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p2p: move rlpx into separate package (#21464)

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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>
This commit is contained in:
rene 2020-09-22 10:17:39 +02:00 committed by GitHub
parent 2c097bb7a2
commit 129cf075e9
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
10 changed files with 962 additions and 803 deletions
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1
cmd/devp2p/main.go
View File

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

94
cmd/devp2p/rlpxcmd.go Normal file
View File

@ -0,0 +1,94 @@
// 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"`
}

11
p2p/message_test.go
View File

@ -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
}

15
p2p/peer_test.go
View File

@ -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)
}

836
p2p/rlpx.go → p2p/rlpx/rlpx.go
View File

@ -14,7 +14,8 @@
// 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
// Package rlpx implements the RLPx transport protocol.
package rlpx
import (
"bytes"
@ -29,23 +30,280 @@ import (
"fmt"
"hash"
"io"
"io/ioutil"
mrand "math/rand"
"net"
"sync"
"time"
"github.com/ethereum/go-ethereum/common/bitutil"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/ecies"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/rlp"
"github.com/golang/snappy"
"golang.org/x/crypto/sha3"
)
// Conn is an RLPx network connection. It wraps a low-level network connection. The
// underlying connection should not be used for other activity when it is wrapped by Conn.
//
// Before sending messages, a handshake must be performed by calling the Handshake method.
// This type is not generally safe for concurrent use, but reading and writing of messages
// may happen concurrently after the handshake.
type Conn struct {
dialDest *ecdsa.PublicKey
conn net.Conn
handshake *handshakeState
snappy bool
}
type handshakeState struct {
enc cipher.Stream
dec cipher.Stream
macCipher cipher.Block
egressMAC hash.Hash
ingressMAC hash.Hash
}
// NewConn wraps the given network connection. If dialDest is non-nil, the connection
// behaves as the initiator during the handshake.
func NewConn(conn net.Conn, dialDest *ecdsa.PublicKey) *Conn {
return &Conn{
dialDest: dialDest,
conn: conn,
}
}
// SetSnappy enables or disables snappy compression of messages. This is usually called
// after the devp2p Hello message exchange when the negotiated version indicates that
// compression is available on both ends of the connection.
func (c *Conn) SetSnappy(snappy bool) {
c.snappy = snappy
}
// SetReadDeadline sets the deadline for all future read operations.
func (c *Conn) SetReadDeadline(time time.Time) error {
return c.conn.SetReadDeadline(time)
}
// SetWriteDeadline sets the deadline for all future write operations.
func (c *Conn) SetWriteDeadline(time time.Time) error {
return c.conn.SetWriteDeadline(time)
}
// SetDeadline sets the deadline for all future read and write operations.
func (c *Conn) SetDeadline(time time.Time) error {
return c.conn.SetDeadline(time)
}
// Read reads a message from the connection.
func (c *Conn) Read() (code uint64, data []byte, wireSize int, err error) {
if c.handshake == nil {
panic("can't ReadMsg before handshake")
}
frame, err := c.handshake.readFrame(c.conn)
if err != nil {
return 0, nil, 0, err
}
code, data, err = rlp.SplitUint64(frame)
if err != nil {
return 0, nil, 0, fmt.Errorf("invalid message code: %v", err)
}
wireSize = len(data)
// If snappy is enabled, verify and decompress message.
if c.snappy {
var actualSize int
actualSize, err = snappy.DecodedLen(data)
if err != nil {
return code, nil, 0, err
}
if actualSize > maxUint24 {
return code, nil, 0, errPlainMessageTooLarge
}
data, err = snappy.Decode(nil, data)
}
return code, data, wireSize, err
}
func (h *handshakeState) readFrame(conn io.Reader) ([]byte, error) {
// read the header
headbuf := make([]byte, 32)
if _, err := io.ReadFull(conn, headbuf); err != nil {
return nil, err
}
// verify header mac
shouldMAC := updateMAC(h.ingressMAC, h.macCipher, headbuf[:16])
if !hmac.Equal(shouldMAC, headbuf[16:]) {
return nil, errors.New("bad header MAC")
}
h.dec.XORKeyStream(headbuf[:16], headbuf[:16]) // first half is now decrypted
fsize := readInt24(headbuf)
// ignore protocol type for now
// read the frame content
var rsize = fsize // frame size rounded up to 16 byte boundary
if padding := fsize % 16; padding > 0 {
rsize += 16 - padding
}
framebuf := make([]byte, rsize)
if _, err := io.ReadFull(conn, framebuf); err != nil {
return nil, err
}
// read and validate frame MAC. we can re-use headbuf for that.
h.ingressMAC.Write(framebuf)
fmacseed := h.ingressMAC.Sum(nil)
if _, err := io.ReadFull(conn, headbuf[:16]); err != nil {
return nil, err
}
shouldMAC = updateMAC(h.ingressMAC, h.macCipher, fmacseed)
if !hmac.Equal(shouldMAC, headbuf[:16]) {
return nil, errors.New("bad frame MAC")
