Move checkpoint tag to params

app/ante_btc_validation_decorator.go

@@ -2,18 +2,24 @@ package app
 
 import (
 	bbn "github.com/babylonchain/babylon/types"
+	btccheckpointkeeper "github.com/babylonchain/babylon/x/btccheckpoint/keeper"
 	btccheckpointtypes "github.com/babylonchain/babylon/x/btccheckpoint/types"
 	btclightclient "github.com/babylonchain/babylon/x/btclightclient/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
 type BtcValidationDecorator struct {
-	BtcCfg bbn.BtcConfig
+	BtcCfg              bbn.BtcConfig
+	btccheckpointKeeper *btccheckpointkeeper.Keeper
 }
 
-func NewBtcValidationDecorator(cfg bbn.BtcConfig) BtcValidationDecorator {
+func NewBtcValidationDecorator(
+	cfg bbn.BtcConfig,
+	k *btccheckpointkeeper.Keeper,
+) BtcValidationDecorator {
 	return BtcValidationDecorator{
-		BtcCfg: cfg,
+		BtcCfg:              cfg,
+		btccheckpointKeeper: k,
 	}
 }
 
@@ -26,7 +32,7 @@ func (bvd BtcValidationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulat
 			switch msg := m.(type) {
 			case *btccheckpointtypes.MsgInsertBTCSpvProof:
 				powLimit := bvd.BtcCfg.PowLimit()
-				_, err := btccheckpointtypes.ParseSubmission(msg, &powLimit, bvd.BtcCfg.CheckpointTag())
+				_, err := btccheckpointtypes.ParseSubmission(msg, &powLimit, bvd.btccheckpointKeeper.GetExpectedTag(ctx))
 
 				if err != nil {
 					return ctx, btccheckpointtypes.ErrInvalidCheckpointProof.Wrap(err.Error())

app/app.go

@@ -606,7 +606,6 @@ func NewBabylonApp(
 			&btclightclientKeeper,
 			app.CheckpointingKeeper,
 			&powLimit,
-			btcConfig.CheckpointTag(),
 			authtypes.NewModuleAddress(govtypes.ModuleName).String(),
 		)
 	app.ZoneConciergeKeeper.SetBtcCheckpointKeeper(app.BtcCheckpointKeeper)
@@ -841,7 +840,7 @@ func NewBabylonApp(
 	anteHandler := sdk.ChainAnteDecorators(
 		NewWrappedAnteHandler(authAnteHandler),
 		epochingkeeper.NewDropValidatorMsgDecorator(app.EpochingKeeper),
-		NewBtcValidationDecorator(btcConfig),
+		NewBtcValidationDecorator(btcConfig, &app.BtcCheckpointKeeper),
 	)
 	app.SetAnteHandler(anteHandler)
 

app/test_helpers.go

@@ -20,7 +20,6 @@ import (
 	errorsmod "cosmossdk.io/errors"
 	"github.com/babylonchain/babylon/app/params"
 	appparams "github.com/babylonchain/babylon/app/params"
-	txformat "github.com/babylonchain/babylon/btctxformatter"
 	bbn "github.com/babylonchain/babylon/types"
 	dbm "github.com/cometbft/cometbft-db"
 	abci "github.com/cometbft/cometbft/abci/types"
@@ -606,10 +605,6 @@ func (ao EmptyAppOptions) Get(o string) interface{} {
 		return string(bbn.BtcSimnet)
 	}
 
-	if o == "btc-config.checkpoint-tag" {
-		return txformat.DefaultMainTagStr
-	}
-
 	return nil
 }
 

btctxformatter/formatter_test.go

@@ -97,7 +97,8 @@ func FuzzDecodingWontPanic(f *testing.F) {
 	f.Add(randNBytes(secondPartLength), uint8(rand.Intn(99)))
 
 	f.Fuzz(func(t *testing.T, bytes []byte, tagIdx uint8) {
-		decoded, err := IsBabylonCheckpointData(MainTag(tagIdx), CurrentVersion, bytes)
+		tag := []byte{0, 1, 2, 3}
+		decoded, err := IsBabylonCheckpointData(BabylonTag(tag), CurrentVersion, bytes)
 
 		if err == nil {
 			if decoded.Index != 0 && decoded.Index != 1 {

cmd/babylond/cmd/custom_babylon_config.go

@@ -4,7 +4,6 @@ import (
 	wasmtypes "github.com/CosmWasm/wasmd/x/wasm/types"
 	serverconfig "github.com/cosmos/cosmos-sdk/server/config"
 
