crypto/keccak: vendor in golang.org/x/crypto/sha3

The upstream libray has removed the assembly-based implementation of keccak.
We need to maintain our own library to avoid a peformance regression.

Author: fjl

crypto/keccak.go

@@ -22,17 +22,17 @@ import (
 	"sync"
 
 	"github.com/ethereum/go-ethereum/common"
-	"golang.org/x/crypto/sha3"
+	"github.com/ethereum/go-ethereum/crypto/keccak"
 )
 
 // NewKeccakState creates a new KeccakState
 func NewKeccakState() KeccakState {
-	return sha3.NewLegacyKeccak256().(KeccakState)
+	return keccak.NewLegacyKeccak256().(KeccakState)
 }
 
 var hasherPool = sync.Pool{
 	New: func() any {
-		return sha3.NewLegacyKeccak256().(KeccakState)
+		return keccak.NewLegacyKeccak256().(KeccakState)
 	},
 }
 

crypto/keccak/README.md

@@ -0,0 +1,5 @@
+This is a vendored and modified copy of golang.org/x/crypto/sha3, with an assembly
+implementation of keccak256.
+
+Ethereum uses a 'legacy' variant of Keccak, which was defined before it became SHA3. As
+such, we cannot use the standard library crypto/sha3 package.

crypto/keccak/hashes.go

@@ -0,0 +1,44 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package keccak
+
+// This file provides functions for creating instances of the SHA-3
+// and SHAKE hash functions, as well as utility functions for hashing
+// bytes.
+
+import (
+	"hash"
+)
+
+const (
+	dsbyteSHA3   = 0b00000110
+	dsbyteKeccak = 0b00000001
+	dsbyteShake  = 0b00011111
+	dsbyteCShake = 0b00000100
+
+	// rateK[c] is the rate in bytes for Keccak[c] where c is the capacity in
+	// bits. Given the sponge size is 1600 bits, the rate is 1600 - c bits.
+	rateK256  = (1600 - 256) / 8
+	rateK448  = (1600 - 448) / 8
+	rateK512  = (1600 - 512) / 8
+	rateK768  = (1600 - 768) / 8
+	rateK1024 = (1600 - 1024) / 8
+)
+
+// NewLegacyKeccak256 creates a new Keccak-256 hash.
+//
+// Only use this function if you require compatibility with an existing cryptosystem
+// that uses non-standard padding. All other users should use New256 instead.
+func NewLegacyKeccak256() hash.Hash {
+	return &state{rate: rateK512, outputLen: 32, dsbyte: dsbyteKeccak}
+}
+
+// NewLegacyKeccak512 creates a new Keccak-512 hash.
+//
+// Only use this function if you require compatibility with an existing cryptosystem
+// that uses non-standard padding. All other users should use New512 instead.
+func NewLegacyKeccak512() hash.Hash {
+	return &state{rate: rateK1024, outputLen: 64, dsbyte: dsbyteKeccak}
+}

crypto/keccak/keccak.go

@@ -0,0 +1,3 @@
+
+
+package keccak