laconicd/app/ante/eth.go
Federico Kunze 65453e4aa0
rpc, evm: secure tx signing (#20)
* rpc, evm: secure signing

* evm, ante: test signer

* tests
2021-05-12 09:08:31 -04:00

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package ante
import (
"fmt"
"math/big"
log "github.com/xlab/suplog"
sdk "github.com/cosmos/cosmos-sdk/types"
sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
authante "github.com/cosmos/cosmos-sdk/x/auth/ante"
ethermint "github.com/cosmos/ethermint/types"
evmtypes "github.com/cosmos/ethermint/x/evm/types"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
ethtypes "github.com/ethereum/go-ethereum/core/types"
)
// EVMKeeper defines the expected keeper interface used on the Eth AnteHandler
type EVMKeeper interface {
GetParams(ctx sdk.Context) evmtypes.Params
GetChainConfig(ctx sdk.Context) (evmtypes.ChainConfig, bool)
}
// EthSetupContextDecorator sets the infinite GasMeter in the Context and wraps
// the next AnteHandler with a defer clause to recover from any downstream
// OutOfGas panics in the AnteHandler chain to return an error with information
// on gas provided and gas used.
// CONTRACT: Must be first decorator in the chain
// CONTRACT: Tx must implement GasTx interface
type EthSetupContextDecorator struct{}
// NewEthSetupContextDecorator creates a new EthSetupContextDecorator
func NewEthSetupContextDecorator() EthSetupContextDecorator {
return EthSetupContextDecorator{}
}
// AnteHandle sets the infinite gas meter to done to ignore costs in AnteHandler checks.
// This is undone at the EthGasConsumeDecorator, where the context is set with the
// ethereum tx GasLimit.
func (escd EthSetupContextDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
ctx = ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
// all transactions must implement GasTx
gasTx, ok := tx.(authante.GasTx)
if !ok {
return ctx, sdkerrors.Wrap(sdkerrors.ErrTxDecode, "Tx must be GasTx")
}
// Decorator will catch an OutOfGasPanic caused in the next antehandler
// AnteHandlers must have their own defer/recover in order for the BaseApp
// to know how much gas was used! This is because the GasMeter is created in
// the AnteHandler, but if it panics the context won't be set properly in
// runTx's recover call.
defer func() {
if r := recover(); r != nil {
switch rType := r.(type) {
case sdk.ErrorOutOfGas:
log := fmt.Sprintf(
"out of gas in location: %v; gasLimit: %d, gasUsed: %d",
rType.Descriptor, gasTx.GetGas(), ctx.GasMeter().GasConsumed(),
)
err = sdkerrors.Wrap(sdkerrors.ErrOutOfGas, log)
default:
log.Errorln(r)
panic(r)
}
}
}()
return next(ctx, tx, simulate)
}
// EthMempoolFeeDecorator validates that sufficient fees have been provided that
// meet a minimum threshold defined by the proposer (for mempool purposes during CheckTx).
type EthMempoolFeeDecorator struct {
evmKeeper EVMKeeper
}
// NewEthMempoolFeeDecorator creates a new EthMempoolFeeDecorator
func NewEthMempoolFeeDecorator(ek EVMKeeper) EthMempoolFeeDecorator {
return EthMempoolFeeDecorator{
evmKeeper: ek,
}
}
// AnteHandle verifies that enough fees have been provided by the
// Ethereum transaction that meet the minimum threshold set by the block
// proposer.
//
// NOTE: This should only be run during a CheckTx mode.
func (emfd EthMempoolFeeDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
if !ctx.IsCheckTx() {
return next(ctx, tx, simulate)
}
msgEthTx, ok := tx.(sdk.FeeTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type, not implements sdk.FeeTx: %T", tx)
}
evmDenom := emfd.evmKeeper.GetParams(ctx).EvmDenom
txFee := msgEthTx.GetFee().AmountOf(evmDenom).Int64()
if txFee < 0 {
return ctx, sdkerrors.Wrap(
sdkerrors.ErrInsufficientFee,
"negative fee not allowed",
)
}
// txFee = GP * GL
fee := sdk.NewInt64DecCoin(evmDenom, txFee)
minGasPrices := ctx.MinGasPrices()
// check that fee provided is greater than the minimum
// NOTE: we only check if injs are present in min gas prices. It is up to the
// sender if they want to send additional fees in other denominations.
