Official Go implementation of the Ethereum protocol
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
go-ethereum/tests/fuzzers/bn256/bn256_fuzz.go

187 lines
5.4 KiB

// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
//go:build gofuzz
// +build gofuzz
package bn256
import (
"bytes"
"fmt"
"io"
"math/big"
"github.com/consensys/gnark-crypto/ecc/bn254"
cloudflare "github.com/ethereum/go-ethereum/crypto/bn256/cloudflare"
google "github.com/ethereum/go-ethereum/crypto/bn256/google"
)
func getG1Points(input io.Reader) (*cloudflare.G1, *google.G1, *bn254.G1Affine) {
_, xc, err := cloudflare.RandomG1(input)
if err != nil {
// insufficient input
return nil, nil, nil
}
xg := new(google.G1)
if _, err := xg.Unmarshal(xc.Marshal()); err != nil {
panic(fmt.Sprintf("Could not marshal cloudflare -> google: %v", err))
}
xs := new(bn254.G1Affine)
if err := xs.Unmarshal(xc.Marshal()); err != nil {
panic(fmt.Sprintf("Could not marshal cloudflare -> gnark: %v", err))
}
return xc, xg, xs
}
func getG2Points(input io.Reader) (*cloudflare.G2, *google.G2, *bn254.G2Affine) {
_, xc, err := cloudflare.RandomG2(input)
if err != nil {
// insufficient input
return nil, nil, nil
}
xg := new(google.G2)
if _, err := xg.Unmarshal(xc.Marshal()); err != nil {
panic(fmt.Sprintf("Could not marshal cloudflare -> google: %v", err))
}
xs := new(bn254.G2Affine)
if err := xs.Unmarshal(xc.Marshal()); err != nil {
panic(fmt.Sprintf("Could not marshal cloudflare -> gnark: %v", err))
}
return xc, xg, xs
}
// FuzzAdd fuzzez bn256 addition between the Google and Cloudflare libraries.
func FuzzAdd(data []byte) int {
input := bytes.NewReader(data)
xc, xg, xs := getG1Points(input)
if xc == nil {
return 0
}
yc, yg, ys := getG1Points(input)
if yc == nil {
return 0
}
// Ensure both libs can parse the second curve point
// Add the two points and ensure they result in the same output
rc := new(cloudflare.G1)
rc.Add(xc, yc)
rg := new(google.G1)
rg.Add(xg, yg)
tmpX := new(bn254.G1Jac).FromAffine(xs)
tmpY := new(bn254.G1Jac).FromAffine(ys)
rs := new(bn254.G1Affine).FromJacobian(tmpX.AddAssign(tmpY))
if !bytes.Equal(rc.Marshal(), rg.Marshal()) {
panic("add mismatch: cloudflare/google")
}
if !bytes.Equal(rc.Marshal(), rs.Marshal()) {
panic("add mismatch: cloudflare/gnark")
}
return 1
}
// FuzzMul fuzzez bn256 scalar multiplication between the Google and Cloudflare
// libraries.
func FuzzMul(data []byte) int {
input := bytes.NewReader(data)
pc, pg, ps := getG1Points(input)
if pc == nil {
return 0
}
// Add the two points and ensure they result in the same output
remaining := input.Len()
if remaining == 0 {
return 0
}
if remaining > 128 {
// The evm only ever uses 32 byte integers, we need to cap this otherwise
// we run into slow exec. A 236Kb byte integer cause oss-fuzz to report it as slow.
// 128 bytes should be fine though
return 0
}
buf := make([]byte, remaining)
input.Read(buf)
rc := new(cloudflare.G1)
rc.ScalarMult(pc, new(big.Int).SetBytes(buf))
rg := new(google.G1)
rg.ScalarMult(pg, new(big.Int).SetBytes(buf))
rs := new(bn254.G1Jac)
psJac := new(bn254.G1Jac).FromAffine(ps)
rs.ScalarMultiplication(psJac, new(big.Int).SetBytes(buf))
rsAffine := new(bn254.G1Affine).FromJacobian(rs)
if !bytes.Equal(rc.Marshal(), rg.Marshal()) {
panic("scalar mul mismatch: cloudflare/google")
}
if !bytes.Equal(rc.Marshal(), rsAffine.Marshal()) {
panic("scalar mul mismatch: cloudflare/gnark")
}
return 1
}
func FuzzPair(data []byte) int {
input := bytes.NewReader(data)
pc, pg, ps := getG1Points(input)
if pc == nil {
return 0
}
tc, tg, ts := getG2Points(input)
if tc == nil {
return 0
}
// Pair the two points and ensure they result in the same output
clPair := cloudflare.Pair(pc, tc).Marshal()
gPair := google.Pair(pg, tg).Marshal()
if !bytes.Equal(clPair, gPair) {
panic("pairing mismatch: cloudflare/google")
}
cPair, err := bn254.Pair([]bn254.G1Affine{*ps}, []bn254.G2Affine{*ts})
if err != nil {
panic(fmt.Sprintf("gnark/bn254 encountered error: %v", err))
}
// gnark uses a different pairing algorithm which might produce
// different but also correct outputs, we need to scale the output by s
u, _ := new(big.Int).SetString("0x44e992b44a6909f1", 0)
u_exp2 := new(big.Int).Exp(u, big.NewInt(2), nil) // u^2
u_6_exp2 := new(big.Int).Mul(big.NewInt(6), u_exp2) // 6*u^2
u_3 := new(big.Int).Mul(big.NewInt(3), u) // 3*u
inner := u_6_exp2.Add(u_6_exp2, u_3) // 6*u^2 + 3*u
inner.Add(inner, big.NewInt(1)) // 6*u^2 + 3*u + 1
u_2 := new(big.Int).Mul(big.NewInt(2), u) // 2*u
s := u_2.Mul(u_2, inner) // 2*u(6*u^2 + 3*u + 1)
gRes := new(bn254.GT)
if err := gRes.SetBytes(clPair); err != nil {
panic(err)
}
gRes = gRes.Exp(*gRes, s)
if !bytes.Equal(cPair.Marshal(), gRes.Marshal()) {
panic("pairing mismatch: cloudflare/gnark")
}
return 1
}