-	txformat "github.com/babylonchain/babylon/btctxformatter"
 	bbn "github.com/babylonchain/babylon/types"
 )
 
@@ -16,14 +15,11 @@ const (
 
 type BtcConfig struct {
 	Network string `mapstructure:"network"`
-
-	CheckpointTag string `mapstructure:"checkpoint-tag"`
 }
 
 func defaultBabylonBtcConfig() BtcConfig {
 	return BtcConfig{
-		Network:       string(bbn.BtcMainnet),
-		CheckpointTag: txformat.DefaultMainTagStr,
+		Network: string(bbn.BtcMainnet),
 	}
 }
 
@@ -72,11 +68,6 @@ func DefaultBabylonTemplate() string {
 # valid values are: [mainnet, testnet, simnet, regtest]
 network = "{{ .BtcConfig.Network }}"
 
-
-# Configures what tag should be prepended to op_return data in btc transaction
-# for it to be considered as valid babylon checkpoint. Must have exactly 4 bytes.
-checkpoint-tag = "{{ .BtcConfig.CheckpointTag }}"
-
 [signer-config]
 
 # Configures which key that the BLS signer uses to sign BLS-sig transactions

cmd/babylond/cmd/flags.go

@@ -4,6 +4,7 @@ import (
 	"time"
 
 	babylonApp "github.com/babylonchain/babylon/app"
+	btcctypes "github.com/babylonchain/babylon/x/btccheckpoint/types"
 	tmrand "github.com/cometbft/cometbft/libs/rand"
 	"github.com/cosmos/cosmos-sdk/client/flags"
 	"github.com/spf13/cobra"
@@ -14,6 +15,7 @@ const (
 	flagBtcConfirmationDepth   = "btc-confirmation-depth"
 	flagEpochInterval          = "epoch-interval"
 	flagBtcFinalizationTimeout = "btc-finalization-timeout"
+	flagCheckpointTag          = "checkpoint-tag"
 	flagBaseBtcHeaderHex       = "btc-base-header"
 	flagBaseBtcHeaderHeight    = "btc-base-header-height"
 	flagInflationRateChange    = "inflation-rate-change"
@@ -30,6 +32,7 @@ type GenesisCLIArgs struct {
 	MaxActiveValidators    uint32
 	BtcConfirmationDepth   uint64
 	BtcFinalizationTimeout uint64
+	CheckpointTag          string
 	EpochInterval          uint64
 	BaseBtcHeaderHex       string
 	BaseBtcHeaderHeight    uint64
@@ -49,6 +52,7 @@ func addGenesisFlags(cmd *cobra.Command) {
 	// btccheckpoint flags
 	cmd.Flags().Uint64(flagBtcConfirmationDepth, 6, "Confirmation depth for Bitcoin headers.")
 	cmd.Flags().Uint64(flagBtcFinalizationTimeout, 20, "Finalization timeout for Bitcoin headers.")
+	cmd.Flags().String(flagCheckpointTag, btcctypes.DefaultCheckpointTag, "Hex encoded tag for babylon checkpoint on btc")
 	// epoch args
 	cmd.Flags().Uint64(flagEpochInterval, 400, "Number of blocks between epochs. Must be more than 0.")
 	// btclightclient args
@@ -69,6 +73,7 @@ func parseGenesisFlags(cmd *cobra.Command) *GenesisCLIArgs {
 	maxActiveValidators, _ := cmd.Flags().GetUint32(flagMaxActiveValidators)
 	btcConfirmationDepth, _ := cmd.Flags().GetUint64(flagBtcConfirmationDepth)
 	btcFinalizationTimeout, _ := cmd.Flags().GetUint64(flagBtcFinalizationTimeout)
+	checkpointTag, _ := cmd.Flags().GetString(flagCheckpointTag)
 	epochInterval, _ := cmd.Flags().GetUint64(flagEpochInterval)
 	baseBtcHeaderHex, _ := cmd.Flags().GetString(flagBaseBtcHeaderHex)
 	baseBtcHeaderHeight, _ := cmd.Flags().GetUint64(flagBaseBtcHeaderHeight)
@@ -91,6 +96,7 @@ func parseGenesisFlags(cmd *cobra.Command) *GenesisCLIArgs {
 		MaxActiveValidators:    maxActiveValidators,
 		BtcConfirmationDepth:   btcConfirmationDepth,
 		BtcFinalizationTimeout: btcFinalizationTimeout,
+		CheckpointTag:          checkpointTag,
 		EpochInterval:          epochInterval,
 		BaseBtcHeaderHeight:    baseBtcHeaderHeight,
 		BaseBtcHeaderHex:       baseBtcHeaderHex,

