/
net_sniff_fuzz.go
118 lines (95 loc) · 2.18 KB
/
net_sniff_fuzz.go
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package net_sniff
import (
"math/rand"
"strings"
"github.com/google/gopacket"
"github.com/evilsocket/islazy/str"
)
var mutators = []func(byte) byte{
func(b byte) byte {
return byte(rand.Intn(256) & 0xff)
},
func(b byte) byte {
return byte(b << uint(rand.Intn(9)))
},
func(b byte) byte {
return byte(b >> uint(rand.Intn(9)))
},
}
func (mod *Sniffer) fuzz(data []byte) int {
changes := 0
for off, b := range data {
if rand.Float64() > mod.fuzzRatio {
continue
}
data[off] = mutators[rand.Intn(len(mutators))](b)
changes++
}
return changes
}
func (mod *Sniffer) doFuzzing(pkt gopacket.Packet) {
if rand.Float64() > mod.fuzzRate {
return
}
layersChanged := 0
bytesChanged := 0
for _, fuzzLayerType := range mod.fuzzLayers {
for _, layer := range pkt.Layers() {
if layer.LayerType().String() == fuzzLayerType {
fuzzData := layer.LayerContents()
changes := mod.fuzz(fuzzData)
if changes > 0 {
layersChanged++
bytesChanged += changes
}
}
}
}
if bytesChanged > 0 {
logFn := mod.Info
if mod.fuzzSilent {
logFn = mod.Debug
}
logFn("changed %d bytes in %d layers.", bytesChanged, layersChanged)
if err := mod.Session.Queue.Send(pkt.Data()); err != nil {
mod.Error("error sending fuzzed packet: %s", err)
}
}
}
func (mod *Sniffer) configureFuzzing() (err error) {
layers := ""
if err, layers = mod.StringParam("net.fuzz.layers"); err != nil {
return
} else {
mod.fuzzLayers = str.Comma(layers)
}
if err, mod.fuzzRate = mod.DecParam("net.fuzz.rate"); err != nil {
return
}
if err, mod.fuzzRatio = mod.DecParam("net.fuzz.ratio"); err != nil {
return
}
if err, mod.fuzzSilent = mod.BoolParam("net.fuzz.silent"); err != nil {
return
}
return
}
func (mod *Sniffer) StartFuzzing() error {
if mod.fuzzActive {
return nil
}
if err := mod.configureFuzzing(); err != nil {
return err
} else if !mod.Running() {
if err := mod.Start(); err != nil {
return err
}
}
mod.fuzzActive = true
mod.Info("active on layer types %s (rate:%f ratio:%f)", strings.Join(mod.fuzzLayers, ","), mod.fuzzRate, mod.fuzzRatio)
return nil
}
func (mod *Sniffer) StopFuzzing() error {
mod.fuzzActive = false
return nil
}