lnwire: add ChannelAnnouncement2 message

And ensure that it implements the ChannelAnnouncement interface.
2025-02-22 14:22:37 +01:00 · 2023-09-29 10:33:24 +02:00 · 2023-09-29 10:33:24 +02:00 · a438eb3af3
commit a438eb3af3
parent 66302ceb29
3 changed files with 342 additions and 43 deletions
--- a/lnwire/channel_announcement_2.go
+++ b/lnwire/channel_announcement_2.go
@ -0,0 +1,234 @@
+package lnwire
+
+import (
+	"bytes"
+	"io"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/lightningnetwork/lnd/tlv"
+)
+
+// ChannelAnnouncement2 message is used to announce the existence of a taproot
+// channel between two peers in the network.
+type ChannelAnnouncement2 struct {
+	// Signature is a Schnorr signature over the TLV stream of the message.
+	Signature Sig
+
+	// ChainHash denotes the target chain that this channel was opened
+	// within. This value should be the genesis hash of the target chain.
+	ChainHash tlv.RecordT[tlv.TlvType0, chainhash.Hash]
+
+	// Features is the feature vector that encodes the features supported
+	// by the target node. This field can be used to signal the type of the
+	// channel, or modifications to the fields that would normally follow
+	// this vector.
+	Features tlv.RecordT[tlv.TlvType2, RawFeatureVector]
+
+	// ShortChannelID is the unique description of the funding transaction,
+	// or where exactly it's located within the target blockchain.
+	ShortChannelID tlv.RecordT[tlv.TlvType4, ShortChannelID]
+
+	// Capacity is the number of satoshis of the capacity of this channel.
+	// It must be less than or equal to the value of the on-chain funding
+	// output.
+	Capacity tlv.RecordT[tlv.TlvType6, uint64]
+
+	// NodeID1 is the numerically-lesser public key ID of one of the channel
+	// operators.
+	NodeID1 tlv.RecordT[tlv.TlvType8, [33]byte]
+
+	// NodeID2 is the numerically-greater public key ID of one of the
+	// channel operators.
+	NodeID2 tlv.RecordT[tlv.TlvType10, [33]byte]
+
+	// BitcoinKey1 is the public key of the key used by Node1 in the
+	// construction of the on-chain funding transaction. This is an optional
+	// field and only needs to be set if the 4-of-4 MuSig construction was
+	// used in the creation of the message signature.
+	BitcoinKey1 tlv.OptionalRecordT[tlv.TlvType12, [33]byte]
+
+	// BitcoinKey2 is the public key of the key used by Node2 in the
+	// construction of the on-chain funding transaction. This is an optional
+	// field and only needs to be set if the 4-of-4 MuSig construction was
+	// used in the creation of the message signature.
+	BitcoinKey2 tlv.OptionalRecordT[tlv.TlvType14, [33]byte]
+
+	// MerkleRootHash is the hash used to create the optional tweak in the
+	// funding output. If this is not set but the bitcoin keys are, then
+	// the funding output is a pure 2-of-2 MuSig aggregate public key.
+	MerkleRootHash tlv.OptionalRecordT[tlv.TlvType16, [32]byte]
+
+	// ExtraOpaqueData is the set of data that was appended to this
+	// message, some of which we may not actually know how to iterate or
+	// parse. By holding onto this data, we ensure that we're able to
+	// properly validate the set of signatures that cover these new fields,
+	// and ensure we're able to make upgrades to the network in a forwards
+	// compatible manner.
+	ExtraOpaqueData ExtraOpaqueData
+}
+
+// Decode deserializes a serialized AnnounceSignatures1 stored in the passed
+// io.Reader observing the specified protocol version.
+//
+// This is part of the lnwire.Message interface.
+func (c *ChannelAnnouncement2) Decode(r io.Reader, _ uint32) error {
+	err := ReadElement(r, &c.Signature)
+	if err != nil {
+		return err
+	}
+	c.Signature.ForceSchnorr()
+
+	return c.DecodeTLVRecords(r)
+}
+
+// DecodeTLVRecords decodes only the TLV section of the message.
+func (c *ChannelAnnouncement2) DecodeTLVRecords(r io.Reader) error {
+	// First extract into extra opaque data.
+	var tlvRecords ExtraOpaqueData
+	if err := ReadElements(r, &tlvRecords); err != nil {
+		return err
+	}
+
+	var (
+		chainHash      = tlv.ZeroRecordT[tlv.TlvType0, [32]byte]()
+		btcKey1        = tlv.ZeroRecordT[tlv.TlvType12, [33]byte]()
+		btcKey2        = tlv.ZeroRecordT[tlv.TlvType14, [33]byte]()
+		merkleRootHash = tlv.ZeroRecordT[tlv.TlvType16, [32]byte]()
+	)