var hasEnoughFees bool
if fee.Amount.GTE(minGasPrices.AmountOf(evmDenom)) {
hasEnoughFees = true
}
// reject transaction if minimum gas price is positive and the transaction does not
// meet the minimum fee
if !ctx.MinGasPrices().IsZero() && !hasEnoughFees {
return ctx, sdkerrors.Wrap(
sdkerrors.ErrInsufficientFee,
fmt.Sprintf("insufficient fee, got: %q required: %q", fee, ctx.MinGasPrices()),
)
}
return next(ctx, tx, simulate)
}
// EthValidateBasicDecorator will call tx.ValidateBasic and return any non-nil error.
// If ValidateBasic passes, decorator calls next AnteHandler in chain. Note,
// EthValidateBasicDecorator decorator will not get executed on ReCheckTx since it
// is not dependent on application state.
type EthValidateBasicDecorator struct{}
func NewEthValidateBasicDecorator() EthValidateBasicDecorator {
return EthValidateBasicDecorator{}
}
func (vbd EthValidateBasicDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
// no need to validate basic on recheck tx, call next antehandler
if ctx.IsReCheckTx() {
return next(ctx, tx, simulate)
}
msgEthTx, ok := getTxMsg(tx).(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", getTxMsg(tx))
}
if err := msgEthTx.ValidateBasic(); err != nil {
return ctx, err
}
return next(ctx, tx, simulate)
}
// EthSigVerificationDecorator validates an ethereum signature
type EthSigVerificationDecorator struct {
evmKeeper EVMKeeper
}
// NewEthSigVerificationDecorator creates a new EthSigVerificationDecorator
func NewEthSigVerificationDecorator(ek EVMKeeper) EthSigVerificationDecorator {
return EthSigVerificationDecorator{
evmKeeper: ek,
}
}
// AnteHandle validates the signature and returns sender address
func (esvd EthSigVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
if simulate {
// when simulating, no signatures required and the from address is explicitly set
return next(ctx, tx, simulate)
}
msgEthTx, ok := getTxMsg(tx).(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", getTxMsg(tx))
}
// parse the chainID from a string to a base-10 integer
chainIDEpoch, err := ethermint.ParseChainID(ctx.ChainID())
if err != nil {
return ctx, err
}
config, found := esvd.evmKeeper.GetChainConfig(ctx)
if !found {
return ctx, evmtypes.ErrChainConfigNotFound
}
ethCfg := config.EthereumConfig(chainIDEpoch)
blockNum := big.NewInt(ctx.BlockHeight())
signer := ethtypes.MakeSigner(ethCfg, blockNum)
chainID := signer.ChainID()
if chainIDEpoch.Cmp(chainID) != 0 {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrInvalidChainID,
"EVM chain ID doesn't match the one derived from the signer (%s ≠ %s)",
chainIDEpoch.String(), chainID.String(),
)
}
sender, err := signer.Sender(msgEthTx.AsTransaction())
if err != nil {
return ctx, sdkerrors.Wrap(sdkerrors.ErrorInvalidSigner, err.Error())
}
// set the sender
msgEthTx.From = sender.String()
// NOTE: when signature verification succeeds, a non-empty signer address can be
// retrieved from the transaction on the next AnteDecorators.
