feat: add check if the covenant is the covenant committee

CHANGELOG.md

@@ -39,9 +39,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ### Improvements
 
+* [#91](https://github.com/babylonlabs-io/covenant-emulator/pull/91) Add verification
+if the covenant public key was present in the params of the versioned BTC delegation
 * [#83](https://github.com/babylonlabs-io/covenant-emulator/pull/83) covenant-signer: remove go.mod
 
-
 ## v0.11.2
 
 ### Bug fixes

covenant/cache_params.go

@@ -0,0 +1,76 @@
+package covenant
+
+import (
+	"sync"
+
+	"github.com/avast/retry-go/v4"
+	"github.com/babylonlabs-io/covenant-emulator/clientcontroller"
+	"github.com/babylonlabs-io/covenant-emulator/types"
+	"go.uber.org/zap"
+)
+
+type (
+	ParamsGetter interface {
+		Get(version uint32) (*types.StakingParams, error)
+	}
+	CacheVersionedParams struct {
+		sync.Mutex
+		paramsByVersion map[uint32]*types.StakingParams
+
+		cc     clientcontroller.ClientController
+		logger *zap.Logger
+	}
+)
+
+func NewCacheVersionedParams(cc clientcontroller.ClientController, logger *zap.Logger) ParamsGetter {
+	return &CacheVersionedParams{
+		paramsByVersion: make(map[uint32]*types.StakingParams),
+		cc:              cc,
+		logger:          logger,
+	}
+}
+
+// Get returns the staking parameter from the
+func (v *CacheVersionedParams) Get(version uint32) (*types.StakingParams, error) {
+	v.Lock()
+	defer v.Unlock()
+
+	params, ok := v.paramsByVersion[version]
+	if ok {
+		return params, nil
+	}
+
+	params, err := v.getParamsByVersion(version)
+	if err != nil {
+		return nil, err
+	}
+
+	v.paramsByVersion[version] = params
+	return params, nil
+}
+
+func (v *CacheVersionedParams) getParamsByVersion(version uint32) (*types.StakingParams, error) {
+	var (
+		err    error
+		params *types.StakingParams
+	)
+
+	if err := retry.Do(func() error {
+		params, err = v.cc.QueryStakingParamsByVersion(version)
+		if err != nil {
+			return err
+		}
+		return nil
+	}, RtyAtt, RtyDel, RtyErr, retry.OnRetry(func(n uint, err error) {
+		v.logger.Debug(
+			"failed to query the consumer chain for the staking params",
+			zap.Uint("attempt", n+1),
+			zap.Uint("max_attempts", RtyAttNum),
+			zap.Error(err),
+		)
+	})); err != nil {
+		return nil, err
+	}
+
+	return params, nil
+}

covenant/covenant.go

@@ -46,6 +46,8 @@ type CovenantEmulator struct {
 
 	config *covcfg.Config
 	logger *zap.Logger
+
+	paramCache ParamsGetter
 }
 
 func NewCovenantEmulator(
@@ -60,12 +62,13 @@ func NewCovenantEmulator(
 	}
 
 	return &CovenantEmulator{
-		cc:     cc,
-		signer: signer,
-		config: config,
-		logger: logger,
-		pk:     pk,
-		quit:   make(chan struct{}),
+		cc:         cc,
+		signer:     signer,
+		config:     config,
+		logger:     logger,
+		pk:         pk,
+		quit:       make(chan struct{}),
+		paramCache: NewCacheVersionedParams(cc, logger),
 	}, nil
 }
 
@@ -100,7 +103,7 @@ func (ce *CovenantEmulator) AddCovenantSignatures(btcDels []*types.Delegation) (
 		}
 
 		// 1. get the params matched to the delegation version
-		params, err := ce.getParamsByVersionWithRetry(btcDel.ParamsVersion)
+		params, err := ce.paramCache.Get(btcDel.ParamsVersion)
 		if err != nil {
 			return nil, fmt.Errorf("failed to get staking params with version %d: %w", btcDel.ParamsVersion, err)
 		}
@@ -436,30 +439,79 @@ func (ce *CovenantEmulator) delegationsToBatches(dels []*types.Delegation) [][]*
 	return batches
 }
 
-func RemoveAlreadySigned(localKey *btcec.PublicKey, dels []*types.Delegation) []*types.Delegation {
-	sanitized := make([]*types.Delegation, 0, len(dels))
-	localKeyBytes := schnorr.SerializePubKey(localKey)
+// IsKeyInCommittee returns true if the covenant serialized public key is in the covenant committee of the
+// parameter in which the BTC delegation was included.
+func IsKeyInCommittee(paramCache ParamsGetter, covenantSerializedPk []byte, del *types.Delegation) (bool, error) {
+	stkParams, err := paramCache.Get(del.ParamsVersion)
+	if err != nil {
+		return false, err
+	}
 