+	typeMap, err := tlvRecords.ExtractRecords(
+		&chainHash, &c.Features, &c.ShortChannelID, &c.Capacity,
+		&c.NodeID1, &c.NodeID2, &btcKey1, &btcKey2, &merkleRootHash,
+	)
+	if err != nil {
+		return err
+	}
+
+	// By default, the chain-hash is the bitcoin mainnet genesis block hash.
+	c.ChainHash.Val = *chaincfg.MainNetParams.GenesisHash
+	if _, ok := typeMap[c.ChainHash.TlvType()]; ok {
+		c.ChainHash.Val = chainHash.Val
+	}
+
+	if _, ok := typeMap[c.BitcoinKey1.TlvType()]; ok {
+		c.BitcoinKey1 = tlv.SomeRecordT(btcKey1)
+	}
+
+	if _, ok := typeMap[c.BitcoinKey2.TlvType()]; ok {
+		c.BitcoinKey2 = tlv.SomeRecordT(btcKey2)
+	}
+
+	if _, ok := typeMap[c.MerkleRootHash.TlvType()]; ok {
+		c.MerkleRootHash = tlv.SomeRecordT(merkleRootHash)
+	}
+
+	if len(tlvRecords) != 0 {
+		c.ExtraOpaqueData = tlvRecords
+	}
+
+	return nil
+}
+
+// Encode serializes the target AnnounceSignatures1 into the passed io.Writer
+// observing the protocol version specified.
+//
+// This is part of the lnwire.Message interface.
+func (c *ChannelAnnouncement2) Encode(w *bytes.Buffer, _ uint32) error {
+	_, err := w.Write(c.Signature.RawBytes())
+	if err != nil {
+		return err
+	}
+	_, err = c.DataToSign()
+	if err != nil {
+		return err
+	}
+
+	return WriteBytes(w, c.ExtraOpaqueData)
+}
+
+// DataToSign encodes the data to be signed into the ExtraOpaqueData member and
+// returns it.
+func (c *ChannelAnnouncement2) DataToSign() ([]byte, error) {
+	// The chain-hash record is only included if it is _not_ equal to the
+	// bitcoin mainnet genisis block hash.
+	var recordProducers []tlv.RecordProducer
+	if !c.ChainHash.Val.IsEqual(chaincfg.MainNetParams.GenesisHash) {
+		hash := tlv.ZeroRecordT[tlv.TlvType0, [32]byte]()
+		hash.Val = c.ChainHash.Val
+
+		recordProducers = append(recordProducers, &hash)
+	}
+
+	recordProducers = append(recordProducers,
+		&c.Features, &c.ShortChannelID, &c.Capacity, &c.NodeID1,
+		&c.NodeID2,
+	)
+
+	c.BitcoinKey1.WhenSome(func(key tlv.RecordT[tlv.TlvType12, [33]byte]) {
+		recordProducers = append(recordProducers, &key)
+	})
+
+	c.BitcoinKey2.WhenSome(func(key tlv.RecordT[tlv.TlvType14, [33]byte]) {
+		recordProducers = append(recordProducers, &key)
+	})
+
+	c.MerkleRootHash.WhenSome(
+		func(hash tlv.RecordT[tlv.TlvType16, [32]byte]) {
+			recordProducers = append(recordProducers, &hash)
+		},
+	)
+
+	err := EncodeMessageExtraData(&c.ExtraOpaqueData, recordProducers...)
+	if err != nil {
+		return nil, err
+	}
+
+	return c.ExtraOpaqueData, nil
+}
+
+// MsgType returns the integer uniquely identifying this message type on the
+// wire.
+//
+// This is part of the lnwire.Message interface.
+func (c *ChannelAnnouncement2) MsgType() MessageType {
+	return MsgChannelAnnouncement2
+}
+
+// A compile time check to ensure ChannelAnnouncement2 implements the
+// lnwire.Message interface.
+var _ Message = (*ChannelAnnouncement2)(nil)
+
+// Node1KeyBytes returns the bytes representing the public key of node 1 in the
+// channel.
+//
+// NOTE: This is part of the ChannelAnnouncement interface.
+func (c *ChannelAnnouncement2) Node1KeyBytes() [33]byte {
+	return c.NodeID1.Val
+}
+
+// Node2KeyBytes returns the bytes representing the public key of node 2 in the
+// channel.
+//
+// NOTE: This is part of the ChannelAnnouncement interface.
+func (c *ChannelAnnouncement2) Node2KeyBytes() [33]byte {
+	return c.NodeID2.Val
+}
+
+// GetChainHash returns the hash of the chain which this channel's funding
+// transaction is confirmed in.
+//
+// NOTE: This is part of the ChannelAnnouncement interface.
+func (c *ChannelAnnouncement2) GetChainHash() chainhash.Hash {
+	return c.ChainHash.Val
+}
+
+// SCID returns the short channel ID of the channel.
+//
+// NOTE: This is part of the ChannelAnnouncement interface.
+func (c *ChannelAnnouncement2) SCID() ShortChannelID {
+	return c.ShortChannelID.Val
+}
+
+// A compile-time check to ensure that ChannelAnnouncement2 implements the
+// ChannelAnnouncement interface.
+var _ ChannelAnnouncement = (*ChannelAnnouncement2)(nil)
--- a/lnwire/lnwire_test.go
+++ b/lnwire/lnwire_test.go
@ -19,6 +19,7 @@ import (
 	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/btcec/v2/ecdsa"
 	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/fn"
@ -30,17 +31,25 @@ import (
 )

