Refactoring

examples/multipro/echo.go

@@ -57,7 +57,7 @@ func (e *EchoProtocol) onEchoRequest(s inet.Stream) {
 	// send response to the request using the message string he provided
 
 	resp := &p2p.EchoResponse{
-		MessageData: NewMessageData(e.node, data.MessageData.Id, false),
+		MessageData: e.node.NewMessageData(data.MessageData.Id, false),
 		Message:     data.Message}
 
 	// sign the data
@@ -121,7 +121,7 @@ func (e *EchoProtocol) Echo(host host.Host) bool {
 
 	// create message data
 	req := &p2p.EchoRequest{
-		MessageData: NewMessageData(e.node, uuid.New().String(), false),
+		MessageData: e.node.NewMessageData(uuid.New().String(), false),
 		Message:     fmt.Sprintf("Echo from %s", e.node.ID())}
 
 	signature, err := e.node.signProtoMessage(req)

examples/multipro/node.go

@@ -5,9 +5,9 @@ import (
 	"github.com/gogo/protobuf/proto"
 	host "gx/ipfs/QmRS46AyqtpJBsf1zmQdeizSDEzo1qkWR7rdEuPFAv8237/go-libp2p-host"
 	peer "gx/ipfs/QmXYjuNuxVzXKJCfWasQk1RqkhVLDM9jtUKhqc2WPQmFSB/go-libp2p-peer"
-
 	crypto "gx/ipfs/QmaPbCnUMBohSGo3KnxEa2bHqyJVVeEEcwtqJAYxerieBo/go-libp2p-crypto"
 	"log"
+	"time"
 )
 
 // Node type - a p2p host implementing one or more p2p protocols
@@ -18,7 +18,7 @@ type Node struct {
 	// add other protocols here...
 }
 
-// create a new node with its implemented protocols
+// Create a new node with its implemented protocols
 func NewNode(host host.Host, done chan bool) *Node {
 	node := &Node{Host: host}
 	node.PingProtocol = NewPingProtocol(node, done)
@@ -26,13 +26,16 @@ func NewNode(host host.Host, done chan bool) *Node {
 	return node
 }
 
+// Authenticate incoming p2p message
+// message: a protobufs go data object
+// data: common p2p message data
 func (n *Node) authenticateMessage(message proto.Message, data *p2p.MessageData) bool {
 
-	// store a temp ref to sig and remove it from data
+	// store a temp ref to signature and remove it from message data
 	sign := data.Sign
 	data.Sign = ""
 
-	// marshall data without the sig to binary format
+	// marshall data without the signature to protobufs3 binary format
 	bin, err := proto.Marshal(message)
 	if err != nil {
 		log.Println(err, "failed to marshal pb message")
@@ -42,15 +45,19 @@ func (n *Node) authenticateMessage(message proto.Message, data *p2p.MessageData)
 	// restore sig in message data (for possible future use)
 	data.Sign = sign
 
+	// restore peer id binary format from base58 encoded node id data
 	peerId, err := peer.IDB58Decode(data.NodeId)
 	if err != nil {
 		log.Println(err, "Failed to decode node id from base58")
 		return false
 	}
 
+	// verify the data was authored by the signing peer identified by the public key
+	// and signature included in the message
 	return n.verifyData(bin, []byte(sign), peerId, data.NodePubKey)
 }
 
+// sign an outgoing p2p message payload
 func (n *Node) signProtoMessage(message proto.Message) ([]byte, error) {
 	data, err := proto.Marshal(message)
 	if err != nil {
@@ -59,17 +66,20 @@ func (n *Node) signProtoMessage(message proto.Message) ([]byte, error) {
 	return n.signData(data)
 }
 
+// sign binary data using the local node's private key
 func (n *Node) signData(data []byte) ([]byte, error) {
 	key := n.Peerstore().PrivKey(n.ID())
 	res, err := key.Sign(data)
 	return res, err
 }
 
