[Malleability] Event

engine/access/rpc/backend/backend_test.go

@@ -1993,14 +1993,6 @@ func (suite *Suite) setupConnectionFactory() connection.ConnectionFactory {
 	return connFactory
 }
 
-func getEvents(n int) []flow.Event {
-	events := make([]flow.Event, n)
-	for i := range events {
-		events[i] = flow.Event{Type: flow.EventAccountCreated}
-	}
-	return events
-}
-
 func generateEncodedEvents(t *testing.T, n int) ([]flow.Event, []flow.Event) {
 	ccfEvents := generator.GetEventsWithEncoding(n, entities.EventEncodingVersion_CCF_V0)
 	jsonEvents := make([]flow.Event, n)

model/flow/event.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/onflow/flow-go/model/encoding/json"
 	"github.com/onflow/flow-go/model/fingerprint"
 	"github.com/onflow/flow-go/storage/merkle"
 )
@@ -39,44 +38,13 @@ func (e Event) String() string {
 
 // ID returns a canonical identifier that is guaranteed to be unique.
 func (e Event) ID() Identifier {
-	return MakeID(wrapEventID(e))
+	return MakeID(e)
 }
 
 func (e Event) Checksum() Identifier {
 	return MakeID(e)
 }
 
-// Encode returns the canonical encoding of this event, containing only the fields necessary to uniquely identify it.
-func (e Event) Encode() []byte {
-	w := wrapEventID(e)
-	return json.NewMarshaler().MustMarshal(w)
-}
-
-func (e Event) Fingerprint() []byte {
-	return fingerprint.Fingerprint(wrapEvent(e))
-}
-
-// Defines only the fields needed to uniquely identify an event.
-type eventIDWrapper struct {
-	TxID  []byte
-	Index uint32
-}
-
-type eventWrapper struct {
-	TxID             []byte
-	Index            uint32
-	Type             string
-	TransactionIndex uint32
-	Payload          []byte
-}
-
-func wrapEventID(e Event) eventIDWrapper {
-	return eventIDWrapper{
-		TxID:  e.TransactionID[:],
-		Index: e.EventIndex,
-	}
-}
-
 // byteSize returns the number of bytes needed to store the wrapped version of the event.
 // returned int is an approximate measure, ignoring the number of bytes needed as headers.
 func (e Event) byteSize() int {
@@ -87,16 +55,6 @@ func (e Event) byteSize() int {
 		len(e.Payload) // Payload
 }
 
-func wrapEvent(e Event) eventWrapper {
-	return eventWrapper{
-		TxID:             e.TransactionID[:],
-		Index:            e.EventIndex,
-		Type:             string(e.Type),
-		TransactionIndex: e.TransactionIndex,
-		Payload:          e.Payload[:],
-	}
-}
-
 // BlockEvents contains events emitted in a single block.
 type BlockEvents struct {
 	BlockID        Identifier
@@ -107,7 +65,7 @@ type BlockEvents struct {
 
 type EventsList []Event
 
-// byteSize returns an approximate number of bytes needed to store the wrapped version of the event.
+// ByteSize returns an approximate number of bytes needed to store the wrapped version of the event.
 func (el EventsList) ByteSize() int {
 	size := 0
 	for _, event := range el {
@@ -125,10 +83,10 @@ func EventsMerkleRootHash(el EventsList) (Identifier, error) {
 	}
 
 	for _, event := range el {
-		// event fingerprint is the rlp encoding of the wrapperevent
+		// event fingerprint is the rlp encoding of the event
 		// eventID is the standard sha3 hash of the event fingerprint
-		fingerPrint := event.Fingerprint()
-		// computing enityID from the fingerprint
+		fingerPrint := fingerprint.Fingerprint(event)
+		// computing entityID from the fingerprint (this is equivalent to `event.ID()`)
 		eventID := MakeIDFromFingerPrint(fingerPrint)
 		_, err = tree.Put(eventID[:], fingerPrint)
 		if err != nil {

model/flow/event_test.go

@@ -12,51 +12,25 @@ import (
 	"github.com/onflow/flow-go/utils/unittest"
 )
 
