) can fetch UTXO', async function() {
  );
 });

+it('Segwit HD (BIP49) can fetch balance with many used addresses in hierarchy', async function() {
+  if (!process.env.HD_MNEMONIC_BIP49_MANY_TX) {
+    console.error('process.env.HD_MNEMONIC_BIP49_MANY_TX not set, skipped');
+    return;
+  }
+
+  jasmine.DEFAULT_TIMEOUT_INTERVAL = 90 * 1000;
+  let hd = new HDSegwitP2SHWallet();
+  hd.setSecret(process.env.HD_MNEMONIC_BIP49_MANY_TX);
+  assert.ok(hd.validateMnemonic());
+  let start = +new Date();
+  await hd.fetchBalance();
+  let end = +new Date();
+  const took = (end - start) / 1000;
+  took > 15 && console.warn('took', took, "sec to fetch huge HD wallet's balance");
+  assert.strictEqual(hd.getBalance(), 0.00051432);
+
+  await hd.fetchUtxo();
+  assert.ok(hd.utxo.length > 0);
+
+  await hd.fetchTransactions();
+  assert.strictEqual(hd.getTransactions().length, 107);
+});
+
 it('can work with malformed mnemonic', () => {
  let mnemonic =
    'honey risk juice trip orient galaxy win situate shoot anchor bounce remind horse traffic exotic since escape mimic ramp skin judge owner topple erode';
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@ -106,6 +106,7 @@ android {
        ndk {
            abiFilters "armeabi-v7a", "x86"
        }
+        multiDexEnabled true
    }
    splits {
        abi {
@ -137,6 +138,7 @@ android {
 }

 dependencies {
+    implementation project(':react-native-tcp')
    implementation project(':@remobile_react-native-qrcode-local-image')
    implementation project(':react-native-image-picker')
    implementation project(':react-native-webview')
@ -155,6 +157,7 @@ dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation "com.android.support:appcompat-v7:${rootProject.ext.supportLibVersion}"
    implementation "com.facebook.react:react-native:+"  // From node_modules
+    implementation 'com.android.support:multidex:1.0.3'
 }

 // Run this once to be able to run the application with BUCK
--- a/android/app/src/main/java/io/bluewallet/bluewallet/MainApplication.java
+++ b/android/app/src/main/java/io/bluewallet/bluewallet/MainApplication.java
@ -3,6 +3,7 @@ package io.bluewallet.bluewallet;
 import android.app.Application;

 import com.facebook.react.ReactApplication;
+import com.peel.react.TcpSocketsModule;
 import com.remobile.qrcodeLocalImage.RCTQRCodeLocalImagePackage;
 import com.imagepicker.ImagePickerPackage;
 import com.reactnativecommunity.webview.RNCWebViewPackage;
@ -55,6 +56,7 @@ public class MainApplication extends Application implements ReactApplication {
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
          new MainReactPackage(),
+            new TcpSocketsModule(),
            new RCTQRCodeLocalImagePackage(),
            new ImagePickerPackage(),
            new RNCWebViewPackage(),
--- a/android/settings.gradle
+++ b/android/settings.gradle
@ -1,4 +1,6 @@
 rootProject.name = 'BlueWallet'
+include ':react-native-tcp'
+project(':react-native-tcp').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-tcp/android')
 include ':@remobile_react-native-qrcode-local-image'
 project(':@remobile_react-native-qrcode-local-image').projectDir = new File(rootProject.projectDir, '../node_modules/@remobile/react-native-qrcode-local-image/android')
 include ':react-native-image-picker'
--- a/class/abstract-hd-wallet.js
+++ b/class/abstract-hd-wallet.js
@ -4,6 +4,7 @@ import { WatchOnlyWallet } from './watch-only-wallet';
 const bip39 = require('bip39');
 const BigNumber = require('bignumber.js');
 const bitcoin = require('bitcoinjs-lib');
+const BlueElectrum = require('../BlueElectrum');

 export class AbstractHDWallet extends LegacyWallet {
  static type = 'abstract';
@ -346,24 +347,69 @@ export class AbstractHDWallet extends LegacyWallet {

  async fetchBalance() {
    try {
-      const api = new Frisbee({ baseURI: 'https://www.blockonomics.co' });
-      let response = await api.post('/api/balance', { body: JSON.stringify({ addr: this.getXpub() }) });
+      // doing binary search for last used externa address