}
// decrypt frame content
h.dec.XORKeyStream(framebuf, framebuf)
return framebuf[:fsize], nil
}
// Write writes a message to the connection.
//
// Write returns the written size of the message data. This may be less than or equal to
// len(data) depending on whether snappy compression is enabled.
func (c *Conn) Write(code uint64, data []byte) (uint32, error) {
if c.handshake == nil {
panic("can't WriteMsg before handshake")
}
if len(data) > maxUint24 {
return 0, errPlainMessageTooLarge
}
if c.snappy {
data = snappy.Encode(nil, data)
}
wireSize := uint32(len(data))
err := c.handshake.writeFrame(c.conn, code, data)
return wireSize, err
}
func (h *handshakeState) writeFrame(conn io.Writer, code uint64, data []byte) error {
ptype, _ := rlp.EncodeToBytes(code)
// write header
headbuf := make([]byte, 32)
fsize := len(ptype) + len(data)
if fsize > maxUint24 {
return errPlainMessageTooLarge
}
putInt24(uint32(fsize), headbuf)
copy(headbuf[3:], zeroHeader)
h.enc.XORKeyStream(headbuf[:16], headbuf[:16]) // first half is now encrypted
// write header MAC
copy(headbuf[16:], updateMAC(h.egressMAC, h.macCipher, headbuf[:16]))
if _, err := conn.Write(headbuf); err != nil {
return err
}
// write encrypted frame, updating the egress MAC hash with
// the data written to conn.
tee := cipher.StreamWriter{S: h.enc, W: io.MultiWriter(conn, h.egressMAC)}
if _, err := tee.Write(ptype); err != nil {
return err
}
if _, err := tee.Write(data); err != nil {
return err
}
if padding := fsize % 16; padding > 0 {
if _, err := tee.Write(zero16[:16-padding]); err != nil {
return err
}
}
// write frame MAC. egress MAC hash is up to date because
// frame content was written to it as well.
fmacseed := h.egressMAC.Sum(nil)
mac := updateMAC(h.egressMAC, h.macCipher, fmacseed)
_, err := conn.Write(mac)
return err
}
func readInt24(b []byte) uint32 {
return uint32(b[2]) | uint32(b[1])<<8 | uint32(b[0])<<16
}
func putInt24(v uint32, b []byte) {
b[0] = byte(v >> 16)
b[1] = byte(v >> 8)
b[2] = byte(v)
}
// updateMAC reseeds the given hash with encrypted seed.
// it returns the first 16 bytes of the hash sum after seeding.
func updateMAC(mac hash.Hash, block cipher.Block, seed []byte) []byte {
aesbuf := make([]byte, aes.BlockSize)
block.Encrypt(aesbuf, mac.Sum(nil))
for i := range aesbuf {
aesbuf[i] ^= seed[i]
}
mac.Write(aesbuf)
return mac.Sum(nil)[:16]
}
// Handshake performs the handshake. This must be called before any data is written
// or read from the connection.
func (c *Conn) Handshake(prv *ecdsa.PrivateKey) (*ecdsa.PublicKey, error) {
var (
sec Secrets
err error
)
if c.dialDest != nil {
sec, err = initiatorEncHandshake(c.conn, prv, c.dialDest)
} else {
sec, err = receiverEncHandshake(c.conn, prv)
}
if err != nil {
return nil, err
}
c.InitWithSecrets(sec)
return sec.remote, err
}
// InitWithSecrets injects connection secrets as if a handshake had
// been performed. This cannot be called after the handshake.
func (c *Conn) InitWithSecrets(sec Secrets) {
if c.handshake != nil {
panic("can't handshake twice")
}
macc, err := aes.NewCipher(sec.MAC)
if err != nil {
panic("invalid MAC secret: " + err.Error())
}
encc, err := aes.NewCipher(sec.AES)
if err != nil {
panic("invalid AES secret: " + err.Error())
}
// we use an all-zeroes IV for AES because the key used
// for encryption is ephemeral.
iv := make([]byte, encc.BlockSize())
c.handshake = &handshakeState{
enc: cipher.NewCTR(encc, iv),
dec: cipher.NewCTR(encc, iv),
macCipher: macc,
egressMAC: sec.EgressMAC,
ingressMAC: sec.IngressMAC,
}
}
// Close closes the underlying network connection.
func (c *Conn) Close() error {
return c.conn.Close()
}
// Constants for the handshake.
const (
maxUint24 = ^uint32(0) >> 8
maxUint24 = int(^uint32(0) >> 8)
sskLen = 16 // ecies.MaxSharedKeyLength(pubKey) / 2
sigLen = crypto.SignatureLength // elliptic S256
@ -59,139 +317,25 @@ const (
encAuthMsgLen = authMsgLen + eciesOverhead // size of encrypted pre-EIP-8 initiator handshake
encAuthRespLen = authRespLen + eciesOverhead // size of encrypted pre-EIP-8 handshake reply
// 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
)
var (
// this is used in place of actual frame header data.
// TODO: replace this when Msg contains the protocol type code.
zeroHeader = []byte{0xC2, 0x80, 0x80}
// sixteen zero bytes
zero16 = make([]byte, 16)
// errPlainMessageTooLarge is returned if a decompressed message length exceeds
// the allowed 24 bits (i.e. length >= 16MB).
var errPlainMessageTooLarge = errors.New("message length >= 16MB")
// rlpx is the transport protocol used by actual (non-test) connections.
// It wraps the frame encoder with locks and read/write deadlines.
type rlpx struct {
fd net.Conn
rmu, wmu sync.Mutex
rw *rlpxFrameRW
}
func newRLPX(fd net.Conn) transport {
fd.SetDeadline(time.Now().Add(handshakeTimeout))
return &rlpx{fd: fd}
}
func (t *rlpx) ReadMsg() (Msg, error) {
t.rmu.Lock()
defer t.rmu.Unlock()
