forked from dvyukov/go-fuzz
/
main.go
112 lines (103 loc) · 2.2 KB
/
main.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
// Copyright 2015 Dmitry Vyukov. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
package multipart
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"mime/multipart"
"net/textproto"
"github.com/dvyukov/go-fuzz/examples/fuzz"
)
type Part struct {
hdr textproto.MIMEHeader
data []byte
}
func Fuzz(data []byte) int {
const boundary = "dfhjksd23f43242f43fv4b4g2g2g23vf2"
{
r := multipart.NewReader(bytes.NewReader(data), boundary)
f, err := r.ReadForm(1 << 20)
if err == nil {
f.RemoveAll()
}
}
r := multipart.NewReader(bytes.NewReader(data), boundary)
var parts []Part
for {
p, err := r.NextPart()
if err == io.EOF {
break
}
if err != nil {
return 0
}
p.FileName()
p.FormName()
pdata, err := ioutil.ReadAll(p)
if err != nil {
return 0
}
p.Close()
// The parser is loose here.
// If data contains \n followed by boundary (but without \r),
// it parses it as part body. However, when it serializes it back,
// it writes \r\n followed by boundary, which becomes new part separator.
if bytes.Contains(pdata, []byte(boundary)) {
continue
}
parts = append(parts, Part{p.Header, pdata})
}
if len(parts) == 0 {
return 0
}
buf := new(bytes.Buffer)
w := multipart.NewWriter(buf)
w.SetBoundary(boundary)
for _, p := range parts {
pw, err := w.CreatePart(p.hdr)
if err != nil {
panic(err)
}
n, err := pw.Write(p.data)
if err != nil {
panic(err)
}
if n != len(p.data) {
panic("partial write")
}
}
w.Close()
data1 := buf.Bytes()
r1 := multipart.NewReader(buf, boundary)
var parts1 []Part
for {
p, err := r1.NextPart()
if err == io.EOF {
break
}
if err != nil {
fmt.Printf("parts0: %+v\n", parts)
fmt.Printf("data0: %q\n", data)
fmt.Printf("data1: %q\n", data1)
panic(err)
}
p.FileName()
p.FormName()
pdata, err := ioutil.ReadAll(p)
if err != nil {
panic(err)
}
p.Close()
parts1 = append(parts1, Part{p.Header, pdata})
}
if !fuzz.DeepEqual(parts, parts1) {
fmt.Printf("parts0: %+v\n", parts)
fmt.Printf("parts1: %+v\n", parts1)
fmt.Printf("data0: %q\n", data)
fmt.Printf("data1: %q\n", data1)
panic("data has changed")
}
return 1
}