return next(ctx, tx, simulate)
}
type noMessages struct{}
func getTxMsg(tx sdk.Tx) interface{} {
msgs := tx.GetMsgs()
if len(msgs) == 0 {
return &noMessages{}
}
return msgs[0]
}
// EthAccountVerificationDecorator validates an account balance checks
type EthAccountVerificationDecorator struct {
ak AccountKeeper
bankKeeper BankKeeper
evmKeeper EVMKeeper
}
// NewEthAccountVerificationDecorator creates a new EthAccountVerificationDecorator
func NewEthAccountVerificationDecorator(ak AccountKeeper, bankKeeper BankKeeper, ek EVMKeeper) EthAccountVerificationDecorator {
return EthAccountVerificationDecorator{
ak: ak,
bankKeeper: bankKeeper,
evmKeeper: ek,
}
}
// AnteHandle validates the signature and returns sender address
func (avd EthAccountVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
if !ctx.IsCheckTx() {
return next(ctx, tx, simulate)
}
msgEthTx, ok := getTxMsg(tx).(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", getTxMsg(tx))
}
// sender address should be in the tx cache from the previous AnteHandle call
address := msgEthTx.GetFrom()
if address.Empty() {
log.Panicln("sender address cannot be empty")
}
acc := avd.ak.GetAccount(ctx, address)
if acc == nil {
acc = avd.ak.NewAccountWithAddress(ctx, address)
avd.ak.SetAccount(ctx, acc)
}
// on InitChain make sure account number == 0
if ctx.BlockHeight() == 0 && acc.GetAccountNumber() != 0 {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrInvalidSequence,
"invalid account number for height zero (got %d)", acc.GetAccountNumber(),
)
}
evmDenom := avd.evmKeeper.GetParams(ctx).EvmDenom
// validate sender has enough funds to pay for gas cost
balance := avd.bankKeeper.GetBalance(ctx, address, evmDenom)
if balance.Amount.BigInt().Cmp(msgEthTx.Cost()) < 0 {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrInsufficientFunds,
"sender balance < tx gas cost (%s < %s%s)", balance.String(), msgEthTx.Cost().String(), evmDenom,
)
}
return next(ctx, tx, simulate)
}
// EthNonceVerificationDecorator checks that the account nonce from the transaction matches
// the sender account sequence.
type EthNonceVerificationDecorator struct {
ak AccountKeeper
}
// NewEthNonceVerificationDecorator creates a new EthNonceVerificationDecorator
func NewEthNonceVerificationDecorator(ak AccountKeeper) EthNonceVerificationDecorator {
return EthNonceVerificationDecorator{
ak: ak,
}
}
// AnteHandle validates that the transaction nonce is valid (equivalent to the sender accounts
// current nonce).
func (nvd EthNonceVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
msgEthTx, ok := getTxMsg(tx).(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", getTxMsg(tx))
}
// sender address should be in the tx cache from the previous AnteHandle call
address := msgEthTx.GetFrom()
if address.Empty() {
log.Panicln("sender address cannot be empty")
}
acc := nvd.ak.GetAccount(ctx, address)
if acc == nil {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrUnknownAddress,
"account %s (%s) is nil", common.BytesToAddress(address.Bytes()), address,
)
}
seq := acc.GetSequence()
// if multiple transactions are submitted in succession with increasing nonces,
// all will be rejected except the first, since the first needs to be included in a block
// before the sequence increments
if msgEthTx.Data.Nonce != seq {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrInvalidSequence,
"invalid nonce; got %d, expected %d", msgEthTx.Data.Nonce, seq,
)
}
return next(ctx, tx, simulate)
}
// EthGasConsumeDecorator validates enough intrinsic gas for the transaction and
// gas consumption.
type EthGasConsumeDecorator struct {
ak AccountKeeper
bankKeeper BankKeeper
evmKeeper EVMKeeper
}
// NewEthGasConsumeDecorator creates a new EthGasConsumeDecorator
func NewEthGasConsumeDecorator(ak AccountKeeper, bankKeeper BankKeeper, ek EVMKeeper) EthGasConsumeDecorator {
return EthGasConsumeDecorator{
ak: ak,
bankKeeper: bankKeeper,
evmKeeper: ek,
}
}
// AnteHandle validates that the Ethereum tx message has enough to cover intrinsic gas
// (during CheckTx only) and that the sender has enough balance to pay for the gas cost.
//
// Intrinsic gas for a transaction is the amount of gas
// that the transaction uses before the transaction is executed. The gas is a
// constant value of 21000 plus any cost inccured by additional bytes of data
// supplied with the transaction.
