check if decryption key is already validated by checking the db and skip validation if key exists

Author: fredo

rolling-shutter/go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/google/go-cmp v0.6.0
 	github.com/google/uuid v1.4.0
 	github.com/hashicorp/go-multierror v1.1.1
+	github.com/hashicorp/golang-lru/v2 v2.0.7
 	github.com/ipfs/go-log/v2 v2.5.1
 	github.com/jackc/pgconn v1.14.1
 	github.com/jackc/pgx/v4 v4.18.1
@@ -126,7 +127,6 @@ require (
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/hashicorp/go-bexpr v0.1.11 // indirect
 	github.com/hashicorp/golang-lru v0.5.5-0.20210104140557-80c98217689d // indirect
-	github.com/hashicorp/golang-lru/v2 v2.0.5 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/holiman/bloomfilter/v2 v2.0.3 // indirect
 	github.com/holiman/uint256 v1.2.4 // indirect

rolling-shutter/go.sum

@@ -418,8 +418,8 @@ github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.5-0.20210104140557-80c98217689d h1:dg1dEPuWpEqDnvIw251EVy4zlP8gWbsGj4BsUKCRpYs=
 github.com/hashicorp/golang-lru v0.5.5-0.20210104140557-80c98217689d/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
-github.com/hashicorp/golang-lru/v2 v2.0.5 h1:wW7h1TG88eUIJ2i69gaE3uNVtEPIagzhGvHgwfx2Vm4=
-github.com/hashicorp/golang-lru/v2 v2.0.5/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
+github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
+github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/holiman/billy v0.0.0-20230718173358-1c7e68d277a7 h1:3JQNjnMRil1yD0IfZKHF9GxxWKDJGj8I0IqOUol//sw=

rolling-shutter/keyper/epochkghandler/key.go

@@ -3,8 +3,8 @@ package epochkghandler
 import (
 	"bytes"
 	"context"
-	"math"
 
+	lru "github.com/hashicorp/golang-lru/v2"
 	"github.com/jackc/pgx/v4"
 	"github.com/jackc/pgx/v4/pgxpool"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
@@ -13,6 +13,7 @@ import (
 	"github.com/shutter-network/shutter/shlib/shcrypto"
 
 	"github.com/shutter-network/rolling-shutter/rolling-shutter/keyper/database"
+	"github.com/shutter-network/rolling-shutter/rolling-shutter/medley"
 	"github.com/shutter-network/rolling-shutter/rolling-shutter/p2p"
 	"github.com/shutter-network/rolling-shutter/rolling-shutter/p2pmsg"
 	"github.com/shutter-network/rolling-shutter/rolling-shutter/shdb"
@@ -21,12 +22,16 @@ import (
 const MaxNumKeysPerMessage = 128
 
 func NewDecryptionKeyHandler(config Config, dbpool *pgxpool.Pool) p2p.MessageHandler {
-	return &DecryptionKeyHandler{config: config, dbpool: dbpool}
+	// Not catching the error as it only can happen if non-positive size was applied
+	cache, _ := lru.New[shcrypto.EpochSecretKey, []byte](1024)
+	return &DecryptionKeyHandler{config: config, dbpool: dbpool, cache: cache}
 }
 
 type DecryptionKeyHandler struct {
 	config Config
 	dbpool *pgxpool.Pool
+	// keep 1024 verified keys in Cache to skip additional verifications
+	cache *lru.Cache[shcrypto.EpochSecretKey, []byte]
 }
 