 var (
-	shaHash1Bytes, _ = hex.DecodeString("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
-	shaHash1, _      = chainhash.NewHash(shaHash1Bytes)
-	outpoint1        = wire.NewOutPoint(shaHash1, 0)
+	shaHash1Bytes, _ = hex.DecodeString("e3b0c44298fc1c149afbf4c8996fb" +
+		"92427ae41e4649b934ca495991b7852b855")

-	testRBytes, _ = hex.DecodeString("8ce2bc69281ce27da07e6683571319d18e949ddfa2965fb6caa1bf0314f882d7")
-	testSBytes, _ = hex.DecodeString("299105481d63e0f4bc2a88121167221b6700d72a0ead154c03be696a292d24ae")
-	testRScalar   = new(btcec.ModNScalar)
-	testSScalar   = new(btcec.ModNScalar)
-	_             = testRScalar.SetByteSlice(testRBytes)
-	_             = testSScalar.SetByteSlice(testSBytes)
-	testSig       = ecdsa.NewSignature(testRScalar, testSScalar)
+	shaHash1, _ = chainhash.NewHash(shaHash1Bytes)
+	outpoint1   = wire.NewOutPoint(shaHash1, 0)
+
+	testRBytes, _ = hex.DecodeString("8ce2bc69281ce27da07e6683571" +
+		"319d18e949ddfa2965fb6caa1bf0314f882d7")
+	testSBytes, _ = hex.DecodeString("299105481d63e0f4bc2a" +
+		"88121167221b6700d72a0ead154c03be696a292d24ae")
+	testRScalar          = new(btcec.ModNScalar)
+	testSScalar          = new(btcec.ModNScalar)
+	_                    = testRScalar.SetByteSlice(testRBytes)
+	_                    = testSScalar.SetByteSlice(testSBytes)
+	testSig              = ecdsa.NewSignature(testRScalar, testSScalar)
+	testSchnorrSigStr, _ = hex.DecodeString("04E7F9037658A92AFEB4F2" +
+		"5BAE5339E3DDCA81A353493827D26F16D92308E49E2A25E9220867" +
+		"8A2DF86970DA91B03A8AF8815A8A60498B358DAF560B347AA557")
+	testSchnorrSig, _ = NewSigFromSchnorrRawSignature(testSchnorrSigStr)
 )

