plugeth/crypto/bn256/bn256_fuzz.go
Martin Holst Swende ebb9591c4d
crypto/bn256: fix bn256Mul fuzzer to not hang on large input (#21872)
* crypto/bn256: fix bn256Mul fuzzer to not hang on large input

* Update crypto/bn256/bn256_fuzz.go

Co-authored-by: ligi <ligi@ligi.de>

Co-authored-by: ligi <ligi@ligi.de>
2020-11-20 08:53:10 +01:00

120 lines
2.8 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"
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) {
_, xc, err := cloudflare.RandomG1(input)
if err != nil {
// insufficient input
return nil, nil
}
xg := new(google.G1)
if _, err := xg.Unmarshal(xc.Marshal()); err != nil {
panic(fmt.Sprintf("Could not marshal cloudflare -> google:", err))
}
return xc, xg
}
func getG2Points(input io.Reader) (*cloudflare.G2, *google.G2) {
_, xc, err := cloudflare.RandomG2(input)
if err != nil {
// insufficient input
return nil, nil
}
xg := new(google.G2)
if _, err := xg.Unmarshal(xc.Marshal()); err != nil {
panic(fmt.Sprintf("Could not marshal cloudflare -> google:", err))
}
return xc, xg
}
// FuzzAdd fuzzez bn256 addition between the Google and Cloudflare libraries.
func FuzzAdd(data []byte) int {
input := bytes.NewReader(data)
xc, xg := getG1Points(input)
if xc == nil {
return 0
}
yc, yg := 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)
if !bytes.Equal(rc.Marshal(), rg.Marshal()) {
panic("add mismatch")
}
return 1
}
// FuzzMul fuzzez bn256 scalar multiplication between the Google and Cloudflare
// libraries.
func FuzzMul(data []byte) int {
input := bytes.NewReader(data)
pc, pg := 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))
if !bytes.Equal(rc.Marshal(), rg.Marshal()) {
panic("scalar mul mismatch")
}
return 1
}
func FuzzPair(data []byte) int {
input := bytes.NewReader(data)
pc, pg := getG1Points(input)
if pc == nil {
return 0
}
tc, tg := getG2Points(input)
if tc == nil {
return 0
}
// Pair the two points and ensure thet result in the same output
if cloudflare.PairingCheck([]*cloudflare.G1{pc}, []*cloudflare.G2{tc}) != google.PairingCheck([]*google.G1{pg}, []*google.G2{tg}) {
panic("pair mismatch")
}
return 1
}