github.com/clem109/go-ethereum@v1.8.3-0.20180316121352-fe6cf00f480a/les/protocol.go (about) 1 // Copyright 2016 The go-ethereum Authors 2 // This file is part of the go-ethereum library. 3 // 4 // The go-ethereum 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-ethereum 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-ethereum library. If not, see <http://www.gnu.org/licenses/>. 16 17 // Package les implements the Light Ethereum Subprotocol. 18 package les 19 20 import ( 21 "bytes" 22 "crypto/ecdsa" 23 "crypto/elliptic" 24 "errors" 25 "fmt" 26 "io" 27 "math/big" 28 29 "github.com/ethereum/go-ethereum/common" 30 "github.com/ethereum/go-ethereum/core" 31 "github.com/ethereum/go-ethereum/crypto" 32 "github.com/ethereum/go-ethereum/crypto/secp256k1" 33 "github.com/ethereum/go-ethereum/rlp" 34 ) 35 36 // Constants to match up protocol versions and messages 37 const ( 38 lpv1 = 1 39 lpv2 = 2 40 ) 41 42 // Supported versions of the les protocol (first is primary) 43 var ( 44 ClientProtocolVersions = []uint{lpv2, lpv1} 45 ServerProtocolVersions = []uint{lpv2, lpv1} 46 AdvertiseProtocolVersions = []uint{lpv2} // clients are searching for the first advertised protocol in the list 47 ) 48 49 // Number of implemented message corresponding to different protocol versions. 50 var ProtocolLengths = map[uint]uint64{lpv1: 15, lpv2: 22} 51 52 const ( 53 NetworkId = 1 54 ProtocolMaxMsgSize = 10 * 1024 * 1024 // Maximum cap on the size of a protocol message 55 ) 56 57 // les protocol message codes 58 const ( 59 // Protocol messages belonging to LPV1 60 StatusMsg = 0x00 61 AnnounceMsg = 0x01 62 GetBlockHeadersMsg = 0x02 63 BlockHeadersMsg = 0x03 64 GetBlockBodiesMsg = 0x04 65 BlockBodiesMsg = 0x05 66 GetReceiptsMsg = 0x06 67 ReceiptsMsg = 0x07 68 GetProofsV1Msg = 0x08 69 ProofsV1Msg = 0x09 70 GetCodeMsg = 0x0a 71 CodeMsg = 0x0b 72 SendTxMsg = 0x0c 73 GetHeaderProofsMsg = 0x0d 74 HeaderProofsMsg = 0x0e 75 // Protocol messages belonging to LPV2 76 GetProofsV2Msg = 0x0f 77 ProofsV2Msg = 0x10 78 GetHelperTrieProofsMsg = 0x11 79 HelperTrieProofsMsg = 0x12 80 SendTxV2Msg = 0x13 81 GetTxStatusMsg = 0x14 82 TxStatusMsg = 0x15 83 ) 84 85 type errCode int 86 87 const ( 88 ErrMsgTooLarge = iota 89 ErrDecode 90 ErrInvalidMsgCode 91 ErrProtocolVersionMismatch 92 ErrNetworkIdMismatch 93 ErrGenesisBlockMismatch 94 ErrNoStatusMsg 95 ErrExtraStatusMsg 96 ErrSuspendedPeer 97 ErrUselessPeer 98 ErrRequestRejected 99 ErrUnexpectedResponse 100 ErrInvalidResponse 101 ErrTooManyTimeouts 102 ErrMissingKey 103 ) 104 105 func (e errCode) String() string { 106 return errorToString[int(e)] 107 } 108 109 // XXX change once legacy code is out 110 var errorToString = map[int]string{ 111 ErrMsgTooLarge: "Message too long", 112 ErrDecode: "Invalid message", 113 ErrInvalidMsgCode: "Invalid message code", 114 ErrProtocolVersionMismatch: "Protocol version mismatch", 115 ErrNetworkIdMismatch: "NetworkId mismatch", 116 ErrGenesisBlockMismatch: "Genesis block mismatch", 117 ErrNoStatusMsg: "No status message", 118 ErrExtraStatusMsg: "Extra status message", 119 ErrSuspendedPeer: "Suspended peer", 120 ErrRequestRejected: "Request rejected", 121 ErrUnexpectedResponse: "Unexpected response", 122 ErrInvalidResponse: "Invalid response", 123 ErrTooManyTimeouts: "Too many request timeouts", 124 ErrMissingKey: "Key missing from list", 125 } 126 127 type announceBlock struct { 128 Hash common.Hash // Hash of one particular block being announced 129 Number uint64 // Number of one particular block being announced 130 Td *big.Int // Total difficulty of one particular block being announced 131 } 132 133 // announceData is the network packet for the block announcements. 