Use PaymentUrlBuilder for ensuring proper formatting of BIP21 addresses (#2723)

BTCPayServer.Common/Altcoins/Liquid/ElementsLikeBtcPayNetwork.cs

@@ -1,6 +1,7 @@
 #if ALTCOINS
 using System.Collections.Generic;
 using System.Linq;
+using BTCPayServer.Common;
 using NBitcoin;
 using NBXplorer;
 using NBXplorer.Models;
@@ -33,13 +34,15 @@ namespace BTCPayServer
                     output.Value is AssetMoney assetMoney && assetMoney.AssetId == AssetId));
         }
 
-        public override string GenerateBIP21(string cryptoInfoAddress, Money cryptoInfoDue)
+        public override PaymentUrlBuilder GenerateBIP21(string cryptoInfoAddress, Money cryptoInfoDue)
         {
             //precision 0: 10 = 0.00000010
             //precision 2: 10 = 0.00001000
             //precision 8: 10 = 10
             var money = cryptoInfoDue is null ? null : new Money(cryptoInfoDue.ToDecimal(MoneyUnit.BTC) / decimal.Parse("1".PadRight(1 + 8 - Divisibility, '0')), MoneyUnit.BTC);
-            return $"{base.GenerateBIP21(cryptoInfoAddress, money)}{(money is null? "?": "&")}assetid={AssetId}";
+            var builder = base.GenerateBIP21(cryptoInfoAddress, money);
+            builder.QueryParams.Add("assetid", AssetId.ToString());
+            return builder;
         }
     }
 }

BTCPayServer.Common/BTCPayNetwork.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using BTCPayServer.Common;
 using NBitcoin;
 using NBXplorer;
 using NBXplorer.Models;
@@ -121,9 +122,15 @@ namespace BTCPayServer
             });
         }
 
-        public virtual string GenerateBIP21(string cryptoInfoAddress, Money cryptoInfoDue)
+        public virtual PaymentUrlBuilder GenerateBIP21(string cryptoInfoAddress, Money cryptoInfoDue)
         {
-            return $"{UriScheme}:{cryptoInfoAddress}{(cryptoInfoDue is null? string.Empty: $"?amount={cryptoInfoDue.ToString(false, true)}")}";
+            var builder = new PaymentUrlBuilder(UriScheme);
+            builder.Host = cryptoInfoAddress;
+            if (cryptoInfoDue != null && cryptoInfoDue != Money.Zero)
+            {
+                builder.QueryParams.Add("amount", cryptoInfoDue.ToString(false, true));
+            }
+            return builder;
         }
 
         public virtual List<TransactionInformation> FilterValidTransactions(List<TransactionInformation> transactionInformationSet)

BTCPayServer.Common/PaymentUrlBuilder.cs

@@ -0,0 +1,30 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BTCPayServer.Common
+{
+    public class PaymentUrlBuilder
+    {
+        public PaymentUrlBuilder(string uriScheme)
+        {
+            UriScheme = uriScheme;
+        }
+        public string UriScheme { get; set; }
+        public Dictionary<string, string> QueryParams { get; set; } = new Dictionary<string, string>();
+        public string? Host { get; set; }
+        public override string ToString()
+        {
+            StringBuilder builder = new StringBuilder($"{UriScheme}:{Host}");
+            if (QueryParams.Count != 0)
+            {
+                var parts = QueryParams.Select(q => Uri.EscapeDataString(q.Key) + "=" + System.Web.NBitcoin.HttpUtility.UrlEncode(q.Value))
+                    .ToArray();
+                builder.Append($"?{string.Join('&', parts)}");
+            }
+            return builder.ToString();
+        }
+    }
+}

BTCPayServer/Controllers/GreenField/StoreOnChainWalletsController.cs

@@ -127,17 +127,16 @@ namespace BTCPayServer.Controllers.GreenField
                 return BadRequest();
             }
 