-      if (response && response.body && response.body.response) {
-        this.balance = 0;
-        this.unconfirmed_balance = 0;
-        this.usedAddresses = [];
-        for (let addr of response.body.response) {
-          this.balance += addr.confirmed;
-          this.unconfirmed_balance += addr.unconfirmed;
-          this.usedAddresses.push(addr.addr);
+      let that = this;
+
+      // refactor me
+      // eslint-disable-next-line
+      async function binarySearchIterationForInternalAddress(index, maxUsedIndex = 0, minUnusedIndex = 100500100, depth = 0) {
+        if (depth >= 20) return maxUsedIndex + 1; // fail
+        let txs = await BlueElectrum.getTransactionsByAddress(that._getInternalAddressByIndex(index));
+        if (txs.length === 0) {
+          minUnusedIndex = Math.min(minUnusedIndex, index); // set
+          index = Math.round((index - maxUsedIndex) / 2 + maxUsedIndex);
+        } else {
+          maxUsedIndex = Math.max(maxUsedIndex, index); // set
+          let txs2 = await BlueElectrum.getTransactionsByAddress(that._getInternalAddressByIndex(index + 1));
+          if (txs2.length === 0) return index + 1; // thats our next free address
+
+          index = Math.round((minUnusedIndex - index) / 2 + index);
        }
-        this.balance = new BigNumber(this.balance).dividedBy(100000000).toString() * 1;
-        this.unconfirmed_balance = new BigNumber(this.unconfirmed_balance).dividedBy(100000000).toString() * 1;
-        this._lastBalanceFetch = +new Date();
-      } else {
-        throw new Error('Could not fetch balance from API: ' + response.err);
+
+        return binarySearchIterationForInternalAddress(index, maxUsedIndex, minUnusedIndex, depth + 1);
      }
+
+      this.next_free_change_address_index = await binarySearchIterationForInternalAddress(100);
+
+      // refactor me
+      // eslint-disable-next-line
+      async function binarySearchIterationForExternalAddress(index, maxUsedIndex = 0, minUnusedIndex = 100500100, depth = 0) {
+        if (depth >= 20) return maxUsedIndex + 1; // fail
+        let txs = await BlueElectrum.getTransactionsByAddress(that._getExternalAddressByIndex(index));
+        if (txs.length === 0) {
+          minUnusedIndex = Math.min(minUnusedIndex, index); // set
+          index = Math.round((index - maxUsedIndex) / 2 + maxUsedIndex);
+        } else {
+          maxUsedIndex = Math.max(maxUsedIndex, index); // set
+          let txs2 = await BlueElectrum.getTransactionsByAddress(that._getExternalAddressByIndex(index + 1));
+          if (txs2.length === 0) return index + 1; // thats our next free address
+
+          index = Math.round((minUnusedIndex - index) / 2 + index);
+        }
+
+        return binarySearchIterationForExternalAddress(index, maxUsedIndex, minUnusedIndex, depth + 1);
+      }
+
+      this.next_free_address_index = await binarySearchIterationForExternalAddress(100);
+
+      this.balance = 0;
+      this.unconfirmed_balance = 0;
+      this.usedAddresses = [];
+
+      // generating all involved addresses:
+      for (let c = 0; c < this.next_free_address_index; c++) {
+        this.usedAddresses.push(this._getExternalAddressByIndex(c));
+      }
+      for (let c = 0; c < this.next_free_change_address_index; c++) {
+        this.usedAddresses.push(this._getInternalAddressByIndex(c));
+      }
+
+      // finally fetching balance
+      let balance = await BlueElectrum.multiGetBalanceByAddress(this.usedAddresses);
+      this.balance = new BigNumber(balance.balance).dividedBy(100000000).toNumber();
+      this.unconfirmed_balance = new BigNumber(balance.unconfirmed_balance).dividedBy(100000000).toNumber();
+      this._lastBalanceFetch = +new Date();
    } catch (err) {
      console.warn(err);
    }
--- a/ios/BlueWallet.xcodeproj/project.pbxproj
+++ b/ios/BlueWallet.xcodeproj/project.pbxproj
@ -5,7 +5,6 @@
 	};
 	objectVersion = 46;
 	objects = {
-
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@ -80,6 +79,7 @@
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+		34582CAA4AD140F7B80C961A /* libTcpSockets.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 9DF4E6C040764E4BA1ACC1EB /* libTcpSockets.a */; };
