evm: state transitions enabled params (#603)

* changelog

* evm: state transitions enabled params

* changelog entry

* changelog

CHANGELOG.md

@@ -35,6 +35,15 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 # Changelog
 
+## Unreleased
+
+### Improvements
+
+* (deps) [\#610](https://github.com/cosmos/ethermint/pull/610) Update Go dependency to 1.15+.
+* (deps) [\#608](https://github.com/cosmos/ethermint/pull/608) Bump Cosmos SDK version to [v0.39.2](https://github.com/cosmos/cosmos-sdk/tag/v0.39.2)
+* (evm) [#603](https://github.com/cosmos/ethermint/pull/603) Add state transition params that enable or disable the EVM `Call` and `Create` operations.
+* (deps) [\#602](https://github.com/cosmos/ethermint/pull/602) Bump tendermint version to [v0.33.9](https://github.com/tendermint/tendermint/releases/tag/v0.33.9)
+
 ## [v0.3.0] - 2020-11-16
 
 ### API Breaking

x/evm/types/errors.go

@@ -15,4 +15,10 @@ var (
 
  // ErrInvalidChainConfig returns an error resulting from an invalid ChainConfig.
  ErrInvalidChainConfig = sdkerrors.Register(ModuleName, 4, "invalid chain configuration")
+
+ // ErrCreateDisabled returns an error if the EnableCreate parameter is false.
+ ErrCreateDisabled = sdkerrors.Register(ModuleName, 5, "EVM Create operation is disabled")
+
+ // ErrCallDisabled returns an error if the EnableCall parameter is false.
+ ErrCallDisabled = sdkerrors.Register(ModuleName, 6, "EVM Call operation is disabled")
 )

x/evm/types/params.go

@@ -18,7 +18,9 @@ const (
 
 // Parameter keys
 var (
- ParamStoreKeyEVMDenom = []byte("EVMDenom")
+ ParamStoreKeyEVMDenom = []byte("EVMDenom")
+ ParamStoreKeyEnableCreate = []byte("EnableCreate")
+ ParamStoreKeyEnableCall = []byte("EnableCall")
 )
 
 // ParamKeyTable returns the parameter key table.
@@ -28,20 +30,30 @@ func ParamKeyTable() params.KeyTable {
 
 // Params defines the EVM module parameters
 type Params struct {
+ // EVMDenom defines the token denomination used for state transitions on the
+ // EVM module.
  EvmDenom string `json:"evm_denom" yaml:"evm_denom"`
+ // EnableCreate toggles state transitions that use the vm.Create function
+ EnableCreate bool `json:"enable_create" yaml:"enable_create"`
+ // EnableCall toggles state transitions that use the vm.Call function
+ EnableCall bool `json:"enable_call" yaml:"enable_call"`
 }
 
 // NewParams creates a new Params instance
-func NewParams(evmDenom string) Params {
+func NewParams(evmDenom string, enableCreate, enableCall bool) Params {
  return Params{
- EvmDenom: evmDenom,
+ EvmDenom: evmDenom,
+ EnableCreate: enableCreate,
+ EnableCall: enableCall,
  }
 }
 
 // DefaultParams returns default evm parameters
 func DefaultParams() Params {
  return Params{
- EvmDenom: ethermint.AttoPhoton,
+ EvmDenom: ethermint.AttoPhoton,
+ EnableCreate: true,
+ EnableCall: true,
  }
 }
 
@@ -55,6 +67,8 @@ func (p Params) String() string {
 func (p *Params) ParamSetPairs() params.ParamSetPairs {
  return params.ParamSetPairs{
  params.NewParamSetPair(ParamStoreKeyEVMDenom, &p.EvmDenom, validateEVMDenom),
+ params.NewParamSetPair(ParamStoreKeyEnableCreate, &p.EnableCreate, validateBool),
+ params.NewParamSetPair(ParamStoreKeyEnableCall, &p.EnableCall, validateBool),
  }
 }
 
@@ -66,8 +80,16 @@ func (p Params) Validate() error {
 func validateEVMDenom(i interface{}) error {
  denom, ok := i.(string)
  if !ok {
- return fmt.Errorf("invalid parameter type: %T", i)
+ return fmt.Errorf("invalid parameter EVM denom type: %T", i)
  }
 
  return sdk.ValidateDenom(denom)
 }
+
+func validateBool(i interface{}) error {
+ _, ok := i.(bool)
+ if !ok {
+ return fmt.Errorf("invalid parameter type: %T", i)
+ }
+ return nil
+}

x/evm/types/params_test.go

@@ -15,7 +15,7 @@ func TestParamsValidate(t *testing.T) {
  {"default", DefaultParams(), false},
  {
  "valid",
- NewParams("ara"),
+ NewParams("ara", true, true),
  false,
  },
  {
@@ -45,8 +45,11 @@ func TestParamsValidate(t *testing.T) {
 
 func TestParamsValidatePriv(t *testing.T) {
  require.Error(t, validateEVMDenom(false))
+ require.NoError(t, validateEVMDenom("aphoton"))
+ require.Error(t, validateBool(""))
+ require.NoError(t, validateBool(true))
 }
 
 func TestParams_String(t *testing.T) {
- require.Equal(t, "evm_denom: aphoton\n", DefaultParams().String())
+ require.Equal(t, "evm_denom: aphoton\nenable_create: true\nenable_call: true\n", DefaultParams().String())
 }

x/evm/types/state_transition.go

@@ -101,8 +101,9 @@ func (st StateTransition) TransitionDb(ctx sdk.Context, config ChainConfig) (*Ex
  // Clear cache of accounts to handle changes outside of the EVM
  csdb.UpdateAccounts()
 
- evmDenom := csdb.GetParams().EvmDenom
- gasPrice := ctx.MinGasPrices().AmountOf(evmDenom)
+ params := csdb.GetParams()
+
+ gasPrice := ctx.MinGasPrices().AmountOf(params.EvmDenom)
  if gasPrice.IsNil() {
  return nil, errors.New("gas price cannot be nil")
  }
@@ -125,9 +126,17 @@ func (st StateTransition) TransitionDb(ctx sdk.Context, config ChainConfig) (*Ex
  // create contract or execute call
  switch contractCreation {
  case true:
+ if !params.EnableCreate {
+ return nil, ErrCreateDisabled
+ }
+
  ret, contractAddress, leftOverGas, err = evm.Create(senderRef, st.Payload, gasLimit, st.Amount)
  recipientLog = fmt.Sprintf("contract address %s", contractAddress.String())
  default:
+ if !params.EnableCall {
+ return nil, ErrCreateDisabled
+ }
+
  // Increment the nonce for the next transaction (just for evm state transition)
  csdb.SetNonce(st.Sender, csdb.GetNonce(st.Sender)+1)
  ret, leftOverGas, err = evm.Call(senderRef, *st.Recipient, st.Payload, gasLimit, st.Amount)