implement LSPS2 for LND

.github/workflows/integration_tests.yaml

@@ -5,7 +5,7 @@ on:
   pull_request:    
 env:
   BITCOIN_VERSION: '25.0'
-  LSP_REF: 'breez-node-v0.17.2-beta'
+  LSP_REF: 'unencrypted-failure-messages'
   CLIENT_REF: 'v0.16.4-breez-3'
   GO_VERSION: '^1.19'
   CLN_VERSION: 'v23.11'
@@ -158,6 +158,7 @@ jobs:
           testLsps2ZeroConfUtxo
         ]
         lsp: [
+          LND,
           CLN
         ]
         client: [

cln/cln_client.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/breez/lspd/common"
 	"github.com/breez/lspd/lightning"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
@@ -88,8 +89,9 @@ func (c *ClnClient) GetInfo() (*lightning.GetInfoResult, error) {
 	}
 
 	return &lightning.GetInfoResult{
-		Alias:  info.Alias,
-		Pubkey: info.Id,
+		ChainHash: common.MapChainHash(info.Network),
+		Alias:     info.Alias,
+		Pubkey:    info.Id,
 	}, nil
 }
 

cln/cln_interceptor.go

@@ -161,7 +161,7 @@ func (i *ClnHtlcInterceptor) intercept() error {
 					interceptorClient.Send(i.resumeWithOnion(request, interceptResult))
 				case common.INTERCEPT_FAIL_HTLC_WITH_CODE:
 					interceptorClient.Send(
-						i.failWithCode(request, interceptResult.FailureCode),
+						i.failWithMessage(request, interceptResult.FailureMessage),
 					)
 				case common.INTERCEPT_IGNORE:
 					// Do nothing
@@ -202,12 +202,12 @@ func (i *ClnHtlcInterceptor) resumeWithOnion(request *proto.HtlcAccepted, interc
 	payload, err := hex.DecodeString(request.Onion.Payload)
 	if err != nil {
 		log.Printf("paymenthash: %s, resumeWithOnion: hex.DecodeString(%v) error: %v", request.Htlc.PaymentHash, request.Onion.Payload, err)
-		return i.failWithCode(request, common.FAILURE_TEMPORARY_CHANNEL_FAILURE)
+		return i.failWithMessage(request, common.FAILURE_TEMPORARY_CHANNEL_FAILURE)
 	}
 	newPayload, err := encodePayloadWithNextHop(payload, interceptResult.Scid, interceptResult.AmountMsat, interceptResult.FeeMsat)
 	if err != nil {
 		log.Printf("paymenthash: %s, encodePayloadWithNextHop error: %v", request.Htlc.PaymentHash, err)
-		return i.failWithCode(request, common.FAILURE_TEMPORARY_CHANNEL_FAILURE)
+		return i.failWithMessage(request, common.FAILURE_TEMPORARY_CHANNEL_FAILURE)
 	}
 
 	newPayloadStr := hex.EncodeToString(newPayload)
@@ -234,14 +234,14 @@ func (i *ClnHtlcInterceptor) defaultResolution(request *proto.HtlcAccepted) *pro
 	}
 }
 