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+		910283A2A9EB4D00902DE78E /* TcpSockets.xcodeproj */ = {isa = PBXFileReference; name = "TcpSockets.xcodeproj"; path = "../node_modules/react-native-tcp/ios/TcpSockets.xcodeproj"; sourceTree = "<group>"; fileEncoding = undefined; lastKnownFileType = wrapper.pb-project; explicitFileType = undefined; includeInIndex = 0; };
+		9DF4E6C040764E4BA1ACC1EB /* libTcpSockets.a */ = {isa = PBXFileReference; name = "libTcpSockets.a"; path = "libTcpSockets.a"; sourceTree = "<group>"; fileEncoding = undefined; lastKnownFileType = archive.ar; explicitFileType = undefined; includeInIndex = 0; };
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@ -661,6 +663,7 @@
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 				C1056BF235EE4E23AAF21975 /* libRCTQRCodeLocalImage.a in Frameworks */,
+				34582CAA4AD140F7B80C961A /* libTcpSockets.a in Frameworks */,
 			);
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@ -898,6 +901,7 @@
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 				7EA61BC8FF6E4AD2A67F1557 /* RCTQRCodeLocalImage.xcodeproj */,
+				910283A2A9EB4D00902DE78E /* TcpSockets.xcodeproj */,
 			);
 			name = Libraries;
 			sourceTree = "<group>";
@ -1964,6 +1968,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = BlueWalletTests/Info.plist;
 				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
@ -1992,6 +1997,7 @@
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
+					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
@ -2028,6 +2034,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = BlueWalletTests/Info.plist;
 				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
@ -2056,6 +2063,7 @@
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
+					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
@ -2093,6 +2101,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = BlueWallet/Info.plist;
 				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
@ -2134,6 +2143,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = BlueWallet/Info.plist;
 				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
@ -2182,6 +2192,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = "BlueWallet-tvOS/Info.plist";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
@ -2209,6 +2220,7 @@
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
+					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
@ -2254,6 +2266,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = "BlueWallet-tvOS/Info.plist";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
@ -2281,6 +2294,7 @@
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
+					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
@ -2325,6 +2339,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = "BlueWallet-tvOSTests/Info.plist";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
@ -2352,6 +2367,7 @@
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
+					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
@ -2396,6 +2412,7 @@
 					"$(SRCROOT)/../node_modules/react-native-wkwebview-reborn/ios/RCTWKWebView",
 					"$(SRCROOT)/../node_modules/react-native-image-picker/ios",
 					"$(SRCROOT)/../node_modules/@remobile/react-native-qrcode-local-image/ios/RCTQRCodeLocalImage",
+					"$(SRCROOT)/../node_modules/react-native-tcp/ios/**",
 				);
 				INFOPLIST_FILE = "BlueWallet-tvOSTests/Info.plist";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
@ -2423,6 +2440,7 @@
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 					"\"$(SRCROOT)/$(TARGET_NAME)\"",
+					"\"$(SRCROOT)/$(TARGET_NAME)\"",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
--- a/package-lock.json
+++ b/package-lock.json
@ -3004,8 +3004,7 @@
    "console-control-strings": {
      "version": "1.1.0",
      "resolved": "https://registry.npmjs.org/console-control-strings/-/console-control-strings-1.1.0.tgz",
-      "integrity": "sha1-PXz0Rk22RG6mRL9LOVB/mFEAjo4=",
-      "optional": true
+      "integrity": "sha1-PXz0Rk22RG6mRL9LOVB/mFEAjo4="
    },
    "constants-browserify": {
      "version": "1.0.0",
@ -3468,6 +3467,15 @@