t.fd.SetReadDeadline(time.Now().Add(frameReadTimeout))
return t.rw.ReadMsg()
}
func (t *rlpx) WriteMsg(msg Msg) error {
t.wmu.Lock()
defer t.wmu.Unlock()
t.fd.SetWriteDeadline(time.Now().Add(frameWriteTimeout))
return t.rw.WriteMsg(msg)
}
func (t *rlpx) close(err error) {
t.wmu.Lock()
defer t.wmu.Unlock()
// Tell the remote end why we're disconnecting if possible.
if t.rw != nil {
if r, ok := err.(DiscReason); ok && r != DiscNetworkError {
// rlpx tries to send DiscReason to disconnected peer
// if the connection is net.Pipe (in-memory simulation)
// it hangs forever, since net.Pipe does not implement
// a write deadline. Because of this only try to send
// the disconnect reason message if there is no error.
if err := t.fd.SetWriteDeadline(time.Now().Add(discWriteTimeout)); err == nil {
SendItems(t.rw, discMsg, r)
}
}
}
t.fd.Close()
}
func (t *rlpx) 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.rw, handshakeMsg, our) }()
if their, err = readProtocolHandshake(t.rw); 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.rw.snappy = 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
}
// doEncHandshake runs the protocol handshake using authenticated
// messages. the protocol handshake is the first authenticated message
// and also verifies whether the encryption handshake 'worked' and the
// remote side actually provided the right public key.
func (t *rlpx) doEncHandshake(prv *ecdsa.PrivateKey, dial *ecdsa.PublicKey) (*ecdsa.PublicKey, error) {
var (
sec secrets
err error
errPlainMessageTooLarge = errors.New("message length >= 16MB")
)
if dial == nil {
sec, err = receiverEncHandshake(t.fd, prv)
} else {
sec, err = initiatorEncHandshake(t.fd, prv, dial)
}
if err != nil {
return nil, err
}
t.wmu.Lock()
t.rw = newRLPXFrameRW(t.fd, sec)
t.wmu.Unlock()
return sec.Remote.ExportECDSA(), nil
// Secrets represents the connection secrets which are negotiated during the handshake.
type Secrets struct {
AES, MAC []byte
EgressMAC, IngressMAC hash.Hash
remote *ecdsa.PublicKey
}
// encHandshake contains the state of the encryption handshake.
@ -203,15 +347,6 @@ type encHandshake struct {
remoteRandomPub *ecies.PublicKey // ecdhe-random-pubk
}
// secrets represents the connection secrets
// which are negotiated during the encryption handshake.
type secrets struct {
Remote *ecies.PublicKey
AES, MAC []byte
EgressMAC, IngressMAC hash.Hash
Token []byte
}
// RLPx v4 handshake auth (defined in EIP-8).
type authMsgV4 struct {
gotPlain bool // whether read packet had plain format.
@ -235,118 +370,11 @@ type authRespV4 struct {
Rest []rlp.RawValue `rlp:"tail"`
}
// secrets is called after the handshake is completed.
// It extracts the connection secrets from the handshake values.
func (h *encHandshake) secrets(auth, authResp []byte) (secrets, error) {
ecdheSecret, err := h.randomPrivKey.GenerateShared(h.remoteRandomPub, sskLen, sskLen)
if err != nil {
return secrets{}, err
}
// derive base secrets from ephemeral key agreement
sharedSecret := crypto.Keccak256(ecdheSecret, crypto.Keccak256(h.respNonce, h.initNonce))
aesSecret := crypto.Keccak256(ecdheSecret, sharedSecret)
s := secrets{
Remote: h.remote,
AES: aesSecret,
MAC: crypto.Keccak256(ecdheSecret, aesSecret),
}
// setup sha3 instances for the MACs
mac1 := sha3.NewLegacyKeccak256()
mac1.Write(xor(s.MAC, h.respNonce))
mac1.Write(auth)
mac2 := sha3.NewLegacyKeccak256()
mac2.Write(xor(s.MAC, h.initNonce))
mac2.Write(authResp)
if h.initiator {
s.EgressMAC, s.IngressMAC = mac1, mac2
} else {
s.EgressMAC, s.IngressMAC = mac2, mac1
}
return s, nil
}
// staticSharedSecret returns the static shared secret, the result
// of key agreement between the local and remote static node key.
func (h *encHandshake) staticSharedSecret(prv *ecdsa.PrivateKey) ([]byte, error) {
return ecies.ImportECDSA(prv).GenerateShared(h.remote, sskLen, sskLen)
}
// initiatorEncHandshake negotiates a session token on conn.
// it should be called on the dialing side of the connection.
//
// prv is the local client's private key.
func initiatorEncHandshake(conn io.ReadWriter, prv *ecdsa.PrivateKey, remote *ecdsa.PublicKey) (s secrets, err error) {
h := &encHandshake{initiator: true, remote: ecies.ImportECDSAPublic(remote)}
authMsg, err := h.makeAuthMsg(prv)
if err != nil {
return s, err
}
authPacket, err := sealEIP8(authMsg, h)
if err != nil {
return s, err
}
if _, err = conn.Write(authPacket); err != nil {
return s, err
}
authRespMsg := new(authRespV4)
authRespPacket, err := readHandshakeMsg(authRespMsg, encAuthRespLen, prv, conn)
if err != nil {
return s, err
}
if err := h.handleAuthResp(authRespMsg); err != nil {
return s, err
}
return h.secrets(authPacket, authRespPacket)
}
// makeAuthMsg creates the initiator handshake message.
func (h *encHandshake) makeAuthMsg(prv *ecdsa.PrivateKey) (*authMsgV4, error) {
// Generate random initiator nonce.
h.initNonce = make([]byte, shaLen)
_, err := rand.Read(h.initNonce)
