feat: add support for RFC31 ENR (#180)

waku/v2/utils/enr.go

@@ -2,6 +2,8 @@ package utils
 
 import (
 	"crypto/ecdsa"
+	"encoding/binary"
+	"errors"
 	"fmt"
 	"math"
 	"net"
@@ -14,6 +16,7 @@ import (
 )
 
 const WakuENRField = "waku2"
+const MultiaddrENRField = "multiaddrs"
 
 // WakuEnrBitfield is a8-bit flag field to indicate Waku capabilities. Only the 4 LSBs are currently defined according to RFC31 (https://rfc.vac.dev/spec/31/).
 type WakuEnrBitfield = uint8
@@ -69,6 +72,44 @@ func GetENRandIP(addr ma.Multiaddr, wakuFlags WakuEnrBitfield, privK *ecdsa.Priv
 		return nil, nil, fmt.Errorf("could not set port %d", port)
 	}
 
+	var multiaddrItems []ma.Multiaddr
+
+	// 31/WAKU2-ENR
+
+	_, err = addr.ValueForProtocol(ma.P_WS)
+	if err == nil {
+		multiaddrItems = append(multiaddrItems, addr)
+	}
+
+	_, err = addr.ValueForProtocol(ma.P_WSS)
+	if err == nil {
+		multiaddrItems = append(multiaddrItems, addr)
+	}
+
+	p2p, err := addr.ValueForProtocol(ma.P_P2P)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	p2pAddr, err := ma.NewMultiaddr("/p2p/" + p2p)
+	if err != nil {
+		return nil, nil, fmt.Errorf("Could not create p2p addr: %w", err)
+	}
+
+	var fieldRaw []byte
+	for _, ma := range multiaddrItems {
+		maRaw := ma.Decapsulate(p2pAddr).Bytes()
+		maSize := make([]byte, 2)
+		binary.BigEndian.PutUint16(maSize, uint16(len(maRaw)))
+
+		fieldRaw = append(fieldRaw, maSize...)
+		fieldRaw = append(fieldRaw, maRaw...)
+	}
+
+	if len(fieldRaw) != 0 {
+		r.Set(enr.WithEntry(MultiaddrENRField, fieldRaw))
+	}
+
 	r.Set(enr.IP(net.ParseIP(ip)))
 	r.Set(enr.WithEntry(WakuENRField, wakuFlags))
 
@@ -91,6 +132,53 @@ func EnodeToMultiAddr(node *enode.Node) (ma.Multiaddr, error) {
 	return ma.NewMultiaddr(fmt.Sprintf("/ip4/%s/tcp/%d/p2p/%s", node.IP(), node.TCP(), peerID))
 }
 
+func Multiaddress(node *enode.Node) ([]ma.Multiaddr, error) {
+	peerID, err := peer.IDFromPublicKey(&ECDSAPublicKey{node.Pubkey()})
+	if err != nil {
+		return nil, err
+	}
+
+	var multiaddrRaw []byte
+	if err := node.Record().Load(enr.WithEntry(MultiaddrENRField, &multiaddrRaw)); err != nil {
+		if !enr.IsNotFound(err) {
+			log.Error("could not retrieve multiaddress field for node ", node)
+		}
+		return nil, err
+	}
+
+	if len(multiaddrRaw) < 2 {
+		return nil, errors.New("invalid multiaddress field length")
+	}
+
+	hostInfo, err := ma.NewMultiaddr(fmt.Sprintf("/p2p/%s", peerID.Pretty()))
+	if err != nil {
+		return nil, err
+	}
+
+	var result []ma.Multiaddr
+	offset := 0
+	for {
+		maSize := binary.BigEndian.Uint16(multiaddrRaw[offset : offset+2])
+		if len(multiaddrRaw) < offset+2+int(maSize) {
+			return nil, errors.New("invalid multiaddress field length")
+		}
+		maRaw := multiaddrRaw[offset+2 : offset+2+int(maSize)]
+		addr, err := ma.NewMultiaddrBytes(maRaw)
+		if err != nil {
+			return nil, fmt.Errorf("invalid multiaddress field length")
+		}
+
+		result = append(result, addr.Encapsulate(hostInfo))
+
+		offset += 2 + int(maSize)
+		if offset >= len(multiaddrRaw) {
+			break
+		}
+	}
+
+	return result, nil
+}
+
 func EnodeToPeerInfo(node *enode.Node) (*peer.AddrInfo, error) {
 	address, err := EnodeToMultiAddr(node)
 	if err != nil {

waku/v2/utils/enr_test.go

@@ -45,3 +45,19 @@ func TestGetENRandIP(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, ogMultiaddress.String(), resMultiaddress.String())
 }
+
+func TestMultiaddr(t *testing.T) {
+	key, _ := gcrypto.GenerateKey()
+	privKey := crypto.PrivKey((*crypto.Secp256k1PrivateKey)(key))
+	id, _ := peer.IDFromPublicKey(privKey.GetPublic())
+	ogMultiaddress, _ := ma.NewMultiaddr("/ip4/10.0.0.241/tcp/60001/ws/p2p/" + id.Pretty())
+	wakuFlag := NewWakuEnrBitfield(true, true, true, true)
+
+	node, _, err := GetENRandIP(ogMultiaddress, wakuFlag, key)
+	require.NoError(t, err)
+
+	multiaddresses, err := Multiaddress(node)
+	require.NoError(t, err)
+	require.Len(t, multiaddresses, 1)
+	require.True(t, ogMultiaddress.Equal(multiaddresses[0]))
+}