github.com/alexdevranger/node-1.8.27@v0.0.0-20221128213301-aa5841e41d2d/p2p/discover/node.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of the go-dubxcoin library.
     3  //
     4  // The go-dubxcoin library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-dubxcoin library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-dubxcoin library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package discover
    18  
    19  import (
    20  	"crypto/ecdsa"
    21  	"errors"
    22  	"math/big"
    23  	"net"
    24  	"time"
    25  
    26  	"github.com/alexdevranger/node-1.8.27/common/math"
    27  	"github.com/alexdevranger/node-1.8.27/crypto"
    28  	"github.com/alexdevranger/node-1.8.27/crypto/secp256k1"
    29  	"github.com/alexdevranger/node-1.8.27/p2p/enode"
    30  )
    31  
    32  // node represents a host on the network.
    33  // The fields of Node may not be modified.
    34  type node struct {
    35  	enode.Node
    36  	addedAt        time.Time // time when the node was added to the table
    37  	livenessChecks uint      // how often liveness was checked
    38  }
    39  
    40  type encPubkey [64]byte
    41  
    42  func encodePubkey(key *ecdsa.PublicKey) encPubkey {
    43  	var e encPubkey
    44  	math.ReadBits(key.X, e[:len(e)/2])
    45  	math.ReadBits(key.Y, e[len(e)/2:])
    46  	return e
    47  }
    48  
    49  func decodePubkey(e encPubkey) (*ecdsa.PublicKey, error) {
    50  	p := &ecdsa.PublicKey{Curve: crypto.S256(), X: new(big.Int), Y: new(big.Int)}
    51  	half := len(e) / 2
    52  	p.X.SetBytes(e[:half])
    53  	p.Y.SetBytes(e[half:])
    54  	if !p.Curve.IsOnCurve(p.X, p.Y) {
    55  		return nil, errors.New("invalid secp256k1 curve point")
    56  	}
    57  	return p, nil
    58  }
    59  
    60  func (e encPubkey) id() enode.ID {
    61  	return enode.ID(crypto.Keccak256Hash(e[:]))
    62  }
    63  
    64  // recoverNodeKey computes the public key used to sign the
    65  // given hash from the signature.
    66  func recoverNodeKey(hash, sig []byte) (key encPubkey, err error) {
    67  	pubkey, err := secp256k1.RecoverPubkey(hash, sig)
    68  	if err != nil {
    69  		return key, err
    70  	}
    71  	copy(key[:], pubkey[1:])
    72  	return key, nil
    73  }
    74  
    75  func wrapNode(n *enode.Node) *node {
    76  	return &node{Node: *n}
    77  }
    78  
    79  func wrapNodes(ns []*enode.Node) []*node {
    80  	result := make([]*node, len(ns))
    81  	for i, n := range ns {
    82  		result[i] = wrapNode(n)
    83  	}
    84  	return result
    85  }
    86  
    87  func unwrapNode(n *node) *enode.Node {
    88  	return &n.Node
    89  }
    90  
    91  func unwrapNodes(ns []*node) []*enode.Node {
    92  	result := make([]*enode.Node, len(ns))
    93  	for i, n := range ns {
    94  		result[i] = unwrapNode(n)
    95  	}
    96  	return result
    97  }
    98  
    99  func (n *node) addr() *net.UDPAddr {
   100  	return &net.UDPAddr{IP: n.IP(), Port: n.UDP()}
   101  }
   102  
   103  func (n *node) String() string {
   104  	return n.Node.String()
   105  }