 func (*DecryptionKeyHandler) MessagePrototypes() []p2pmsg.Message {
@@ -39,23 +44,23 @@ func (handler *DecryptionKeyHandler) ValidateMessage(ctx context.Context, msg p2
 		return pubsub.ValidationReject,
 			errors.Errorf("instance ID mismatch (want=%d, have=%d)", handler.config.GetInstanceID(), key.GetInstanceID())
 	}
-	if key.Eon > math.MaxInt64 {
-		return pubsub.ValidationReject, errors.Errorf("eon %d overflows int64", key.Eon)
+	eon, err := medley.Uint64ToInt64Safe(key.Eon)
+	if err != nil {
+		return pubsub.ValidationReject, errors.Wrapf(err, "overflow error while converting eon to int64 %d", eon)
 	}
-
-	dkgResultDB, err := database.New(handler.dbpool).GetDKGResultForKeyperConfigIndex(ctx, int64(key.Eon))
-	if err == pgx.ErrNoRows {
-		return pubsub.ValidationReject, errors.Errorf("no DKG result found for eon %d", key.Eon)
+	dkgResultDB, err := database.New(handler.dbpool).GetDKGResultForKeyperConfigIndex(ctx, eon)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return pubsub.ValidationReject, errors.Errorf("no DKG result found for eon %d", eon)
 	}
 	if err != nil {
-		return pubsub.ValidationReject, errors.Wrapf(err, "failed to get dkg result for eon %d from db", key.Eon)
+		return pubsub.ValidationReject, errors.Wrapf(err, "failed to get dkg result for eon %d from db", eon)
 	}
 	if !dkgResultDB.Success {
-		return pubsub.ValidationReject, errors.Errorf("no successful DKG result found for eon %d", key.Eon)
+		return pubsub.ValidationReject, errors.Errorf("no successful DKG result found for eon %d", eon)
 	}
 	pureDKGResult, err := shdb.DecodePureDKGResult(dkgResultDB.PureResult)
 	if err != nil {
-		return pubsub.ValidationReject, errors.Wrapf(err, "error while decoding pure DKG result for eon %d", key.Eon)
+		return pubsub.ValidationReject, errors.Wrapf(err, "error while decoding pure DKG result for eon %d", eon)
 	}
 
 	if len(key.Keys) == 0 {
@@ -64,19 +69,26 @@ func (handler *DecryptionKeyHandler) ValidateMessage(ctx context.Context, msg p2
 	if len(key.Keys) > MaxNumKeysPerMessage {
 		return pubsub.ValidationReject, errors.Errorf("too many keys in message (%d > %d)", len(key.Keys), MaxNumKeysPerMessage)
 	}
+
 	for i, k := range key.Keys {
 		epochSecretKey, err := k.GetEpochSecretKey()
 		if err != nil {
 			return pubsub.ValidationReject, err
 		}
+		identity, exists := handler.cache.Get(*epochSecretKey)
+		if exists {
+			if bytes.Equal(k.Identity, identity) {
+				continue
+			}
+			return pubsub.ValidationReject, errors.Errorf("epoch secret key for identity %x is not valid", k.Identity)
+		}
 		ok, err := shcrypto.VerifyEpochSecretKey(epochSecretKey, pureDKGResult.PublicKey, k.Identity)
 		if err != nil {
 			return pubsub.ValidationReject, errors.Wrapf(err, "error while checking epoch secret key for identity %x", k.Identity)
 		}
 		if !ok {
 			return pubsub.ValidationReject, errors.Errorf("epoch secret key for identity %x is not valid", k.Identity)
 		}
-
 		if i > 0 && bytes.Compare(k.Identity, key.Keys[i-1].Identity) < 0 {
 			return pubsub.ValidationReject, errors.Errorf("keys not ordered")
 		}
@@ -87,7 +99,15 @@ func (handler *DecryptionKeyHandler) ValidateMessage(ctx context.Context, msg p2
 func (handler *DecryptionKeyHandler) HandleMessage(ctx context.Context, msg p2pmsg.Message) ([]p2pmsg.Message, error) {
 	metricsEpochKGDecryptionKeysReceived.Inc()
 	key := msg.(*p2pmsg.DecryptionKeys)
-	// Insert the key into the db. We assume that it's valid as it already passed the libp2p
-	// validator.
+	// We assume that it's valid as it already passed the libp2p validator.
+	// Insert the key into the cache.
+	for _, k := range key.Keys {
+		epochSecretKey, err := k.GetEpochSecretKey()
+		if err != nil {
+			return nil, err
+		}
+		handler.cache.Add(*epochSecretKey, k.Identity)
+	}
+	// Insert the key into the db.
 	return nil, database.New(handler.dbpool).InsertDecryptionKeysMsg(ctx, key)
 }