 const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
@ -156,17 +165,15 @@ func generateRandomBytes(n int) ([]byte, error) {
 	return b, nil
 }

-func randRawKey() ([33]byte, error) {
+func randRawKey(t *testing.T) [33]byte {
 	var n [33]byte

 	priv, err := btcec.NewPrivateKey()
-	if err != nil {
-		return n, err
-	}
+	require.NoError(t, err)

 	copy(n[:], priv.PubKey().SerializeCompressed())

-	return n, nil
+	return n
 }

 func randDeliveryAddress(r *rand.Rand) (DeliveryAddress, error) {
@ -993,7 +1000,13 @@ func TestLightningWireProtocol(t *testing.T) {
 		MsgChannelAnnouncement: func(v []reflect.Value, r *rand.Rand) {
 			var err error
 			req := ChannelAnnouncement1{
-				ShortChannelID:  NewShortChanIDFromInt(uint64(r.Int63())),
+				ShortChannelID: NewShortChanIDFromInt(
+					uint64(r.Int63()),
+				),
+				NodeID1:         randRawKey(t),
+				NodeID2:         randRawKey(t),
+				BitcoinKey1:     randRawKey(t),
+				BitcoinKey2:     randRawKey(t),
 				Features:        randRawFeatureVector(r),
 				ExtraOpaqueData: make([]byte, 0),
 			}
@ -1018,26 +1031,6 @@ func TestLightningWireProtocol(t *testing.T) {
 				return
 			}

-			req.NodeID1, err = randRawKey()
-			if err != nil {
-				t.Fatalf("unable to generate key: %v", err)
-				return
-			}
-			req.NodeID2, err = randRawKey()
-			if err != nil {
-				t.Fatalf("unable to generate key: %v", err)
-				return
-			}
-			req.BitcoinKey1, err = randRawKey()
-			if err != nil {
-				t.Fatalf("unable to generate key: %v", err)
-				return
-			}
-			req.BitcoinKey2, err = randRawKey()
-			if err != nil {
-				t.Fatalf("unable to generate key: %v", err)
-				return
-			}
 			if _, err := r.Read(req.ChainHash[:]); err != nil {
 				t.Fatalf("unable to generate chain hash: %v", err)
 				return
@ -1059,6 +1052,7 @@ func TestLightningWireProtocol(t *testing.T) {
 		MsgNodeAnnouncement: func(v []reflect.Value, r *rand.Rand) {
 			var err error
 			req := NodeAnnouncement{
+				NodeID:    randRawKey(t),
 				Features:  randRawFeatureVector(r),
 				Timestamp: uint32(r.Int31()),
 				Alias:     randAlias(r),
@ -1075,12 +1069,6 @@ func TestLightningWireProtocol(t *testing.T) {
 				return
 			}

-			req.NodeID, err = randRawKey()
-			if err != nil {
-				t.Fatalf("unable to generate key: %v", err)
-				return
-			}
-
 			req.Addresses, err = randAddrs(r)
 			if err != nil {
 				t.Fatalf("unable to generate addresses: %v", err)
@ -1114,7 +1102,9 @@ func TestLightningWireProtocol(t *testing.T) {
 			}

 			req := ChannelUpdate1{
-				ShortChannelID:  NewShortChanIDFromInt(uint64(r.Int63())),
+				ShortChannelID: NewShortChanIDFromInt(
+					uint64(r.Int63()),
+				),
 				Timestamp:       uint32(r.Int31()),
 				MessageFlags:    msgFlags,
 				ChannelFlags:    ChanUpdateChanFlags(r.Int31()),
@ -1536,6 +1526,70 @@ func TestLightningWireProtocol(t *testing.T) {
 				require.NoError(t, err)
 			}

