BIP79 Support

WalletWasabi.Gui/Controls/WalletExplorer/SendControlView.xaml

@@ -30,7 +30,7 @@
       <DockPanel LastChildFill="True" Margin="20">
         <StackPanel DockPanel.Dock="Bottom" Margin="0 10" Spacing="10" HorizontalAlignment="Left">
           <TextBlock>Select coins you want to spend.</TextBlock>
-          <controls:ExtendedTextBox Classes="monospaceFont" Text="{Binding Address}" Watermark="Address" UseFloatingWatermark="True">
+          <controls:ExtendedTextBox IsVisible="{Binding !Bip79UrlIsVisible}" Classes="monospaceFont" Text="{Binding Address}" Watermark="Destination" UseFloatingWatermark="True">
             <i:Interaction.Behaviors>
               <behaviors:PasteAddressOnClickBehavior Command="{Binding OnAddressPasteCommand}" />
             </i:Interaction.Behaviors>
@@ -42,8 +42,9 @@
             </i:Interaction.Behaviors>
           </controls:ExtendedTextBox>
 
-          <suggestions:SuggestLabelView DataContext="{Binding LabelSuggestion}" />
+          <controls:ExtendedTextBox IsVisible="{Binding Bip79UrlIsVisible}" Classes="monospaceFont" Text="{Binding Bip79Url}" Watermark="PayJoin EndPoint" UseFloatingWatermark="True" />
 
+          <suggestions:SuggestLabelView DataContext="{Binding LabelSuggestion}" />
           <StackPanel Orientation="Horizontal" Spacing="10">
             <Button Content="{Binding IsMax, Converter={StaticResource BooleanStringConverter}, ConverterParameter=Clear:Max}" Command="{Binding MaxCommand}" VerticalAlignment="Top" Height="40" />
             <controls:ExtendedTextBox

WalletWasabi.Gui/Controls/WalletExplorer/SendControlViewModel.cs

@@ -71,6 +71,8 @@ public abstract class SendControlViewModel : WasabiDocumentTabViewModel
 		private bool _isHardwareBusy;
 		private bool _isCustomFee;
 		private bool _isCustomChangeAddress;
+		private string _bip79;
+		private ObservableAsPropertyHelper<bool> _bip79UrlIsVisible;
 
 		private const string WaitingForHardwareWalletButtonTextString = "Waiting for Hardware Wallet...";
 
@@ -230,6 +232,10 @@ protected SendControlViewModel(Wallet wallet, string title)
 				.ObserveOn(RxApp.MainThreadScheduler)
 				.Subscribe(_ => this.RaisePropertyChanged(nameof(Address)));
 
+			_bip79UrlIsVisible = this.WhenAnyValue(x => x.Bip79Url)
+				.Select(x => !string.IsNullOrWhiteSpace(x))
+				.ToProperty(this, x => x.Bip79UrlIsVisible, scheduler: RxApp.MainThreadScheduler);
+
 			FeeRateCommand = ReactiveCommand.Create(ChangeFeeRateDisplay, outputScheduler: RxApp.MainThreadScheduler);
 
 			OnAddressPasteCommand = ReactiveCommand.Create((BitcoinUrlBuilder url) =>
@@ -244,6 +250,15 @@ protected SendControlViewModel(Wallet wallet, string title)
 				{
 					AmountText = url.Amount.ToString(false, true);
 				}
+
+				if (url.UnknowParameters.ContainsKey("bpu"))
+				{
+					Bip79Url = url.UnknowParameters["bpu"];
+				}
+				else
+				{
+					Bip79Url = "";
+				}
 			});
 
 			BuildTransactionCommand = ReactiveCommand.CreateFromTask(async () =>
@@ -380,7 +395,7 @@ protected SendControlViewModel(Wallet wallet, string title)
 						}
 					}
 
-					BuildTransactionResult result = await Task.Run(() => Wallet.BuildTransaction(Password, intent, feeStrategy, allowUnconfirmed: true, allowedInputs: selectedCoinReferences));
+					BuildTransactionResult result = await Task.Run(() => Wallet.BuildTransaction(Password, intent, feeStrategy, allowUnconfirmed: true, allowedInputs: selectedCoinReferences, Bip79Url));
 
 					await DoAfterBuildTransaction(result);
 				}
@@ -787,6 +802,7 @@ public decimal FeePercentage
 		}
 
 		public decimal UsdExchangeRate => _usdExchangeRate?.Value ?? 0m;
+		public bool Bip79UrlIsVisible => _bip79UrlIsVisible?.Value ?? false;
 
 		public Money AllSelectedAmount
 		{
@@ -830,6 +846,19 @@ public ErrorDescriptors ValidateActiveAddress()
 			return new ErrorDescriptors(new ErrorDescriptor(ErrorSeverity.Error, "Invalid address."));
 		}
 