-            var bip21 = network.GenerateBIP21(kpi.Address.ToString(), null);
+            var bip21 = network.GenerateBIP21(kpi.Address?.ToString(), null);
             var allowedPayjoin = derivationScheme.IsHotWallet && Store.GetStoreBlob().PayJoinEnabled;
             if (allowedPayjoin)
             {
-               bip21 +=
+                bip21.QueryParams.Add(PayjoinClient.BIP21EndpointKey, Request.GetAbsoluteUri(Url.Action(nameof(PayJoinEndpointController.Submit), "PayJoinEndpoint", new { cryptoCode })));
-                   $"?{PayjoinClient.BIP21EndpointKey}={Request.GetAbsoluteUri(Url.Action(nameof(PayJoinEndpointController.Submit), "PayJoinEndpoint", new {cryptoCode}))}";
             }
             return Ok(new OnChainWalletAddressData()
             {
-                Address = kpi.Address.ToString(),
+                Address = kpi.Address?.ToString(),
-                PaymentLink =  bip21,
+                PaymentLink = bip21.ToString(),
                 KeyPath = kpi.KeyPath
             });
         }

BTCPayServer/Controllers/WalletsController.PullPayments.cs

@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 using BTCPayServer.Abstractions.Extensions;
 using BTCPayServer.Abstractions.Models;
 using BTCPayServer.Client.Models;
+using BTCPayServer.Common;
 using BTCPayServer.Data;
 using BTCPayServer.HostedServices;
 using BTCPayServer.ModelBinders;
@@ -285,7 +286,7 @@ namespace BTCPayServer.Controllers
                             continue;
                         }
                         var blob = payout.GetBlob(_jsonSerializerSettings);
-                        bip21.Add(network.GenerateBIP21(payout.Destination, new Money(blob.CryptoAmount.Value, MoneyUnit.BTC)));
+                        bip21.Add(network.GenerateBIP21(payout.Destination, new Money(blob.CryptoAmount.Value, MoneyUnit.BTC)).ToString());
                         
                     }
                     if(bip21.Any())

BTCPayServer/Controllers/WalletsController.cs

@@ -368,18 +368,17 @@ namespace BTCPayServer.Controllers
                 return NotFound();
             var address = _walletReceiveService.Get(walletId)?.Address;
             var allowedPayjoin = paymentMethod.IsHotWallet && CurrentStore.GetStoreBlob().PayJoinEnabled;
-            var bip21 = address is null ? null : network.GenerateBIP21(address.ToString(), null);
+            var bip21 = network.GenerateBIP21(address?.ToString(), null);
             if (allowedPayjoin)
             {
-                bip21 +=
+                bip21.QueryParams.Add(PayjoinClient.BIP21EndpointKey, Request.GetAbsoluteUri(Url.Action(nameof(PayJoinEndpointController.Submit), "PayJoinEndpoint", new { walletId.CryptoCode })));
-                    $"?{PayjoinClient.BIP21EndpointKey}={Request.GetAbsoluteUri(Url.Action(nameof(PayJoinEndpointController.Submit), "PayJoinEndpoint", new {walletId.CryptoCode}))}";
             }
             return View(new WalletReceiveViewModel()
             {
                 CryptoCode = walletId.CryptoCode,
                 Address = address?.ToString(),
                 CryptoImage = GetImage(paymentMethod.PaymentId, network),
-                PaymentLink = bip21
+                PaymentLink = bip21.ToString()
             });
         }
 

BTCPayServer/Payments/PaymentTypes.Bitcoin.cs

@@ -79,9 +79,9 @@ namespace BTCPayServer.Payments
 
             if ((paymentMethodDetails as BitcoinLikeOnChainPaymentMethod)?.PayjoinEnabled is true && serverUri != null)
             {
-                bip21 += $"&{PayjoinClient.BIP21EndpointKey}={serverUri.WithTrailingSlash()}{network.CryptoCode}/{PayjoinClient.BIP21EndpointKey}";
+                bip21.QueryParams.Add(PayjoinClient.BIP21EndpointKey, $"{serverUri.WithTrailingSlash()}{network.CryptoCode}/{PayjoinClient.BIP21EndpointKey}");
             }
-            return bip21;
+            return bip21.ToString();
         }
 
         public override string InvoiceViewPaymentPartialName { get; } = "Bitcoin/ViewBitcoinLikePaymentData";