-type eventWrapper struct {
-	TxID             []byte
-	Index            uint32
-	Type             string
-	TransactionIndex uint32
-	Payload          []byte
-}
-
-func wrapEvent(e flow.Event) eventWrapper {
-	return eventWrapper{
-		TxID:             e.TransactionID[:],
-		Index:            e.EventIndex,
-		Type:             string(e.Type),
-		TransactionIndex: e.TransactionIndex,
-		Payload:          e.Payload,
-	}
-}
-
+// TestEventFingerprint verifies that the Fingerprint function produces
+// a consistent RLP-encoded representation of an Event. It ensures that
+// decoding the fingerprint results in a correctly ordered structure.
 func TestEventFingerprint(t *testing.T) {
 	evt := unittest.EventFixture(flow.EventAccountCreated, 13, 12, unittest.IdentifierFixture(), 32)
 
 	data := fingerprint.Fingerprint(evt)
-	var decoded eventWrapper
+	var decoded flow.Event
 	rlp.NewMarshaler().MustUnmarshal(data, &decoded)
-	assert.Equal(t, wrapEvent(evt), decoded)
+	assert.Equal(t, evt, decoded)
 }
 
-func TestEventID(t *testing.T) {
-
-	// EventID was historically calculated from just TxID and eventIndex which are enough to uniquely identify it in a system
-	// This test ensures we don't break this promise while introducing proper fingerprinting (which accounts for all the fields)
-
+// TestEventMalleability checks that Event is not malleable: any change in its data
+// should result in a different ID.
+func TestEventMalleability(t *testing.T) {
 	txID := unittest.IdentifierFixture()
-	evtA := unittest.EventFixture(flow.EventAccountUpdated, 21, 37, txID, 2)
-	evtB := unittest.EventFixture(flow.EventAccountCreated, 0, 37, txID, 22)
-
-	evtC := unittest.EventFixture(evtA.Type, evtA.TransactionIndex, evtA.EventIndex+1, txID, 2)
-	evtC.Payload = evtA.Payload
-
-	a := evtA.ID()
-	b := evtB.ID()
-	c := evtC.ID()
+	event := unittest.EventFixture(flow.EventAccountUpdated, 21, 37, txID, 2)
 
-	assert.Equal(t, a, b)
-	assert.NotEqual(t, a, c)
+	unittest.RequireEntityNonMalleable(t, &event)
 }
 
 func TestEventsList(t *testing.T) {
@@ -113,7 +87,7 @@ func TestEventsMerkleRootHash(t *testing.T) {
 		TransactionID:    [flow.IdentifierLen]byte{1, 2, 3},
 	}
 
-	expectedRootHashHex := "355446d7b2b9653403abe28ccc405f46c059d2059cb7863f4964c401ee1aa83b"
+	expectedRootHashHex := "c53a6592de573a24547b616172abd9131651d6b7d829e5694a25fa183db7ae01"
 
 	ABHash, err := flow.EventsMerkleRootHash([]flow.Event{eventA, eventB})
 	assert.NoError(t, err)

module/chunks/chunkVerifier.go

@@ -17,6 +17,7 @@ import (
 	"github.com/onflow/flow-go/ledger"
 	"github.com/onflow/flow-go/ledger/partial"
 	chmodels "github.com/onflow/flow-go/model/chunks"
+	"github.com/onflow/flow-go/model/fingerprint"
 	"github.com/onflow/flow-go/model/flow"
 	"github.com/onflow/flow-go/model/verification"
 	"github.com/onflow/flow-go/module/executiondatasync/execution_data"
@@ -263,7 +264,7 @@ func (fcv *ChunkVerifier) verifyTransactionsInContext(
 		for i, event := range events {
 			fcv.logger.Warn().Int("list_index", i).
 				Str("event_id", event.ID().String()).
-				Hex("event_fingerptint", event.Fingerprint()).
+				Hex("event_fingerprint", fingerprint.Fingerprint(event)).
 				Str("event_type", string(event.Type)).
 				Str("event_tx_id", event.TransactionID.String()).
 				Uint32("event_tx_index", event.TransactionIndex).

utils/unittest/entity.go

@@ -2,11 +2,11 @@ package unittest
 
 import (
 	"fmt"
-	"github.com/onflow/crypto"
 	"math/rand"
 	"reflect"
 	"testing"
 
+	"github.com/onflow/crypto"
 	"github.com/stretchr/testify/require"
 
 	"github.com/onflow/flow-go/model/flow"