134 type announceData struct { 135 Hash common.Hash // Hash of one particular block being announced 136 Number uint64 // Number of one particular block being announced 137 Td *big.Int // Total difficulty of one particular block being announced 138 ReorgDepth uint64 139 Update keyValueList 140 } 141 142 // sign adds a signature to the block announcement by the given privKey 143 func (a *announceData) sign(privKey *ecdsa.PrivateKey) { 144 rlp, _ := rlp.EncodeToBytes(announceBlock{a.Hash, a.Number, a.Td}) 145 sig, _ := crypto.Sign(crypto.Keccak256(rlp), privKey) 146 a.Update = a.Update.add("sign", sig) 147 } 148 149 // checkSignature verifies if the block announcement has a valid signature by the given pubKey 150 func (a *announceData) checkSignature(pubKey *ecdsa.PublicKey) error { 151 var sig []byte 152 if err := a.Update.decode().get("sign", &sig); err != nil { 153 return err 154 } 155 rlp, _ := rlp.EncodeToBytes(announceBlock{a.Hash, a.Number, a.Td}) 156 recPubkey, err := secp256k1.RecoverPubkey(crypto.Keccak256(rlp), sig) 157 if err != nil { 158 return err 159 } 160 pbytes := elliptic.Marshal(pubKey.Curve, pubKey.X, pubKey.Y) 161 if bytes.Equal(pbytes, recPubkey) { 162 return nil 163 } else { 164 return errors.New("Wrong signature") 165 } 166 } 167 168 type blockInfo struct { 169 Hash common.Hash // Hash of one particular block being announced 170 Number uint64 // Number of one particular block being announced 171 Td *big.Int // Total difficulty of one particular block being announced 172 } 173 174 // getBlockHeadersData represents a block header query. 175 type getBlockHeadersData struct { 176 Origin hashOrNumber // Block from which to retrieve headers 177 Amount uint64 // Maximum number of headers to retrieve 178 Skip uint64 // Blocks to skip between consecutive headers 179 Reverse bool // Query direction (false = rising towards latest, true = falling towards genesis) 180 } 181 182 // hashOrNumber is a combined field for specifying an origin block. 183 type hashOrNumber struct { 184 Hash common.Hash // Block hash from which to retrieve headers (excludes Number) 185 Number uint64 // Block hash from which to retrieve headers (excludes Hash) 186 } 187 188 // EncodeRLP is a specialized encoder for hashOrNumber to encode only one of the 189 // two contained union fields. 190 func (hn *hashOrNumber) EncodeRLP(w io.Writer) error { 191 if hn.Hash == (common.Hash{}) { 192 return rlp.Encode(w, hn.Number) 193 } 194 if hn.Number != 0 { 195 return fmt.Errorf("both origin hash (%x) and number (%d) provided", hn.Hash, hn.Number) 196 } 197 return rlp.Encode(w, hn.Hash) 198 } 199 200 // DecodeRLP is a specialized decoder for hashOrNumber to decode the contents 201 // into either a block hash or a block number. 202 func (hn *hashOrNumber) DecodeRLP(s *rlp.Stream) error { 203 _, size, _ := s.Kind() 204 origin, err := s.Raw() 205 if err == nil { 206 switch { 207 case size == 32: 208 err = rlp.DecodeBytes(origin, &hn.Hash) 209 case size <= 8: 210 err = rlp.DecodeBytes(origin, &hn.Number) 211 default: 212 err = fmt.Errorf("invalid input size %d for origin", size) 213 } 214 } 215 return err 216 } 217 218 // CodeData is the network response packet for a node data retrieval. 219 type CodeData []struct { 220 Value []byte 221 } 222 223 type proofsData [][]rlp.RawValue 224 225 type txStatus struct { 226 Status core.TxStatus 227 Lookup *core.TxLookupEntry `rlp:"nil"` 228 Error string 229 }