fix: padding bytes in ComputeBatchID (#124)

common/utils/contracts.go

@@ -10,9 +10,10 @@ import (
 // ComputeBatchID compute a unique hash for a batch using "endBlockHash" & "endBlockHash in last batch"
 // & "batch height", following the logic in `_computeBatchId` in contracts/src/L1/rollup/ZKRollup.sol
 func ComputeBatchID(endBlockHash common.Hash, lastEndBlockHash common.Hash, index *big.Int) string {
+	indexBytes := make([]byte, 32)
 	return crypto.Keccak256Hash(
 		endBlockHash.Bytes(),
 		lastEndBlockHash.Bytes(),
-		index.Bytes(),
+		index.FillBytes(indexBytes),
 	).String()
 }

common/utils/contracts_test.go

@@ -1,6 +1,7 @@
 package utils_test
 
 import (
+	"math/big"
 	"testing"
 
 	"github.com/scroll-tech/go-ethereum/common"
@@ -29,4 +30,11 @@ func TestComputeBatchID(t *testing.T) {
 	expected := "0xafe1e714d2cd3ed5b0fa0a04ee95cd564b955ab8661c5665588758b48b66e263"
 	actual := utils.ComputeBatchID(common.Hash{}, common.Hash{}, math.MaxBig256)
 	assert.Equal(t, expected, actual)
+
+	expected = "0xe05698242b035c0e4d1d58e8ab89507ac7a1403b17fd6a7ea87621a32674ec88"
+	actual = utils.ComputeBatchID(
+		common.HexToHash("0xfaef7761204f43c4ab2528a65fcc7ec2108709e5ebb646bdce9ce3c8862d3f25"),
+		common.HexToHash("0xe3abef08cce4b8a0dcc6b7e4dd11f32863007a86f46c1d136682b5d77bdf0f7a"),
+		big.NewInt(77233900))
+	assert.Equal(t, expected, actual)
 }

common/version/version.go

@@ -5,7 +5,7 @@ import (
 	"runtime/debug"
 )
 
-var tag = "prealpha-v6.4"
+var tag = "prealpha-v6.5"
 
 var commit = func() string {
 	if info, ok := debug.ReadBuildInfo(); ok {