mautrix-whatsapp/vendor/github.com/Rhymen/go-whatsapp/conn.go

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2018-08-26 16:29:51 +02:00
//Package whatsapp provides a developer API to interact with the WhatsAppWeb-Servers.
package whatsapp
import (
"crypto/hmac"
"crypto/sha256"
"encoding/json"
"fmt"
"github.com/Rhymen/go-whatsapp/binary"
"github.com/Rhymen/go-whatsapp/crypto/cbc"
"github.com/gorilla/websocket"
"math/rand"
"net/http"
"os"
"strconv"
"strings"
"sync"
"time"
)
type metric byte
const (
debugLog metric = iota + 1
queryResume
queryReceipt
queryMedia
queryChat
queryContacts
queryMessages
presence
presenceSubscribe
group
read
chat
received
pic
status
message
queryActions
block
queryGroup
queryPreview
queryEmoji
queryMessageInfo
spam
querySearch
queryIdentity
queryUrl
profile
contact
queryVcard
queryStatus
queryStatusUpdate
privacyStatus
queryLiveLocations
liveLocation
queryVname
queryLabels
call
queryCall
queryQuickReplies
)
type flag byte
const (
ignore flag = 1 << (7 - iota)
ackRequest
available
notAvailable
expires
skipOffline
)
/*
Conn is created by NewConn. Interacting with the initialized Conn is the main way of interacting with our package.
It holds all necessary information to make the package work internally.
*/
type Conn struct {
wsConn *websocket.Conn
session *Session
listener map[string]chan string
listenerMutex sync.RWMutex
writeChan chan wsMsg
handler []Handler
msgCount int
msgTimeout time.Duration
Info *Info
Store *Store
ServerLastSeen time.Time
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longClientName string
shortClientName string
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}
type wsMsg struct {
messageType int
data []byte
}
/*
Creates a new connection with a given timeout. The websocket connection to the WhatsAppWeb servers get´s established.
The goroutine for handling incoming messages is started
*/
func NewConn(timeout time.Duration) (*Conn, error) {
dialer := &websocket.Dialer{
ReadBufferSize: 25 * 1024 * 1024,
WriteBufferSize: 10 * 1024 * 1024,
HandshakeTimeout: timeout,
}
headers := http.Header{"Origin": []string{"https://web.whatsapp.com"}}
wsConn, _, err := dialer.Dial("wss://w3.web.whatsapp.com/ws", headers)
if err != nil {
return nil, fmt.Errorf("couldn't dial whatsapp web websocket: %v", err)
}
wac := &Conn{
wsConn: wsConn,
listener: make(map[string]chan string),
listenerMutex: sync.RWMutex{},
writeChan: make(chan wsMsg),
handler: make([]Handler, 0),
msgCount: 0,
msgTimeout: timeout,
Store: newStore(),
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longClientName: "github.com/rhymen/go-whatsapp",
shortClientName: "go-whatsapp",
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}
go wac.readPump()
go wac.writePump()
go wac.keepAlive(20000, 90000)
return wac, nil
}
func (wac *Conn) write(data []interface{}) (<-chan string, error) {
d, err := json.Marshal(data)
if err != nil {
return nil, err
}
ts := time.Now().Unix()
messageTag := fmt.Sprintf("%d.--%d", ts, wac.msgCount)
msg := fmt.Sprintf("%s,%s", messageTag, d)
ch := make(chan string, 1)
wac.listenerMutex.Lock()
wac.listener[messageTag] = ch
wac.listenerMutex.Unlock()
wac.writeChan <- wsMsg{websocket.TextMessage, []byte(msg)}
wac.msgCount++
return ch, nil
}
func (wac *Conn) writeBinary(node binary.Node, metric metric, flag flag, tag string) (<-chan string, error) {
if len(tag) < 2 {
return nil, fmt.Errorf("no tag specified or to short")
}
b, err := binary.Marshal(node)
if err != nil {
return nil, err
}
cipher, err := cbc.Encrypt(wac.session.EncKey, nil, b)
if err != nil {
return nil, err
}
h := hmac.New(sha256.New, wac.session.MacKey)
h.Write(cipher)
hash := h.Sum(nil)
data := []byte(tag + ",")
data = append(data, byte(metric), byte(flag))
data = append(data, hash[:32]...)
data = append(data, cipher...)
ch := make(chan string, 1)
wac.listenerMutex.Lock()
wac.listener[tag] = ch
wac.listenerMutex.Unlock()
msg := wsMsg{websocket.BinaryMessage, data}
wac.writeChan <- msg
wac.msgCount++
return ch, nil
}
func (wac *Conn) readPump() {
defer wac.wsConn.Close()
for {
msgType, msg, err := wac.wsConn.ReadMessage()
if err != nil {
if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway) {
wac.handle(fmt.Errorf("unexpected websocket close: %v", err))
}
break
}
data := strings.SplitN(string(msg), ",", 2)
//Kepp-Alive Timestmap
if data[0][0] == '!' {
msecs, err := strconv.ParseInt(data[0][1:], 10, 64)
if err != nil {
fmt.Fprintf(os.Stderr, "Error converting time string to uint: %v\n", err)
continue
}
wac.ServerLastSeen = time.Unix(msecs/1000, (msecs%1000)*int64(time.Millisecond))
continue
}
wac.listenerMutex.RLock()
listener, hasListener := wac.listener[data[0]]
wac.listenerMutex.RUnlock()
if hasListener && len(data[1]) > 0 {
listener <- data[1]
wac.listenerMutex.Lock()
delete(wac.listener, data[0])
wac.listenerMutex.Unlock()
} else if msgType == 2 && wac.session != nil && wac.session.EncKey != nil {
message, err := wac.decryptBinaryMessage([]byte(data[1]))
if err != nil {
wac.handle(fmt.Errorf("error decoding binary: %v", err))
continue
}
wac.dispatch(message)
} else {
if len(data[1]) > 0 {
wac.handle(string(data[1]))
}
}
}
}
func (wac *Conn) writePump() {
for msg := range wac.writeChan {
if err := wac.wsConn.WriteMessage(msg.messageType, msg.data); err != nil {
fmt.Fprintf(os.Stderr, "error writing to socket: %v", err)
}
}
}
func (wac *Conn) keepAlive(minIntervalMs int, maxIntervalMs int) {
for {
wac.writeChan <- wsMsg{
messageType: websocket.TextMessage,
data: []byte("?,,"),
}
interval := rand.Intn(maxIntervalMs-minIntervalMs) + minIntervalMs
<-time.After(time.Duration(interval) * time.Millisecond)
}
}
func (wac *Conn) decryptBinaryMessage(msg []byte) (*binary.Node, error) {
//message validation
h2 := hmac.New(sha256.New, wac.session.MacKey)
h2.Write([]byte(msg[32:]))
if !hmac.Equal(h2.Sum(nil), msg[:32]) {
return nil, fmt.Errorf("message received with invalid hmac")
}
// message decrypt
d, err := cbc.Decrypt(wac.session.EncKey, nil, msg[32:])
if err != nil {
return nil, fmt.Errorf("error decrypting message with AES: %v", err)
}
// message unmarshal
message, err := binary.Unmarshal(d)
if err != nil {
return nil, fmt.Errorf("error decoding binary: %v", err)
}
return message, nil
}