node: Add chain registration payload

Change-Id: I0c7d7a5c3d776c924e8ab54314b8b99ab2483a4f

node/pkg/vaa/payloads.go

@@ -21,6 +21,13 @@ type (
 		Keys     []common.Address
 		NewIndex uint32
 	}
+
+	// BodyRegisterChain is a governance message to register a chain on the token bridge
+	BodyRegisterChain struct {
+		Header         [32]byte
+		ChainID        ChainID
+		EmitterAddress Address
+	}
 )
 
 func (b BodyContractUpgrade) Serialize() []byte {
@@ -56,3 +63,20 @@ func (b BodyGuardianSetUpdate) Serialize() []byte {
 
 	return buf.Bytes()
 }
+
+func (r BodyRegisterChain) Serialize() []byte {
+	buf := &bytes.Buffer{}
+
+	// Write token bridge header
+	buf.Write(r.Header[:])
+	// Write action ID
+	MustWrite(buf, binary.BigEndian, uint8(1))
+	// Write target chain (0 = universal)
+	MustWrite(buf, binary.BigEndian, uint16(0))
+	// Write chain to be registered
+	MustWrite(buf, binary.BigEndian, r.ChainID)
+	// Write emitter address of chain to be registered
+	buf.Write(r.EmitterAddress[:])
+
+	return buf.Bytes()
+}

node/pkg/vaa/types_test.go

@@ -85,3 +85,19 @@ func TestVerifySignature(t *testing.T) {
 		addr,
 	}))
 }
+
+func TestBodyRegisterChain_Serialize(t *testing.T) {
+	header, _ := hex.DecodeString("000000000000000000000000000000000000000000546f6b656e427269646765")
+	require.Len(t, header, 32)
+
+	var headerB [32]byte
+	copy(headerB[:], header)
+	msg := &BodyRegisterChain{
+		Header:         headerB,
+		ChainID:        8,
+		EmitterAddress: Address{1, 2, 3, 4},
+	}
+
+	data := msg.Serialize()
+	require.Equal(t, "000000000000000000000000000000000000000000546f6b656e42726964676501000000080102030400000000000000000000000000000000000000000000000000000000", hex.EncodeToString(data))
+}