p2p: move rlpx into separate package (#21464)

This change moves the RLPx protocol implementation into a separate package,
p2p/rlpx. The new package can be used to establish RLPx connections for
protocol testing purposes.
Co-authored-by: Felix Lange <fjl@twurst.com>

cmd/devp2p/main.go

@@ -63,6 +63,7 @@ func init() {
 		discv5Command,
 		dnsCommand,
 		nodesetCommand,
+		rlpxCommand,
 	}
 }
 

cmd/devp2p/rlpxcmd.go

+// Copyright 2020 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/rlpx"
+	"github.com/ethereum/go-ethereum/rlp"
+	"gopkg.in/urfave/cli.v1"
+)
+
+var (
+	rlpxCommand = cli.Command{
+		Name:  "rlpx",
+		Usage: "RLPx Commands",
+		Subcommands: []cli.Command{
+			rlpxPingCommand,
+		},
+	}
+	rlpxPingCommand = cli.Command{
+		Name:      "ping",
+		Usage:     "Perform a RLPx handshake",
+		ArgsUsage: "<node>",
+		Action:    rlpxPing,
+	}
+)
+
+func rlpxPing(ctx *cli.Context) error {
+	n := getNodeArg(ctx)
+
+	fd, err := net.Dial("tcp", fmt.Sprintf("%v:%d", n.IP(), n.TCP()))
+	if err != nil {
+		return err
+	}
+	conn := rlpx.NewConn(fd, n.Pubkey())
+
+	ourKey, _ := crypto.GenerateKey()
+	_, err = conn.Handshake(ourKey)
+	if err != nil {
+		return err
+	}
+
+	code, data, _, err := conn.Read()
+	if err != nil {
+		return err
+	}
+	switch code {
+	case 0:
+		var h devp2pHandshake
+		if err := rlp.DecodeBytes(data, &h); err != nil {
+			return fmt.Errorf("invalid handshake: %v", err)
+		}
+		fmt.Printf("%+v\n", h)
+	case 1:
+		var msg []p2p.DiscReason
+		if rlp.DecodeBytes(data, &msg); len(msg) == 0 {
+			return fmt.Errorf("invalid disconnect message")
+		}
+		return fmt.Errorf("received disconnect message: %v", msg[0])
+	default:
+		return fmt.Errorf("invalid message code %d, expected handshake (code zero)", code)
+	}
+	return nil
+}
+
+// devp2pHandshake is the RLP structure of the devp2p protocol handshake.
+type devp2pHandshake struct {
+	Version    uint64
+	Name       string
+	Caps       []p2p.Cap
+	ListenPort uint64
+	ID         hexutil.Bytes // secp256k1 public key
+	// Ignore additional fields (for forward compatibility).
+	Rest []rlp.RawValue `rlp:"tail"`
+}

p2p/message_test.go

@@ -18,11 +18,9 @@ package p2p
 
 import (
 	"bytes"
-	"encoding/hex"
 	"fmt"
 	"io"
 	"runtime"
-	"strings"
 	"testing"
 	"time"
 )
@@ -141,12 +139,3 @@ func TestEOFSignal(t *testing.T) {
 	default:
 	}
 }
-
-func unhex(str string) []byte {
-	r := strings.NewReplacer("\t", "", " ", "", "\n", "")
-	b, err := hex.DecodeString(r.Replace(str))
-	if err != nil {
-		panic(fmt.Sprintf("invalid hex string: %q", str))
-	}
-	return b
-}