cmd/babylond/cmd/genesis.go

@@ -63,7 +63,7 @@ Example:
 			var genesisParams GenesisParams
 			if network == "testnet" {
 				genesisParams = TestnetGenesisParams(genesisCliArgs.MaxActiveValidators,
-					genesisCliArgs.BtcConfirmationDepth, genesisCliArgs.BtcFinalizationTimeout,
+					genesisCliArgs.BtcConfirmationDepth, genesisCliArgs.BtcFinalizationTimeout, genesisCliArgs.CheckpointTag,
 					genesisCliArgs.EpochInterval, genesisCliArgs.BaseBtcHeaderHex,
 					genesisCliArgs.BaseBtcHeaderHeight, genesisCliArgs.InflationRateChange,
 					genesisCliArgs.InflationMin, genesisCliArgs.InflationMax, genesisCliArgs.GoalBonded,
@@ -211,7 +211,7 @@ type GenesisParams struct {
 }
 
 func TestnetGenesisParams(maxActiveValidators uint32, btcConfirmationDepth uint64,
-	btcFinalizationTimeout uint64, epochInterval uint64, baseBtcHeaderHex string,
+	btcFinalizationTimeout uint64, checkpointTag string, epochInterval uint64, baseBtcHeaderHex string,
 	baseBtcHeaderHeight uint64, inflationRateChange float64,
 	inflationMin float64, inflationMax float64, goalBonded float64,
 	blocksPerYear uint64, genesisTime time.Time, blockGasLimit int64) GenesisParams {
@@ -270,6 +270,11 @@ func TestnetGenesisParams(maxActiveValidators uint32, btcConfirmationDepth uint6
 	genParams.BtccheckpointParams = btccheckpointtypes.DefaultParams()
 	genParams.BtccheckpointParams.BtcConfirmationDepth = btcConfirmationDepth
 	genParams.BtccheckpointParams.CheckpointFinalizationTimeout = btcFinalizationTimeout
+	genParams.BtccheckpointParams.CheckpointTag = checkpointTag
+
+	if err := genParams.BtccheckpointParams.Validate(); err != nil {
+		panic(err)
+	}
 
 	// set the base BTC header in the genesis state
 	baseBtcHeader, err := bbn.NewBTCHeaderBytesFromHex(baseBtcHeaderHex)

cmd/babylond/cmd/testnet.go

@@ -12,7 +12,6 @@ import (
 	"path/filepath"
 
 	appparams "github.com/babylonchain/babylon/app/params"
-	txformat "github.com/babylonchain/babylon/btctxformatter"
 	bbn "github.com/babylonchain/babylon/types"
 	cryptocodec "github.com/cosmos/cosmos-sdk/crypto/codec"
 
@@ -53,7 +52,6 @@ var (
 	flagNodeDaemonHome          = "node-daemon-home"
 	flagStartingIPAddress       = "starting-ip-address"
 	flagBtcNetwork              = "btc-network"
-	flagBtcCheckpointTag        = "btc-checkpoint-tag"
 	flagAdditionalSenderAccount = "additional-sender-account"
 )
 
