containerd/vendor/github.com/AdaLogics/go-fuzz-headers/consumer.go
AdamKorcz 2556aac675 Fuzzing: Add archive fuzzer
Signed-off-by: AdamKorcz <adam@adalogics.com>
2021-07-22 16:39:27 +01:00

340 lines
7.7 KiB
Go

package gofuzzheaders
import (
"archive/tar"
"bytes"
"errors"
//"fmt"
"reflect"
"unsafe"
)
type ConsumeFuzzer struct {
data []byte
CommandPart []byte
RestOfArray []byte
NumberOfCalls int
position int
fuzzUnexportedFields bool
}
func IsDivisibleBy(n int, divisibleby int) bool {
return (n % divisibleby) == 0
}
func NewConsumer(fuzzData []byte) *ConsumeFuzzer {
f := &ConsumeFuzzer{data: fuzzData, position: 0}
return f
}
func (f *ConsumeFuzzer) Split(minCalls, maxCalls int) error {
if len(f.data) == 0 {
return errors.New("Could not split")
}
numberOfCalls := int(f.data[0])
if numberOfCalls < minCalls || numberOfCalls > maxCalls {
return errors.New("Bad number of calls")
}
if len(f.data) < numberOfCalls+numberOfCalls+1 {
return errors.New("Length of data does not match required parameters")
}
// Define part 2 and 3 of the data array
commandPart := f.data[1 : numberOfCalls+1]
restOfArray := f.data[numberOfCalls+1:]
// Just a small check. It is necessary
if len(commandPart) != numberOfCalls {
return errors.New("Length of commandPart does not match number of calls")
}
// Check if restOfArray is divisible by numberOfCalls
if !IsDivisibleBy(len(restOfArray), numberOfCalls) {
return errors.New("Length of commandPart does not match number of calls")
}
f.CommandPart = commandPart
f.RestOfArray = restOfArray
f.NumberOfCalls = numberOfCalls
return nil
}
func (f *ConsumeFuzzer) AllowUnexportedFields() {
f.fuzzUnexportedFields = true
}
func (f *ConsumeFuzzer) DisallowUnexportedFields() {
f.fuzzUnexportedFields = false
}
func (f *ConsumeFuzzer) GenerateStruct(targetStruct interface{}) error {
v := reflect.ValueOf(targetStruct)
/*if !v.CanSet() {
return errors.New("This interface cannot be set")
}*/
e := v.Elem()
err := f.fuzzStruct(e)
if err != nil {
return err
}
return nil
}
func (f *ConsumeFuzzer) fuzzStruct(e reflect.Value) error {
switch e.Kind() {
case reflect.Struct:
for i := 0; i < e.NumField(); i++ {
// Useful for debugging, so we leave it for now:
//vt := e.Type().Field(i).Name
//fmt.Println("vt:::::::::::::::::::::: ", vt)
var v reflect.Value
if !e.Field(i).CanSet() {
if f.fuzzUnexportedFields {
v = reflect.NewAt(e.Field(i).Type(), unsafe.Pointer(e.Field(i).UnsafeAddr())).Elem()
}
} else {
v = e.Field(i)
}
err := f.fuzzStruct(v)
if err != nil {
return err
}
}
case reflect.String:
str, err := f.GetString()
if err != nil {
return err
}
if e.CanSet() {
e.SetString(str)
}
case reflect.Slice:
maxElements := 50
randQty, err := f.GetInt()
if err != nil {
return err
}
numOfElements := randQty % maxElements
uu := reflect.MakeSlice(e.Type(), numOfElements, numOfElements)
for i := 0; i < numOfElements; i++ {
err := f.fuzzStruct(uu.Index(i))
if err != nil {
return err
}
}
if e.CanSet() {
e.Set(uu)
}
case reflect.Uint64:
newInt, err := f.GetInt()
if err != nil {
return err
}
if e.CanSet() {
e.SetUint(uint64(newInt))
}
case reflect.Int:
newInt, err := f.GetInt()
if err != nil {
return err
}
if e.CanSet() {
e.SetInt(int64(newInt))
}
case reflect.Map:
if e.CanSet() {
e.Set(reflect.MakeMap(e.Type()))
maxElements := 50
randQty, err := f.GetInt()
if err != nil {
return err
}
numOfElements := randQty % maxElements
for i := 0; i < numOfElements; i++ {
key := reflect.New(e.Type().Key()).Elem()
err := f.fuzzStruct(key)
if err != nil {
return err
}
val := reflect.New(e.Type().Elem()).Elem()
err = f.fuzzStruct(val)
if err != nil {
return err
}
e.SetMapIndex(key, val)
}
}
case reflect.Ptr:
if e.CanSet() {
e.Set(reflect.New(e.Type().Elem()))
err := f.fuzzStruct(e.Elem())
if err != nil {
