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
|
package main
import (
"bytes"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"fyne.io/fyne/v2/data/binding"
"io/ioutil"
"net/http"
"strings"
"sync"
"time"
)
const (
Register = "/api/register"
SendMessage = "/api/sendMessage"
PollMessages = "/api/pollMessages"
GetUserKey = "/api/getUserKey"
TryAuth = "/api/tryAuth"
)
var storage struct {
sync.RWMutex
messages []Message
data []string
binding binding.ExternalStringList
}
var userKeys = make(map[string]string)
type Request struct {
User string
Data string
}
type Response struct {
Message string
}
type Message struct {
User string
Data string
Payload string
Signature string
}
func (msg *Message) toString() string {
return fmt.Sprintf("%s: %s", msg.User, msg.Data)
}
func makeRequest(request Request, apiMethod string, user UserData) (*http.Response, error) {
signedRequest, err := signRequest(request, user.ParsedUserKey)
if err != nil {
return nil, err
}
reader := bytes.NewReader([]byte(signedRequest))
return http.Post(user.ServerUrl+apiMethod, "application/json", reader)
}
func sendMessage(user UserData, message string) {
// TODO(andrew): Добавить отображение ошибки в интерфейс
_, _ = makeRequest(Request{
User: user.Username,
Data: message,
}, SendMessage, user)
}
func register(user UserData, serverKey string) (Response, error) {
var resp Response
httpResp, err := makeRequest(Request{
User: user.Username,
Data: serverKey,
}, Register, user)
if err != nil {
return resp, err
}
body, _ := ioutil.ReadAll(httpResp.Body)
_ = json.Unmarshal(body, &resp)
if httpResp.StatusCode == http.StatusOK {
return resp, nil
} else {
return resp, errors.New(resp.Message)
}
}
func tryAuth(user UserData) (bool, error) {
var resp Response
httpResp, err := makeRequest(Request{
User: user.Username,
Data: "auth",
}, TryAuth, user)
if err != nil {
return false, err
}
body, _ := ioutil.ReadAll(httpResp.Body)
_ = json.Unmarshal(body, &resp)
if httpResp.StatusCode == http.StatusOK {
return true, nil
} else {
return false, errors.New(resp.Message)
}
}
func getUserKey(user UserData, checkedUser string) (string, error) {
var resp Response
httpResp, err := makeRequest(Request{
User: user.Username,
Data: checkedUser,
}, GetUserKey, user)
if err != nil {
return "", err
}
body, _ := ioutil.ReadAll(httpResp.Body)
_ = json.Unmarshal(body, &resp)
if httpResp.StatusCode == http.StatusOK {
return resp.Message, nil
} else {
return "", errors.New(resp.Message)
}
}
func pingServer(user UserData) error {
_, err := http.Get(user.ServerUrl)
return err
}
func parseMessage(signedMessage string) (Message, error) {
var msg Message
parts := strings.Split(signedMessage, ".")
if len(parts) != 2 {
return msg, errors.New("request doesn't contain exactly two parts")
}
payload := parts[0]
signature := parts[1]
messageBody, err := base64.StdEncoding.DecodeString(payload)
if err != nil {
return msg, err
}
err = json.Unmarshal(messageBody, &msg)
if err != nil {
return msg, errors.New("unable to parse message")
}
msg.Payload = payload
msg.Signature = signature
return msg, nil
}
// TODO(andrew): Заменить сбор новых сообщений через http запрос к серверу на
// получения обновлений через сокет от сервера.
func runClient(user UserData) {
var lastPoll int64 = 0
for {
httpResp, _ := makeRequest(Request{
User: user.Username,
Data: fmt.Sprint(lastPoll),
}, PollMessages, user)
lastPoll = time.Now().UnixNano()
if httpResp.StatusCode == http.StatusOK {
body, _ := ioutil.ReadAll(httpResp.Body)
var resp Response
_ = json.Unmarshal(body, &resp)
var signedMessages []string
_ = json.Unmarshal([]byte(resp.Message), &signedMessages)
storage.Lock()
for _, signedMessage := range signedMessages {
msg, _ := parseMessage(signedMessage)
userKey, ok := userKeys[msg.User]
if !ok {
key, err := getUserKey(user, msg.User)
if err != nil {
fmt.Printf("Error occurred when polling user (%s) key\n", msg.User)
continue
}
userKey = key
userKeys[msg.User] = key
}
passed, err := checkSignature(msg.Payload, msg.Signature, userKey)
if !passed {
fmt.Printf("Message didn't pass signature check. From %s: %s\n", msg.User, msg.Data)
continue
}
if err != nil {
fmt.Printf(
"Error occurred when checking signature of message. From %s: %s\n",
msg.User, msg.Data)
}
fmt.Printf("Polled new message from %s: %s\n", msg.User, msg.Data)
_ = storage.binding.Append(msg.toString())
storage.messages = append(storage.messages, msg)
}
storage.Unlock()
} else {
fmt.Println(httpResp.StatusCode)
ae, _ := ioutil.ReadAll(httpResp.Body)
fmt.Println(string(ae))
}
time.Sleep(100 * time.Millisecond)
}
}
|