-// precondition: we have info about the signer peer in the local peer store
+// Verify incoming p2p message data integrity
+// data: data to verify
+// signature: author signature provided in the message payload
+// peerId: author peer id from the message payload
+// pubKeyData: author public key from the message payload
 func (n *Node) verifyData(data []byte, signature []byte, peerId peer.ID, pubKeyData []byte) bool {
-
 	key, err := crypto.UnmarshalPublicKey(pubKeyData)
-
 	if err != nil {
 		log.Println(err, "Failed to extract key from message key data")
 		return false
@@ -90,7 +100,6 @@ func (n *Node) verifyData(data []byte, signature []byte, peerId peer.ID, pubKeyD
 	}
 
 	res, err := key.Verify(data, signature)
-
 	if err != nil {
 		log.Println(err, "Error authenticating data")
 		return false
@@ -98,3 +107,23 @@ func (n *Node) verifyData(data []byte, signature []byte, peerId peer.ID, pubKeyD
 
 	return res
 }
+
+// helper method - generate message data shared between all node's p2p protocols
+// messageId: unique for requests, copied from request for responses
+func (n *Node) NewMessageData(messageId string, gossip bool) *p2p.MessageData {
+
+	// Add protobufs bin data for message author public key
+	// this is useful for authenticating  messages forwarded by a node authored by another node
+	nodePubKey, err := n.Peerstore().PubKey(n.ID()).Bytes()
+
+	if err != nil {
+		panic("Failed to get public key for sender from local peer store.")
+	}
+
+	return &p2p.MessageData{ClientVersion: clientVersion,
+		NodeId:     peer.IDB58Encode(n.ID()),
+		NodePubKey: nodePubKey,
+		Timestamp:  time.Now().Unix(),
+		Id:         messageId,
+		Gossip:     gossip}
+}

examples/multipro/ping.go

@@ -56,7 +56,7 @@ func (p *PingProtocol) onPingRequest(s inet.Stream) {
 	// generate response message
 	log.Printf("%s: Sending ping response to %s. Message id: %s...", s.Conn().LocalPeer(), s.Conn().RemotePeer(), data.MessageData.Id)
 
-	resp := &p2p.PingResponse{MessageData: NewMessageData(p.node, data.MessageData.Id, false),
+	resp := &p2p.PingResponse{MessageData: p.node.NewMessageData(data.MessageData.Id, false),
 		Message: fmt.Sprintf("Ping response from %s", p.node.ID())}
 
 	// sign the data
@@ -117,7 +117,7 @@ func (p *PingProtocol) Ping(host host.Host) bool {
 	log.Printf("%s: Sending ping to: %s....", p.node.ID(), host.ID())
 
 	// create message data
-	req := &p2p.PingRequest{MessageData: NewMessageData(p.node, uuid.New().String(), false),
+	req := &p2p.PingRequest{MessageData: p.node.NewMessageData(uuid.New().String(), false),
 		Message: fmt.Sprintf("Ping from %s", p.node.ID())}
 
 	// sign the data

examples/multipro/protocol.go

@@ -2,13 +2,10 @@ package main
 
 import (
 	"bufio"
-	p2p "github.com/avive/go-libp2p/examples/multipro/pb"
 	"github.com/gogo/protobuf/proto"
 	protobufCodec "github.com/multiformats/go-multicodec/protobuf"
-	"gx/ipfs/QmXYjuNuxVzXKJCfWasQk1RqkhVLDM9jtUKhqc2WPQmFSB/go-libp2p-peer"
 	inet "gx/ipfs/QmbD5yKbXahNvoMqzeuNyKQA9vAs9fUvJg2GXeWU1fVqY5/go-libp2p-net"
 	"log"
-	"time"
 )
 
 // node version
@@ -28,23 +25,3 @@ func sendProtoMessage(data proto.Message, s inet.Stream) bool {
 	writer.Flush()
 	return true
 }
-
-// helper method - generate message data shared between all node's p2p protocols
-// messageId - unique for requests, copied from request for responses
-func NewMessageData(node *Node, messageId string, gossip bool) *p2p.MessageData {
-
-	// Add protobufs bin data for message author public key
-	// this is useful for authenticating  messages forwarded by a node authored by another node
-	nodePubKey, err := node.Peerstore().PubKey(node.ID()).Bytes()
-
-	if err != nil {
-		panic("Failed to get public key for sender from local peer store.")
-	}
-
-	return &p2p.MessageData{ClientVersion: clientVersion,
-		NodeId:     peer.IDB58Encode(node.ID()),
-		NodePubKey: nodePubKey,
-		Timestamp:  time.Now().Unix(),
-		Id:         messageId,
-		Gossip:     gossip}
-}