return err
}
return nil
}
case reflect.Uint8:
b, err := f.GetByte()
if err != nil {
return err
}
if e.CanSet() {
e.SetUint(uint64(b))
}
default:
return nil
}
return nil
}
func (f *ConsumeFuzzer) GetStringArray() (reflect.Value, error) {
// The max size of the array:
max := 20
arraySize := f.position
if arraySize > max {
arraySize = max
}
elemType := reflect.TypeOf("string")
stringArray := reflect.MakeSlice(reflect.SliceOf(elemType), arraySize, arraySize)
if f.position+arraySize >= len(f.data) {
return stringArray, errors.New("Could not make string array")
}
for i := 0; i < arraySize; i++ {
stringSize := int(f.data[f.position])
if f.position+stringSize >= len(f.data) {
return stringArray, nil
}
stringToAppend := string(f.data[f.position : f.position+stringSize])
strVal := reflect.ValueOf(stringToAppend)
stringArray = reflect.Append(stringArray, strVal)
f.position = f.position + stringSize
}
return stringArray, nil
}
func (f *ConsumeFuzzer) GetInt() (int, error) {
if f.position >= len(f.data) {
return 0, errors.New("Not enough bytes to create int")
}
returnInt := int(f.data[f.position])
f.position++
return returnInt, nil
}
func (f *ConsumeFuzzer) GetByte() (byte, error) {
if len(f.data) == 0 {
return 0x00, errors.New("Not enough bytes to get byte")
}
if f.position >= len(f.data) {
return 0x00, errors.New("Not enough bytes to get byte")
}
returnByte := f.data[f.position]
f.position += 1
return returnByte, nil
}
func (f *ConsumeFuzzer) GetBytes() ([]byte, error) {
if len(f.data) == 0 || f.position >= len(f.data) {
return nil, errors.New("Not enough bytes to create byte array")
}
length := int(f.data[f.position])
byteBegin := f.position + 1
if byteBegin >= len(f.data) {
return nil, errors.New("Not enough bytes to create byte array")
}
if length == 0 {
return nil, errors.New("Zero-length is not supported")
}
if byteBegin+length >= len(f.data) {
return nil, errors.New("Not enough bytes to create byte array")
}
b := f.data[byteBegin : byteBegin+length]
f.position = byteBegin + length
return b, nil
}
func (f *ConsumeFuzzer) GetString() (string, error) {
if f.position >= len(f.data) {
return "nil", errors.New("Not enough bytes to create string")
}
length := int(f.data[f.position])
byteBegin := f.position + 1
if byteBegin >= len(f.data) {
return "nil", errors.New("Not enough bytes to create string")
}
if byteBegin+length > len(f.data) {
return "nil", errors.New("Not enough bytes to create string")
}
str := string(f.data[byteBegin : byteBegin+length])
f.position = byteBegin + length
return str, nil
}
func (f *ConsumeFuzzer) GetBool() (bool, error) {
if f.position >= len(f.data) {
return false, errors.New("Not enough bytes to create bool")
}
if IsDivisibleBy(int(f.data[f.position]), 2) {
f.position++
return true, nil
} else {
f.position++
return false, nil
}
}
func (f *ConsumeFuzzer) FuzzMap(m interface{}) error {
err := f.GenerateStruct(m)
if err != nil {
return err
}
return nil
}
// TarBytes returns valid tar bytes for a tar archive
func (f *ConsumeFuzzer) TarBytes() ([]byte, error) {
var buf bytes.Buffer
tw := tar.NewWriter(&buf)
numberOfFiles, err := f.GetInt()
if err != nil {
return nil, err
}
maxNoOfFiles := 100000
for i := 0; i < numberOfFiles%maxNoOfFiles; i++ {
filename, err := f.GetString()
if err != nil {
return nil, err
}
filebody, err := f.GetBytes()
if err != nil {
return nil, err
}
hdr := &tar.Header{}
err = f.GenerateStruct(hdr)
if err != nil {
return nil, err
}
hdr.Name = filename
hdr.Size = int64(len(filebody))
hdr.Mode = 0600
if err := tw.WriteHeader(hdr); err != nil {
return nil, err
}
if _, err := tw.Write(filebody); err != nil {
return nil, err
}
}
if err := tw.Close(); err != nil {
return nil, err
}
//fmt.Println(string(buf.Bytes()))
return buf.Bytes(), nil
}