plugeth/p2p/discover/node.go
Felix Lange f0c6f92140
p2p/discover, p2p/enode: rework endpoint proof handling, packet logging (#18963)
This change resolves multiple issues around handling of endpoint proofs.
The proof is now done separately for each IP and completing the proof
requires a matching ping hash.

Also remove waitping because it's equivalent to sleep. waitping was
slightly more efficient, but that may cause issues with findnode if
packets are reordered and the remote end sees findnode before pong.

Logging of received packets was hitherto done after handling the packet,
which meant that sent replies were logged before the packet that
generated them. This change splits up packet handling into 'preverify'
and 'handle'. The error from 'preverify' is logged, but 'handle' happens
after the message is logged. This fixes the order. Packet logs now
contain the node ID.
2019-01-29 17:39:20 +01:00

106 lines
2.7 KiB
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 discover
import (
"crypto/ecdsa"
"errors"
"math/big"
"net"
"time"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/secp256k1"
"github.com/ethereum/go-ethereum/p2p/enode"
)
// node represents a host on the network.
// The fields of Node may not be modified.
type node struct {
enode.Node
addedAt time.Time // time when the node was added to the table
livenessChecks uint // how often liveness was checked
}
type encPubkey [64]byte
func encodePubkey(key *ecdsa.PublicKey) encPubkey {
var e encPubkey
math.ReadBits(key.X, e[:len(e)/2])
math.ReadBits(key.Y, e[len(e)/2:])
return e
}
func decodePubkey(e encPubkey) (*ecdsa.PublicKey, error) {
p := &ecdsa.PublicKey{Curve: crypto.S256(), X: new(big.Int), Y: new(big.Int)}
half := len(e) / 2
p.X.SetBytes(e[:half])
p.Y.SetBytes(e[half:])
if !p.Curve.IsOnCurve(p.X, p.Y) {
return nil, errors.New("invalid secp256k1 curve point")
}
return p, nil
}
func (e encPubkey) id() enode.ID {
return enode.ID(crypto.Keccak256Hash(e[:]))
}
// recoverNodeKey computes the public key used to sign the
// given hash from the signature.
func recoverNodeKey(hash, sig []byte) (key encPubkey, err error) {
pubkey, err := secp256k1.RecoverPubkey(hash, sig)
if err != nil {
return key, err
}
copy(key[:], pubkey[1:])
return key, nil
}
func wrapNode(n *enode.Node) *node {
return &node{Node: *n}
}
func wrapNodes(ns []*enode.Node) []*node {
result := make([]*node, len(ns))
for i, n := range ns {
result[i] = wrapNode(n)
}
return result
}
func unwrapNode(n *node) *enode.Node {
return &n.Node
}
func unwrapNodes(ns []*node) []*enode.Node {
result := make([]*enode.Node, len(ns))
for i, n := range ns {
result[i] = unwrapNode(n)
}
return result
}
func (n *node) addr() *net.UDPAddr {
return &net.UDPAddr{IP: n.IP(), Port: n.UDP()}
}
func (n *node) String() string {
return n.Node.String()
}