if err != nil {
return nil, err
}
// Generate random keypair to for ECDH.
h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, crypto.S256(), nil)
if err != nil {
return nil, err
}
// Sign known message: static-shared-secret ^ nonce
token, err := h.staticSharedSecret(prv)
if err != nil {
return nil, err
}
signed := xor(token, h.initNonce)
signature, err := crypto.Sign(signed, h.randomPrivKey.ExportECDSA())
if err != nil {
return nil, err
}
msg := new(authMsgV4)
copy(msg.Signature[:], signature)
copy(msg.InitiatorPubkey[:], crypto.FromECDSAPub(&prv.PublicKey)[1:])
copy(msg.Nonce[:], h.initNonce)
msg.Version = 4
return msg, nil
}
func (h *encHandshake) handleAuthResp(msg *authRespV4) (err error) {
h.respNonce = msg.Nonce[:]
h.remoteRandomPub, err = importPublicKey(msg.RandomPubkey[:])
return err
}
// receiverEncHandshake negotiates a session token on conn.
// it should be called on the listening side of the connection.
//
// prv is the local client's private key.
func receiverEncHandshake(conn io.ReadWriter, prv *ecdsa.PrivateKey) (s secrets, err error) {
func receiverEncHandshake(conn io.ReadWriter, prv *ecdsa.PrivateKey) (s Secrets, err error) {
authMsg := new(authMsgV4)
authPacket, err := readHandshakeMsg(authMsg, encAuthMsgLen, prv, conn)
if err != nil {
@ -408,6 +436,114 @@ func (h *encHandshake) handleAuthMsg(msg *authMsgV4, prv *ecdsa.PrivateKey) erro
return nil
}
// secrets is called after the handshake is completed.
// It extracts the connection secrets from the handshake values.
func (h *encHandshake) secrets(auth, authResp []byte) (Secrets, error) {
ecdheSecret, err := h.randomPrivKey.GenerateShared(h.remoteRandomPub, sskLen, sskLen)
if err != nil {
return Secrets{}, err
}
// derive base secrets from ephemeral key agreement
sharedSecret := crypto.Keccak256(ecdheSecret, crypto.Keccak256(h.respNonce, h.initNonce))
aesSecret := crypto.Keccak256(ecdheSecret, sharedSecret)
s := Secrets{
remote: h.remote.ExportECDSA(),
AES: aesSecret,
MAC: crypto.Keccak256(ecdheSecret, aesSecret),
}
// setup sha3 instances for the MACs
mac1 := sha3.NewLegacyKeccak256()
mac1.Write(xor(s.MAC, h.respNonce))
mac1.Write(auth)
mac2 := sha3.NewLegacyKeccak256()
mac2.Write(xor(s.MAC, h.initNonce))
mac2.Write(authResp)
if h.initiator {
s.EgressMAC, s.IngressMAC = mac1, mac2
} else {
s.EgressMAC, s.IngressMAC = mac2, mac1
}
return s, nil
}
// staticSharedSecret returns the static shared secret, the result
// of key agreement between the local and remote static node key.
func (h *encHandshake) staticSharedSecret(prv *ecdsa.PrivateKey) ([]byte, error) {
return ecies.ImportECDSA(prv).GenerateShared(h.remote, sskLen, sskLen)
}
// initiatorEncHandshake negotiates a session token on conn.
// it should be called on the dialing side of the connection.
//
// prv is the local client's private key.
func initiatorEncHandshake(conn io.ReadWriter, prv *ecdsa.PrivateKey, remote *ecdsa.PublicKey) (s Secrets, err error) {
h := &encHandshake{initiator: true, remote: ecies.ImportECDSAPublic(remote)}
authMsg, err := h.makeAuthMsg(prv)
if err != nil {
return s, err
}
authPacket, err := sealEIP8(authMsg, h)
if err != nil {
return s, err
}
if _, err = conn.Write(authPacket); err != nil {
return s, err
}
authRespMsg := new(authRespV4)
authRespPacket, err := readHandshakeMsg(authRespMsg, encAuthRespLen, prv, conn)
if err != nil {
return s, err
}
if err := h.handleAuthResp(authRespMsg); err != nil {
return s, err
}
return h.secrets(authPacket, authRespPacket)
}
// makeAuthMsg creates the initiator handshake message.
func (h *encHandshake) makeAuthMsg(prv *ecdsa.PrivateKey) (*authMsgV4, error) {
// Generate random initiator nonce.
h.initNonce = make([]byte, shaLen)
_, err := rand.Read(h.initNonce)
if err != nil {
return nil, err
}
// Generate random keypair to for ECDH.
h.randomPrivKey, err = ecies.GenerateKey(rand.Reader, crypto.S256(), nil)
if err != nil {
return nil, err
}
// Sign known message: static-shared-secret ^ nonce
token, err := h.staticSharedSecret(prv)
if err != nil {
return nil, err
}
signed := xor(token, h.initNonce)
signature, err := crypto.Sign(signed, h.randomPrivKey.ExportECDSA())
if err != nil {
return nil, err
}
msg := new(authMsgV4)
copy(msg.Signature[:], signature)
copy(msg.InitiatorPubkey[:], crypto.FromECDSAPub(&prv.PublicKey)[1:])
copy(msg.Nonce[:], h.initNonce)
msg.Version = 4
return msg, nil
}
func (h *encHandshake) handleAuthResp(msg *authRespV4) (err error) {
h.respNonce = msg.Nonce[:]
h.remoteRandomPub, err = importPublicKey(msg.RandomPubkey[:])
return err
}
func (h *encHandshake) makeAuthResp() (msg *authRespV4, err error) {
// Generate random nonce.
h.respNonce = make([]byte, shaLen)
@ -531,201 +667,3 @@ func xor(one, other []byte) (xor []byte) {
}
return xor
}
var (
// this is used in place of actual frame header data.
// TODO: replace this when Msg contains the protocol type code.
zeroHeader = []byte{0xC2, 0x80, 0x80}