func (egcd EthGasConsumeDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
msgEthTx, ok := getTxMsg(tx).(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", getTxMsg(tx))
}
// sender address should be in the tx cache from the previous AnteHandle call
address := msgEthTx.GetFrom()
if address.Empty() {
log.Panicln("sender address cannot be empty")
}
// fetch sender account from signature
senderAcc, err := authante.GetSignerAcc(ctx, egcd.ak, address)
if err != nil {
return ctx, err
}
if senderAcc == nil {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrUnknownAddress,
"sender account %s (%s) is nil", common.BytesToAddress(address.Bytes()), address,
)
}
gasLimit := msgEthTx.GetGas()
var accessList ethtypes.AccessList
if msgEthTx.Data.Accesses != nil {
accessList = *msgEthTx.Data.Accesses.ToEthAccessList()
}
gas, err := core.IntrinsicGas(msgEthTx.Data.Input, accessList, msgEthTx.To() == nil, true, false)
if err != nil {
return ctx, sdkerrors.Wrap(err, "failed to compute intrinsic gas cost")
}
// intrinsic gas verification during CheckTx
if ctx.IsCheckTx() && gasLimit < gas {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrOutOfGas, "intrinsic gas too low: %d < %d", gasLimit, gas)
}
// Charge sender for gas up to limit
if gasLimit != 0 {
// Cost calculates the fees paid to validators based on gas limit and price
cost := new(big.Int).Mul(new(big.Int).SetBytes(msgEthTx.Data.GasPrice), new(big.Int).SetUint64(gasLimit))
evmDenom := egcd.evmKeeper.GetParams(ctx).EvmDenom
feeAmt := sdk.NewCoins(
sdk.NewCoin(evmDenom, sdk.NewIntFromBigInt(cost)),
)
err = authante.DeductFees(egcd.bankKeeper, ctx, senderAcc, feeAmt)
if err != nil {
return ctx, err
}
}
// Set gas meter after ante handler to ignore gaskv costs
newCtx = authante.SetGasMeter(simulate, ctx, gasLimit)
return next(newCtx, tx, simulate)
}
// EthIncrementSenderSequenceDecorator increments the sequence of the signers. The
// main difference with the SDK's IncrementSequenceDecorator is that the MsgEthereumTx
// doesn't implement the SigVerifiableTx interface.
//
// CONTRACT: must be called after msg.VerifySig in order to cache the sender address.
type EthIncrementSenderSequenceDecorator struct {
ak AccountKeeper
}
// NewEthIncrementSenderSequenceDecorator creates a new EthIncrementSenderSequenceDecorator.
func NewEthIncrementSenderSequenceDecorator(ak AccountKeeper) EthIncrementSenderSequenceDecorator {
return EthIncrementSenderSequenceDecorator{
ak: ak,
}
}
// AnteHandle handles incrementing the sequence of the sender.
func (issd EthIncrementSenderSequenceDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
gasMeter := ctx.GasMeter()
ctx = ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
msgEthTx, ok := getTxMsg(tx).(*evmtypes.MsgEthereumTx)
if !ok {
ctx = ctx.WithGasMeter(gasMeter)
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", getTxMsg(tx))
}
// increment sequence of all signers
for _, addr := range msgEthTx.GetSigners() {
acc := issd.ak.GetAccount(ctx, addr)
if err := acc.SetSequence(acc.GetSequence() + 1); err != nil {
log.WithError(err).Panicln("failed to set acc sequence")
}
issd.ak.SetAccount(ctx, acc)
}
// set the original gas meter
ctx = ctx.WithGasMeter(gasMeter)
return next(ctx, tx, simulate)
}
// EthAccountSetupDecorator sets an account to state if it's not stored already. This only applies for MsgEthermint.
type EthAccountSetupDecorator struct {
ak AccountKeeper
}
// NewEthAccountSetupDecorator creates a new EthAccountSetupDecorator instance
func NewEthAccountSetupDecorator(ak AccountKeeper) EthAccountSetupDecorator {
return EthAccountSetupDecorator{
ak: ak,
}
}
// AnteHandle sets an account for MsgEthereumTx (evm) if the sender is registered.
func (asd EthAccountSetupDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
gasMeter := ctx.GasMeter()
ctx = ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
msgEthTx, ok := getTxMsg(tx).(*evmtypes.MsgEthereumTx)
if !ok {
ctx = ctx.WithGasMeter(gasMeter)
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", getTxMsg(tx))
}
setupAccount(asd.ak, ctx, msgEthTx.GetFrom())
// set the original gas meter
ctx = ctx.WithGasMeter(gasMeter)
return next(ctx, tx, simulate)
}
func setupAccount(ak AccountKeeper, ctx sdk.Context, addr sdk.AccAddress) {
acc := ak.GetAccount(ctx, addr)
if acc != nil {
return
}
acc = ak.NewAccountWithAddress(ctx, addr)
ak.SetAccount(ctx, acc)
}