p2p/peer_test.go

@@ -86,9 +86,15 @@ func newNode(id enode.ID, addr string) *enode.Node {
 }
 
 func testPeer(protos []Protocol) (func(), *conn, *Peer, <-chan error) {
-	fd1, fd2 := net.Pipe()
-	c1 := &conn{fd: fd1, node: newNode(randomID(), ""), transport: newTestTransport(&newkey().PublicKey, fd1)}
-	c2 := &conn{fd: fd2, node: newNode(randomID(), ""), transport: newTestTransport(&newkey().PublicKey, fd2)}
+	var (
+		fd1, fd2   = net.Pipe()
+		key1, key2 = newkey(), newkey()
+		t1         = newTestTransport(&key2.PublicKey, fd1, nil)
+		t2         = newTestTransport(&key1.PublicKey, fd2, &key1.PublicKey)
+	)
+
+	c1 := &conn{fd: fd1, node: newNode(uintID(1), ""), transport: t1}
+	c2 := &conn{fd: fd2, node: newNode(uintID(2), ""), transport: t2}
 	for _, p := range protos {
 		c1.caps = append(c1.caps, p.cap())
 		c2.caps = append(c2.caps, p.cap())
@@ -173,9 +179,12 @@ func TestPeerPing(t *testing.T) {
 	}
 }
 
+// This test checks that a disconnect message sent by a peer is returned
+// as the error from Peer.run.
 func TestPeerDisconnect(t *testing.T) {
 	closer, rw, _, disc := testPeer(nil)
 	defer closer()
+
 	if err := SendItems(rw, discMsg, DiscQuitting); err != nil {
 		t.Fatal(err)
 	}

p2p/server.go

@@ -166,7 +166,7 @@ type Server struct {
 
 	// Hooks for testing. These are useful because we can inhibit
 	// the whole protocol stack.
-	newTransport func(net.Conn) transport
+	newTransport func(net.Conn, *ecdsa.PublicKey) transport
 	newPeerHook  func(*Peer)
 	listenFunc   func(network, addr string) (net.Listener, error)
 
@@ -231,7 +231,7 @@ type conn struct {
 
 type transport interface {
 	// The two handshakes.
-	doEncHandshake(prv *ecdsa.PrivateKey, dialDest *ecdsa.PublicKey) (*ecdsa.PublicKey, error)
+	doEncHandshake(prv *ecdsa.PrivateKey) (*ecdsa.PublicKey, error)
 	doProtoHandshake(our *protoHandshake) (*protoHandshake, error)
 	// The MsgReadWriter can only be used after the encryption
 	// handshake has completed. The code uses conn.id to track this
@@ -914,7 +914,13 @@ func (srv *Server) checkInboundConn(fd net.Conn, remoteIP net.IP) error {
 // as a peer. It returns when the connection has been added as a peer
 // or the handshakes have failed.
 func (srv *Server) SetupConn(fd net.Conn, flags connFlag, dialDest *enode.Node) error {
-	c := &conn{fd: fd, transport: srv.newTransport(fd), flags: flags, cont: make(chan error)}
+	c := &conn{fd: fd, flags: flags, cont: make(chan error)}
+	if dialDest == nil {
+		c.transport = srv.newTransport(fd, nil)
+	} else {
+		c.transport = srv.newTransport(fd, dialDest.Pubkey())
+	}
+
 	err := srv.setupConn(c, flags, dialDest)
 	if err != nil {
 		c.close(err)
@@ -943,16 +949,12 @@ func (srv *Server) setupConn(c *conn, flags connFlag, dialDest *enode.Node) erro
 	}
 
 	// Run the RLPx handshake.
-	remotePubkey, err := c.doEncHandshake(srv.PrivateKey, dialPubkey)
+	remotePubkey, err := c.doEncHandshake(srv.PrivateKey)
 	if err != nil {
 		srv.log.Trace("Failed RLPx handshake", "addr", c.fd.RemoteAddr(), "conn", c.flags, "err", err)
 		return err
 	}
 	if dialDest != nil {
-		// For dialed connections, check that the remote public key matches.
-		if dialPubkey.X.Cmp(remotePubkey.X) != 0 || dialPubkey.Y.Cmp(remotePubkey.Y) != 0 {
-			return DiscUnexpectedIdentity
-		}
 		c.node = dialDest
 	} else {
 		c.node = nodeFromConn(remotePubkey, c.fd)

p2p/server_test.go

@@ -18,6 +18,7 @@ package p2p
 
 import (
 	"crypto/ecdsa"
+	"crypto/sha256"
 	"errors"
 	"io"
 	"math/rand"
@@ -31,28 +32,27 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
-	"golang.org/x/crypto/sha3"
+	"github.com/ethereum/go-ethereum/p2p/rlpx"
 )
 
 type testTransport struct {
-	rpub *ecdsa.PublicKey
-	*rlpx
-
+	*rlpxTransport
+	rpub     *ecdsa.PublicKey
 	closeErr error
 }
 
