feat: Waku v2 bridge

Issue #12610

vendor/github.com/holiman/uint256/fuzz.go

@@ -0,0 +1,133 @@
+// uint256: Fixed size 256-bit math library
+// Copyright 2020 uint256 Authors
+// SPDX-License-Identifier: BSD-3-Clause
+
+// +build gofuzz
+
+package uint256
+
+import (
+	"fmt"
+	"math/big"
+	"reflect"
+	"runtime"
+)
+
+const (
+	opUdivrem = 0
+	opMul     = 1
+	opLsh     = 2
+	opAdd     = 4
+	opSub     = 5
+)
+
+type opFunc func(*Int, *Int, *Int) *Int
+type bigFunc func(*big.Int, *big.Int, *big.Int) *big.Int
+
+func crash(op opFunc, x, y Int, msg string) {
+	fn := runtime.FuncForPC(reflect.ValueOf(op).Pointer())
+	fnName := fn.Name()
+	fnFile, fnLine := fn.FileLine(fn.Entry())
+	panic(fmt.Sprintf("%s\nfor %s (%s:%d)\nx: %x\ny: %x", msg, fnName, fnFile, fnLine, &x, &y))
+}
+
+func checkOp(op opFunc, bigOp bigFunc, x, y Int) {
+	origX := x
+	origY := y
+
+	var result Int
+	ret := op(&result, &x, &y)
+	if ret != &result {
+		crash(op, x, y, "returned not the pointer receiver")
+	}
+	if x != origX {
+		crash(op, x, y, "first argument modified")
+	}
+	if y != origY {
+		crash(op, x, y, "second argument modified")
+	}
+
+	expected, _ := FromBig(bigOp(new(big.Int), x.ToBig(), y.ToBig()))
+	if result != *expected {
+		crash(op, x, y, "unexpected result")
+	}
+
+	// Test again when the receiver is not zero.
+	var garbage Int
+	garbage.Xor(&x, &y)
+	ret = op(&garbage, &x, &y)
+	if ret != &garbage {
+		crash(op, x, y, "returned not the pointer receiver")
+	}
+	if garbage != *expected {
+		crash(op, x, y, "unexpected result")
+	}
+	if x != origX {
+		crash(op, x, y, "first argument modified")
+	}
+	if y != origY {
+		crash(op, x, y, "second argument modified")
+	}
+
+	// Test again with the receiver aliasing arguments.
+	ret = op(&x, &x, &y)
+	if ret != &x {
+		crash(op, x, y, "returned not the pointer receiver")
+	}
+	if x != *expected {
+		crash(op, x, y, "unexpected result")
+	}
+
+	ret = op(&y, &origX, &y)
+	if ret != &y {
+		crash(op, x, y, "returned not the pointer receiver")
+	}
+	if y != *expected {
+		crash(op, x, y, "unexpected result")
+	}
+}
+
+func Fuzz(data []byte) int {
+	if len(data) != 65 {
+		return 0
+	}
+
+	op := data[0]
+
+	var x, y Int
+	x.SetBytes(data[1:33])
+	y.SetBytes(data[33:])
+
+	switch op {
+	case opUdivrem:
+		if y.IsZero() {
+			return 0
+		}
+		checkOp((*Int).Div, (*big.Int).Div, x, y)
+		checkOp((*Int).Mod, (*big.Int).Mod, x, y)
+
+	case opMul:
+		checkOp((*Int).Mul, (*big.Int).Mul, x, y)
+
+	case opLsh:
+		lsh := func(z, x, y *Int) *Int {
+			return z.Lsh(x, uint(y[0]))
+		}
+		bigLsh := func(z, x, y *big.Int) *big.Int {
+			n := uint(y.Uint64())
+			if n > 256 {
+				n = 256
+			}
+			return z.Lsh(x, n)
+		}
+		checkOp(lsh, bigLsh, x, y)
+
+	case opAdd:
+		checkOp((*Int).Add, (*big.Int).Add, x, y)
+
+	case opSub:
+		checkOp((*Int).Sub, (*big.Int).Sub, x, y)
+	}
+
+	return 0
+}