Coconut_lib

The Coconut_lib is a development tool for mobile air gap Bitcoin wallets. It is written in Dart. Coconut Vault and Coconut Wallet were created using this library. Download from Appstore and Play Store.

• Coconut Vault (for iOS)
• Coconut Wallet (for iOS)
• Coconut Vault (for Android)
• Coconut Wallet (for Android)

And visit tutorial page for Self-custody we provided. (www.coconut.onl)

⚠ The Coconut_lib is still a project under development. Therefore, we are not responsible for any problems that may arise while using it. Please review it carefully and use it.

About

The Coconut_lib provides the base code for developing Bitcoin vaults and wallets based on Bitcoin airgap. Since coconut_lib is developed in Dart, it is specialized for developing applications for iPhone and Android by utilizing the Flutter. In particular, The Coconut_lib designed to develop air-gap-based vault and wallet apps separately by clearly distinguishing the vault area and wallet area. You can use the Coconut_lib to create your own air-gap based vault and wallet.

"Don't trust, verify and develop!"

Architecture

• wallet: Provides a cryptography-based key management method. Create two apps instancing the Wallet and Vault classes.
• transaction: Provides code related to Bitcoin scripts and transactions. Also use PSBT(BIP-0174) to communicate vaults and wallets.

For more development information, visit the coconut_lib docs.

Example

import 'package:coconut_lib/coconut_lib.dart';

import '../../test/mock_factory.dart';

void main() async {
  print("0. Set the Bitcoin Network");
  NetworkType.setNetworkType(NetworkType.regtest);

  print("1-1. Create a single signature vault");
  Seed seed = Seed.fromMnemonic(
      'thank split shrimp error own spirit slow glow act evidence globe slight');

  SingleSignatureVault singleSignatureVault =
      SingleSignatureVault.fromSeed(seed);
  print(
      ' - Master Fingerprint: ${singleSignatureVault.keyStore.masterFingerprint}');

  print("1-2. Create a 2-of-3 Multisignature vault");
  SingleSignatureVault insideVault1 = SingleSignatureVault.fromMnemonic(
      'abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about',
      passphrase: 'ABC');

  SingleSignatureVault outsideVault1 = SingleSignatureVault.fromMnemonic(
      'abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about',
      passphrase: 'DEF');

  SingleSignatureVault outsideVault2 = SingleSignatureVault.fromMnemonic(
      'abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about',
      passphrase: 'GHI');

  //Generate P2WSH Keystore
  KeyStore insideKey1 =
      KeyStore.fromSeed(insideVault1.keyStore.seed, AddressType.p2wsh);
  KeyStore outsideKey1 = KeyStore.fromSignerBsms(
      outsideVault1.getSignerBsms(AddressType.p2wsh, "OutsideSigner1"));
  KeyStore outsideKey2 = KeyStore.fromSignerBsms(
      outsideVault2.getSignerBsms(AddressType.p2wsh, "OutsideSigner2"));

  MultisignatureVault multisignatureVault =
      MultisignatureVault.fromKeyStoreList(
          [insideKey1, outsideKey1, outsideKey2], 2);

  // Share Coordinator BSMS with Outside Signers
  MultisignatureVault outsideMultisignatureVault =
      MultisignatureVault.fromCoordinatorBsms(
          multisignatureVault.getCoordinatorBsms());

  // Find Seed in Outside Vault and bind it to KeyStore
  outsideMultisignatureVault.bindSeedToKeyStore(outsideVault1.keyStore.seed);

  print(
      ' - Master Fingerprint of Key Store [0]: ${multisignatureVault.keyStoreList[0].masterFingerprint}');
  print(
      ' - Master Fingerprint of Key Store [1]: ${multisignatureVault.keyStoreList[1].masterFingerprint}');
  print(
      ' - Master Fingerprint of Key Store [2]: ${multisignatureVault.keyStoreList[2].masterFingerprint}');

  print("2-1. Sync to the single signature wallet");
  // Repository.initialize('Coconut_Wallet');
  SingleSignatureWallet singleSignatureWallet =
      SingleSignatureWallet.fromDescriptor(singleSignatureVault.descriptor);
  print(
      ' - Extended Public Key: ${singleSignatureWallet.keyStore.extendedPublicKey.serialize()}');

  print("2-2. Sync to the multisignature wallet");
  MultisignatureWallet multisignatureWallet;

