laconicd-deprecated/types/tx.go
Aleksandr Bezobchuk ccc6ae6984 Fix linting errors
2018-10-24 10:53:23 -04:00

368 lines
9.9 KiB
Go

package types
import (
"bytes"
"crypto/ecdsa"
"fmt"
"io"
"math/big"
"sync/atomic"
"github.com/cosmos/cosmos-sdk/codec"
sdk "github.com/cosmos/cosmos-sdk/types"
ethcmn "github.com/ethereum/go-ethereum/common"
ethtypes "github.com/ethereum/go-ethereum/core/types"
ethcrypto "github.com/ethereum/go-ethereum/crypto"
ethsha "github.com/ethereum/go-ethereum/crypto/sha3"
"github.com/ethereum/go-ethereum/rlp"
"github.com/pkg/errors"
)
// TODO: Move to the EVM module
// message constants
const (
TypeTxEthereum = "Ethereum"
RouteTxEthereum = "evm"
)
// ----------------------------------------------------------------------------
// Ethereum transaction
// ----------------------------------------------------------------------------
var _ sdk.Tx = (*Transaction)(nil)
type (
// Transaction implements the Ethereum transaction structure as an exact
// replica. It implements the Cosmos sdk.Tx interface. Due to the private
// fields, it must be replicated here and cannot be embedded or used
// directly.
//
// Note: The transaction also implements the sdk.Msg interface to perform
// basic validation that is done in the BaseApp.
Transaction struct {
data TxData
// caches
hash atomic.Value
size atomic.Value
from atomic.Value
}
// TxData implements the Ethereum transaction data structure as an exact
// copy. It is used solely as intended in Ethereum abiding by the protocol
// except for the payload field which may embed a Cosmos SDK transaction.
TxData struct {
AccountNonce uint64 `json:"nonce"`
Price *big.Int `json:"gasPrice"`
GasLimit uint64 `json:"gas"`
Recipient *ethcmn.Address `json:"to" rlp:"nil"` // nil means contract creation
Amount *big.Int `json:"value"`
Payload []byte `json:"input"`
// signature values
V *big.Int `json:"v"`
R *big.Int `json:"r"`
S *big.Int `json:"s"`
// hash is only used when marshaling to JSON
Hash *ethcmn.Hash `json:"hash" rlp:"-"`
}
// sigCache is used to cache the derived sender and contains the signer used
// to derive it.
sigCache struct {
signer ethtypes.Signer
from ethcmn.Address
}
)
// NewTransaction returns a reference to a new Ethereum transaction.
func NewTransaction(
nonce uint64, to ethcmn.Address, amount *big.Int, gasLimit uint64, gasPrice *big.Int, payload []byte,
) *Transaction {
return newTransaction(nonce, &to, amount, gasLimit, gasPrice, payload)
}
// NewContractCreation returns a reference to a new Ethereum transaction
// designated for contract creation.
func NewContractCreation(
nonce uint64, amount *big.Int, gasLimit uint64, gasPrice *big.Int, payload []byte,
) *Transaction {
return newTransaction(nonce, nil, amount, gasLimit, gasPrice, payload)
}
func newTransaction(
nonce uint64, to *ethcmn.Address, amount *big.Int,
gasLimit uint64, gasPrice *big.Int, payload []byte,
) *Transaction {
if len(payload) > 0 {
payload = ethcmn.CopyBytes(payload)
}
txData := TxData{
AccountNonce: nonce,
Recipient: to,
Payload: payload,
GasLimit: gasLimit,
Amount: new(big.Int),
Price: new(big.Int),
V: new(big.Int),
R: new(big.Int),
S: new(big.Int),
}
if amount != nil {
txData.Amount.Set(amount)
}
if gasPrice != nil {
txData.Price.Set(gasPrice)
}
return &Transaction{data: txData}
}
// Data returns the Transaction's data.
func (tx Transaction) Data() TxData {
return tx.data
}
// EncodeRLP implements the rlp.Encoder interface.
func (tx *Transaction) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, &tx.data)
}
// DecodeRLP implements the rlp.Decoder interface.
func (tx *Transaction) DecodeRLP(s *rlp.Stream) error {
_, size, _ := s.Kind()
err := s.Decode(&tx.data)
if err == nil {
tx.size.Store(ethcmn.StorageSize(rlp.ListSize(size)))
}
return err
}
// Hash hashes the RLP encoding of a transaction.
func (tx *Transaction) Hash() ethcmn.Hash {
if hash := tx.hash.Load(); hash != nil {
return hash.(ethcmn.Hash)
}
v := rlpHash(tx)
tx.hash.Store(v)
return v
}
// SigHash returns the RLP hash of a transaction with a given chainID used for
// signing.
func (tx Transaction) SigHash(chainID *big.Int) ethcmn.Hash {
return rlpHash([]interface{}{
tx.data.AccountNonce,
tx.data.Price,
tx.data.GasLimit,
tx.data.Recipient,
tx.data.Amount,
tx.data.Payload,
chainID, uint(0), uint(0),
})
}
// Sign calculates a secp256k1 ECDSA signature and signs the transaction. It
// takes a private key and chainID to sign an Ethereum transaction according to
// EIP155 standard. It mutates the transaction as it populates the V, R, S
// fields of the Transaction's Signature.
func (tx *Transaction) Sign(chainID *big.Int, priv *ecdsa.PrivateKey) {
txHash := tx.SigHash(chainID)
sig, err := ethcrypto.Sign(txHash[:], priv)
if err != nil {
panic(err)
}
if len(sig) != 65 {
panic(fmt.Sprintf("wrong size for signature: got %d, want 65", len(sig)))
}
r := new(big.Int).SetBytes(sig[:32])
s := new(big.Int).SetBytes(sig[32:64])
var v *big.Int
if chainID.Sign() == 0 {
v = new(big.Int).SetBytes([]byte{sig[64] + 27})
} else {
v = big.NewInt(int64(sig[64] + 35))
chainIDMul := new(big.Int).Mul(chainID, big.NewInt(2))
v.Add(v, chainIDMul)
}
tx.data.V = v
tx.data.R = r
tx.data.S = s
}
// VerifySig attempts to verify a Transaction's signature for a given chainID.
