feat: Bitcoin Output descriptors for wallets

src/Helpers/WalletParser.cs

@@ -1,6 +1,9 @@
+using System.Text;
+using Humanizer;
 using NBitcoin;
 using NBitcoin.Scripting;
 using NBXplorer.DerivationStrategy;
+using NodeGuard.Data.Models;
 
 namespace NodeGuard.Helpers;
 
@@ -105,4 +108,120 @@ DerivationStrategyBase Parse(string str)
             return strategy;
         }
     }
+
+    /// <summary>
+    /// Generates an output descriptor for a given wallet based on its type and the Bitcoin network it's associated with.
+    /// </summary>
+    /// <param name="wallet">The wallet for which the output descriptor is to be generated.</param>
+    /// <param name="bitcoinNetwork">The Bitcoin network associated with the wallet.</param>
+    /// <returns>A string representation of the output descriptor.</returns>
+    /// <exception cref="System.NotImplementedException">Thrown when the wallet address type is Taproot, which is not currently supported.</exception>
+    /// <exception cref="System.Exception">Thrown when the output descriptor could not be generated for some reason.</exception>
+    /// <remarks>
+    /// This method first determines the network based on the provided string. It then checks if the wallet is a hot wallet or not.
+    /// If it is, it generates the output descriptor based on the first key in the wallet and the wallet's address type.
+    /// If it's not a hot wallet, it generates a multi-signature output descriptor based on all the keys in the wallet and the wallet's address type.
+    /// </remarks>
+    public static string GetOutputDescriptor(this Wallet wallet, string bitcoinNetwork)
+    {
+        var network = Network.GetNetwork(bitcoinNetwork);
+        OutputDescriptor outputDescriptor = null;
+        PubKeyProvider pubKeyProvider;
+
+        if (wallet.IsHotWallet)
+        {
+            var key = wallet.Keys.FirstOrDefault();
+            pubKeyProvider = PubKeyProvider.NewHD(
+                new BitcoinExtPubKey(
+                    ExtPubKey.Parse(key.XPUB, network),
+                    network
+                ),
+                new KeyPath("/0"),
+                PubKeyProvider.DeriveType.UNHARDENED
+            );
+            var fingerprint = GetMasterFingerprint(key.MasterFingerprint);
+            var rootedKeyPath = new RootedKeyPath(
+                new HDFingerprint(fingerprint),
+                KeyPath.Parse(key.Path)
+            );
+            pubKeyProvider = PubKeyProvider.NewOrigin(rootedKeyPath, pubKeyProvider);
+
+            switch (wallet.WalletAddressType)
+            {
+                case WalletAddressType.NativeSegwit:
+                    outputDescriptor = OutputDescriptor.NewWPKH(pubKeyProvider, network);
+                    break;
+                case WalletAddressType.NestedSegwit:
+                    outputDescriptor = OutputDescriptor.NewWPKH(pubKeyProvider, network);
+                    outputDescriptor = OutputDescriptor.NewSH(outputDescriptor, network);
+                    break;
+                case WalletAddressType.Legacy:
+                    outputDescriptor = OutputDescriptor.NewPKH(pubKeyProvider, network);
+                    break;
+                case WalletAddressType.Taproot:
+                    throw new NotImplementedException();
+            }
+        }
+        else
+        {
+            var pubKeyProviders = new List<PubKeyProvider>();
+            foreach (var k in wallet.Keys)
+            {
+                var rootedKeyPath = new RootedKeyPath(
+                    new HDFingerprint(GetMasterFingerprint(k.MasterFingerprint)),
+                    KeyPath.Parse(k.Path)
+                );
+                pubKeyProvider = PubKeyProvider.NewOrigin(
+                    rootedKeyPath,
+                    PubKeyProvider.NewHD(
+                        new BitcoinExtPubKey(
+                            ExtPubKey.Parse(k.XPUB, network),
+                            network
+                        ),
+                        new KeyPath("/0"),
+                        PubKeyProvider.DeriveType.UNHARDENED
+                    )
+                );
+                pubKeyProviders.Add(pubKeyProvider);
+            }
+            outputDescriptor = OutputDescriptor.NewMulti(
+                (uint)wallet.MofN,
+                pubKeyProviders,
+                !wallet.IsUnSortedMultiSig,
+                network);
+
+            switch (wallet.WalletAddressType)
+            {
+                case WalletAddressType.NativeSegwit:
+                    outputDescriptor = OutputDescriptor.NewWSH(outputDescriptor, network);
+                    break;
+                case WalletAddressType.NestedSegwit:
+                    outputDescriptor = OutputDescriptor.NewSH(outputDescriptor, network);
+                    break;
+                case WalletAddressType.Legacy:
+                    break;
+                case WalletAddressType.Taproot:
+                    throw new NotImplementedException();
+            }
+        }
+
+        return outputDescriptor is not null ? outputDescriptor.ToString() : throw new Exception("Something went wrong");
+    }
+
+    /// <summary>
+    /// Converts a hexadecimal string representation of a master fingerprint into a byte array.
+    /// </summary>
+    /// <param name="masterFingerprint">The hexadecimal string representation of the master fingerprint.</param>
+    /// <returns>A byte array that represents the master fingerprint.</returns>
+    /// <remarks>
+    /// This method works by iterating over the input string two characters at a time (since each byte in a hexadecimal string is represented by two characters), converting those two characters into a byte, and then adding that byte to the output array.
+    /// </remarks>
+    public static byte[] GetMasterFingerprint(string masterFingerprint)
+    {
+        var internalBytes = Enumerable.Range(0, masterFingerprint.Length)
+            .Where(x => x % 2 == 0)
+            .Select(x => Convert.ToByte(masterFingerprint.Substring(x, 2), 16))
+            .ToArray();
+        return internalBytes;
+    }
 }