-func newTestTransport(rpub *ecdsa.PublicKey, fd net.Conn) transport {
-	wrapped := newRLPX(fd).(*rlpx)
-	wrapped.rw = newRLPXFrameRW(fd, secrets{
-		MAC:        zero16,
-		AES:        zero16,
-		IngressMAC: sha3.NewLegacyKeccak256(),
-		EgressMAC:  sha3.NewLegacyKeccak256(),
+func newTestTransport(rpub *ecdsa.PublicKey, fd net.Conn, dialDest *ecdsa.PublicKey) transport {
+	wrapped := newRLPX(fd, dialDest).(*rlpxTransport)
+	wrapped.conn.InitWithSecrets(rlpx.Secrets{
+		AES:        make([]byte, 16),
+		MAC:        make([]byte, 16),
+		EgressMAC:  sha256.New(),
+		IngressMAC: sha256.New(),
 	})
-	return &testTransport{rpub: rpub, rlpx: wrapped}
+	return &testTransport{rpub: rpub, rlpxTransport: wrapped}
 }
 
-func (c *testTransport) doEncHandshake(prv *ecdsa.PrivateKey, dialDest *ecdsa.PublicKey) (*ecdsa.PublicKey, error) {
+func (c *testTransport) doEncHandshake(prv *ecdsa.PrivateKey) (*ecdsa.PublicKey, error) {
 	return c.rpub, nil
 }
 
@@ -62,7 +62,7 @@ func (c *testTransport) doProtoHandshake(our *protoHandshake) (*protoHandshake,
 }
 
 func (c *testTransport) close(err error) {
-	c.rlpx.fd.Close()
+	c.conn.Close()
 	c.closeErr = err
 }
 
@@ -76,9 +76,11 @@ func startTestServer(t *testing.T, remoteKey *ecdsa.PublicKey, pf func(*Peer)) *
 		Logger:      testlog.Logger(t, log.LvlTrace),
 	}
 	server := &Server{
-		Config:       config,
-		newPeerHook:  pf,
-		newTransport: func(fd net.Conn) transport { return newTestTransport(remoteKey, fd) },
+		Config:      config,
+		newPeerHook: pf,
+		newTransport: func(fd net.Conn, dialDest *ecdsa.PublicKey) transport {
+			return newTestTransport(remoteKey, fd, dialDest)
+		},
 	}
 	if err := server.Start(); err != nil {
 		t.Fatalf("Could not start server: %v", err)
@@ -253,7 +255,7 @@ func TestServerAtCap(t *testing.T) {
 
 	newconn := func(id enode.ID) *conn {
 		fd, _ := net.Pipe()
-		tx := newTestTransport(&trustedNode.PublicKey, fd)
+		tx := newTestTransport(&trustedNode.PublicKey, fd, nil)
 		node := enode.SignNull(new(enr.Record), id)
 		return &conn{fd: fd, transport: tx, flags: inboundConn, node: node, cont: make(chan error)}
 	}
@@ -321,7 +323,7 @@ func TestServerPeerLimits(t *testing.T) {
 			Protocols:   []Protocol{discard},
 			Logger:      testlog.Logger(t, log.LvlTrace),
 		},
-		newTransport: func(fd net.Conn) transport { return tp },
+		newTransport: func(fd net.Conn, dialDest *ecdsa.PublicKey) transport { return tp },
 	}
 	if err := srv.Start(); err != nil {
 		t.Fatalf("couldn't start server: %v", err)
@@ -390,13 +392,6 @@ func TestServerSetupConn(t *testing.T) {
 			wantCalls:    "doEncHandshake,close,",
 			wantCloseErr: errors.New("read error"),
 		},
-		{
-			tt:           &setupTransport{pubkey: clientpub},
-			dialDest:     enode.NewV4(&newkey().PublicKey, nil, 0, 0),
-			flags:        dynDialedConn,
-			wantCalls:    "doEncHandshake,close,",
-			wantCloseErr: DiscUnexpectedIdentity,
-		},
 		{
 			tt:           &setupTransport{pubkey: clientpub, phs: protoHandshake{ID: randomID().Bytes()}},
 			dialDest:     enode.NewV4(clientpub, nil, 0, 0),
@@ -437,7 +432,7 @@ func TestServerSetupConn(t *testing.T) {
 			}
 			srv := &Server{
 				Config:       cfg,
-				newTransport: func(fd net.Conn) transport { return test.tt },
+				newTransport: func(fd net.Conn, dialDest *ecdsa.PublicKey) transport { return test.tt },
 				log:          cfg.Logger,
 			}
 			if !test.dontstart {
@@ -468,7 +463,7 @@ type setupTransport struct {
 	closeErr error
 }
 
