Can combine PSBT

BTCPayServer/BTCPayServer.csproj

@@ -47,7 +47,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="NBitcoin" Version="4.1.2.17" />
+    <PackageReference Include="NBitcoin" Version="4.1.2.19" />
     <PackageReference Include="NBitpayClient" Version="1.0.0.34" />	  
     <PackageReference Include="DBriize" Version="1.0.0.4" />
     <PackageReference Include="NBXplorer.Client" Version="2.0.0.12" />
@@ -182,6 +182,9 @@
 	  <Content Update="Views\Wallets\ListWallets.cshtml">
 	    <Pack>$(IncludeRazorContentInPack)</Pack>
 	  </Content>
+	  <Content Update="Views\Wallets\WalletPSBTCombine.cshtml">
+	    <Pack>$(IncludeRazorContentInPack)</Pack>
+	  </Content>
 	  <Content Update="Views\Wallets\WalletPSBTReady.cshtml">
 	    <Pack>$(IncludeRazorContentInPack)</Pack>
 	  </Content>

BTCPayServer/Controllers/WalletsController.PSBT.cs

@@ -14,50 +14,6 @@ namespace BTCPayServer.Controllers
     public partial class WalletsController
     {
 
-
-        [HttpPost]
-        [Route("{walletId}/psbt/sign")]
-        public async Task<IActionResult> WalletPSBTSign(
-            [ModelBinder(typeof(WalletIdModelBinder))]
-            WalletId walletId,
-            WalletPSBTViewModel vm,
-            string command = null
-            )
-        {
-            var network = NetworkProvider.GetNetwork(walletId.CryptoCode);
-            var psbt = PSBT.Parse(vm.PSBT, network.NBitcoinNetwork);
-            if (command == "ledger")
-            {
-                return ViewWalletSendLedger(psbt);
-            }
-            else if (command == "broadcast")
-            {
-                if (!psbt.IsAllFinalized() && !psbt.TryFinalize(out var errors))
-                {
-                    return ViewPSBT(psbt, errors);
-                }
-                var transaction = psbt.ExtractTransaction();
-                try
-                {
-                    var broadcastResult = await ExplorerClientProvider.GetExplorerClient(network).BroadcastAsync(transaction);
-                    if (!broadcastResult.Success)
-                    {
-                        return ViewPSBT(psbt, new[] { $"RPC Error while broadcasting: {broadcastResult.RPCCode} {broadcastResult.RPCCodeMessage} {broadcastResult.RPCMessage}" });
-                    }
-                }
-                catch (Exception ex)
-                {
-                    return ViewPSBT(psbt, "Error while broadcasting: " + ex.Message);
-                }
-                return await RedirectToWalletTransaction(walletId, transaction);
-            }
-            else
-            {
-                (await GetDerivationSchemeSettings(walletId)).RebaseKeyPaths(psbt);
-                return FilePSBT(psbt, "psbt-export.psbt");
-            }
-        }
-
         [NonAction]
         public async Task<CreatePSBTResponse> CreatePSBT(BTCPayNetwork network, DerivationSchemeSettings derivationSettings, WalletSendModel sendModel, CancellationToken cancellationToken)
         {
@@ -93,21 +49,59 @@ namespace BTCPayServer.Controllers
         }
         [HttpPost]
         [Route("{walletId}/psbt")]
-        public IActionResult WalletPSBT(
+        public async Task<IActionResult> WalletPSBT(
             [ModelBinder(typeof(WalletIdModelBinder))]
             WalletId walletId,
-            WalletPSBTViewModel vm)
+            WalletPSBTViewModel vm, string command = null)
         {
-            try
+            var network = NetworkProvider.GetNetwork(walletId.CryptoCode);
+            var psbt = vm.GetPSBT(network.NBitcoinNetwork);
+            if (psbt == null)
             {
-                if (!string.IsNullOrEmpty(vm.PSBT))
+                ModelState.AddModelError(nameof(vm.PSBT), "Invalid PSBT");
-                    vm.Decoded = PSBT.Parse(vm.PSBT, NetworkProvider.GetNetwork(walletId.CryptoCode).NBitcoinNetwork).ToString();
+                return View(vm);
             }
-            catch (FormatException ex)
+
+            if (command == null)
             {
-                ModelState.AddModelError(nameof(vm.PSBT), ex.Message);
+                vm.Decoded = psbt.ToString();
+                return View(vm);
+            }
+            else if (command == "ledger")
+            {
+                return ViewWalletSendLedger(psbt);
+            }
+            else if (command == "broadcast")
+            {
+                if (!psbt.IsAllFinalized() && !psbt.TryFinalize(out var errors))
+                {
+                    return ViewPSBT(psbt, errors);
+                }
+                var transaction = psbt.ExtractTransaction();
+                try
+                {
+                    var broadcastResult = await ExplorerClientProvider.GetExplorerClient(network).BroadcastAsync(transaction);
+                    if (!broadcastResult.Success)
+                    {
+                        return ViewPSBT(psbt, new[] { $"RPC Error while broadcasting: {broadcastResult.RPCCode} {broadcastResult.RPCCodeMessage} {broadcastResult.RPCMessage}" });
+                    }
+                }
+                catch (Exception ex)
+                {
+                    return ViewPSBT(psbt, "Error while broadcasting: " + ex.Message);
+                }
+                return await RedirectToWalletTransaction(walletId, transaction);
+            }
+            else if (command == "combine")
+            {
+                ModelState.Remove(nameof(vm.PSBT));
+                return View(nameof(WalletPSBTCombine), new WalletPSBTCombineViewModel() { OtherPSBT = psbt.ToBase64() });
+            }
+            else
+            {
+                (await GetDerivationSchemeSettings(walletId)).RebaseKeyPaths(psbt);
+                return FilePSBT(psbt, "psbt-export.psbt");
             }
-            return View(vm);
         }
 
