From 1b0bf9608f81298066f0ce01d952f731058252df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Miko=C5=82ajczyk?= <piomiko41@gmail.com>
Date: Tue, 18 Nov 2025 11:23:28 +0100
Subject: [PATCH] eth: use stateless keccak

---
 eth/protocols/snap/sync.go      | 25 +++++--------------------
 eth/protocols/snap/sync_test.go | 12 ++----------
 2 files changed, 7 insertions(+), 30 deletions(-)

diff --git a/eth/protocols/snap/sync.go b/eth/protocols/snap/sync.go
index cf4e494645..0c919f8886 100644
--- a/eth/protocols/snap/sync.go
+++ b/eth/protocols/snap/sync.go
@@ -2672,15 +2672,10 @@ func (s *Syncer) onByteCodes(peer SyncPeer, id uint64, bytecodes [][]byte) error
 
 	// Cross reference the requested bytecodes with the response to find gaps
 	// that the serving node is missing
-	hasher := crypto.NewKeccakState()
-	hash := make([]byte, 32)
-
 	codes := make([][]byte, len(req.hashes))
 	for i, j := 0, 0; i < len(bytecodes); i++ {
 		// Find the next hash that we've been served, leaving misses with nils
-		hasher.Reset()
-		hasher.Write(bytecodes[i])
-		hasher.Read(hash)
+		hash := crypto.Keccak256(bytecodes[i])
 
 		for j < len(req.hashes) && !bytes.Equal(hash, req.hashes[j][:]) {
 			j++
@@ -2920,16 +2915,12 @@ func (s *Syncer) OnTrieNodes(peer SyncPeer, id uint64, trienodes [][]byte) error
 	// Cross reference the requested trienodes with the response to find gaps
 	// that the serving node is missing
 	var (
-		hasher = crypto.NewKeccakState()
-		hash   = make([]byte, 32)
-		nodes  = make([][]byte, len(req.hashes))
-		fills  uint64
+		nodes = make([][]byte, len(req.hashes))
+		fills uint64
 	)
 	for i, j := 0, 0; i < len(trienodes); i++ {
 		// Find the next hash that we've been served, leaving misses with nils
-		hasher.Reset()
-		hasher.Write(trienodes[i])
-		hasher.Read(hash)
+		hash := crypto.Keccak256(trienodes[i])
 
 		for j < len(req.hashes) && !bytes.Equal(hash, req.hashes[j][:]) {
 			j++
@@ -3026,16 +3017,10 @@ func (s *Syncer) onHealByteCodes(peer SyncPeer, id uint64, bytecodes [][]byte) e
 
 	// Cross reference the requested bytecodes with the response to find gaps
 	// that the serving node is missing
-	hasher := crypto.NewKeccakState()
-	hash := make([]byte, 32)
-
 	codes := make([][]byte, len(req.hashes))
 	for i, j := 0, 0; i < len(bytecodes); i++ {
 		// Find the next hash that we've been served, leaving misses with nils
-		hasher.Reset()
-		hasher.Write(bytecodes[i])
-		hasher.Read(hash)
-
+		hash := crypto.Keccak256(bytecodes[i])
 		for j < len(req.hashes) && !bytes.Equal(hash, req.hashes[j][:]) {
 			j++
 		}
diff --git a/eth/protocols/snap/sync_test.go b/eth/protocols/snap/sync_test.go
index 713b358ff8..175bade62d 100644
--- a/eth/protocols/snap/sync_test.go
+++ b/eth/protocols/snap/sync_test.go
@@ -64,12 +64,8 @@ func TestHashing(t *testing.T) {
 		}
 	}
 	var new = func() {
-		hasher := crypto.NewKeccakState()
-		var hash = make([]byte, 32)
 		for i := 0; i < len(bytecodes); i++ {
-			hasher.Reset()
-			hasher.Write(bytecodes[i])
-			hasher.Read(hash)
+			hash := crypto.Keccak256(bytecodes[i])
 			want = fmt.Sprintf("%v\n%v", want, hash)
 		}
 	}
@@ -96,12 +92,8 @@ func BenchmarkHashing(b *testing.B) {
 		}
 	}
 	var new = func() {
-		hasher := crypto.NewKeccakState()
-		var hash = make([]byte, 32)
 		for i := 0; i < len(bytecodes); i++ {
-			hasher.Reset()
-			hasher.Write(bytecodes[i])
-			hasher.Read(hash)
+			crypto.Keccak256(bytecodes[i])
 		}
 	}
 	b.Run("old", func(b *testing.B) {