@@ -89,14 +87,13 @@ Example:
 			numValidators, _ := cmd.Flags().GetInt(flagNumValidators)
 			algo, _ := cmd.Flags().GetString(flags.FlagKeyAlgorithm)
 			btcNetwork, _ := cmd.Flags().GetString(flagBtcNetwork)
-			btcCheckpointTag, _ := cmd.Flags().GetString(flagBtcCheckpointTag)
 			additionalAccount, _ := cmd.Flags().GetBool(flagAdditionalSenderAccount)
 			if err != nil {
 				return errors.New("base Bitcoin header height should be a uint64")
 			}
 
 			genesisParams := TestnetGenesisParams(genesisCliArgs.MaxActiveValidators,
-				genesisCliArgs.BtcConfirmationDepth, genesisCliArgs.BtcFinalizationTimeout,
+				genesisCliArgs.BtcConfirmationDepth, genesisCliArgs.BtcFinalizationTimeout, genesisCliArgs.CheckpointTag,
 				genesisCliArgs.EpochInterval, genesisCliArgs.BaseBtcHeaderHex,
 				genesisCliArgs.BaseBtcHeaderHeight, genesisCliArgs.InflationRateChange,
 				genesisCliArgs.InflationMin, genesisCliArgs.InflationMax, genesisCliArgs.GoalBonded,
@@ -105,7 +102,7 @@ Example:
 			return InitTestnet(
 				clientCtx, cmd, config, mbm, genBalIterator, outputDir, genesisCliArgs.ChainID, minGasPrices,
 				nodeDirPrefix, nodeDaemonHome, startingIPAddress, keyringBackend, algo, numValidators,
-				btcNetwork, btcCheckpointTag, additionalAccount, genesisParams,
+				btcNetwork, additionalAccount, genesisParams,
 			)
 		},
 	}
@@ -119,7 +116,6 @@ Example:
 	cmd.Flags().String(flags.FlagKeyringBackend, flags.DefaultKeyringBackend, "Select keyring's backend (os|file|test)")
 	cmd.Flags().String(flags.FlagKeyAlgorithm, string(hd.Secp256k1Type), "Key signing algorithm to generate keys for")
 	cmd.Flags().String(flagBtcNetwork, string(bbn.BtcSimnet), "Bitcoin network to use. Available networks: simnet, testnet, regtest, mainnet")
-	cmd.Flags().String(flagBtcCheckpointTag, string(txformat.DefaultTestTagStr), "Tag to use for Bitcoin checkpoints.")
 	cmd.Flags().Bool(flagAdditionalSenderAccount, false, "If there should be additional pre funded account per validator")
 	addGenesisFlags(cmd)
 
@@ -145,7 +141,6 @@ func InitTestnet(
 	algoStr string,
 	numValidators int,
 	btcNetwork string,
-	btcCheckpointTag string,
 	additionalAccount bool,
 	genesisParams GenesisParams,
 ) error {
@@ -162,7 +157,6 @@ func InitTestnet(
 	babylonConfig.Telemetry.GlobalLabels = [][]string{{"chain_id", chainID}}
 	// BTC related config. Default values "simnet" and "BBT1"
 	babylonConfig.BtcConfig.Network = btcNetwork
-	babylonConfig.BtcConfig.CheckpointTag = btcCheckpointTag
 	// Explorer related config. Allow CORS connections.
 	babylonConfig.API.EnableUnsafeCORS = true
 	babylonConfig.GRPC.Address = "0.0.0.0:9090"

proto/babylon/btccheckpoint/v1/params.proto

@@ -23,4 +23,9 @@ message Params {
   // has dishonest majority and is stalling checkpoints (w in research paper)
   uint64 checkpoint_finalization_timeout = 2
       [ (gogoproto.moretags) = "yaml:\"checkpoint_finalization_timeout\"" ];
+
+  // 4byte tag in hex format, required to be present in the OP_RETURN transaction
+  // related to babylon
+  string checkpoint_tag = 3
+      [ (gogoproto.moretags) = "yaml:\"checkpoint_tag\"" ];
 }

test/e2e/configurer/chain/commands.go

@@ -126,8 +126,9 @@ func (n *NodeConfig) FinalizeSealedEpochs(startingEpoch uint64, lastEpoch uint64
 
 		require.NoError(n.t, err)
 
