fix: audit (#71)

* deteach burn permission from the owner

* convert precompiles out-of-gas to evm out-of-gas

* change burn function on initiaerc20

* burn left balance in the self destructed account at commit

* return zero hash if the account does not have code

* fix to update balance before commit

* return empty code hash when account exists but code is empty

* implement gas refunds at post handler

* use gas consumped to limit

* add IsEVMTx check at gas refunds

* remove unnecessary override

* call next()

* remove print

Makefile

@@ -164,7 +164,7 @@ proto-pulsar-gen:
 	@$(protoImage) sh ./scripts/protocgen-pulsar.sh
 
 proto-format:
-	@$(protoImage) find ./ -name "*.proto" -exec clang-format -i {} \;
+	@$(protoImage) find ./ -name "*.proto" -exec buf format {} -w \;
 
 proto-lint:
 	@$(protoImage) buf lint --error-format=json ./proto

app/ante/ante.go

@@ -30,7 +30,7 @@ type HandlerOptions struct {
 	IBCkeeper     *ibckeeper.Keeper
 	OPChildKeeper opchildtypes.AnteKeeper
 	AuctionKeeper auctionkeeper.Keeper
-	EVMKeeper     *evmkeeper.Keeper
+	EVMKeeper     EVMKeeper
 
 	TxEncoder sdk.TxEncoder
 	MevLane   auctionante.MEVLane

app/ante/expected_keepers.go

@@ -0,0 +1,12 @@
+package ante
+
+import (
+	"context"
+
+	evmtypes "github.com/initia-labs/minievm/x/evm/types"
+)
+
+type EVMKeeper interface {
+	GetFeeDenom(ctx context.Context) (string, error)
+	TxUtils() evmtypes.TxUtils
+}

app/ante/fee.go

@@ -8,8 +8,6 @@ import (
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/cosmos/cosmos-sdk/x/auth/ante"
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
-
-	evmkeeper "github.com/initia-labs/minievm/x/evm/keeper"
 )
 
 // feeDeductionGasAmount is a estimated gas amount of fee payment
@@ -23,12 +21,12 @@ type GasFreeFeeDecorator struct {
 	inner ante.DeductFeeDecorator
 
 	// ek is used to get the fee denom from the x/evm params.
-	ek *evmkeeper.Keeper
+	ek EVMKeeper
 }
 
 func NewGasFreeFeeDecorator(
 	ak ante.AccountKeeper, bk types.BankKeeper,
-	fk ante.FeegrantKeeper, ek *evmkeeper.Keeper,
+	fk ante.FeegrantKeeper, ek EVMKeeper,
 	tfc ante.TxFeeChecker) GasFreeFeeDecorator {
 	return GasFreeFeeDecorator{
 		inner: ante.NewDeductFeeDecorator(ak, bk, fk, tfc),

app/ante/sigverify.go

@@ -22,7 +22,6 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
 
 	"github.com/initia-labs/initia/crypto/ethsecp256k1"
-	evmkeeper "github.com/initia-labs/minievm/x/evm/keeper"
 	evmtypes "github.com/initia-labs/minievm/x/evm/types"
 )
 
@@ -33,13 +32,13 @@ import (
 // CONTRACT: Tx must implement SigVerifiableTx interface
 type SigVerificationDecorator struct {
 	ak              authante.AccountKeeper
-	ek              *evmkeeper.Keeper
+	ek              EVMKeeper
 	signModeHandler *txsigning.HandlerMap
 }
 
 func NewSigVerificationDecorator(
 	ak authante.AccountKeeper,
-	ek *evmkeeper.Keeper,
+	ek EVMKeeper,
 	signModeHandler *txsigning.HandlerMap) SigVerificationDecorator {
 	return SigVerificationDecorator{
 		ak:              ak,