// sixteen zero bytes
zero16 = make([]byte, 16)
)
// rlpxFrameRW implements a simplified version of RLPx framing.
// chunked messages are not supported and all headers are equal to
// zeroHeader.
//
// rlpxFrameRW is not safe for concurrent use from multiple goroutines.
type rlpxFrameRW struct {
conn io.ReadWriter
enc cipher.Stream
dec cipher.Stream
macCipher cipher.Block
egressMAC hash.Hash
ingressMAC hash.Hash
snappy bool
}
func newRLPXFrameRW(conn io.ReadWriter, s secrets) *rlpxFrameRW {
macc, err := aes.NewCipher(s.MAC)
if err != nil {
panic("invalid MAC secret: " + err.Error())
}
encc, err := aes.NewCipher(s.AES)
if err != nil {
panic("invalid AES secret: " + err.Error())
}
// we use an all-zeroes IV for AES because the key used
// for encryption is ephemeral.
iv := make([]byte, encc.BlockSize())
return &rlpxFrameRW{
conn: conn,
enc: cipher.NewCTR(encc, iv),
dec: cipher.NewCTR(encc, iv),
macCipher: macc,
egressMAC: s.EgressMAC,
ingressMAC: s.IngressMAC,
}
}
func (rw *rlpxFrameRW) WriteMsg(msg Msg) error {
ptype, _ := rlp.EncodeToBytes(msg.Code)
// if snappy is enabled, compress message now
if rw.snappy {
if msg.Size > maxUint24 {
return errPlainMessageTooLarge
}
payload, _ := ioutil.ReadAll(msg.Payload)
payload = snappy.Encode(nil, payload)
msg.Payload = bytes.NewReader(payload)
msg.Size = uint32(len(payload))
}
msg.meterSize = msg.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)
}
// write header
headbuf := make([]byte, 32)
fsize := uint32(len(ptype)) + msg.Size
if fsize > maxUint24 {
return errors.New("message size overflows uint24")
}
putInt24(fsize, headbuf) // TODO: check overflow
copy(headbuf[3:], zeroHeader)
rw.enc.XORKeyStream(headbuf[:16], headbuf[:16]) // first half is now encrypted
// write header MAC
copy(headbuf[16:], updateMAC(rw.egressMAC, rw.macCipher, headbuf[:16]))
if _, err := rw.conn.Write(headbuf); err != nil {
return err
}
// write encrypted frame, updating the egress MAC hash with
// the data written to conn.
tee := cipher.StreamWriter{S: rw.enc, W: io.MultiWriter(rw.conn, rw.egressMAC)}
if _, err := tee.Write(ptype); err != nil {
return err
}
if _, err := io.Copy(tee, msg.Payload); err != nil {
return err
}
if padding := fsize % 16; padding > 0 {
if _, err := tee.Write(zero16[:16-padding]); err != nil {
return err
}
}
// write frame MAC. egress MAC hash is up to date because
// frame content was written to it as well.
fmacseed := rw.egressMAC.Sum(nil)
mac := updateMAC(rw.egressMAC, rw.macCipher, fmacseed)
_, err := rw.conn.Write(mac)
return err
}
func (rw *rlpxFrameRW) ReadMsg() (msg Msg, err error) {
// read the header
headbuf := make([]byte, 32)
if _, err := io.ReadFull(rw.conn, headbuf); err != nil {
return msg, err
}
// verify header mac
shouldMAC := updateMAC(rw.ingressMAC, rw.macCipher, headbuf[:16])
if !hmac.Equal(shouldMAC, headbuf[16:]) {
return msg, errors.New("bad header MAC")
}
rw.dec.XORKeyStream(headbuf[:16], headbuf[:16]) // first half is now decrypted
fsize := readInt24(headbuf)
// ignore protocol type for now
// read the frame content
var rsize = fsize // frame size rounded up to 16 byte boundary
if padding := fsize % 16; padding > 0 {
rsize += 16 - padding
}
framebuf := make([]byte, rsize)
if _, err := io.ReadFull(rw.conn, framebuf); err != nil {
return msg, err
}
// read and validate frame MAC. we can re-use headbuf for that.
rw.ingressMAC.Write(framebuf)
fmacseed := rw.ingressMAC.Sum(nil)
if _, err := io.ReadFull(rw.conn, headbuf[:16]); err != nil {
return msg, err
}
shouldMAC = updateMAC(rw.ingressMAC, rw.macCipher, fmacseed)
if !hmac.Equal(shouldMAC, headbuf[:16]) {
return msg, errors.New("bad frame MAC")
}
// decrypt frame content
rw.dec.XORKeyStream(framebuf, framebuf)
// decode message code
content := bytes.NewReader(framebuf[:fsize])
if err := rlp.Decode(content, &msg.Code); err != nil {
return msg, err
}
msg.Size = uint32(content.Len())
msg.meterSize = msg.Size
msg.Payload = content
// if snappy is enabled, verify and decompress message
if rw.snappy {
payload, err := ioutil.ReadAll(msg.Payload)
if err != nil {
return msg, err
}
size, err := snappy.DecodedLen(payload)
if err != nil {
return msg, err
}
if size > int(maxUint24) {
return msg, errPlainMessageTooLarge
}
payload, err = snappy.Decode(nil, payload)
if err != nil {
return msg, err
}
msg.Size, msg.Payload = uint32(size), bytes.NewReader(payload)
}
return msg, nil
}
// updateMAC reseeds the given hash with encrypted seed.
// it returns the first 16 bytes of the hash sum after seeding.
func updateMAC(mac hash.Hash, block cipher.Block, seed []byte) []byte {
aesbuf := make([]byte, aes.BlockSize)
block.Encrypt(aesbuf, mac.Sum(nil))
for i := range aesbuf {
aesbuf[i] ^= seed[i]
}
mac.Write(aesbuf)
return mac.Sum(nil)[:16]
}
func readInt24(b []byte) uint32 {
return uint32(b[2]) | uint32(b[1])<<8 | uint32(b[0])<<16
}
func putInt24(v uint32, b []byte) {
b[0] = byte(v >> 16)
b[1] = byte(v >> 8)
b[2] = byte(v)
}