-func (c *setupTransport) doEncHandshake(prv *ecdsa.PrivateKey, dialDest *ecdsa.PublicKey) (*ecdsa.PublicKey, error) {
+func (c *setupTransport) doEncHandshake(prv *ecdsa.PrivateKey) (*ecdsa.PublicKey, error) {
 	c.calls += "doEncHandshake,"
 	return c.pubkey, c.encHandshakeErr
 }
@@ -522,9 +517,9 @@ func TestServerInboundThrottle(t *testing.T) {
 			Protocols:   []Protocol{discard},
 			Logger:      testlog.Logger(t, log.LvlTrace),
 		},
-		newTransport: func(fd net.Conn) transport {
+		newTransport: func(fd net.Conn, dialDest *ecdsa.PublicKey) transport {
 			newTransportCalled <- struct{}{}
-			return newRLPX(fd)
+			return newRLPX(fd, dialDest)
 		},
 		listenFunc: func(network, laddr string) (net.Listener, error) {
 			fakeAddr := &net.TCPAddr{IP: net.IP{95, 33, 21, 2}, Port: 4444}

p2p/transport.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package p2p
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"fmt"
+	"io"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common/bitutil"
+	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethereum/go-ethereum/p2p/rlpx"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+const (
+	// total timeout for encryption handshake and protocol
+	// handshake in both directions.
+	handshakeTimeout = 5 * time.Second
+
+	// This is the timeout for sending the disconnect reason.
+	// This is shorter than the usual timeout because we don't want
+	// to wait if the connection is known to be bad anyway.
+	discWriteTimeout = 1 * time.Second
+)
+
+// rlpxTransport is the transport used by actual (non-test) connections.
+// It wraps an RLPx connection with locks and read/write deadlines.
+type rlpxTransport struct {
+	rmu, wmu sync.Mutex
+	wbuf     bytes.Buffer
+	conn     *rlpx.Conn
+}
+
+func newRLPX(conn net.Conn, dialDest *ecdsa.PublicKey) transport {
+	return &rlpxTransport{conn: rlpx.NewConn(conn, dialDest)}
+}
+
+func (t *rlpxTransport) ReadMsg() (Msg, error) {
+	t.rmu.Lock()
+	defer t.rmu.Unlock()
+
+	var msg Msg
+	t.conn.SetReadDeadline(time.Now().Add(frameReadTimeout))
+	code, data, wireSize, err := t.conn.Read()
+	if err == nil {
+		msg = Msg{
+			ReceivedAt: time.Now(),
+			Code:       code,
+			Size:       uint32(len(data)),
+			meterSize:  uint32(wireSize),
+			Payload:    bytes.NewReader(data),
+		}
+	}
+	return msg, err
+}
+
+func (t *rlpxTransport) WriteMsg(msg Msg) error {
+	t.wmu.Lock()
+	defer t.wmu.Unlock()
+
+	// Copy message data to write buffer.
+	t.wbuf.Reset()
+	if _, err := io.CopyN(&t.wbuf, msg.Payload, int64(msg.Size)); err != nil {
+		return err
+	}
+
+	// Write the message.
+	t.conn.SetWriteDeadline(time.Now().Add(frameWriteTimeout))
+	size, err := t.conn.Write(msg.Code, t.wbuf.Bytes())
+	if err != nil {
+		return err
+	}
+
+	// Set metrics.
+	msg.meterSize = size