         [HttpGet]
@@ -194,5 +188,28 @@ namespace BTCPayServer.Controllers
         {
             return File(psbt.ToBytes(), "application/octet-stream", fileName);
         }
+
+        [HttpPost]
+        [Route("{walletId}/psbt/combine")]
+        public async Task<IActionResult> WalletPSBTCombine([ModelBinder(typeof(WalletIdModelBinder))]
+            WalletId walletId, WalletPSBTCombineViewModel vm)
+        {
+            var network = NetworkProvider.GetNetwork(walletId.CryptoCode);
+            var psbt = await vm.GetPSBT(network.NBitcoinNetwork);
+            if (psbt == null)
+            {
+                ModelState.AddModelError(nameof(vm.PSBT), "Invalid PSBT");
+                return View(vm);
+            }
+            var sourcePSBT = vm.GetSourcePSBT(network.NBitcoinNetwork);
+            if (sourcePSBT == null)
+            {
+                ModelState.AddModelError(nameof(vm.OtherPSBT), "Invalid PSBT");
+                return View(vm);
+            }
+            sourcePSBT = sourcePSBT.Combine(psbt);
+            StatusMessage = "PSBT Successfully combined!";
+            return ViewPSBT(sourcePSBT);
+        }
     }
 }

BTCPayServer/Models/WalletViewModels/WalletPSBTCombineViewModel.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using NBitcoin;
+
+namespace BTCPayServer.Models.WalletViewModels
+{
+    public class WalletPSBTCombineViewModel
+    {
+        public string OtherPSBT { get; set; }
+        [Display(Name = "PSBT to combine with...")]
+        public string PSBT { get; set; }
+        [Display(Name = "Upload PSBT from file...")]
+        public IFormFile UploadedPSBTFile { get; set; }
+
+        public PSBT GetSourcePSBT(Network network)
+        {
+            if (!string.IsNullOrEmpty(OtherPSBT))
+            {
+                try
+                {
+                    return NBitcoin.PSBT.Parse(OtherPSBT, network);
+                }
+                catch
+                { }
+            }
+            return null;
+        }
+        public async Task<PSBT> GetPSBT(Network network)
+        {
+            if (UploadedPSBTFile != null)
+            {
+                if (UploadedPSBTFile.Length > 500 * 1024)
+                    return null;
+                byte[] bytes = new byte[UploadedPSBTFile.Length];
+                using (var stream = UploadedPSBTFile.OpenReadStream())
+                {
+                    await stream.ReadAsync(bytes, 0, (int)UploadedPSBTFile.Length);
+                }
+                try
+                {
+                    return NBitcoin.PSBT.Load(bytes, network);
+                }
+                catch
+                {
+                    return null;
+                }
+            }
+            if (!string.IsNullOrEmpty(PSBT))
+            {
+                try
+                {
+                    return NBitcoin.PSBT.Parse(PSBT, network);
+                }
+                catch
+                { }
+            }
+            return null;
+        }
+    }
+}