392
p2p/rlpx_test.go → p2p/rlpx/rlpx_test.go
View File

@ -1,4 +1,4 @@
// Copyright 2015 The go-ethereum Authors
// Copyright 2020 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
@ -14,265 +14,117 @@
// 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
package rlpx
import (
"bytes"
"crypto/ecdsa"
"crypto/rand"
"errors"
"encoding/hex"
"fmt"
"io"
"io/ioutil"
"net"
"reflect"
"strings"
"sync"
"testing"
"time"
"github.com/davecgh/go-spew/spew"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/ecies"
"github.com/ethereum/go-ethereum/p2p/simulations/pipes"
"github.com/ethereum/go-ethereum/rlp"
"golang.org/x/crypto/sha3"
"github.com/stretchr/testify/assert"
)
func TestSharedSecret(t *testing.T) {
prv0, _ := crypto.GenerateKey() // = ecdsa.GenerateKey(crypto.S256(), rand.Reader)
pub0 := &prv0.PublicKey
prv1, _ := crypto.GenerateKey()
pub1 := &prv1.PublicKey
ss0, err := ecies.ImportECDSA(prv0).GenerateShared(ecies.ImportECDSAPublic(pub1), sskLen, sskLen)
if err != nil {
return
}
ss1, err := ecies.ImportECDSA(prv1).GenerateShared(ecies.ImportECDSAPublic(pub0), sskLen, sskLen)
if err != nil {
return
}
t.Logf("Secret:\n%v %x\n%v %x", len(ss0), ss0, len(ss0), ss1)
if !bytes.Equal(ss0, ss1) {
t.Errorf("don't match :(")
}
}
func TestEncHandshake(t *testing.T) {
for i := 0; i < 10; i++ {
start := time.Now()
if err := testEncHandshake(nil); err != nil {
t.Fatalf("i=%d %v", i, err)
}
t.Logf("(without token) %d %v\n", i+1, time.Since(start))
}
for i := 0; i < 10; i++ {
tok := make([]byte, shaLen)
rand.Reader.Read(tok)
start := time.Now()
if err := testEncHandshake(tok); err != nil {
t.Fatalf("i=%d %v", i, err)
}
t.Logf("(with token) %d %v\n", i+1, time.Since(start))
}
}
func testEncHandshake(token []byte) error {
type result struct {
side string
pubkey *ecdsa.PublicKey
type message struct {
code uint64
data []byte
err error
}
var (
prv0, _ = crypto.GenerateKey()
prv1, _ = crypto.GenerateKey()
fd0, fd1 = net.Pipe()
c0, c1 = newRLPX(fd0).(*rlpx), newRLPX(fd1).(*rlpx)
output = make(chan result)
)
func TestHandshake(t *testing.T) {
p1, p2 := createPeers(t)
p1.Close()
p2.Close()
}
// This test checks that messages can be sent and received through WriteMsg/ReadMsg.
func TestReadWriteMsg(t *testing.T) {
peer1, peer2 := createPeers(t)
defer peer1.Close()
defer peer2.Close()
testCode := uint64(23)
testData := []byte("test")
checkMsgReadWrite(t, peer1, peer2, testCode, testData)
t.Log("enabling snappy")
peer1.SetSnappy(true)
peer2.SetSnappy(true)
checkMsgReadWrite(t, peer1, peer2, testCode, testData)
}
func checkMsgReadWrite(t *testing.T, p1, p2 *Conn, msgCode uint64, msgData []byte) {
// Set up the reader.
ch := make(chan message, 1)
go func() {
r := result{side: "initiator"}
defer func() { output <- r }()
defer fd0.Close()
r.pubkey, r.err = c0.doEncHandshake(prv0, &prv1.PublicKey)
if r.err != nil {
return
}
if !reflect.DeepEqual(r.pubkey, &prv1.PublicKey) {
r.err = fmt.Errorf("remote pubkey mismatch: got %v, want: %v", r.pubkey, &prv1.PublicKey)
}
}()
go func() {
r := result{side: "receiver"}
defer func() { output <- r }()
defer fd1.Close()
r.pubkey, r.err = c1.doEncHandshake(prv1, nil)
if r.err != nil {
return
}
if !reflect.DeepEqual(r.pubkey, &prv0.PublicKey) {
r.err = fmt.Errorf("remote ID mismatch: got %v, want: %v", r.pubkey, &prv0.PublicKey)
}
var msg message
msg.code, msg.data, _, msg.err = p1.Read()
ch <- msg
}()
// wait for results from both sides
r1, r2 := <-output, <-output
if r1.err != nil {
return fmt.Errorf("%s side error: %v", r1.side, r1.err)
}
if r2.err != nil {
return fmt.Errorf("%s side error: %v", r2.side, r2.err)
}
// compare derived secrets
if !reflect.DeepEqual(c0.rw.egressMAC, c1.rw.ingressMAC) {