+	if metrics.Enabled && msg.meterCap.Name != "" { // don't meter non-subprotocol messages
+		m := fmt.Sprintf("%s/%s/%d/%#02x", egressMeterName, msg.meterCap.Name, msg.meterCap.Version, msg.meterCode)
+		metrics.GetOrRegisterMeter(m, nil).Mark(int64(msg.meterSize))
+		metrics.GetOrRegisterMeter(m+"/packets", nil).Mark(1)
+	}
+	return nil
+}
+
+func (t *rlpxTransport) close(err error) {
+	t.wmu.Lock()
+	defer t.wmu.Unlock()
+
+	// Tell the remote end why we're disconnecting if possible.
+	// We only bother doing this if the underlying connection supports
+	// setting a timeout tough.
+	if t.conn != nil {
+		if r, ok := err.(DiscReason); ok && r != DiscNetworkError {
+			deadline := time.Now().Add(discWriteTimeout)
+			if err := t.conn.SetWriteDeadline(deadline); err == nil {
+				// Connection supports write deadline.
+				t.wbuf.Reset()
+				rlp.Encode(&t.wbuf, []DiscReason{r})
+				t.conn.Write(discMsg, t.wbuf.Bytes())
+			}
+		}
+	}
+	t.conn.Close()
+}
+
+func (t *rlpxTransport) doEncHandshake(prv *ecdsa.PrivateKey) (*ecdsa.PublicKey, error) {
+	t.conn.SetDeadline(time.Now().Add(handshakeTimeout))
+	return t.conn.Handshake(prv)
+}
+
+func (t *rlpxTransport) doProtoHandshake(our *protoHandshake) (their *protoHandshake, err error) {
+	// Writing our handshake happens concurrently, we prefer
+	// returning the handshake read error. If the remote side
+	// disconnects us early with a valid reason, we should return it
+	// as the error so it can be tracked elsewhere.
+	werr := make(chan error, 1)
+	go func() { werr <- Send(t, handshakeMsg, our) }()
+	if their, err = readProtocolHandshake(t); err != nil {
+		<-werr // make sure the write terminates too
+		return nil, err
+	}
+	if err := <-werr; err != nil {
+		return nil, fmt.Errorf("write error: %v", err)
+	}
+	// If the protocol version supports Snappy encoding, upgrade immediately
+	t.conn.SetSnappy(their.Version >= snappyProtocolVersion)
+
+	return their, nil
+}
+
+func readProtocolHandshake(rw MsgReader) (*protoHandshake, error) {
+	msg, err := rw.ReadMsg()
+	if err != nil {
+		return nil, err
+	}
+	if msg.Size > baseProtocolMaxMsgSize {
+		return nil, fmt.Errorf("message too big")
+	}
+	if msg.Code == discMsg {
+		// Disconnect before protocol handshake is valid according to the
+		// spec and we send it ourself if the post-handshake checks fail.
+		// We can't return the reason directly, though, because it is echoed
+		// back otherwise. Wrap it in a string instead.
+		var reason [1]DiscReason
+		rlp.Decode(msg.Payload, &reason)
+		return nil, reason[0]
+	}
+	if msg.Code != handshakeMsg {
+		return nil, fmt.Errorf("expected handshake, got %x", msg.Code)
+	}
+	var hs protoHandshake
+	if err := msg.Decode(&hs); err != nil {
+		return nil, err
+	}
+	if len(hs.ID) != 64 || !bitutil.TestBytes(hs.ID) {
+		return nil, DiscInvalidIdentity
+	}
+	return &hs, nil
+}