app/ante/verify.go

@@ -48,14 +48,14 @@ func verifySignature(
 	handler *txsigning.HandlerMap,
 	txData txsigning.TxData,
 	// required to verify EVM signatures
-	ek *evmkeeper.Keeper,
+	ek EVMKeeper,
 	tx sdk.Tx,
 ) error {
 	switch data := signatureData.(type) {
 	case *signing.SingleSignatureData:
 		if data.SignMode == evmkeeper.SignMode_SIGN_MODE_ETHEREUM {
 			// eth sign mode
-			ethTx, expectedSender, err := evmkeeper.NewTxUtils(ek).ConvertCosmosTxToEthereumTx(ctx, tx)
+			ethTx, expectedSender, err := ek.TxUtils().ConvertCosmosTxToEthereumTx(ctx, tx)
 			if err != nil {
 				return err
 			}

app/app.go

@@ -363,6 +363,7 @@ func (app *MinitiaApp) SetCheckTx(handler blockchecktx.CheckTx) {
 func (app *MinitiaApp) setPostHandler() {
 	app.SetPostHandler(posthandler.NewPostHandler(
 		app.AccountKeeper,
+		app.EVMKeeper,
 	))
 }
 

app/posthandler/gasrefund.go

@@ -0,0 +1,91 @@
+package posthandler
+
+import (
+	"fmt"
+
+	errorsmod "cosmossdk.io/errors"
+	"cosmossdk.io/math"
+	storetypes "cosmossdk.io/store/types"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+
+	evmante "github.com/initia-labs/minievm/x/evm/ante"
+)
+
+var _ sdk.PostDecorator = &GasRefundDecorator{}
+
+type GasRefundDecorator struct {
+	ek EVMKeeper
+}
+
+func NewGasRefundDecorator(ek EVMKeeper) sdk.PostDecorator {
+	return &GasRefundDecorator{
+		ek,
+	}
+}
+
+// PostHandle handles the gas refund logic for EVM transactions.
+func (erd *GasRefundDecorator) PostHandle(ctx sdk.Context, tx sdk.Tx, simulate, success bool, next sdk.PostHandler) (newCtx sdk.Context, err error) {
+	if success && ctx.ExecMode() == sdk.ExecModeFinalize {
+		// Conduct gas refund only for the successful EVM transactions
+		if ok, err := erd.ek.TxUtils().IsEthereumTx(ctx, tx); err != nil || !ok {
+			return next(ctx, tx, simulate, success)
+		}
+
+		feeTx, ok := tx.(sdk.FeeTx)
+		if !ok {
+			return ctx, errorsmod.Wrap(sdkerrors.ErrTxDecode, "Tx must be a FeeTx")
+		}
+
+		value := ctx.Value(evmante.ContextKeyGasPrices)
+		if value == nil {
+			return next(ctx, tx, simulate, success)
+		}
+		gasRefundRatio, err := erd.ek.GasRefundRatio(ctx)
+		if err != nil {
+			return ctx, err
+		}
+
+		gasPrices := value.(sdk.DecCoins)
+		gasLeft := ctx.GasMeter().Limit() - ctx.GasMeter().GasConsumedToLimit()
+		gasRefund := gasRefundRatio.MulInt64(int64(gasLeft)).TruncateInt().Uint64()
+
+		// gas used for refund operation
+		coinsRefund, _ := gasPrices.MulDec(math.LegacyNewDecFromInt(math.NewIntFromUint64(gasRefund))).TruncateDecimal()
+		if coinsRefund.Empty() || coinsRefund.IsZero() {
+			return next(ctx, tx, simulate, success)
+		}
+
+		feePayer := feeTx.FeePayer()
+		if feeGranter := feeTx.FeeGranter(); feeGranter != nil {
+			feePayer = feeGranter
+		}
+
+		// emit gas refund event
+		ctx.EventManager().EmitEvent(sdk.NewEvent(
+			EventTypeGasRefund,
+			sdk.NewAttribute(AttributeKeyGas, fmt.Sprintf("%d", gasRefund)),
+			sdk.NewAttribute(AttributeKeyCoins, coinsRefund.String()),
+		))
+
+		// TODO - should we charge gas for refund?
+		//
+		// for now, we use infinite gas meter to prevent out of gas error or inconsistency between
+		// used gas and refunded gas.
+		feeCollectorAddr := authtypes.NewModuleAddress(authtypes.FeeCollectorName)
+		err = erd.ek.ERC20Keeper().SendCoins(ctx.WithGasMeter(storetypes.NewInfiniteGasMeter()), feeCollectorAddr, feePayer, coinsRefund)
+		if err != nil {
+			return ctx, err
+		}
+	}
+
+	return next(ctx, tx, simulate, success)
+}
+
+const (
+	EventTypeGasRefund = "gas_refund"
+	AttributeKeyGas    = "gas"
+	AttributeKeyCoins  = "coins"
+)