-	for _, del := range dels {
-		delCopy := del
-		alreadySigned := false
-		for _, covSig := range delCopy.CovenantSigs {
-			remoteKey := schnorr.SerializePubKey(covSig.Pk)
-			if bytes.Equal(remoteKey, localKeyBytes) {
-				alreadySigned = true
-				break
-			}
+	for _, pk := range stkParams.CovenantPks {
+		remoteKey := schnorr.SerializePubKey(pk)
+		if !bytes.Equal(remoteKey, covenantSerializedPk) {
+			continue
 		}
-		if !alreadySigned {
-			sanitized = append(sanitized, delCopy)
+		return true, nil
+	}
+
+	return false, fmt.Errorf("serialized pub key is not in the list of covenants for the param version: %d", del.ParamsVersion)
+}
+
+// CovenantAlreadySigned returns true if the covenant already signed the BTC Delegation
+func CovenantAlreadySigned(covenantSerializedPk []byte, del *types.Delegation) bool {
+	for _, covSig := range del.CovenantSigs {
+		remoteKey := schnorr.SerializePubKey(covSig.Pk)
+		if !bytes.Equal(remoteKey, covenantSerializedPk) {
+			continue
 		}
+		return true
 	}
-	return sanitized
+
+	return false
+}
+
+// sanitizeDelegations removes any delegations that have already been signed by the covenant and
+// remove delegations that were not constructed with this covenant public key
+func (ce *CovenantEmulator) sanitizeDelegations(dels []*types.Delegation) []*types.Delegation {
+	return SanitizeDelegations(ce.logger, ce.pk, ce.paramCache, dels)
 }
 
-// removeAlreadySigned removes any delegations that have already been signed by the covenant
-func (ce *CovenantEmulator) removeAlreadySigned(dels []*types.Delegation) []*types.Delegation {
-	return RemoveAlreadySigned(ce.pk, dels)
+// SanitizeDelegations remove the delegations in which the covenant public key already signed
+// or the delegation was not constructed with that covenant public key
+func SanitizeDelegations(
+	logger *zap.Logger,
+	pk *btcec.PublicKey,
+	paramCache ParamsGetter,
+	dels []*types.Delegation,
+) []*types.Delegation {
+	covenantSerializedPk := schnorr.SerializePubKey(pk)
+
+	sanitized := make([]*types.Delegation, 0, len(dels))
+	for _, del := range dels {
+		// 1. Remove delegations that do not need the covenant's signature because
+		// this covenant already signed
+		if CovenantAlreadySigned(covenantSerializedPk, del) {
+			continue
+		}
+		// 2. Remove delegations that were not constructed with this covenant public key
+		isInCommittee, err := IsKeyInCommittee(paramCache, covenantSerializedPk, del)
+		if err != nil {
+			logger.Error(
+				"invalid delegation",
+				zap.String("staker_pk", hex.EncodeToString(covenantSerializedPk)),
+				zap.String("staking_tx_hex", del.StakingTxHex),
+				zap.String("reason", "covenant key is not in committee"),
+				zap.Error(err),
+			)
+		}
+		if !isInCommittee {
+			continue
+		}
+		sanitized = append(sanitized, del)
+	}
+
+	return sanitized
 }
 
 // covenantSigSubmissionLoop is the reactor to submit Covenant signature for BTC delegations
@@ -490,7 +542,7 @@ func (ce *CovenantEmulator) covenantSigSubmissionLoop() {
 				ce.logger.Debug("no pending delegations are found")
 			}
 			// 2. Remove delegations that do not need the covenant's signature
-			sanitizedDels := ce.removeAlreadySigned(dels)
+			sanitizedDels := ce.sanitizeDelegations(dels)
 
 			// 3. Split delegations into batches for submission
 			batches := ce.delegationsToBatches(sanitizedDels)
@@ -532,32 +584,6 @@ func (ce *CovenantEmulator) metricsUpdateLoop() {
 	}
 }
 
-func (ce *CovenantEmulator) getParamsByVersionWithRetry(version uint32) (*types.StakingParams, error) {
-	var (
-		params *types.StakingParams
-		err    error
-	)
-
-	if err := retry.Do(func() error {
-		params, err = ce.cc.QueryStakingParamsByVersion(version)
-		if err != nil {
-			return err
-		}
-		return nil
-	}, RtyAtt, RtyDel, RtyErr, retry.OnRetry(func(n uint, err error) {
-		ce.logger.Debug(
-			"failed to query the consumer chain for the staking params",
-			zap.Uint("attempt", n+1),
-			zap.Uint("max_attempts", RtyAttNum),
-			zap.Error(err),
-		)
-	})); err != nil {
-		return nil, err
-	}
-
-	return params, nil
-}
-
 func (ce *CovenantEmulator) recordMetricsFailedSignDelegations(n int) {
 	failedSignDelegations.WithLabelValues(ce.PublicKeyStr()).Add(float64(n))
 }