return fmt.Errorf("egress mac mismatch:\n c0.rw: %#v\n c1.rw: %#v", c0.rw.egressMAC, c1.rw.ingressMAC)
}
if !reflect.DeepEqual(c0.rw.ingressMAC, c1.rw.egressMAC) {
return fmt.Errorf("ingress mac mismatch:\n c0.rw: %#v\n c1.rw: %#v", c0.rw.ingressMAC, c1.rw.egressMAC)
}
if !reflect.DeepEqual(c0.rw.enc, c1.rw.enc) {
return fmt.Errorf("enc cipher mismatch:\n c0.rw: %#v\n c1.rw: %#v", c0.rw.enc, c1.rw.enc)
}
if !reflect.DeepEqual(c0.rw.dec, c1.rw.dec) {
return fmt.Errorf("dec cipher mismatch:\n c0.rw: %#v\n c1.rw: %#v", c0.rw.dec, c1.rw.dec)
}
return nil
}
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()
// Write the message.
_, err := p2.Write(msgCode, msgData)
if err != nil {
t.Fatal(err)
}
wg.Add(2)
// Check it was received correctly.
msg := <-ch
assert.Equal(t, msgCode, msg.code, "wrong message code returned from ReadMsg")
assert.Equal(t, msgData, msg.data, "wrong message data returned from ReadMsg")
}
func createPeers(t *testing.T) (peer1, peer2 *Conn) {
conn1, conn2 := net.Pipe()
key1, key2 := newkey(), newkey()
peer1 = NewConn(conn1, &key2.PublicKey) // dialer
peer2 = NewConn(conn2, nil) // listener
doHandshake(t, peer1, peer2, key1, key2)
return peer1, peer2
}
func doHandshake(t *testing.T, peer1, peer2 *Conn, key1, key2 *ecdsa.PrivateKey) {
keyChan := make(chan *ecdsa.PublicKey, 1)
go func() {
defer wg.Done()
defer fd0.Close()
rlpx := newRLPX(fd0)
rpubkey, err := rlpx.doEncHandshake(prv0, &prv1.PublicKey)
pubKey, err := peer2.Handshake(key2)
if err != nil {
t.Errorf("dial side enc handshake failed: %v", err)
return
t.Errorf("peer2 could not do handshake: %v", err)
}
if !reflect.DeepEqual(rpubkey, &prv1.PublicKey) {
t.Errorf("dial side remote pubkey mismatch: got %v, want %v", rpubkey, &prv1.PublicKey)
return
}
phs, err := rlpx.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
}
rlpx.close(DiscQuitting)
keyChan <- pubKey
}()
go func() {
defer wg.Done()
defer fd1.Close()
rlpx := newRLPX(fd1)
rpubkey, err := rlpx.doEncHandshake(prv1, nil)
pubKey2, err := peer1.Handshake(key1)
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
t.Errorf("peer1 could not do handshake: %v", err)
}
pubKey1 := <-keyChan
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)
}
// Confirm the handshake was successful.
if !reflect.DeepEqual(pubKey1, &key1.PublicKey) || !reflect.DeepEqual(pubKey2, &key2.PublicKey) {
t.Fatal("unsuccessful handshake")
}
}
func TestRLPXFrameFake(t *testing.T) {
buf := new(bytes.Buffer)
// This test checks the frame data of written messages.
func TestFrameReadWrite(t *testing.T) {
conn := NewConn(nil, nil)
hash := fakeHash([]byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1})
rw := newRLPXFrameRW(buf, secrets{
conn.InitWithSecrets(Secrets{
AES: crypto.Keccak256(),
MAC: crypto.Keccak256(),
IngressMAC: hash,
EgressMAC: hash,
})
h := conn.handshake
golden := unhex(`
00828ddae471818bb0bfa6b551d1cb42
@ -280,32 +132,27 @@ func TestRLPXFrameFake(t *testing.T) {
ba628a4ba590cb43f7848f41c4382885
01010101010101010101010101010101
`)
msgCode := uint64(8)
msg := []uint{1, 2, 3, 4}
msgEnc, _ := rlp.EncodeToBytes(msg)
// Check WriteMsg. This puts a message into the buffer.
if err := Send(rw, 8, []uint{1, 2, 3, 4}); err != nil {
// Check writeFrame. The frame that's written should be equal to the test vector.
buf := new(bytes.Buffer)
if err := h.writeFrame(buf, msgCode, msgEnc); err != nil {
t.Fatalf("WriteMsg error: %v", err)
}
written := buf.Bytes()
if !bytes.Equal(written, golden) {
t.Fatalf("output mismatch:\n got: %x\n want: %x", written, golden)
if !bytes.Equal(buf.Bytes(), golden) {
t.Fatalf("output mismatch:\n got: %x\n want: %x", buf.Bytes(), golden)
}
// Check ReadMsg. It reads the message encoded by WriteMsg, which