// A derived address is returned upon success or an error if recovery fails.
func (tx Transaction) VerifySig(chainID *big.Int) (ethcmn.Address, error) {
signer := ethtypes.NewEIP155Signer(chainID)
if sc := tx.from.Load(); sc != nil {
sigCache := sc.(sigCache)
// If the signer used to derive from in a previous
// call is not the same as used current, invalidate
// the cache.
if sigCache.signer.Equal(signer) {
return sigCache.from, nil
}
}
// do not allow recovery for transactions with an unprotected chainID
if chainID.Sign() == 0 {
return ethcmn.Address{}, errors.New("invalid chainID")
}
txHash := tx.SigHash(chainID)
sig := recoverEthSig(tx.data.R, tx.data.S, tx.data.V, chainID)
pub, err := ethcrypto.Ecrecover(txHash[:], sig)
if err != nil {
return ethcmn.Address{}, err
}
var addr ethcmn.Address
copy(addr[:], ethcrypto.Keccak256(pub[1:])[12:])
tx.from.Store(sigCache{signer: signer, from: addr})
return addr, nil
}
// Type implements the sdk.Msg interface. It returns the type of the
// Transaction.
func (tx Transaction) Type() string { return TypeTxEthereum }
// Route implements the sdk.Msg interface. It returns the route of the
// Transaction.
func (tx Transaction) Route() string { return RouteTxEthereum }
// ValidateBasic implements the sdk.Msg interface. It performs basic validation
// checks of a Transaction. If returns an sdk.Error if validation fails.
func (tx Transaction) ValidateBasic() sdk.Error {
if tx.data.Price.Sign() != 1 {
return ErrInvalidValue(DefaultCodespace, "price must be positive")
}
if tx.data.Amount.Sign() != 1 {
return ErrInvalidValue(DefaultCodespace, "amount must be positive")
}
return nil
}
// GetSignBytes performs a no-op and should not be used. It implements the
// sdk.Msg Interface
func (tx Transaction) GetSignBytes() (sigBytes []byte) { return }
// GetSigners performs a no-op and should not be used. It implements the
// sdk.Msg Interface
//
// CONTRACT: The transaction must already be signed.
func (tx Transaction) GetSigners() (signers []sdk.AccAddress) { return }
// GetMsgs returns a single message containing the Transaction itself. It
// implements the Cosmos sdk.Tx interface.
func (tx Transaction) GetMsgs() []sdk.Msg {
return []sdk.Msg{tx}
}
// hasEmbeddedTx returns a boolean reflecting if the transaction contains an
// SDK transaction or not based on the recipient address.
func (tx Transaction) hasEmbeddedTx(addr ethcmn.Address) bool {
return bytes.Equal(tx.data.Recipient.Bytes(), addr.Bytes())
}
// GetEmbeddedTx returns the embedded SDK transaction from an Ethereum
// transaction. It returns an error if decoding the inner transaction fails.
//
// CONTRACT: The payload field of an Ethereum transaction must contain a valid
// encoded SDK transaction.
func (tx Transaction) GetEmbeddedTx(codec *codec.Codec) (sdk.Tx, sdk.Error) {
var etx sdk.Tx
err := codec.UnmarshalBinary(tx.data.Payload, &etx)
if err != nil {
return etx, sdk.ErrTxDecode("failed to decode embedded transaction")
}
return etx, nil
}
// ----------------------------------------------------------------------------
// Utilities
// ----------------------------------------------------------------------------
// TxDecoder returns an sdk.TxDecoder that given raw transaction bytes and an
// SDK address, attempts to decode them into a Transaction or an EmbeddedTx or
// returning an error if decoding fails.
func TxDecoder(codec *codec.Codec, sdkAddress ethcmn.Address) sdk.TxDecoder {
return func(txBytes []byte) (sdk.Tx, sdk.Error) {
var tx = Transaction{}
if len(txBytes) == 0 {
return nil, sdk.ErrTxDecode("transaction bytes are empty")
}
err := rlp.DecodeBytes(txBytes, &tx)
if err != nil {
return nil, sdk.ErrTxDecode("failed to decode transaction").TraceSDK(err.Error())
}
// If the transaction is routed as an SDK transaction, decode and return
// the embedded SDK transaction.
if tx.hasEmbeddedTx(sdkAddress) {
etx, err := tx.GetEmbeddedTx(codec)
if err != nil {
return nil, err
}
return etx, nil
}
return tx, nil
}
}
// recoverEthSig recovers a signature according to the Ethereum specification.
func recoverEthSig(R, S, Vb, chainID *big.Int) []byte {
var v byte
r, s := R.Bytes(), S.Bytes()
sig := make([]byte, 65)
copy(sig[32-len(r):32], r)
copy(sig[64-len(s):64], s)
if chainID.Sign() == 0 {
v = byte(Vb.Uint64() - 27)
} else {
chainIDMul := new(big.Int).Mul(chainID, big.NewInt(2))
V := new(big.Int).Sub(Vb, chainIDMul)
v = byte(V.Uint64() - 35)
}
sig[64] = v
return sig
}
func rlpHash(x interface{}) (hash ethcmn.Hash) {
hasher := ethsha.NewKeccak256()
rlp.Encode(hasher, x)
hasher.Sum(hash[:0])
return
}