src/Pages/Wallets.razor

@@ -21,6 +21,7 @@
 @inject ILocalStorageService LocalStorageService
 @inject ISchedulerFactory SchedulerFactory
 @inject IPriceConversionService PriceConversionService
+@inject IInternalWalletRepository InternalWalletRepository
 @inject INBXplorerService NBXplorerService
 
 @attribute [Authorize(Roles = "NodeManager, FinanceManager, Superadmin")]
@@ -80,6 +81,7 @@
                                 <DropdownItem Disabled="!context.Item.IsFinalised" Clicked="@(() => LoadAndOpenModalTextModalUnusedAddress(context.Item))">Get address</DropdownItem>
                                 <DropdownItem Disabled="!context.Item.IsFinalised || context.Item.IsWatchOnly" Clicked="@(() => ShowTransferFundsModal(context.Item))">Transfer funds</DropdownItem>
                                 <DropdownItem Disabled="!context.Item.IsFinalised" Clicked="@(() => RescanWallet(context.Item))">Rescan wallet</DropdownItem>
+                                <DropdownItem Disabled="!context.Item.IsFinalised" Clicked="@(() => LoadAndOpenExportOutputDescriptor(context.Item))">Export output descriptor</DropdownItem>
 
                             </DropdownMenu>
                         </Dropdown>
@@ -700,6 +702,25 @@
         </ModalFooter>
     </ModalContent>
 </Modal>
+<Modal @ref="_exportOutputDescriptorModal">
+    <ModalContent Size="ModalSize.Large">
+        <ModalHeader>
+            @($"Export wallet") 
+        </ModalHeader>
+        <ModalBody>
+            <Paragraph>
+                @("Output descriptor: " + StringHelper.TruncateHeadAndTail(_outputDescriptorContentModal, 25))
+                <Button Color="Color.Primary" Clicked="@(()=> CopyStrToClipboard(_outputDescriptorContentModal))">Copy</Button>
+            </Paragraph>
+                @("Wallet derivation strategy (NBITCOIN): " + StringHelper.TruncateHeadAndTail(_derivationScheme, 25))
+                <Button Color="Color.Primary" Clicked="@(()=> CopyStrToClipboard(_derivationScheme))">Copy</Button>
+        </ModalBody>
+        <ModalFooter>
+            <Button Color="Color.Secondary" Clicked="@CloseExportOutputDescriptorModal">Close</Button>
+        </ModalFooter>
+    </ModalContent>
+</Modal>
+
 <ConfirmationModal
     @ref="_multisigTransferModal"
     Title="Transferring from a multisig wallet"
@@ -735,6 +756,10 @@
     private List<Key> _selectedWalletKeysPlusInternalWalletKey = new();
     private List<Key> _selectedFinanceManagerAvailableKeys = new();
     private Key? _selectedWalletKey;
+
+    private Modal _exportOutputDescriptorModal;
+    private string _outputDescriptorContentModal;
+    private string _derivationScheme;
 
     private Modal _textModalRef;
     private string _textModalTitle = string.Empty;
@@ -917,8 +942,7 @@
         }
         return _sourceBalanceAfterTransaction;
     }
-
-
+
     private async Task OnRowUpdated(SavedRowItem<Wallet, Dictionary<string, object>> arg)
     {
         if (arg.Item == null) return;
@@ -1619,6 +1643,31 @@
         _transferAllFunds = value;
         _amountToTransfer = _sourceBalance;
     }
+
+    private async Task LoadAndOpenExportOutputDescriptor(Wallet contextItem)
+    {
+        await CleanTextModal();
+        if (contextItem != null)
+        {
+            try
+            {
+                _outputDescriptorContentModal = contextItem.GetOutputDescriptor(Constants.BITCOIN_NETWORK);
+                _derivationScheme = contextItem.GetDerivationStrategy().ToString();
+                await _exportOutputDescriptorModal.Show();
+            }
+            catch (Exception e)
+            {
+                ToastService.ShowError("Error while getting the wallet descriptor");
+            }
+        }
+    }
 
+    private async Task CloseExportOutputDescriptorModal()
+    {
+        await _exportOutputDescriptorModal.Close(CloseReason.UserClosing);
+
+        _outputDescriptorContentModal = string.Empty;
+        _derivationScheme = string.Empty;
+    }
 
 }