// is equivalent to the golden message above.
msg, err := rw.ReadMsg()
// Check readFrame on the test vector.
content, err := h.readFrame(bytes.NewReader(golden))
if err != nil {
t.Fatalf("ReadMsg error: %v", err)
}
if msg.Size != 5 {
t.Errorf("msg size mismatch: got %d, want %d", msg.Size, 5)
}
if msg.Code != 8 {
t.Errorf("msg code mismatch: got %d, want %d", msg.Code, 8)
}
payload, _ := ioutil.ReadAll(msg.Payload)
wantPayload := unhex("C401020304")
if !bytes.Equal(payload, wantPayload) {
t.Errorf("msg payload mismatch:\ngot %x\nwant %x", payload, wantPayload)
wantContent := unhex("08C401020304")
if !bytes.Equal(content, wantContent) {
t.Errorf("frame content mismatch:\ngot %x\nwant %x", content, wantContent)
}
}
@ -314,67 +161,9 @@ type fakeHash []byte
func (fakeHash) Write(p []byte) (int, error) { return len(p), nil }
func (fakeHash) Reset() {}
func (fakeHash) BlockSize() int { return 0 }
func (h fakeHash) Size() int { return len(h) }
func (h fakeHash) Sum(b []byte) []byte { return append(b, h...) }
func TestRLPXFrameRW(t *testing.T) {
var (
aesSecret = make([]byte, 16)
macSecret = make([]byte, 16)
egressMACinit = make([]byte, 32)
ingressMACinit = make([]byte, 32)
)
for _, s := range [][]byte{aesSecret, macSecret, egressMACinit, ingressMACinit} {
rand.Read(s)
}
conn := new(bytes.Buffer)
s1 := secrets{
AES: aesSecret,
MAC: macSecret,
EgressMAC: sha3.NewLegacyKeccak256(),
IngressMAC: sha3.NewLegacyKeccak256(),
}
s1.EgressMAC.Write(egressMACinit)
s1.IngressMAC.Write(ingressMACinit)
rw1 := newRLPXFrameRW(conn, s1)
s2 := secrets{
AES: aesSecret,
MAC: macSecret,
EgressMAC: sha3.NewLegacyKeccak256(),
IngressMAC: sha3.NewLegacyKeccak256(),
}
s2.EgressMAC.Write(ingressMACinit)
s2.IngressMAC.Write(egressMACinit)
rw2 := newRLPXFrameRW(conn, s2)
// send some messages
for i := 0; i < 10; i++ {
// write message into conn buffer
wmsg := []interface{}{"foo", "bar", strings.Repeat("test", i)}
err := Send(rw1, uint64(i), wmsg)
if err != nil {
t.Fatalf("WriteMsg error (i=%d): %v", i, err)
}
// read message that rw1 just wrote
msg, err := rw2.ReadMsg()
if err != nil {
t.Fatalf("ReadMsg error (i=%d): %v", i, err)
}
if msg.Code != uint64(i) {
t.Fatalf("msg code mismatch: got %d, want %d", msg.Code, i)
}
payload, _ := ioutil.ReadAll(msg.Payload)
wantPayload, _ := rlp.EncodeToBytes(wmsg)
if !bytes.Equal(payload, wantPayload) {
t.Fatalf("msg payload mismatch:\ngot %x\nwant %x", payload, wantPayload)
}
}
}
type handshakeAuthTest struct {
input string
isPlain bool
@ -598,3 +387,20 @@ func TestHandshakeForwardCompatibility(t *testing.T) {
t.Errorf("ingress-mac('foo') mismatch:\ngot %x\nwant %x", fooIngressHash, wantFooIngressHash)
}
}
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
}
func newkey() *ecdsa.PrivateKey {
key, err := crypto.GenerateKey()
if err != nil {
panic("couldn't generate key: " + err.Error())
}
return key
}

18
p2p/server.go
View File

@ -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)

49
p2p/server_test.go
View File

@ -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 {
*rlpxTransport
rpub *ecdsa.PublicKey
*rlpx
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
}
@ -78,7 +78,9 @@ func startTestServer(t *testing.T, remoteKey *ecdsa.PublicKey, pf func(*Peer)) *
server := &Server{
Config: config,
newPeerHook: pf,
newTransport: func(fd net.Conn) transport { return newTestTransport(remoteKey, fd) },
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}

177
p2p/transport.go Normal file
View File

@ -0,0 +1,177 @@
// 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
}

148
p2p/transport_test.go Normal file
View File

@ -0,0 +1,148 @@
// 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)
}
}
}