      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.3.105.tgz",
      "integrity": "sha512-MWZZTThmQR82yzSPOn0BJ2ayZL1l7QyQpS22Frkxn1se9ZJ1WlSwnH8/CeBVhv4IStRxUDBvypeNy2dqsKR6sQ=="
    },
+    "electrum-client": {
+      "version": "git+https://github.com/Overtorment/node-electrum-client.git#59712b3b7dbe666431eeb5649d6f6541529d386a",
+      "from": "git+https://github.com/Overtorment/node-electrum-client.git"
+    },
+    "electrum-host-parse": {
+      "version": "0.1.1",
+      "resolved": "https://registry.npmjs.org/electrum-host-parse/-/electrum-host-parse-0.1.1.tgz",
+      "integrity": "sha512-N1ua6Xc5aMcVWPqxlIyiSV/tDGlbGP+S4bIR6KKGDv227VnzXibcin+4t25b5spjDmhfbbk0rIqV1T3MV5WlBQ=="
+    },
    "elliptic": {
      "version": "6.4.1",
      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.4.1.tgz",
@ -9665,7 +9673,6 @@
      "version": "2.3.5",
      "resolved": "https://registry.npmjs.org/minipass/-/minipass-2.3.5.tgz",
      "integrity": "sha512-Gi1W4k059gyRbyVUZQ4mEqLm0YIUiGYfvxhF6SIlk3ui1WVxMTGfGdQ2SInh3PDrRTVvPKgULkpJtT4RH10+VA==",
-      "optional": true,
      "requires": {
        "safe-buffer": "^5.1.2",
        "yallist": "^3.0.0"
@ -9674,8 +9681,7 @@
        "yallist": {
          "version": "3.0.3",
          "resolved": "https://registry.npmjs.org/yallist/-/yallist-3.0.3.tgz",
-          "integrity": "sha512-S+Zk8DEWE6oKpV+vI3qWkaK+jSbIK86pCwe2IF/xwIpQ8jEuxpw9NyaGjmp9+BoJv5FV2piqCDcoCtStppiq2A==",
-          "optional": true
+          "integrity": "sha512-S+Zk8DEWE6oKpV+vI3qWkaK+jSbIK86pCwe2IF/xwIpQ8jEuxpw9NyaGjmp9+BoJv5FV2piqCDcoCtStppiq2A=="
        }
      }
    },
@ -11763,6 +11769,39 @@
        "prop-types": "^15.6.1"
      }
    },
+    "react-native-tcp": {
+      "version": "3.3.0",
+      "resolved": "https://registry.npmjs.org/react-native-tcp/-/react-native-tcp-3.3.0.tgz",
+      "integrity": "sha512-WAiL3IGhVxvmM0iw7/5ZRzdkiJBfBbLoFKNaHLJIsTZVqD/N5ZHUlJMjIQ+RrmB/f5nJ82bUEZ2vPCxe+rlNqQ==",
+      "requires": {
+        "base64-js": "0.0.8",
+        "buffer": "^5.0.0",
+        "events": "^1.0.2",
+        "ip-regex": "^1.0.3",
+        "process": "^0.11.9",
+        "util": "^0.10.3"
+      },
+      "dependencies": {
+        "base64-js": {
+          "version": "0.0.8",
+          "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-0.0.8.tgz",
+          "integrity": "sha1-EQHpVE9KdrG8OybUUsqW16NeeXg="
+        },
+        "ip-regex": {
+          "version": "1.0.3",
+          "resolved": "https://registry.npmjs.org/ip-regex/-/ip-regex-1.0.3.tgz",
+          "integrity": "sha1-3FiQdvZZ9BnCIgOaMzFvHHOH7/0="
+        },
+        "util": {
+          "version": "0.10.4",
+          "resolved": "https://registry.npmjs.org/util/-/util-0.10.4.tgz",
+          "integrity": "sha512-0Pm9hTQ3se5ll1XihRic3FDIku70C+iHUdT/W926rSgHV5QgXsYbKZN8MSC3tJtSkhuROzvsQjAaFENRXr+19A==",
+          "requires": {
+            "inherits": "2.0.3"
+          }
+        }
+      }
+    },
    "react-native-vector-icons": {
      "version": "6.2.0",
      "resolved": "https://registry.npmjs.org/react-native-vector-icons/-/react-native-vector-icons-6.2.0.tgz",
--- a/package.json
+++ b/package.json
@ -45,6 +45,8 @@
    "buffer-reverse": "^1.0.1",
    "crypto-js": "^3.1.9-1",
    "dayjs": "^1.8.0",
+    "electrum-client": "git+https://github.com/Overtorment/node-electrum-client.git",
+    "electrum-host-parse": "^0.1.1",
    "eslint-config-prettier": "^3.6.0",
    "eslint-config-standard": "^12.0.0",
    "eslint-config-standard-react": "^7.0.2",
@ -83,6 +85,7 @@
    "react-native-snap-carousel": "^3.7.5",
    "react-native-sortable-list": "0.0.22",
    "react-native-svg": "^9.0.4",
+    "react-native-tcp": "^3.3.0",
    "react-native-vector-icons": "^6.2.0",
    "react-native-webview": "^3.2.1",
    "react-native-wkwebview-reborn": "^2.0.0",
--- a/screen/selftest.js
+++ b/screen/selftest.js
@ -5,6 +5,8 @@ import PropTypes from 'prop-types';
 import { SegwitP2SHWallet, LegacyWallet, HDSegwitP2SHWallet } from '../class';
 let BigNumber = require('bignumber.js');
 let encryption = require('../encryption');
+let bitcoin = require('bitcoinjs-lib');
+let BlueElectrum = require('../BlueElectrum');

