bsc/les/protocol.go
2018-01-26 19:30:45 +02:00

230 lines
7.1 KiB
Go

// Copyright 2016 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 les implements the Light Ethereum Subprotocol.
package les
import (
"bytes"
"crypto/ecdsa"
"crypto/elliptic"
"errors"
"fmt"
"io"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/secp256k1"
"github.com/ethereum/go-ethereum/rlp"
)
// Constants to match up protocol versions and messages
const (
lpv1 = 1
lpv2 = 2
)
// Supported versions of the les protocol (first is primary)
var (
ClientProtocolVersions = []uint{lpv2, lpv1}
ServerProtocolVersions = []uint{lpv2, lpv1}
AdvertiseProtocolVersions = []uint{lpv2} // clients are searching for the first advertised protocol in the list
)
// Number of implemented message corresponding to different protocol versions.
var ProtocolLengths = map[uint]uint64{lpv1: 15, lpv2: 22}
const (
NetworkId = 1
ProtocolMaxMsgSize = 10 * 1024 * 1024 // Maximum cap on the size of a protocol message
)
// les protocol message codes
const (
// Protocol messages belonging to LPV1
StatusMsg = 0x00
AnnounceMsg = 0x01
GetBlockHeadersMsg = 0x02
BlockHeadersMsg = 0x03
GetBlockBodiesMsg = 0x04
BlockBodiesMsg = 0x05
GetReceiptsMsg = 0x06
ReceiptsMsg = 0x07
GetProofsV1Msg = 0x08
ProofsV1Msg = 0x09
GetCodeMsg = 0x0a
CodeMsg = 0x0b
SendTxMsg = 0x0c
GetHeaderProofsMsg = 0x0d
HeaderProofsMsg = 0x0e
// Protocol messages belonging to LPV2
GetProofsV2Msg = 0x0f
ProofsV2Msg = 0x10
GetHelperTrieProofsMsg = 0x11
HelperTrieProofsMsg = 0x12
SendTxV2Msg = 0x13
GetTxStatusMsg = 0x14
TxStatusMsg = 0x15
)
type errCode int
const (
ErrMsgTooLarge = iota
ErrDecode
ErrInvalidMsgCode
ErrProtocolVersionMismatch
ErrNetworkIdMismatch
ErrGenesisBlockMismatch
ErrNoStatusMsg
ErrExtraStatusMsg
ErrSuspendedPeer
ErrUselessPeer
ErrRequestRejected
ErrUnexpectedResponse
ErrInvalidResponse
ErrTooManyTimeouts
ErrMissingKey
)
func (e errCode) String() string {
return errorToString[int(e)]
}
// XXX change once legacy code is out
var errorToString = map[int]string{
ErrMsgTooLarge: "Message too long",
ErrDecode: "Invalid message",
ErrInvalidMsgCode: "Invalid message code",
ErrProtocolVersionMismatch: "Protocol version mismatch",
ErrNetworkIdMismatch: "NetworkId mismatch",
ErrGenesisBlockMismatch: "Genesis block mismatch",
ErrNoStatusMsg: "No status message",
ErrExtraStatusMsg: "Extra status message",
ErrSuspendedPeer: "Suspended peer",
ErrRequestRejected: "Request rejected",
ErrUnexpectedResponse: "Unexpected response",
ErrInvalidResponse: "Invalid response",
ErrTooManyTimeouts: "Too many request timeouts",
ErrMissingKey: "Key missing from list",
}
type announceBlock struct {
Hash common.Hash // Hash of one particular block being announced
Number uint64 // Number of one particular block being announced
Td *big.Int // Total difficulty of one particular block being announced
}
// announceData is the network packet for the block announcements.
type announceData struct {
Hash common.Hash // Hash of one particular block being announced
Number uint64 // Number of one particular block being announced
Td *big.Int // Total difficulty of one particular block being announced
ReorgDepth uint64
Update keyValueList
}
// sign adds a signature to the block announcement by the given privKey
func (a *announceData) sign(privKey *ecdsa.PrivateKey) {
rlp, _ := rlp.EncodeToBytes(announceBlock{a.Hash, a.Number, a.Td})
sig, _ := crypto.Sign(crypto.Keccak256(rlp), privKey)
a.Update = a.Update.add("sign", sig)
}
// checkSignature verifies if the block announcement has a valid signature by the given pubKey
func (a *announceData) checkSignature(pubKey *ecdsa.PublicKey) error {
var sig []byte
if err := a.Update.decode().get("sign", &sig); err != nil {
return err
}
rlp, _ := rlp.EncodeToBytes(announceBlock{a.Hash, a.Number, a.Td})
recPubkey, err := secp256k1.RecoverPubkey(crypto.Keccak256(rlp), sig)
if err != nil {
return err
}
pbytes := elliptic.Marshal(pubKey.Curve, pubKey.X, pubKey.Y)
if bytes.Equal(pbytes, recPubkey) {
return nil
} else {
return errors.New("Wrong signature")
}
}
type blockInfo struct {
Hash common.Hash // Hash of one particular block being announced
Number uint64 // Number of one particular block being announced
Td *big.Int // Total difficulty of one particular block being announced
}
// getBlockHeadersData represents a block header query.
type getBlockHeadersData struct {
Origin hashOrNumber // Block from which to retrieve headers
Amount uint64 // Maximum number of headers to retrieve
Skip uint64 // Blocks to skip between consecutive headers
Reverse bool // Query direction (false = rising towards latest, true = falling towards genesis)
}
// hashOrNumber is a combined field for specifying an origin block.
type hashOrNumber struct {
Hash common.Hash // Block hash from which to retrieve headers (excludes Number)
Number uint64 // Block hash from which to retrieve headers (excludes Hash)
}
// EncodeRLP is a specialized encoder for hashOrNumber to encode only one of the
// two contained union fields.
func (hn *hashOrNumber) EncodeRLP(w io.Writer) error {
if hn.Hash == (common.Hash{}) {
return rlp.Encode(w, hn.Number)
}
if hn.Number != 0 {
return fmt.Errorf("both origin hash (%x) and number (%d) provided", hn.Hash, hn.Number)
}
return rlp.Encode(w, hn.Hash)
}
// DecodeRLP is a specialized decoder for hashOrNumber to decode the contents
// into either a block hash or a block number.
func (hn *hashOrNumber) DecodeRLP(s *rlp.Stream) error {
_, size, _ := s.Kind()
origin, err := s.Raw()
if err == nil {
switch {
case size == 32:
err = rlp.DecodeBytes(origin, &hn.Hash)
case size <= 8:
err = rlp.DecodeBytes(origin, &hn.Number)
default:
err = fmt.Errorf("invalid input size %d for origin", size)
}
}
return err
}
// CodeData is the network response packet for a node data retrieval.
type CodeData []struct {
Value []byte
}
type proofsData [][]rlp.RawValue
type txStatus struct {
Status core.TxStatus
Lookup *core.TxLookupEntry `rlp:"nil"`
Error string
}