+		babylonTagBytes, _ := hex.DecodeString(initialization.BabylonOpReturnTag)
 		p1, p2, err := txformat.EncodeCheckpointData(
-			txformat.BabylonTag(initialization.BabylonOpReturnTag),
+			txformat.BabylonTag(babylonTagBytes),
 			txformat.CurrentVersion,
 			btcCheckpoint,
 		)

test/e2e/initialization/config.go

@@ -43,10 +43,11 @@ type NodeConfig struct {
 
 const (
 	// common
-	BabylonDenom                 = "ubbn"
-	MinGasPrice                  = "0.000"
-	ValidatorWalletName          = "val"
-	BabylonOpReturnTag           = "bbni"
+	BabylonDenom        = "ubbn"
+	MinGasPrice         = "0.000"
+	ValidatorWalletName = "val"
+	BabylonOpReturnTag  = "01020304"
+
 	BabylonBtcConfirmationPeriod = 2
 	BabylonBtcFinalizationPeriod = 4
 	// chainA
@@ -308,6 +309,7 @@ func updateBtccheckpointGenesis(btccheckpointGenState *btccheckpointtypes.Genesi
 	btccheckpointGenState.Params = btccheckpointtypes.DefaultParams()
 	btccheckpointGenState.Params.BtcConfirmationDepth = BabylonBtcConfirmationPeriod
 	btccheckpointGenState.Params.CheckpointFinalizationTimeout = BabylonBtcFinalizationPeriod
+	btccheckpointGenState.Params.CheckpointTag = BabylonOpReturnTag
 }
 
 func updateGenUtilGenesis(c *internalChain) func(*genutiltypes.GenesisState) {

test/e2e/initialization/node.go

@@ -131,7 +131,6 @@ func (n *internalNode) createAppConfig(nodeConfig *NodeConfig) {
 	appConfig.StateSync.SnapshotKeepRecent = nodeConfig.SnapshotKeepRecent
 	appConfig.SignerConfig.KeyName = ValidatorWalletName
 	appConfig.BtcConfig.Network = string(bbn.BtcSimnet)
-	appConfig.BtcConfig.CheckpointTag = BabylonOpReturnTag
 	appConfig.GRPC.Enable = true
 	appConfig.GRPC.Address = "0.0.0.0:9090"
 

test/integration_test.go

@@ -5,6 +5,7 @@ package babylon_integration
 
 import (
 	"context"
+	"encoding/hex"
 	"errors"
 	"fmt"
 	"os"
@@ -15,6 +16,7 @@ import (
 	txformat "github.com/babylonchain/babylon/btctxformatter"
 	"github.com/babylonchain/babylon/testutil/datagen"
 	bbn "github.com/babylonchain/babylon/types"
+	btcctypes "github.com/babylonchain/babylon/x/btccheckpoint/types"
 	lightclient "github.com/babylonchain/babylon/x/btclightclient/types"
 	checkpointingtypes "github.com/babylonchain/babylon/x/checkpointing/types"
 	epochingtypes "github.com/babylonchain/babylon/x/epoching/types"
@@ -291,8 +293,10 @@ func TestSubmitCheckpoint(t *testing.T) {
 		t.Fatalf("Could not create raw btc checkpoint from raw chekpoint")
 	}
 
+	tagAsBytes, _ := hex.DecodeString(btcctypes.DefaultCheckpointTag)
+
 	p1, p2 := txformat.MustEncodeCheckpointData(
-		txformat.BabylonTag(txformat.DefaultTestTagStr),
+		txformat.BabylonTag(tagAsBytes),
 		txformat.CurrentVersion,
 		rawBtcCheckpoint,
 	)