p2p/transport_test.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package p2p
+
+import (
+	"errors"
+	"reflect"
+	"sync"
+	"testing"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/p2p/simulations/pipes"
+)
+
+func TestProtocolHandshake(t *testing.T) {
+	var (
+		prv0, _ = crypto.GenerateKey()
+		pub0    = crypto.FromECDSAPub(&prv0.PublicKey)[1:]
+		hs0     = &protoHandshake{Version: 3, ID: pub0, Caps: []Cap{{"a", 0}, {"b", 2}}}
+
+		prv1, _ = crypto.GenerateKey()
+		pub1    = crypto.FromECDSAPub(&prv1.PublicKey)[1:]
+		hs1     = &protoHandshake{Version: 3, ID: pub1, Caps: []Cap{{"c", 1}, {"d", 3}}}
+
+		wg sync.WaitGroup
+	)
+
+	fd0, fd1, err := pipes.TCPPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		defer fd0.Close()
+		frame := newRLPX(fd0, &prv1.PublicKey)
+		rpubkey, err := frame.doEncHandshake(prv0)
+		if err != nil {
+			t.Errorf("dial side enc handshake failed: %v", err)
+			return
+		}
+		if !reflect.DeepEqual(rpubkey, &prv1.PublicKey) {
+			t.Errorf("dial side remote pubkey mismatch: got %v, want %v", rpubkey, &prv1.PublicKey)
+			return
+		}
+
+		phs, err := frame.doProtoHandshake(hs0)
+		if err != nil {
+			t.Errorf("dial side proto handshake error: %v", err)
+			return
+		}
+		phs.Rest = nil
+		if !reflect.DeepEqual(phs, hs1) {
+			t.Errorf("dial side proto handshake mismatch:\ngot: %s\nwant: %s\n", spew.Sdump(phs), spew.Sdump(hs1))
+			return
+		}
+		frame.close(DiscQuitting)
+	}()
+	go func() {
+		defer wg.Done()
+		defer fd1.Close()
+		rlpx := newRLPX(fd1, nil)
+		rpubkey, err := rlpx.doEncHandshake(prv1)
+		if err != nil {
+			t.Errorf("listen side enc handshake failed: %v", err)
+			return
+		}
+		if !reflect.DeepEqual(rpubkey, &prv0.PublicKey) {
+			t.Errorf("listen side remote pubkey mismatch: got %v, want %v", rpubkey, &prv0.PublicKey)
+			return
+		}
+
+		phs, err := rlpx.doProtoHandshake(hs1)
+		if err != nil {
+			t.Errorf("listen side proto handshake error: %v", err)
+			return
+		}
+		phs.Rest = nil
+		if !reflect.DeepEqual(phs, hs0) {
+			t.Errorf("listen side proto handshake mismatch:\ngot: %s\nwant: %s\n", spew.Sdump(phs), spew.Sdump(hs0))
+			return
+		}
+
+		if err := ExpectMsg(rlpx, discMsg, []DiscReason{DiscQuitting}); err != nil {
+			t.Errorf("error receiving disconnect: %v", err)
+		}
+	}()
+	wg.Wait()
+}
+
+func TestProtocolHandshakeErrors(t *testing.T) {
+	tests := []struct {
+		code uint64
+		msg  interface{}
+		err  error
+	}{
+		{
+			code: discMsg,
+			msg:  []DiscReason{DiscQuitting},
+			err:  DiscQuitting,
+		},
+		{
+			code: 0x989898,
+			msg:  []byte{1},
+			err:  errors.New("expected handshake, got 989898"),
+		},
+		{
+			code: handshakeMsg,
+			msg:  make([]byte, baseProtocolMaxMsgSize+2),
+			err:  errors.New("message too big"),
+		},
+		{
+			code: handshakeMsg,
+			msg:  []byte{1, 2, 3},
+			err:  newPeerError(errInvalidMsg, "(code 0) (size 4) rlp: expected input list for p2p.protoHandshake"),
+		},
+		{
+			code: handshakeMsg,
+			msg:  &protoHandshake{Version: 3},
+			err:  DiscInvalidIdentity,
+		},
+	}
+
+	for i, test := range tests {
+		p1, p2 := MsgPipe()
+		go Send(p1, test.code, test.msg)
+		_, err := readProtocolHandshake(p2)
+		if !reflect.DeepEqual(err, test.err) {
+			t.Errorf("test %d: error mismatch: got %q, want %q", i, err, test.err)
+		}
+	}
+}