+		public ErrorDescriptors ValidateBip79Url()
+		{
+			if (string.IsNullOrWhiteSpace(Bip79Url))
+			{
+				return ErrorDescriptors.Empty;
+			}
+			if (Uri.TryCreate(Bip79Url, UriKind.Absolute, out _))
+			{
+				return ErrorDescriptors.Empty;
+			}
+			return new ErrorDescriptors(new ErrorDescriptor(ErrorSeverity.Error, "Invalid url."));
+		}
+
 		public ErrorDescriptors ValidateCustomChangeAddress()
 		{
 			if (string.IsNullOrWhiteSpace(CustomChangeAddress))
@@ -869,6 +898,13 @@ public string CustomChangeAddress
 			set => this.RaiseAndSetIfChanged(ref _customChangeAddress, value?.Trim());
 		}
 
+		[ValidateMethod(nameof(ValidateBip79Url))]
+		public string Bip79Url
+		{
+			get => _bip79;
+			set => this.RaiseAndSetIfChanged(ref _bip79, value);
+		}
+
 		public string LabelToolTip
 		{
 			get => _labelToolTip;

WalletWasabi/Blockchain/Transactions/TransactionFactory.cs

@@ -3,6 +3,8 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Net.Http;
+using System.Text;
 using WalletWasabi.Blockchain.Analysis.Clustering;
 using WalletWasabi.Blockchain.Keys;
 using WalletWasabi.Blockchain.TransactionBuilding;
@@ -11,6 +13,7 @@
 using WalletWasabi.Helpers;
 using WalletWasabi.Logging;
 using WalletWasabi.Models;
+using WalletWasabi.TorSocks5;
 
 namespace WalletWasabi.Blockchain.Transactions
 {
@@ -48,7 +51,9 @@ public TransactionFactory(Network network, KeyManager keyManager, ICoinsView coi
 			PaymentIntent payments,
 			Func<FeeRate> feeRateFetcher,
 			IEnumerable<OutPoint> allowedInputs = null,
-			Func<LockTime> lockTimeSelector = null)
+			Func<LockTime> lockTimeSelector = null,
+			ITorHttpClient httpClient = null,
+			string uri = null)
 		{
 			payments = Guard.NotNull(nameof(payments), payments);
 			lockTimeSelector ??= () => LockTime.Zero;
@@ -222,6 +227,43 @@ public TransactionFactory(Network network, KeyManager keyManager, ICoinsView coi
 				builder.SetLockTime(lockTimeSelector());
 				builder.SignPSBT(psbt);
 				psbt.Finalize();
+				if (uri is { } && httpClient is { })
+				{
+					using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, uri)
+					{
+						Content = new StringContent(psbt.ToBase64(), Encoding.UTF8, "text/plain")
+					};
+					using var response = httpClient.SendAsync(httpRequestMessage).Result;
+					if (response.IsSuccessStatusCode && PSBT.TryParse(response.Content.ReadAsStringAsync().Result, Network, out var payjoinPSBT))
+					{
+						bool valid = false;
+						var existingInputs = psbt.Inputs.Select(input => input.PrevOut).ToList();
+						foreach (var input in payjoinPSBT.Inputs)
+						{
+							var existingInput = existingInputs.SingleOrDefault(point => point == input.PrevOut);
+							if (existingInput is { })
+							{
+								existingInputs.Remove(existingInput);
+								continue;
+							}
+
+							if (!input.TryFinalizeInput(out _))
+							{
+								valid = false;
+								break;
+							}
+							// a new signed input was provided
+							valid = true;
+						}
+
+						if (valid && !existingInputs.Any())
+						{
+							builder.SignPSBT(payjoinPSBT);
+							payjoinPSBT.Finalize();
+							psbt = payjoinPSBT;
+						}
+					}
+				}
 				tx = psbt.ExtractTransaction();
 
 				var checkResults = builder.Check(tx).ToList();

WalletWasabi/Wallets/Wallet.cs

@@ -289,7 +289,8 @@ public async Task<int> CountBlocksAsync()
 			PaymentIntent payments,
 			FeeStrategy feeStrategy,
 			bool allowUnconfirmed = false,
-			IEnumerable<OutPoint> allowedInputs = null)
+			IEnumerable<OutPoint> allowedInputs = null,
+			string bip79 = null)
 		{
 			var builder = new TransactionFactory(Network, KeyManager, Coins, password, allowUnconfirmed);
 			return builder.BuildTransaction(
@@ -310,7 +311,9 @@ public async Task<int> CountBlocksAsync()
 					}
 				},
 				allowedInputs,
-				SelectLockTimeForTransaction);
+				SelectLockTimeForTransaction,
+				Synchronizer.WasabiClient.TorClient, 
+				bip79);
 		}
 
 		public void RenameLabel(SmartCoin coin, SmartLabel newLabel)