Fix for 5.10 reshare denial of service via predicable instance ids (#152

)

* fix 5.10 Reshare Denial-of-Service via Predicable
Instance IDs

* refactor

* lint

pkgs/initiator/initiator.go

@@ -215,11 +215,11 @@ func (c *Initiator) ResignMessageFlowHandling(signedResign *wire.SignedResign, i
 	// reqIDtracker is used to track if all ceremony are in the responses in the expected order
 	reqIDs := make([][24]byte, 0)
 	for _, msg := range signedResign.Messages {
-		reqID, err := utils.GetReqIDfromMsg(msg)
+		msgID, err := utils.GetReqIDfromMsg(msg, id)
 		if err != nil {
 			return nil, err
 		}
-		reqIDs = append(reqIDs, reqID)
+		reqIDs = append(reqIDs, msgID)
 	}
 	resignResult, errs, err := c.SendResignMsg(id, signedResign, operators)
 	if err != nil {
@@ -270,11 +270,11 @@ func (c *Initiator) ReshareMessageFlowHandling(id [24]byte, signedReshare *wire.
 	// reqIDtracker is used to track if all ceremony are in the responses in the expected order
 	reqIDs := make([][24]byte, 0)
 	for _, msg := range signedReshare.Messages {
-		reqID, err := utils.GetReqIDfromMsg(msg)
+		msgID, err := utils.GetReqIDfromMsg(msg, id)
 		if err != nil {
 			return nil, err
 		}
-		reqIDs = append(reqIDs, reqID)
+		reqIDs = append(reqIDs, msgID)
 	}
 	c.Logger.Info("sending signed reshare message to all operators")
 	var errs map[uint64]error
@@ -394,11 +394,11 @@ func (c *Initiator) StartResigning(id [24]byte, signedResign *wire.SignedResign)
 	}
 	resignIDMap := make(map[[24]byte]*spec.Resign)
 	for _, msg := range signedResign.Messages {
-		reqID, err := utils.GetReqIDfromMsg(msg)
+		msgID, err := utils.GetReqIDfromMsg(msg, id)
 		if err != nil {
 			return nil, nil, nil, err
 		}
-		resignIDMap[reqID] = msg.Resign
+		resignIDMap[msgID] = msg.Resign
 	}
 	var operatorIDs []uint64
 	for _, op := range signedResign.Messages[0].Operators {
@@ -511,11 +511,11 @@ func (c *Initiator) StartResharing(id [24]byte, signedReshare *wire.SignedReshar
 	}
 	reshareIDMap := make(map[[24]byte]*spec.Reshare)
 	for _, msg := range signedReshare.Messages {
-		reqID, err := utils.GetReqIDfromMsg(msg)
+		msgID, err := utils.GetReqIDfromMsg(msg, id)
 		if err != nil {
 			return nil, nil, nil, err
 		}
-		reshareIDMap[reqID] = msg.Reshare
+		reshareIDMap[msgID] = msg.Reshare
 	}
 	oldOperatorIDs := make([]uint64, 0)
 	for _, op := range signedReshare.Messages[0].Reshare.OldOperators {
@@ -970,3 +970,4 @@ func (c *Initiator) createBulkResults(resultsBytes [][][]byte, signedMsg, msgIDM
 	}
 	return bulkDepositData, bulkKeyShares, bulkProofs, nil
 }
+

pkgs/operator/instances_manager.go

@@ -195,7 +195,7 @@ func (s *Switch) HandleInstanceOperation(reqID [24]byte, transportMsg *wire.Tran
 		resps := [][]byte{}
 		// Run all resign/reshare ceremonies
 		for _, instance := range signedResign.Messages {
-			resp, err := s.runInstance(instance, allOps, initiatorPubKey, operationType)
+			resp, err := s.runInstance(reqID, instance, allOps, initiatorPubKey, operationType)
 			if err != nil {
 				return nil, fmt.Errorf("%s: failed to run instance: %w", operationType, err)
 			}
@@ -246,7 +246,7 @@ func (s *Switch) HandleInstanceOperation(reqID [24]byte, transportMsg *wire.Tran
 		resps := [][]byte{}
 		// Run all resign/reshare ceremonies
 		for _, instance := range signedReshare.Messages {
-			resp, err := s.runInstance(instance, allOps, initiatorPubKey, operationType)
+			resp, err := s.runInstance(reqID, instance, allOps, initiatorPubKey, operationType)
 			if err != nil {
 				return nil, fmt.Errorf("%s: failed to run instance: %w", operationType, err)
 			}
@@ -285,23 +285,23 @@ func (s *Switch) validateInstances(reqID InstanceID) error {
 	return nil
 }
 
-func (s *Switch) runInstance(instance interface{}, allOps []*spec.Operator, initiatorPubKey *rsa.PublicKey, operationType string) ([]byte, error) {
-	reqID, err := utils.GetReqIDfromMsg(instance)
+func (s *Switch) runInstance(reqID [24]byte, instance interface{}, allOps []*spec.Operator, initiatorPubKey *rsa.PublicKey, operationType string) ([]byte, error) {
+	instanceID, err := utils.GetReqIDfromMsg(instance, reqID)
 	if err != nil {
 		return nil, err
 	}
-	if err := s.validateInstances(reqID); err != nil {
+	if err := s.validateInstances(instanceID); err != nil {
 		return nil, err
 	}
 
-	inst, resp, err := s.CreateInstance(reqID, allOps, instance, initiatorPubKey)
+	inst, resp, err := s.CreateInstance(instanceID, allOps, instance, initiatorPubKey)
 	if err != nil {
 		return nil, fmt.Errorf("%s: failed to create instance: %w", operationType, err)
 	}
 
 	s.Mtx.Lock()
-	s.Instances[reqID] = inst
-	s.InstanceInitTime[reqID] = time.Now()
+	s.Instances[instanceID] = inst
+	s.InstanceInitTime[instanceID] = time.Now()
 	s.Mtx.Unlock()
 
 	return resp, nil

pkgs/utils/utils.go

@@ -264,14 +264,15 @@ func GetMessageHash(msg interface{}) ([32]byte, error) {
 	return hash, nil
 }
 
-func GetReqIDfromMsg(instance interface{}) ([24]byte, error) {
+func GetReqIDfromMsg(instance interface{}, id [24]byte) ([24]byte, error) {
 	// make a unique ID for each reshare using the instance hash
 	reqID := [24]byte{}
 	instanceHash, err := GetMessageHash(instance)
 	if err != nil {
 		return reqID, fmt.Errorf("failed to get reqID: %w", err)
 	}
-	copy(reqID[:], instanceHash[:])
+	copy(reqID[:12], id[:12])
+	copy(reqID[12:24], instanceHash[:12])
 	return reqID, nil
 }