 export default class Selftest extends Component {
  static navigationOptions = () => ({
@ -42,6 +44,20 @@ export default class Selftest extends Component {

      //

+      if (typeof navigator !== 'undefined' && navigator.product === 'ReactNative') {
+        let addr4elect = '3GCvDBAktgQQtsbN6x5DYiQCMmgZ9Yk8BK';
+        let electrumBalance = await BlueElectrum.getBalanceByAddress(addr4elect);
+        if (electrumBalance.confirmed !== 51432)
+          throw new Error('BlueElectrum getBalanceByAddress failure, got ' + JSON.stringify(electrumBalance));
+
+        let electrumTxs = await BlueElectrum.getTransactionsByAddress(addr4elect);
+        if (electrumTxs.length !== 1) throw new Error('BlueElectrum getTransactionsByAddress failure, got ' + JSON.stringify(electrumTxs));
+      } else {
+        console.warn('skipping RN-specific test');
+      }
+
+      //
+
      let l = new LegacyWallet();
      l.setSecret('Kxr9tQED9H44gCmp6HAdmemAzU3n84H3dGkuWTKvE23JgHMW8gct');
      if (l.getAddress() !== '19AAjaTUbRjQCMuVczepkoPswiZRhjtg31') {
@ -158,7 +174,6 @@ export default class Selftest extends Component {
      ];

      let tx = l.createTx(utxo, 0.001, 0.0001, '1QHf8Gp3wfmFiSdEX4FtrssCGR68diN1cj');
-      let bitcoin = require('bitcoinjs-lib');
      let txDecoded = bitcoin.Transaction.fromHex(tx);
      let txid = txDecoded.getId();

--- a/screen/wallets/list.js
+++ b/screen/wallets/list.js
@ -82,7 +82,10 @@ export default class WalletsList extends Component {
          // more responsive
          let noErr = true;
          try {
+            let balanceStart = +new Date();
            await BlueApp.fetchWalletBalances(that.lastSnappedTo || 0);
+            let balanceEnd = +new Date();
+            console.log('fetch balance took', (balanceEnd - balanceStart) / 1000, 'sec');
            let start = +new Date();
            await BlueApp.fetchWalletTransactions(that.lastSnappedTo || 0);
            let end = +new Date();
--- a/screen/wallets/transactions.js
+++ b/screen/wallets/transactions.js
@ -150,9 +150,12 @@ export default class WalletTransactions extends Component {
          try {
            /** @type {LegacyWallet} */
            let wallet = that.state.wallet;
+            let balanceStart = +new Date();
            const oldBalance = wallet.getBalance();
            await wallet.fetchBalance();
            if (oldBalance !== wallet.getBalance()) smthChanged = true;
+            let balanceEnd = +new Date();
+            console.log(wallet.getLabel(), 'fetch balance took', (balanceEnd - balanceStart) / 1000, 'sec');
            let start = +new Date();
            const oldTxLen = wallet.getTransactions().length;
            await wallet.fetchTransactions();
--- a/shim.js
+++ b/shim.js
@ -1,4 +1,5 @@
 /* global __DEV__, localStorage */
+global.net = require('react-native-tcp');
 if (typeof __dirname === 'undefined') global.__dirname = '/';
 if (typeof __filename === 'undefined') global.__filename = '';
 if (typeof process === 'undefined') {