b7394d7942
This adds an implementation of the current discovery v5 spec. There is full integration with cmd/devp2p and enode.Iterator in this version. In theory we could enable the new protocol as a replacement of discovery v4 at any time. In practice, there will likely be a few more changes to the spec and implementation before this can happen.
106 lines
2.7 KiB
Go
106 lines
2.7 KiB
Go
// Copyright 2015 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package discover
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import (
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"crypto/ecdsa"
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"crypto/elliptic"
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"errors"
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"math/big"
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"net"
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"time"
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"github.com/ethereum/go-ethereum/common/math"
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"github.com/ethereum/go-ethereum/crypto"
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"github.com/ethereum/go-ethereum/p2p/enode"
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)
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// node represents a host on the network.
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// The fields of Node may not be modified.
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type node struct {
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enode.Node
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addedAt time.Time // time when the node was added to the table
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livenessChecks uint // how often liveness was checked
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}
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type encPubkey [64]byte
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func encodePubkey(key *ecdsa.PublicKey) encPubkey {
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var e encPubkey
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math.ReadBits(key.X, e[:len(e)/2])
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math.ReadBits(key.Y, e[len(e)/2:])
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return e
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}
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func decodePubkey(curve elliptic.Curve, e encPubkey) (*ecdsa.PublicKey, error) {
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p := &ecdsa.PublicKey{Curve: curve, X: new(big.Int), Y: new(big.Int)}
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half := len(e) / 2
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p.X.SetBytes(e[:half])
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p.Y.SetBytes(e[half:])
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if !p.Curve.IsOnCurve(p.X, p.Y) {
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return nil, errors.New("invalid curve point")
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}
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return p, nil
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}
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func (e encPubkey) id() enode.ID {
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return enode.ID(crypto.Keccak256Hash(e[:]))
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}
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// recoverNodeKey computes the public key used to sign the
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// given hash from the signature.
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func recoverNodeKey(hash, sig []byte) (key encPubkey, err error) {
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pubkey, err := crypto.Ecrecover(hash, sig)
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if err != nil {
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return key, err
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}
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copy(key[:], pubkey[1:])
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return key, nil
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}
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func wrapNode(n *enode.Node) *node {
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return &node{Node: *n}
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}
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func wrapNodes(ns []*enode.Node) []*node {
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result := make([]*node, len(ns))
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for i, n := range ns {
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result[i] = wrapNode(n)
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}
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return result
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}
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func unwrapNode(n *node) *enode.Node {
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return &n.Node
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}
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func unwrapNodes(ns []*node) []*enode.Node {
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result := make([]*enode.Node, len(ns))
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for i, n := range ns {
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result[i] = unwrapNode(n)
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}
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return result
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}
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func (n *node) addr() *net.UDPAddr {
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return &net.UDPAddr{IP: n.IP(), Port: n.UDP()}
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}
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func (n *node) String() string {
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return n.Node.String()
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}
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