Problem: eip-2935 is not implemented (cosmos#407)

* Problem: eip-2935 is not implemented

Solution:
- adapt the implementation from geth

* change BLOCKHASH opcode to query contract storage

* commit statedb

* fix panic

* temp

* just emulate the contract behavior with native code

* fix test

* fix lint

* fix lint

* revert unneeded changes

* fix test

* revert

* only set contract storage if it's deployed

* fix build

* add history serve window parameter

* cleanup

* fix lint

---------

Co-authored-by: Alex | Interchain Labs <[email protected]>
Co-authored-by: Vlad J <[email protected]>

Author: 3 people

api/cosmos/evm/vm/v1/evm.pulsar.go

@@ -35,6 +35,7 @@ message Params {
   // active_static_precompiles defines the slice of hex addresses of the
   // precompiled contracts that are active
   repeated string active_static_precompiles = 9;
+  uint64 history_serve_window = 10;
 }
 
 // AccessControl defines the permission policy of the EVM

proto/cosmos/evm/vm/v1/evm.proto

@@ -222,7 +222,7 @@ func (s *GenesisTestSuite) TestExportGenesis() {
 
 	genState := vm.ExportGenesis(s.network.GetContext(), s.network.App.GetEVMKeeper())
 	// Exported accounts 4 default preinstalls
-	s.Require().Len(genState.Accounts, 7)
+	s.Require().Len(genState.Accounts, 8)
 
 	addrs := make([]string, len(genState.Accounts))
 	for i, acct := range genState.Accounts {

tests/integration/x/vm/test_genesis.go

@@ -67,7 +67,7 @@ func TestIterateContracts(t *testing.T, create network.CreateEvmApp, options ...
 		return false
 	})
 
-	require.Len(t, foundAddrs, 6, "expected 6 contracts to be found when iterating (4 preinstalled + 2 deployed)")
+	require.Len(t, foundAddrs, 7, "expected 7 contracts to be found when iterating (5 preinstalled + 2 deployed)")
 	require.Contains(t, foundAddrs, contractAddr, "expected contract 1 to be found when iterating")
 	require.Contains(t, foundAddrs, contractAddr2, "expected contract 2 to be found when iterating")
 

tests/integration/x/vm/test_iterate_contracts.go

@@ -5,6 +5,7 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	ethparams "github.com/ethereum/go-ethereum/params"
 	"github.com/holiman/uint256"
 
 	"github.com/cosmos/evm/utils"
@@ -89,7 +90,7 @@ func (s *KeeperTestSuite) TestGetAccountStorage() {
 
 				storage := s.Network.App.GetEVMKeeper().GetAccountStorage(ctx, address)
 
-				if address == contractAddr {
+				if address == contractAddr || address == ethparams.HistoryStorageAddress {
 					s.Require().NotEqual(0, len(storage),
 						"expected account %d to have non-zero amount of storage slots, got %d",
 						i, len(storage),

tests/integration/x/vm/test_keeper.go

@@ -12,7 +12,6 @@ import (
 
 	"github.com/cometbft/cometbft/crypto/tmhash"
 	tmproto "github.com/cometbft/cometbft/proto/tendermint/types"
-	cmttypes "github.com/cometbft/cometbft/types"
 
 	"github.com/cosmos/evm/testutil/config"
 	"github.com/cosmos/evm/testutil/integration/evm/factory"
@@ -33,7 +32,6 @@ import (
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	consensustypes "github.com/cosmos/cosmos-sdk/x/consensus/types"
 	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
-	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 )
 
 func (s *KeeperTestSuite) TestContextSetConsensusParams() {
@@ -81,9 +79,11 @@ func (s *KeeperTestSuite) TestContextSetConsensusParams() {
 
 func (s *KeeperTestSuite) TestGetHashFn() {
 	s.SetupTest()
-	header := s.Network.GetContext().BlockHeader()
-	h, _ := cmttypes.HeaderFromProto(&header)
-	hash := h.Hash()
+	s.Require().NoError(s.Network.NextBlock())
+	ctx := s.Network.GetContext()
+	height := uint64(ctx.BlockHeight()) //nolint:gosec // G115
+	headerHash := common.BytesToHash(ctx.HeaderHash())
+	fmt.Println("get headerHash", height, headerHash)
 
