crypto/bn256: refactor to use bitutil.TestBytes (ethereum#32435)

Author: cuiweixie

crypto/bn256/gnark/g1.go

@@ -5,6 +5,7 @@ import (
 	"math/big"
 
 	"github.com/consensys/gnark-crypto/ecc/bn254"
+	"github.com/ethereum/go-ethereum/common/bitutil"
 )
 
 // G1 is the affine representation of a G1 group element.
@@ -43,7 +44,7 @@ func (g *G1) Unmarshal(buf []byte) (int, error) {
 		return 0, errors.New("invalid G1 point size")
 	}
 
-	if allZeroes(buf[:64]) {
+	if !bitutil.TestBytes(buf[:64]) {
 		// point at infinity
 		g.inner.X.SetZero()
 		g.inner.Y.SetZero()
@@ -82,12 +83,3 @@ func (p *G1) Marshal() []byte {
 
 	return output
 }
-
-func allZeroes(buf []byte) bool {
-	for i := range buf {
-		if buf[i] != 0 {
-			return false
-		}
-	}
-	return true
-}

crypto/bn256/gnark/g2.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 
 	"github.com/consensys/gnark-crypto/ecc/bn254"
+	"github.com/ethereum/go-ethereum/common/bitutil"
 )
 
 // G2 is the affine representation of a G2 group element.
@@ -31,7 +32,7 @@ func (g *G2) Unmarshal(buf []byte) (int, error) {
 		return 0, errors.New("invalid G2 point size")
 	}
 
-	if allZeroes(buf[:128]) {
+	if !bitutil.TestBytes(buf[:128]) {
 		// point at infinity
 		g.inner.X.A0.SetZero()
 		g.inner.X.A1.SetZero()