+			v[0] = reflect.ValueOf(req)
+		},
+		MsgChannelAnnouncement2: func(v []reflect.Value, r *rand.Rand) {
+			req := ChannelAnnouncement2{
+				Signature:       testSchnorrSig,
+				ExtraOpaqueData: make([]byte, 0),
+			}
+
+			req.ShortChannelID.Val = NewShortChanIDFromInt(
+				uint64(r.Int63()),
+			)
+			req.Capacity.Val = rand.Uint64()
+
+			req.Features.Val = *randRawFeatureVector(r)
+
+			req.NodeID1.Val = randRawKey(t)
+			req.NodeID2.Val = randRawKey(t)
+
+			// Sometimes set chain hash to bitcoin mainnet genesis
+			// hash.
+			req.ChainHash.Val = *chaincfg.MainNetParams.GenesisHash
+			if r.Int31()%2 == 0 {
+				_, err := r.Read(req.ChainHash.Val[:])
+				require.NoError(t, err)
+			}
+
+			// Sometimes set the bitcoin keys.
+			if r.Int31()%2 == 0 {
+				btcKey1 := tlv.ZeroRecordT[
+					tlv.TlvType12, [33]byte,
+				]()
+				btcKey1.Val = randRawKey(t)
+				req.BitcoinKey1 = tlv.SomeRecordT(btcKey1)
+
+				btcKey2 := tlv.ZeroRecordT[
+					tlv.TlvType14, [33]byte,
+				]()
+				btcKey2.Val = randRawKey(t)
+				req.BitcoinKey2 = tlv.SomeRecordT(btcKey2)
+
+				// Occasionally also set the merkle root hash.
+				if r.Int31()%2 == 0 {
+					hash := tlv.ZeroRecordT[
+						tlv.TlvType16, [32]byte,
+					]()
+
+					_, err := r.Read(hash.Val[:])
+					require.NoError(t, err)
+
+					req.MerkleRootHash = tlv.SomeRecordT(
+						hash,
+					)
+				}
+			}
+
+			numExtraBytes := r.Int31n(1000)
+			if numExtraBytes > 0 {
+				req.ExtraOpaqueData = make(
+					[]byte, numExtraBytes,
+				)
+				_, err := r.Read(req.ExtraOpaqueData[:])
+				require.NoError(t, err)
+			}
+
 			v[0] = reflect.ValueOf(req)
 		},
 	}
@ -1772,6 +1826,12 @@ func TestLightningWireProtocol(t *testing.T) {
 				return mainScenario(&m)
 			},
 		},
+		{
+			msgType: MsgChannelAnnouncement2,
+			scenario: func(m ChannelAnnouncement2) bool {
+				return mainScenario(&m)
+			},
+		},
 	}
 	for _, test := range tests {
 		var config *quick.Config
--- a/lnwire/message.go
+++ b/lnwire/message.go
@ -58,6 +58,7 @@ const (
 	MsgQueryChannelRange                   = 263
 	MsgReplyChannelRange                   = 264
 	MsgGossipTimestampRange                = 265
+	MsgChannelAnnouncement2                = 267
 	MsgKickoffSig                          = 777
 )

@ -158,6 +159,8 @@ func (t MessageType) String() string {
 		return "ClosingSig"
 	case MsgAnnounceSignatures2:
 		return "MsgAnnounceSignatures2"
+	case MsgChannelAnnouncement2:
+		return "ChannelAnnouncement2"
 	default:
 		return "<unknown>"
 	}
@ -289,6 +292,8 @@ func makeEmptyMessage(msgType MessageType) (Message, error) {
 		msg = &ClosingSig{}
 	case MsgAnnounceSignatures2:
 		msg = &AnnounceSignatures2{}
+	case MsgChannelAnnouncement2:
+		msg = &ChannelAnnouncement2{}
 	default:
 		// If the message is not within our custom range and has not
 		// specifically been overridden, return an unknown message.