 	testCases := []struct {
 		msg      string
@@ -93,7 +93,7 @@ func (s *KeeperTestSuite) TestGetHashFn() {
 	}{
 		{
 			"case 1.1: context hash cached",
-			uint64(s.Network.GetContext().BlockHeight()), //nolint:gosec // G115
+			height,
 			func() sdk.Context {
 				return s.Network.GetContext().WithHeaderHash(
 					tmhash.Sum([]byte("header")),
@@ -102,51 +102,22 @@ func (s *KeeperTestSuite) TestGetHashFn() {
 			common.BytesToHash(tmhash.Sum([]byte("header"))),
 		},
 		{
-			"case 1.2: failed to cast CometBFT header",
-			uint64(s.Network.GetContext().BlockHeight()), //nolint:gosec // G115
+			"case 1.2: works for invalid CometBFT header",
+			height,
 			func() sdk.Context {
 				header := tmproto.Header{}
 				header.Height = s.Network.GetContext().BlockHeight()
 				return s.Network.GetContext().WithBlockHeader(header)
 			},
-			common.Hash{},
-		},
-		{
-			"case 1.3: hash calculated from CometBFT header",
-			uint64(s.Network.GetContext().BlockHeight()), //nolint:gosec // G115
-			func() sdk.Context {
-				return s.Network.GetContext().WithBlockHeader(header)
-			},
-			common.BytesToHash(hash),
+			headerHash,
 		},
 		{
-			"case 2.1: height lower than current one, hist info not found",
-			1,
+			"case 2.1: height lower than current one works",
+			height,
 			func() sdk.Context {
 				return s.Network.GetContext().WithBlockHeight(10)
 			},
-			common.Hash{},
-		},
-		{
-			"case 2.2: height lower than current one, invalid hist info header",
-			1,
-			func() sdk.Context {
-				s.Require().NoError(s.Network.App.GetStakingKeeper().SetHistoricalInfo(s.Network.GetContext(), 1, &stakingtypes.HistoricalInfo{}))
-				return s.Network.GetContext().WithBlockHeight(10)
-			},
-			common.Hash{},
-		},
-		{
-			"case 2.3: height lower than current one, calculated from hist info header",
-			1,
-			func() sdk.Context {
-				histInfo := &stakingtypes.HistoricalInfo{
-					Header: header,
-				}
-				s.Require().NoError(s.Network.App.GetStakingKeeper().SetHistoricalInfo(s.Network.GetContext(), 1, histInfo))
-				return s.Network.GetContext().WithBlockHeight(10)
-			},
-			common.BytesToHash(hash),
+			headerHash,
 		},
 		{
 			"case 3: height greater than current one",

tests/integration/x/vm/test_state_transition.go

@@ -60,6 +60,7 @@ func (n *IntegrationNetwork) finalizeBlockAndCommit(duration time.Duration, txBy
 	// This might have to be changed with time if we want to test gas limits
 	newCtx = newCtx.WithBlockGasMeter(storetypes.NewInfiniteGasMeter())
 	newCtx = newCtx.WithVoteInfos(req.DecidedLastCommit.GetVotes())
+	newCtx = newCtx.WithHeaderHash(header.AppHash)
 	n.ctx = newCtx
 
 	// commit changes

testutil/integration/evm/network/abci.go

@@ -31,6 +31,8 @@ func (k *Keeper) BeginBlock(ctx sdk.Context) error {
 			),
 		})
 	}
+
+	k.SetHeaderHash(ctx)
 	return nil
 }
 

x/vm/keeper/abci.go

@@ -1,14 +1,15 @@
 package keeper
 
 import (
+	"encoding/binary"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/tracing"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
-	"github.com/ethereum/go-ethereum/params"
+	ethparams "github.com/ethereum/go-ethereum/params"
 	"github.com/holiman/uint256"
 
 	evmmempool "github.com/cosmos/evm/mempool"
@@ -254,7 +255,7 @@ func (k Keeper) GetAccountStorage(ctx sdk.Context, address common.Address) types
 // ----------------------------------------------------------------------------
 
