Add custom TLV records to invoice

Custom [TLV records](https://github.com/satoshisstream/satoshis.stream/blob/main/TLV_registry.md) only work for LND right now, Core Lightning support might come, see ElementsProject/lightning#4470
dennisreimann · Sep 21, 2022 · 3ccee21 · 3ccee21
1 parent 6fcf55f
commit 3ccee21
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Showing 4 changed files with 32 additions and 7 deletions.
diff --git a/src/BTCPayServer.Lightning.Common/LightningInvoice.cs b/src/BTCPayServer.Lightning.Common/LightningInvoice.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 
 namespace BTCPayServer.Lightning
 {
@@ -11,5 +12,6 @@ public class LightningInvoice
         public DateTimeOffset ExpiresAt { get; set; }
         public LightMoney Amount { get; set; }
         public LightMoney AmountReceived { get; set; }
+        public Dictionary<ulong, string> CustomRecords { get; set; }
     }
 }
diff --git a/src/BTCPayServer.Lightning.Common/PayInvoiceParams.cs b/src/BTCPayServer.Lightning.Common/PayInvoiceParams.cs
@@ -10,10 +10,10 @@ public class PayInvoiceParams
         public Money? MaxFeeFlat { get; set; }
         public LightMoney? Amount { get; set; }
 
-        public PubKey Destination { get; set; }
+        public PubKey? Destination { get; set; }
 
-        public uint256 PaymentHash { get; set; }
+        public uint256? PaymentHash { get; set; }
 
-        public Dictionary<ulong,string> CustomRecords { get; set; }
+        public Dictionary<ulong,string>? CustomRecords { get; set; }
     }
 }
diff --git a/src/BTCPayServer.Lightning.LND/LndClient.cs b/src/BTCPayServer.Lightning.LND/LndClient.cs
@@ -488,10 +488,17 @@ private static LightningInvoice ConvertLndInvoice(LnrpcInvoice resp)
                 Status = LightningInvoiceStatus.Unpaid,
                 ExpiresAt = DateTimeOffset.FromUnixTimeSeconds(ConvertInv.ToInt64(resp.Creation_date) + ConvertInv.ToInt64(resp.Expiry))
             };
+
+            if (resp.Htlcs != null && resp.Htlcs.Any())
+            {
+                invoice.CustomRecords = resp.Htlcs
+                    .SelectMany(htlc => htlc.CustomRecords)
+                    .ToDictionary(x => x.Key, y => y.Value);
+            }
+
             if (resp.Settled == true)
             {
                 invoice.PaidAt = DateTimeOffset.FromUnixTimeSeconds(ConvertInv.ToInt64(resp.Settle_date));
-
                 invoice.Status = LightningInvoiceStatus.Paid;
             }
             else

diff --git a/tests/CommonTests.cs b/tests/CommonTests.cs
@@ -359,11 +359,14 @@ public async Task CanHandleKeysend()
                 var paymentHash = new uint256(Hashes.SHA256(preimage));
 
                 // https://github.com/satoshisstream/satoshis.stream/blob/main/TLV_registry.md
+                var val5482373484 = Encoders.Base64.EncodeData(preimage);
+                var val696969 = Encoders.Base64.EncodeData(Encoding.Default.GetBytes("123456"));
+                var val112111100 = Encoders.Base64.EncodeData(Encoding.Default.GetBytes("wal_hrDHs0RBEM576"));
                 var tlvData = new Dictionary<ulong,string>
                 {
-                    { 5482373484, Encoders.Base64.EncodeData(preimage) },
-                    { 696969, Encoders.Base64.EncodeData(Encoding.Default.GetBytes("123456")) },
-                    { 112111100, Encoders.Base64.EncodeData(Encoding.Default.GetBytes("wal_hrDHs0RBEM576")) }
+                    { 696969, val696969 },
+                    { 112111100, val112111100 },
+                    { 5482373484, val5482373484 }
                 };
                 var param = new PayInvoiceParams
                 {
@@ -394,6 +397,19 @@ await Assert.ThrowsAsync<NotSupportedException>(async () =>
                         });
                         break;
                 }
+
+                // Check the custom records are present in the invoice
+                // Only works for LND right now, Core Lightning support might come, see:
+                // https://github.com/ElementsProject/lightning/issues/4470#issuecomment-873599548
+                if (src is LndClient)
+                {
+                    var invoiceId = Encoders.Hex.EncodeData(paymentHash.ToBytes());
+                    var invoice = await dest.GetInvoice(invoiceId);
+                    Assert.NotNull(invoice.CustomRecords);
+                    Assert.Contains(invoice.CustomRecords, pair => pair.Key == 696969 && pair.Value == val696969);
+                    Assert.Contains(invoice.CustomRecords, pair => pair.Key == 112111100 && pair.Value == val112111100);
+                    Assert.Contains(invoice.CustomRecords, pair => pair.Key == 5482373484 && pair.Value == val5482373484);
+                }
             }
         }