plugeth/tests/fuzzers/bn256/bn256_fuzz.go
Gautam Botrel 9e5bb84c0e
tests/fuzzers: crypto/bn256 and crypto/bls12381 tests against gnark-crypto (#22755)
Add more cross-fuzzers to fuzz bls with gnark versus geth's own bls12-381 library
2021-04-28 12:04:25 +02:00

157 lines
4.0 KiB
Go

// Copyright 2018 Péter Szilágyi. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be found
// in the LICENSE file.
// +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))
}
if !bytes.Equal(clPair, cPair.Marshal()) {
panic("pairing mismatch: cloudflare/gnark")
}
return 1
}