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
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
package whatsapp
import (
"bytes"
"crypto/hmac"
"crypto/rand"
"crypto/sha256"
"encoding/base64"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"net/url"
"time"
"github.com/Rhymen/go-whatsapp/crypto/cbc"
"github.com/Rhymen/go-whatsapp/crypto/hkdf"
)
func Download(url string, mediaKey []byte, appInfo MediaType, fileLength int) ([]byte, error) {
if url == "" {
return nil, fmt.Errorf("no url present")
}
file, mac, err := downloadMedia(url)
if err != nil {
return nil, err
}
iv, cipherKey, macKey, _, err := getMediaKeys(mediaKey, appInfo)
if err != nil {
return nil, err
}
if err = validateMedia(iv, file, macKey, mac); err != nil {
return nil, err
}
data, err := cbc.Decrypt(cipherKey, iv, file)
if err != nil {
return nil, err
}
if len(data) != fileLength {
return nil, fmt.Errorf("file length does not match. Expected: %v, got: %v", fileLength, len(data))
}
return data, nil
}
func validateMedia(iv []byte, file []byte, macKey []byte, mac []byte) error {
h := hmac.New(sha256.New, macKey)
n, err := h.Write(append(iv, file...))
if err != nil {
return err
}
if n < 10 {
return fmt.Errorf("hash to short")
}
if !hmac.Equal(h.Sum(nil)[:10], mac) {
return fmt.Errorf("invalid media hmac")
}
return nil
}
func getMediaKeys(mediaKey []byte, appInfo MediaType) (iv, cipherKey, macKey, refKey []byte, err error) {
mediaKeyExpanded, err := hkdf.Expand(mediaKey, 112, string(appInfo))
if err != nil {
return nil, nil, nil, nil, err
}
return mediaKeyExpanded[:16], mediaKeyExpanded[16:48], mediaKeyExpanded[48:80], mediaKeyExpanded[80:], nil
}
func downloadMedia(url string) (file []byte, mac []byte, err error) {
resp, err := http.Get(url)
if err != nil {
return nil, nil, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return nil, nil, fmt.Errorf("download failed with status code %d", resp.StatusCode)
}
if resp.ContentLength <= 10 {
return nil, nil, fmt.Errorf("file to short")
}
data, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, nil, err
}
n := len(data)
return data[:n-10], data[n-10 : n], nil
}
type MediaConn struct {
Status int `json:"status"`
MediaConn struct {
Auth string `json:"auth"`
TTL int `json:"ttl"`
Hosts []struct {
Hostname string `json:"hostname"`
IPs []struct {
IP4 net.IP `json:"ip4"`
IP6 net.IP `json:"ip6"`
} `json:"ips"`
} `json:"hosts"`
} `json:"media_conn"`
}
func (wac *Conn) queryMediaConn() (hostname, auth string, ttl int, err error) {
queryReq := []interface{}{"query", "mediaConn"}
ch, err := wac.writeJson(queryReq)
if err != nil {
return "", "", 0, err
}
var resp MediaConn
select {
case r := <-ch:
if err = json.Unmarshal([]byte(r), &resp); err != nil {
return "", "", 0, fmt.Errorf("error decoding query media conn response: %v", err)
}
case <-time.After(wac.msgTimeout):
return "", "", 0, fmt.Errorf("query media conn timed out")
}
if resp.Status != http.StatusOK {
return "", "", 0, fmt.Errorf("query media conn responded with %d", resp.Status)
}
for _, h := range resp.MediaConn.Hosts {
if h.Hostname != "" {
return h.Hostname, resp.MediaConn.Auth, resp.MediaConn.TTL, nil
}
}
return "", "", 0, fmt.Errorf("query media conn responded with no host")
}
var mediaTypeMap = map[MediaType]string{
MediaImage: "/mms/image",
MediaVideo: "/mms/video",
MediaDocument: "/mms/document",
MediaAudio: "/mms/audio",
}
func (wac *Conn) Upload(reader io.Reader, appInfo MediaType) (downloadURL string, mediaKey []byte, fileEncSha256 []byte, fileSha256 []byte, fileLength uint64, err error) {
data, err := ioutil.ReadAll(reader)
if err != nil {
return "", nil, nil, nil, 0, err
}
mediaKey = make([]byte, 32)
rand.Read(mediaKey)
iv, cipherKey, macKey, _, err := getMediaKeys(mediaKey, appInfo)
if err != nil {
return "", nil, nil, nil, 0, err
}
enc, err := cbc.Encrypt(cipherKey, iv, data)
if err != nil {
return "", nil, nil, nil, 0, err
}
fileLength = uint64(len(data))
h := hmac.New(sha256.New, macKey)
h.Write(append(iv, enc...))
mac := h.Sum(nil)[:10]
sha := sha256.New()
sha.Write(data)
fileSha256 = sha.Sum(nil)
sha.Reset()
sha.Write(append(enc, mac...))
fileEncSha256 = sha.Sum(nil)
hostname, auth, _, err := wac.queryMediaConn()
if err != nil {
return "", nil, nil, nil, 0, err
}
token := base64.URLEncoding.EncodeToString(fileEncSha256)
q := url.Values{
"auth": []string{auth},
"token": []string{token},
}
path := mediaTypeMap[appInfo]
uploadURL := url.URL{
Scheme: "https",
Host: hostname,
Path: fmt.Sprintf("%s/%s", path, token),
RawQuery: q.Encode(),
}
body := bytes.NewReader(append(enc, mac...))
req, err := http.NewRequest(http.MethodPost, uploadURL.String(), body)
if err != nil {
return "", nil, nil, nil, 0, err
}
req.Header.Set("Origin", "https://web.whatsapp.com")
req.Header.Set("Referer", "https://web.whatsapp.com/")
client := &http.Client{}
// Submit the request
res, err := client.Do(req)
if err != nil {
return "", nil, nil, nil, 0, err
}
if res.StatusCode != http.StatusOK {
return "", nil, nil, nil, 0, fmt.Errorf("upload failed with status code %d", res.StatusCode)
}
var jsonRes map[string]string
if err := json.NewDecoder(res.Body).Decode(&jsonRes); err != nil {
return "", nil, nil, nil, 0, err
}
return jsonRes["url"], mediaKey, fileEncSha256, fileSha256, fileLength, nil
}
|