-func (i *ClnHtlcInterceptor) failWithCode(request *proto.HtlcAccepted, code common.InterceptFailureCode) *proto.HtlcResolution {
-	log.Printf("paymenthash: %s, failing htlc with code: '%x'", request.Htlc.PaymentHash, code)
+func (i *ClnHtlcInterceptor) failWithMessage(request *proto.HtlcAccepted, message []byte) *proto.HtlcResolution {
+	log.Printf("paymenthash: %s, failing htlc with message '%x'", request.Htlc.PaymentHash, message)
 	return &proto.HtlcResolution{
 		Correlationid: request.Correlationid,
 		Outcome: &proto.HtlcResolution_Fail{
 			Fail: &proto.HtlcFail{
 				Failure: &proto.HtlcFail_FailureMessage{
-					FailureMessage: i.mapFailureCode(code),
+					FailureMessage: hex.EncodeToString(message),
 				},
 			},
 		},
@@ -305,23 +305,3 @@ func encodePayloadWithNextHop(payload []byte, scid lightning.ShortChannelID, amo
 	}
 	return newPayloadBuf.Bytes(), nil
 }
-
-func (i *ClnHtlcInterceptor) mapFailureCode(original common.InterceptFailureCode) string {
-	switch original {
-	case common.FAILURE_TEMPORARY_CHANNEL_FAILURE:
-		return "1007"
-	case common.FAILURE_AMOUNT_BELOW_MINIMUM:
-		return "100B"
-	case common.FAILURE_INCORRECT_CLTV_EXPIRY:
-		return "100D"
-	case common.FAILURE_TEMPORARY_NODE_FAILURE:
-		return "2002"
-	case common.FAILURE_UNKNOWN_NEXT_PEER:
-		return "400A"
-	case common.FAILURE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS:
-		return "400F"
-	default:
-		log.Printf("Unknown failure code %v, default to temporary channel failure.", original)
-		return "1007" // temporary channel failure
-	}
-}

common/chain_hash.go

@@ -0,0 +1,19 @@
+package common
+
+import (
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+)
+
+func MapChainHash(network string) *chainhash.Hash {
+	switch network {
+	case "bitcoin":
+		return chaincfg.MainNetParams.GenesisHash
+	case "testnet":
+		return chaincfg.TestNet3Params.GenesisHash
+	case "regtest":
+		return chaincfg.RegressionNetParams.GenesisHash
+	default:
+		return chaincfg.MainNetParams.GenesisHash
+	}
+}

common/chan_update.go

@@ -0,0 +1,38 @@
+package common
+
+import (
+	"bytes"
+	"time"
+
+	"github.com/breez/lspd/lightning"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/lightningnetwork/lnd/lnwire"
+)
+
+func ConstructChanUpdate(
+	chainhash chainhash.Hash,
+	node []byte,
+	destination []byte,
+	scid lightning.ShortChannelID,
+	timeLockDelta uint16,
+	htlcMinimumMsat,
+	htlcMaximumMsat uint64,
+) lnwire.ChannelUpdate {
+	channelFlags := lnwire.ChanUpdateChanFlags(0)
+	if bytes.Compare(node, destination) > 0 {
+		channelFlags = 1
+	}
+
+	return lnwire.ChannelUpdate{
+		ChainHash:       chainhash,
+		ShortChannelID:  scid.ToLnwire(),
+		Timestamp:       uint32(time.Now().Unix()),
+		TimeLockDelta:   timeLockDelta,
+		HtlcMinimumMsat: lnwire.MilliSatoshi(htlcMinimumMsat),
+		HtlcMaximumMsat: lnwire.MilliSatoshi(htlcMaximumMsat),
+		BaseFee:         0,
+		FeeRate:         0,
+		MessageFlags:    lnwire.ChanUpdateRequiredMaxHtlc,
+		ChannelFlags:    channelFlags,
+	}
+}

common/intercept_handler.go

@@ -1,10 +1,13 @@
 package common
 
 import (
+	"bytes"
 	"fmt"
+	"log"
 
 	"github.com/breez/lspd/lightning"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/lnwire"
 )
 
 type InterceptAction int
@@ -16,17 +19,41 @@ const (
 	INTERCEPT_IGNORE              InterceptAction = 3
 )
 
-type InterceptFailureCode uint16
+type InterceptFailureCode []byte
 
 var (
-	FAILURE_TEMPORARY_CHANNEL_FAILURE            InterceptFailureCode = 0x1007
-	FAILURE_AMOUNT_BELOW_MINIMUM                 InterceptFailureCode = 0x100B
-	FAILURE_INCORRECT_CLTV_EXPIRY                InterceptFailureCode = 0x100D
-	FAILURE_TEMPORARY_NODE_FAILURE               InterceptFailureCode = 0x2002
-	FAILURE_UNKNOWN_NEXT_PEER                    InterceptFailureCode = 0x400A
-	FAILURE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS InterceptFailureCode = 0x400F
+	FAILURE_TEMPORARY_CHANNEL_FAILURE            InterceptFailureCode = []byte{0x10, 0x07}
+	FAILURE_AMOUNT_BELOW_MINIMUM                 InterceptFailureCode = []byte{0x10, 0x0B}
+	FAILURE_INCORRECT_CLTV_EXPIRY                InterceptFailureCode = []byte{0x10, 0x0D}
+	FAILURE_TEMPORARY_NODE_FAILURE               InterceptFailureCode = []byte{0x20, 0x02}
+	FAILURE_UNKNOWN_NEXT_PEER                    InterceptFailureCode = []byte{0x40, 0x0A}
+	FAILURE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS InterceptFailureCode = []byte{0x40, 0x0F}
 )
 