app/posthandler/posthandler.go

@@ -1,11 +1,28 @@
 package posthandler
 
 import (
+	"context"
+
+	"cosmossdk.io/math"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	authante "github.com/cosmos/cosmos-sdk/x/auth/ante"
+
+	evmtypes "github.com/initia-labs/minievm/x/evm/types"
 )
 
 // NewPostHandler returns a new sdk.PostHandler that is composed of the sdk.ChainPostDecorators
-func NewPostHandler(ak authante.AccountKeeper) sdk.PostHandler {
-	return sdk.ChainPostDecorators(NewSequenceIncrementDecorator(ak))
+func NewPostHandler(
+	ak authante.AccountKeeper,
+	ek EVMKeeper,
+) sdk.PostHandler {
+	return sdk.ChainPostDecorators(
+		NewSequenceIncrementDecorator(ak),
+		NewGasRefundDecorator(ek),
+	)
+}
+
+type EVMKeeper interface {
+	GasRefundRatio(context.Context) (math.LegacyDec, error)
+	ERC20Keeper() evmtypes.IERC20Keeper
+	TxUtils() evmtypes.TxUtils
 }

indexer/abci.go

@@ -97,7 +97,7 @@ func (e *EVMIndexerImpl) ListenFinalizeBlock(ctx context.Context, req abci.Reque
 			EffectiveGasPrice: ethTx.GasPrice(),
 		}
 
-		// currently we do not support fee refund, so the effective gas price is the same as the gas price
+		// currently we do not support fee refund for gas tip, so the effective gas price is the same as the gas price
 		// if ethTx.Type() == coretypes.DynamicFeeTxType {
 		// 	receipt.EffectiveGasPrice = new(big.Int).Add(ethTx.EffectiveGasTipValue(baseFee.ToInt()), baseFee.ToInt())
 		// }

proto/minievm/evm/v1/auth.proto

@@ -9,11 +9,11 @@ option go_package = "github.com/initia-labs/minievm/x/evm/types";
 
 // ContractAccount defines an account of contract.
 message ContractAccount {
-  option (amino.name)                = "evm/ContractAccount";
+  option (amino.name) = "evm/ContractAccount";
   option (gogoproto.goproto_getters) = false;
 
   cosmos.auth.v1beta1.BaseAccount base_account = 1 [(gogoproto.embed) = true];
-  bytes                           code_hash    = 2;
+  bytes code_hash = 2;
 }
 
 // ShorthandAccount defines an account of shorthand address
@@ -22,9 +22,9 @@ message ContractAccount {
 // Also it is used to check the existence of the account before
 // creating a new account.
 message ShorthandAccount {
-  option (amino.name)                = "evm/ShorthandAccount";
+  option (amino.name) = "evm/ShorthandAccount";
   option (gogoproto.goproto_getters) = false;
 
-  cosmos.auth.v1beta1.BaseAccount base_account     = 1 [(gogoproto.embed) = true];
-  string                          original_address = 2;
+  cosmos.auth.v1beta1.BaseAccount base_account = 1 [(gogoproto.embed) = true];
+  string original_address = 2;
 }

proto/minievm/evm/v1/genesis.proto

@@ -12,33 +12,40 @@ message GenesisState {
   Params params = 1 [(gogoproto.nullable) = false];
 
   // vm kv store
-  repeated GenesisKeyValue key_values = 2 [(gogoproto.moretags) = "yaml:\"key_values\"", (gogoproto.nullable) = false];
+  repeated GenesisKeyValue key_values = 2 [
+    (gogoproto.moretags) = "yaml:\"key_values\"",
+    (gogoproto.nullable) = false
+  ];
 