BTCPayServer/Models/WalletViewModels/WalletPSBTViewModel.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using NBitcoin;
 
 namespace BTCPayServer.Models.WalletViewModels
 {
@@ -10,5 +11,15 @@ namespace BTCPayServer.Models.WalletViewModels
         public string Decoded { get; set; }
         public string PSBT { get; set; }
         public List<string> Errors { get; set; } = new List<string>();
+
+        internal PSBT GetPSBT(Network network)
+        {
+            try
+            {
+                return NBitcoin.PSBT.Parse(PSBT, network);
+            }
+            catch { }
+            return null;
+        }
     }
 }

BTCPayServer/Services/LedgerHardwareWalletService.cs

@@ -141,6 +141,8 @@ namespace BTCPayServer.Services
             psbt = psbt.Clone();
             foreach (var signature in signatureRequests)
             {
+                if (signature.Signature == null)
+                    continue;
                 var input = psbt.Inputs.FindIndexedInput(signature.InputCoin.Outpoint);
                 if (input == null)
                     continue;

BTCPayServer/Views/Wallets/WalletPSBT.cshtml

@@ -4,6 +4,12 @@
     ViewData["Title"] = "PSBT";
     ViewData.SetActivePageAndTitle(WalletsNavPages.PSBT);
 }
+
+<div class="row">
+    <div class="col-md-10 text-center">
+        <partial name="_StatusMessage" for="@TempData["TempDataProperty-StatusMessage"]" />
+    </div>
+</div>
 <div class="row">
     <div class="col-md-10">
         @if (Model.Errors != null && Model.Errors.Count != 0)
@@ -21,7 +27,7 @@
             <h3>Decoded PSBT</h3>
             <pre><code class="json">@Model.Decoded</code></pre>
             <div class="form-group">
-                <form method="post" asp-action="WalletPSBTSign">
+                <form method="post" asp-action="WalletPSBT">
                     <div class="dropdown" style="margin-top:16px;">
                         <button class="btn btn-primary dropdown-toggle" type="button" id="SendMenu" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                             Sign with...
@@ -31,8 +37,8 @@
                             <button name="command" type="submit" class="dropdown-item" value="ledger">... your Ledger Wallet device</button>
                             <button name="command" type="submit" class="dropdown-item" value="save-psbt">... a wallet supporting PSBT files</button>
                         </div>
-                        or
                         <button name="command" type="submit" class="btn btn-primary" value="broadcast">Broadcast</button>
+                        <button name="command" type="submit" class="btn btn-primary" value="combine">Combine with another PSBT</button>
                     </div>
                 </form>
             </div>

BTCPayServer/Views/Wallets/WalletPSBTCombine.cshtml

@@ -0,0 +1,25 @@
+@model WalletPSBTCombineViewModel
+@{
+    Layout = "../Shared/_NavLayout.cshtml";
+    ViewData["Title"] = "PSBT";
+    ViewData.SetActivePageAndTitle(WalletsNavPages.PSBT);
+}
+
+<h4>Combine PSBT</h4>
+<div class="row">
+    <div class="col-md-10">
+        <form class="form-group" method="post" asp-action="WalletPSBTCombine">
+            <input type="hidden" asp-for="OtherPSBT" />
+            <div class="form-group">
+                <label asp-for="PSBT"></label>
+                <textarea class="form-control" rows="5" asp-for="PSBT"></textarea>
+                <span asp-validation-for="PSBT" class="text-danger"></span>
+            </div>
+            <div class="form-group">
+                <label asp-for="UploadedPSBTFile"></label>
+                <input type="file" class="form-control-file" asp-for="UploadedPSBTFile">
+            </div>
+            <button type="submit" class="btn btn-primary">Combine</button>
+        </form>
+    </div>
+</div>