+func FailureTemporaryChannelFailure(update *lnwire.ChannelUpdate) []byte {
+	var buf bytes.Buffer
+	msg := lnwire.NewTemporaryChannelFailure(update)
+	err := lnwire.EncodeFailureMessage(&buf, msg, 0)
+	if err != nil {
+		log.Printf("Failed to encode failure message for temporary channel failure: %v", err)
+		return FAILURE_TEMPORARY_CHANNEL_FAILURE
+	}
+
+	return buf.Bytes()
+}
+
+func FailureIncorrectCltvExpiry(cltvExpiry uint32, update lnwire.ChannelUpdate) []byte {
+	var buf bytes.Buffer
+	msg := lnwire.NewIncorrectCltvExpiry(cltvExpiry, update)
+	err := lnwire.EncodeFailureMessage(&buf, msg, 0)
+	if err != nil {
+		log.Printf("Failed to encode failure message for incorrect cltv expiry: %v", err)
+		return FAILURE_INCORRECT_CLTV_EXPIRY
+	}
+
+	return buf.Bytes()
+}
+
 type InterceptRequest struct {
 	// Identifier that uniquely identifies this htlc.
 	// For cln, that's hash of the next onion or the shared secret.
@@ -49,7 +76,7 @@ func (r *InterceptRequest) HtlcId() string {
 
 type InterceptResult struct {
 	Action             InterceptAction
-	FailureCode        InterceptFailureCode
+	FailureMessage     []byte
 	Destination        []byte
 	AmountMsat         uint64
 	FeeMsat            *uint64

common/nodes_service.go

@@ -7,11 +7,14 @@ import (
 	"github.com/breez/lspd/config"
 	"github.com/breez/lspd/lightning"
 	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	ecies "github.com/ecies/go/v2"
 	"golang.org/x/sync/singleflight"
 )
 
 type Node struct {
+	NodeId              []byte
+	ChainHash           chainhash.Hash
 	Client              lightning.Client
 	NodeConfig          *config.NodeConfig
 	PrivateKey          *btcec.PrivateKey

go.mod

@@ -14,7 +14,6 @@ require (
 	github.com/docker/docker v20.10.24+incompatible
 	github.com/docker/go-connections v0.4.0
 	github.com/elementsproject/glightning v0.0.0-20230525134205-ef34d849f564
-	github.com/golang/protobuf v1.5.3
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0
 	github.com/jackc/pgtype v1.14.0
 	github.com/jackc/pgx/v5 v5.4.3
@@ -38,6 +37,7 @@ require (
 	github.com/docker/go-units v0.5.0 // indirect
 	github.com/ethereum/go-ethereum v1.13.5 // indirect
 	github.com/golang-jwt/jwt/v4 v4.5.0 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/jackc/chunkreader/v2 v2.0.1 // indirect
 	github.com/jackc/pgconn v1.14.0 // indirect
@@ -194,7 +194,7 @@ require (
 	sigs.k8s.io/yaml v1.2.0 // indirect
 )
 
-replace github.com/lightningnetwork/lnd v0.17.2-beta => github.com/breez/lnd v0.15.0-beta.rc6.0.20231122093500-0c939786ced7
+replace github.com/lightningnetwork/lnd v0.17.2-beta => github.com/breez/lnd v0.15.0-beta.rc6.0.20240105103917-ec16df3d9d48
 
 replace google.golang.org/protobuf => github.com/lightninglabs/protobuf-go-hex-display v1.30.0-hex-display