   // erc20 stores
-  repeated GenesisERC20Stores erc20_stores = 3
-      [(gogoproto.moretags) = "yaml:\"erc20_stores\"", (gogoproto.nullable) = false];
+  repeated GenesisERC20Stores erc20_stores = 3 [
+    (gogoproto.moretags) = "yaml:\"erc20_stores\"",
+    (gogoproto.nullable) = false
+  ];
 
-  repeated GenesisDenomAddress denom_addresses = 4
-      [(gogoproto.moretags) = "yaml:\"denom_addresses\"", (gogoproto.nullable) = false];
+  repeated GenesisDenomAddress denom_addresses = 4 [
+    (gogoproto.moretags) = "yaml:\"denom_addresses\"",
+    (gogoproto.nullable) = false
+  ];
 
   // erc20 factory contract address
   bytes erc20_factory = 5;
 }
 
 // GenesisKeyValue defines store KV values.
 message GenesisKeyValue {
-  bytes key   = 1;
+  bytes key = 1;
   bytes value = 2;
 }
 
 // GenesisERC20Stores defines erc20 contract addresses of an account.
 message GenesisERC20Stores {
-  bytes          address = 1;
-  repeated bytes stores  = 2;
+  bytes address = 1;
+  repeated bytes stores = 2;
 }
 
 // GenesisDenomAddress defines erc20 contract address of denom.
 message GenesisDenomAddress {
-  string denom            = 1;
-  bytes  contract_address = 2;
-}
+  string denom = 1;
+  bytes contract_address = 2;
+}

proto/minievm/evm/v1/query.proto

@@ -6,8 +6,8 @@ import "gogoproto/gogo.proto";
 import "google/api/annotations.proto";
 import "minievm/evm/v1/types.proto";
 
-option go_package                      = "github.com/initia-labs/minievm/x/evm/types";
-option (gogoproto.equal_all)           = false;
+option go_package = "github.com/initia-labs/minievm/x/evm/types";
+option (gogoproto.equal_all) = false;
 option (gogoproto.goproto_getters_all) = false;
 
 // Query provides defines the gRPC querier service
@@ -62,7 +62,7 @@ message QueryCodeRequest {
 // method
 message QueryCodeResponse {
   option (gogoproto.equal) = true;
-  string code              = 1;
+  string code = 1;
 }
 
 // QueryStateRequest is the request type for the Query/State RPC
@@ -119,7 +119,7 @@ message QueryDenomRequest {
 // method
 message QueryDenomResponse {
   option (gogoproto.equal) = true;
-  string denom             = 1;
+  string denom = 1;
 }
 
 // QueryCallRequest is the request type for the Query/Call RPC
@@ -132,8 +132,11 @@ message QueryCallRequest {
   // hex encoded call input
   string input = 3;
   // Value is the amount of fee denom token to transfer to the contract.
-  string value = 4
-      [(gogoproto.customtype) = "cosmossdk.io/math.Int", (gogoproto.nullable) = false, (amino.dont_omitempty) = true];
+  string value = 4 [
+    (gogoproto.customtype) = "cosmossdk.io/math.Int",
+    (gogoproto.nullable) = false,
+    (amino.dont_omitempty) = true
+  ];
   // whether to trace the call
   // `nil` means no trace
   TraceOptions trace_options = 5;
@@ -155,11 +158,14 @@ message TraceOptions {
 // method
 message QueryCallResponse {
   // hex encoded response bytes.
-  string       response     = 1;
-  uint64       used_gas     = 2;
-  repeated Log logs         = 3 [(gogoproto.nullable) = false, (amino.dont_omitempty) = true];
-  string       trace_output = 4;
-  string       error        = 5;
+  string response = 1;
+  uint64 used_gas = 2;
+  repeated Log logs = 3 [
+    (gogoproto.nullable) = false,
+    (amino.dont_omitempty) = true
+  ];
+  string trace_output = 4;
+  string error = 5;
 }
 
 // QueryParamsRequest is the request type for the Query/Params RPC method.