lnwire: add AnnounceSignatures2 message

And ensure that it implements the AnnounceSignatures interface.

lnwire/announcement_signatures_2.go

@@ -0,0 +1,97 @@
+package lnwire
+
+import (
+	"bytes"
+	"io"
+)
+
+// AnnounceSignatures2 is a direct message between two endpoints of a
+// channel and serves as an opt-in mechanism to allow the announcement of
+// a taproot channel to the rest of the network. It contains the necessary
+// signatures by the sender to construct the channel_announcement_2 message.
+type AnnounceSignatures2 struct {
+	// ChannelID is the unique description of the funding transaction.
+	// Channel id is better for users and debugging and short channel id is
+	// used for quick test on existence of the particular utxo inside the
+	// blockchain, because it contains information about block.
+	ChannelID ChannelID
+
+	// ShortChannelID is the unique description of the funding transaction.
+	// It is constructed with the most significant 3 bytes as the block
+	// height, the next 3 bytes indicating the transaction index within the
+	// block, and the least significant two bytes indicating the output
+	// index which pays to the channel.
+	ShortChannelID ShortChannelID
+
+	// PartialSignature is the combination of the partial Schnorr signature
+	// created for the node's bitcoin key with the partial signature created
+	// for the node's node ID key.
+	PartialSignature PartialSig
+
+	// 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
+}
+
+// A compile time check to ensure AnnounceSignatures2 implements the
+// lnwire.Message interface.
+var _ Message = (*AnnounceSignatures2)(nil)
+
+// Decode deserializes a serialized AnnounceSignatures2 stored in the passed
+// io.Reader observing the specified protocol version.
+//
+// This is part of the lnwire.Message interface.
+func (a *AnnounceSignatures2) Decode(r io.Reader, _ uint32) error {
+	return ReadElements(r,
+		&a.ChannelID,
+		&a.ShortChannelID,
+		&a.PartialSignature,
+		&a.ExtraOpaqueData,
+	)
+}
+
+// Encode serializes the target AnnounceSignatures2 into the passed io.Writer
+// observing the protocol version specified.
+//
+// This is part of the lnwire.Message interface.
+func (a *AnnounceSignatures2) Encode(w *bytes.Buffer, _ uint32) error {
+	if err := WriteChannelID(w, a.ChannelID); err != nil {
+		return err
+	}
+
+	if err := WriteShortChannelID(w, a.ShortChannelID); err != nil {
+		return err
+	}
+
+	if err := WriteElement(w, a.PartialSignature); err != nil {
+		return err
+	}
+
+	return WriteBytes(w, a.ExtraOpaqueData)
+}
+
+// MsgType returns the integer uniquely identifying this message type on the
+// wire.
+//
+// This is part of the lnwire.Message interface.
+func (a *AnnounceSignatures2) MsgType() MessageType {
+	return MsgAnnounceSignatures2
+}
+
+// SCID returns the ShortChannelID of the channel.
+//
+// NOTE: this is part of the AnnounceSignatures interface.
+func (a *AnnounceSignatures2) SCID() ShortChannelID {
+	return a.ShortChannelID
+}
+
+// ChanID returns the ChannelID identifying the channel.
+//
+// NOTE: this is part of the AnnounceSignatures interface.
+func (a *AnnounceSignatures2) ChanID() ChannelID {
+	return a.ChannelID
+}

lnwire/lnwire.go

@@ -187,6 +187,11 @@ func WriteElement(w *bytes.Buffer, element interface{}) error {
 			return err
 		}
 
+	case PartialSig:
+		if err := e.Encode(w); err != nil {
+			return err
+		}
+
 	case PingPayload:
 		var l [2]byte
 		binary.BigEndian.PutUint16(l[:], uint16(len(e)))
@@ -936,6 +941,13 @@ func ReadElement(r io.Reader, element interface{}) error {
 		}
 		*e = addrBytes[:length]
 
+	case *PartialSig:
+		var sig PartialSig
+		if err = sig.Decode(r); err != nil {
+			return err
+		}
+		*e = sig
+
 	case *ExtraOpaqueData:
 		return e.Decode(r)
 

lnwire/lnwire_test.go

@@ -1509,6 +1509,35 @@ func TestLightningWireProtocol(t *testing.T) {
 
 			v[0] = reflect.ValueOf(*req)
 		},
+		MsgAnnounceSignatures2: func(v []reflect.Value,
+			r *rand.Rand) {
+
+			req := AnnounceSignatures2{
+				ShortChannelID: NewShortChanIDFromInt(
+					uint64(r.Int63()),
+				),
+				ExtraOpaqueData: make([]byte, 0),
+			}
+
+			_, err := r.Read(req.ChannelID[:])
+			require.NoError(t, err)
+
+			partialSig, err := randPartialSig(r)
+			require.NoError(t, err)
+
+			req.PartialSignature = *partialSig
+
+			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)
+		},
 	}
 
 	// With the above types defined, we'll now generate a slice of
@@ -1737,6 +1766,12 @@ func TestLightningWireProtocol(t *testing.T) {
 				return mainScenario(&m)
 			},
 		},
+		{
+			msgType: MsgAnnounceSignatures2,
+			scenario: func(m AnnounceSignatures2) bool {
+				return mainScenario(&m)
+			},
+		},
 	}
 	for _, test := range tests {
 		var config *quick.Config

lnwire/message.go

@@ -52,6 +52,7 @@ const (
 	MsgNodeAnnouncement                    = 257
 	MsgChannelUpdate                       = 258
 	MsgAnnounceSignatures                  = 259
+	MsgAnnounceSignatures2                 = 260
 	MsgQueryShortChanIDs                   = 261
 	MsgReplyShortChanIDsEnd                = 262
 	MsgQueryChannelRange                   = 263
@@ -155,6 +156,8 @@ func (t MessageType) String() string {
 		return "ClosingComplete"
 	case MsgClosingSig:
 		return "ClosingSig"
+	case MsgAnnounceSignatures2:
+		return "MsgAnnounceSignatures2"
 	default:
 		return "<unknown>"
 	}
@@ -284,6 +287,8 @@ func makeEmptyMessage(msgType MessageType) (Message, error) {
 		msg = &ClosingComplete{}
 	case MsgClosingSig:
 		msg = &ClosingSig{}
+	case MsgAnnounceSignatures2:
+		msg = &AnnounceSignatures2{}
 	default:
 		// If the message is not within our custom range and has not
 		// specifically been overridden, return an unknown message.