  Descriptor descriptor = Descriptor.parse(multisignatureVault.descriptor);
  if (descriptor.scriptType == 'wsh') {
    multisignatureWallet =
        MultisignatureWallet.fromDescriptor(multisignatureVault.descriptor);
    // } else if (descriptor.scriptType == 'wpkh') {
    //   watchOnlyWallet =
    //       SingleSignatureWallet.fromDescriptor(multisignatureVault.descriptor);
  } else {
    throw Exception('Unsupported Address Type');
  }
  print(
      ' - Extended Public Key of Key Store [0]: ${multisignatureWallet.keyStoreList[0].extendedPublicKey.serialize()}');
  print(
      ' - Extended Public Key of Key Store [1]: ${multisignatureWallet.keyStoreList[1].extendedPublicKey.serialize()}');
  print(
      ' - Extended Public Key of Key Store [2]: ${multisignatureWallet.keyStoreList[2].extendedPublicKey.serialize()}');

  print(
      "4. Send Bitcoin from the single signature wallet to the multisignature wallet");
  String receiverAddress = multisignatureWallet.getAddress(0);
  String changeAddress = singleSignatureWallet.getAddress(0, isChange: true);
  int sendingAmount = 1000;
  double feeRate = 3.0;
  List<Utxo> utxosForSingleSignatureWallet = [
    Utxo('5c5fa04bc94647ee339083d6fd381a3b1ac4de7d7bfa966788971d62072a1e66', 1,
        100000000, "m/84'/1'/0'/0/68")
  ];
  print(' - Generating unsigned PSBT');
  List<Utxo> utxoList = [
    Utxo('393a2d56f910019a6df975672989a449648f355b1fb7889fb831f0402c5550f3', 0,
        21000, "m/84'/1'/0'/0/0")
  ];
  Transaction unsignedTransaction = Transaction.forSinglePayment(utxoList,
      receiverAddress, "m/84'/1'/0'/1/0", 2000, 2, singleSignatureWallet);
  String unsignedPsbt =
      Psbt.fromTransaction(unsignedTransaction, singleSignatureWallet)
          .serialize();

  print(' - Add signature from vault');
  String signedPsbt = singleSignatureVault.addSignatureToPsbt(unsignedPsbt);
  Psbt walletReceivedPsbt = Psbt.parse(signedPsbt);
  Transaction signedTransaction = walletReceivedPsbt
      .getSignedTransaction(singleSignatureWallet.addressType);
  print(' - Final Transaction : ${signedTransaction.serialize()}');
}

Tests

Generate Mock Classes

dart pub run build_runner build

Unit Test

dart test -t unit

E2E Test

dart test -t e2e

Coverage

The following tools are required to generate test coverage (for MacOS):

dart pub global activate coverage

brew install lcov

To generate test coverage, run the following command:

sh ./generate_unit_coverage.sh

Bip Support List

• BIP-11: M-of-N Standard Transactions
• BIP-32: Hierarchical Deterministic Wallets
• BIP-39: Mnemonic code for generating deterministic keys
• BIP-44: Multi-Account Hierarchy for Deterministic Wallets
• BIP-48: Multi-Script Hierarchy for Multi-Sig Wallets
• BIP-67: Deterministic Multisig Key Sorting
• BIP-84: Derivation scheme for P2WPKH based accounts
• BIP-86: Key Derivation for Single Key P2TR Outputs
• BIP-129: Bitcoin Secure Multisig Setup (BSMS)
• BIP-142: Address Format for Segregated Witness
• BIP-143: Transaction Signature Verification for Version 0 Witness Program
• BIP-173: Base32 address format for native v0-16 witness outputs
• BIP-174: Partially Signed Bitcoin Transaction Format
• BIP-327: MuSig2 for BIP340-compatible Multi-Signatures
• BIP-340: Schnorr Signatures for secp256k1
• BIP-341: SegWit version 1 spending rules
• BIP-370: PSBT Version 2
• BIP-371: Taproot Fields for PSBT
• BIP-380: Output Script Descriptors General Operation
• BIP-381: Non-Segwit Output Script Descriptors
• BIP-382: Segwit Output Script Descriptors
• BIP-383: Multisig Output Script Descriptors

Contribution

Reference CONTRIBUTING

Bug report and Contact us

• Github Issue, PR
• hello@noncelab.com
• coconut.onl

License

Reference LICENSE