fix: block header hash not available in staking module

x/vm/keeper/abci.go

@@ -10,6 +10,8 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
+const DefaultHeaderHashNum = int64(10000)
+
 // BeginBlock emits a base fee event which will be adjusted to the evm decimals
 func (k *Keeper) BeginBlock(ctx sdk.Context) error {
 	logger := ctx.Logger().With("begin_block", "evm")
@@ -31,6 +33,13 @@ func (k *Keeper) BeginBlock(ctx sdk.Context) error {
 			),
 		})
 	}
+
+	// store block header hash and rotate the old ones.
+	k.SetHeaderHash(ctx)
+	if i := ctx.BlockHeight() - DefaultHeaderHashNum; i > 0 {
+		k.DeleteHeaderHash(ctx, i)
+	}
+
 	return nil
 }
 

x/vm/keeper/keeper.go

@@ -351,3 +351,21 @@ func (k Keeper) AddTransientGasUsed(ctx sdk.Context, gasUsed uint64) (uint64, er
 	k.SetTransientGasUsed(ctx, result)
 	return result, nil
 }
+
+// SetHeaderHash stores the hash of the current block header in the store.
+func (k Keeper) SetHeaderHash(ctx sdk.Context) {
+	store := ctx.KVStore(k.storeKey)
+	store.Set(types.GetHeaderHashKey(ctx.BlockHeight()), ctx.HeaderHash())
+}
+
+// GetHeaderHash retrieves the hash of a block header from the store by height.
+func (k Keeper) GetHeaderHash(ctx sdk.Context, height int64) []byte {
+	store := ctx.KVStore(k.storeKey)
+	return store.Get(types.GetHeaderHashKey(height))
+}
+
+// DeleteHeaderHash removes the hash of a block header from the store by height
+func (k Keeper) DeleteHeaderHash(ctx sdk.Context, height int64) {
+	store := ctx.KVStore(k.storeKey)
+	store.Delete(types.GetHeaderHashKey(height))
+}

x/vm/keeper/state_transition.go

@@ -11,8 +11,6 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
 
-	cmttypes "github.com/cometbft/cometbft/types"
-
 	cosmosevmtypes "github.com/cosmos/evm/types"
 	"github.com/cosmos/evm/utils"
 	"github.com/cosmos/evm/x/vm/statedb"
@@ -86,47 +84,7 @@ func (k Keeper) GetHashFn(ctx sdk.Context) vm.GetHashFunc {
 			return common.Hash{}
 		}
 
-		switch {
-		case ctx.BlockHeight() == h:
-			// Case 1: The requested height matches the one from the context so we can retrieve the header
-			// hash directly from the context.
-			// Note: The headerHash is only set at begin block, it will be nil in case of a query context
-			headerHash := ctx.HeaderHash()
-			if len(headerHash) != 0 {
-				return common.BytesToHash(headerHash)
-			}
-
-			// only recompute the hash if not set (eg: checkTxState)
-			contextBlockHeader := ctx.BlockHeader()
-			header, err := cmttypes.HeaderFromProto(&contextBlockHeader)
-			if err != nil {
-				k.Logger(ctx).Error("failed to cast tendermint header from proto", "error", err)
-				return common.Hash{}
-			}
-
-			headerHash = header.Hash()
-			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 tendermint header from proto", "error", err)
-				return common.Hash{}
-			}
-
-			return common.BytesToHash(header.Hash())
-		default:
-			// Case 3: heights greater than the current one returns an empty hash.
-			return common.Hash{}
-		}
+		return common.BytesToHash(k.GetHeaderHash(ctx, h))
 	}
 }
 

x/vm/types/key.go

@@ -1,6 +1,8 @@
 package types
 
 import (
+	"encoding/binary"
+
 	"github.com/ethereum/go-ethereum/common"
 )
 
@@ -27,6 +29,7 @@ const (
 	prefixStorage
 	prefixParams
 	prefixCodeHash
+	prefixHeaderHash
 )
 
 // prefix bytes for the EVM transient store
@@ -39,10 +42,11 @@ const (
 
 // KVStore key prefixes
 var (
-	KeyPrefixCode     = []byte{prefixCode}
-	KeyPrefixStorage  = []byte{prefixStorage}
-	KeyPrefixParams   = []byte{prefixParams}
-	KeyPrefixCodeHash = []byte{prefixCodeHash}
+	KeyPrefixCode       = []byte{prefixCode}
+	KeyPrefixStorage    = []byte{prefixStorage}
+	KeyPrefixParams     = []byte{prefixParams}
+	KeyPrefixCodeHash   = []byte{prefixCodeHash}
+	KeyPrefixHeaderHash = []byte{prefixHeaderHash}
 )
 
 // Transient Store key prefixes
@@ -62,3 +66,10 @@ func AddressStoragePrefix(address common.Address) []byte {
 func StateKey(address common.Address, key []byte) []byte {
 	return append(AddressStoragePrefix(address), key...)
 }
+
+func GetHeaderHashKey(height int64) []byte {
+	var key [1 + 8]byte
+	key[0] = prefixHeaderHash
+	binary.BigEndian.PutUint64(key[1:], uint64(height))
+	return key[:]
+}