 // Tracer return a default vm.Tracer based on current keeper state
-func (k Keeper) Tracer(ctx sdk.Context, msg core.Message, ethCfg *params.ChainConfig) *tracing.Hooks {
+func (k Keeper) Tracer(ctx sdk.Context, msg core.Message, ethCfg *ethparams.ChainConfig) *tracing.Hooks {
 	return types.NewTracer(k.tracer, msg, ethCfg, ctx.BlockHeight(), uint64(ctx.BlockTime().Unix())) //#nosec G115 -- int overflow is not a concern here
 }
 
@@ -401,3 +402,35 @@ func (k *Keeper) SetEvmMempool(evmMempool *evmmempool.ExperimentalEVMMempool) {
 func (k Keeper) GetEvmMempool() *evmmempool.ExperimentalEVMMempool {
 	return k.evmMempool
 }
+
+// SetHeaderHash sets current block hash into EIP-2935 compatible storage contract.
+func (k Keeper) SetHeaderHash(ctx sdk.Context) {
+	window := uint64(types.DefaultHistoryServeWindow)
+	params := k.GetParams(ctx)
+	if params.HistoryServeWindow > 0 {
+		window = params.HistoryServeWindow
+	}
+
+	acct := k.GetAccount(ctx, ethparams.HistoryStorageAddress)
+	if acct != nil && acct.IsContract() {
+		// set current block hash in the contract storage, compatible with EIP-2935
+		ringIndex := uint64(ctx.BlockHeight()) % window //nolint:gosec // G115 // won't exceed uint64
+		var key common.Hash
+		binary.BigEndian.PutUint64(key[24:], ringIndex)
+		k.SetState(ctx, ethparams.HistoryStorageAddress, key, ctx.HeaderHash())
+	}
+}
+
+// GetHeaderHash sets block hash into EIP-2935 compatible storage contract.
+func (k Keeper) GetHeaderHash(ctx sdk.Context, height uint64) common.Hash {
+	window := uint64(types.DefaultHistoryServeWindow)
+	params := k.GetParams(ctx)
+	if params.HistoryServeWindow > 0 {
+		window = params.HistoryServeWindow
+	}
+
+	ringIndex := height % window
+	var key common.Hash
+	binary.BigEndian.PutUint64(key[24:], ringIndex)
+	return k.GetState(ctx, ethparams.HistoryStorageAddress, key)
+}

x/vm/keeper/keeper.go

@@ -112,23 +112,11 @@ func (k Keeper) GetHashFn(ctx sdk.Context) vm.GetHashFunc {
 			return common.BytesToHash(headerHash)
 
 		case ctx.BlockHeight() > h:
-			// Case 2: if the chain is not the current height we need to retrieve the hash from the store for the
-			// current chain epoch. This only applies if the current height is greater than the requested height.
-			histInfo, err := k.stakingKeeper.GetHistoricalInfo(ctx, h)
-			if err != nil {
-				k.Logger(ctx).Debug("error while getting historical info", "height", h, "error", err.Error())
-				return common.Hash{}
-			}
-
-			header, err := cmttypes.HeaderFromProto(&histInfo.Header)
-			if err != nil {
-				k.Logger(ctx).Error("failed to cast CometBFT header from proto", "error", err)
-				return common.Hash{}
-			}
-
-			return common.BytesToHash(header.Hash())
+			// Case 2: The requested height is historical, query EIP-2935 contract storage for that
+			// see: https://github.com/cosmos/evm/issues/406
+			return k.GetHeaderHash(ctx, height)
 		default:
-			// Case 3: heights greater than the current one returns an empty hash.
+			// Case 3: The requested height is greater than the latest one, return empty hash
 			return common.Hash{}
 		}
 	}