1 files changed, 389 insertions, 0 deletions
diff --git a/vendor/github.com/matterbridge/go-whatsapp/session.go b/vendor/github.com/matterbridge/go-whatsapp/session.go
new file mode 100644
index 00000000..2dd8d582
--- /dev/null
+++ b/vendor/github.com/matterbridge/go-whatsapp/session.go
@@ -0,0 +1,389 @@
+package whatsapp
+
+import (
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/matterbridge/go-whatsapp/crypto/cbc"
+	"github.com/matterbridge/go-whatsapp/crypto/curve25519"
+	"github.com/matterbridge/go-whatsapp/crypto/hkdf"
+)
+
+/*
+Session contains session individual information. To be able to resume the connection without scanning the qr code
+every time you should save the Session returned by Login and use RestoreSession the next time you want to login.
+Every successful created connection returns a new Session. The Session(ClientToken, ServerToken) is altered after
+every re-login and should be saved every time.
+*/
+type Session struct {
+	ClientId    string
+	ClientToken string
+	ServerToken string
+	EncKey      []byte
+	MacKey      []byte
+	Wid         string
+}
+
+type Info struct {
+	Battery   int
+	Platform  string
+	Connected bool
+	Pushname  string
+	Wid       string
+	Lc        string
+	Phone     *PhoneInfo
+	Plugged   bool
+	Tos       int
+	Lg        string
+	Is24h     bool
+}
+
+type PhoneInfo struct {
+	Mcc                string
+	Mnc                string
+	OsVersion          string
+	DeviceManufacturer string
+	DeviceModel        string
+	OsBuildNumber      string
+	WaVersion          string
+}
+
+func newInfoFromReq(info map[string]interface{}) *Info {
+	phoneInfo := info["phone"].(map[string]interface{})
+
+	ret := &Info{
+		Battery:   int(info["battery"].(float64)),
+		Platform:  info["platform"].(string),
+		Connected: info["connected"].(bool),
+		Pushname:  info["pushname"].(string),
+		Wid:       info["wid"].(string),
+		Lc:        info["lc"].(string),
+		Phone: &PhoneInfo{
+			phoneInfo["mcc"].(string),
+			phoneInfo["mnc"].(string),
+			phoneInfo["os_version"].(string),
+			phoneInfo["device_manufacturer"].(string),
+			phoneInfo["device_model"].(string),
+			phoneInfo["os_build_number"].(string),
+			phoneInfo["wa_version"].(string),
+		},
+		Plugged: info["plugged"].(bool),
+		Lg:      info["lg"].(string),
+		Tos:     int(info["tos"].(float64)),
+	}
+
+	if is24h, ok := info["is24h"]; ok {
+		ret.Is24h = is24h.(bool)
+	}
+
+	return ret
+}
+
+/*
+SetClientName sets the long and short client names that are sent to WhatsApp when logging in and displayed in the
+WhatsApp Web device list. As the values are only sent when logging in, changing them after logging in is not possible.
+*/
+func (wac *Conn) SetClientName(long, short string) error {
+	if wac.session != nil && (wac.session.EncKey != nil || wac.session.MacKey != nil) {
+		return fmt.Errorf("cannot change client name after logging in")
+	}
+	wac.longClientName, wac.shortClientName = long, short
+	return nil
+}
+
+/*
+Login is the function that creates a new whatsapp session and logs you in. If you do not want to scan the qr code
+every time, you should save the returned session and use RestoreSession the next time. Login takes a writable channel
+as an parameter. This channel is used to push the data represented by the qr code back to the user. The received data
+should be displayed as an qr code in a way you prefer. To print a qr code to console you can use:
+github.com/Baozisoftware/qrcode-terminal-go Example login procedure:
+	wac, err := whatsapp.NewConn(5 * time.Second)
+	if err != nil {
+		panic(err)
+	}
+
+	qr := make(chan string)
+	go func() {
+		terminal := qrcodeTerminal.New()
+		terminal.Get(<-qr).Print()
+	}()
+
+	session, err := wac.Login(qr)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error during login: %v\n", err)
+	}
+	fmt.Printf("login successful, session: %v\n", session)
+*/
+func (wac *Conn) Login(qrChan chan<- string) (Session, error) {
+	session := Session{}
+
+	if wac.session != nil && (wac.session.EncKey != nil || wac.session.MacKey != nil) {
+		return session, fmt.Errorf("already logged in")
+	}
+
+	clientId := make([]byte, 16)
+	_, err := rand.Read(clientId)
+	if err != nil {
+		return session, fmt.Errorf("error creating random ClientId: %v", err)
+	}
+
+	session.ClientId = base64.StdEncoding.EncodeToString(clientId)
+	//oldVersion=8691
+	login := []interface{}{"admin", "init", []int{0, 3, 225}, []string{wac.longClientName, wac.shortClientName}, session.ClientId, true}
+	loginChan, err := wac.write(login)
+	if err != nil {
+		return session, fmt.Errorf("error writing login: %v\n", err)
+	}
+
+	var r string
+	select {
+	case r = <-loginChan:
+	case <-time.After(wac.msgTimeout):
+		return session, fmt.Errorf("login connection timed out")
+	}
+
+	var resp map[string]interface{}
+	if err = json.Unmarshal([]byte(r), &resp); err != nil {
+		return session, fmt.Errorf("error decoding login resp: %v\n", err)
+	}
+
+	ref := resp["ref"].(string)
+
+	priv, pub, err := curve25519.GenerateKey()
+	if err != nil {
+		return session, fmt.Errorf("error generating keys: %v\n", err)
+	}
+
+	//listener for Login response
+	messageTag := "s1"
+	wac.listener[messageTag] = make(chan string, 1)
+
+	qrChan <- fmt.Sprintf("%v,%v,%v", ref, base64.StdEncoding.EncodeToString(pub[:]), session.ClientId)
+
+	var resp2 []interface{}
+	select {
+	case r1 := <-wac.listener[messageTag]:
+		if err := json.Unmarshal([]byte(r1), &resp2); err != nil {
+			return session, fmt.Errorf("error decoding qr code resp: %v", err)
+		}
+	case <-time.After(time.Duration(resp["ttl"].(float64)) * time.Millisecond):
+		return session, fmt.Errorf("qr code scan timed out")
+	}
+
+	info := resp2[1].(map[string]interface{})
+
+	wac.Info = newInfoFromReq(info)
+
+	session.ClientToken = info["clientToken"].(string)
+	session.ServerToken = info["serverToken"].(string)
+	session.Wid = info["wid"].(string)
+	s := info["secret"].(string)
+	decodedSecret, err := base64.StdEncoding.DecodeString(s)
+	if err != nil {
+		return session, fmt.Errorf("error decoding secret: %v", err)
+	}
+
+	var pubKey [32]byte
+	copy(pubKey[:], decodedSecret[:32])
+
+	sharedSecret := curve25519.GenerateSharedSecret(*priv, pubKey)
+
+	hash := sha256.New
+
+	nullKey := make([]byte, 32)
+	h := hmac.New(hash, nullKey)
+	h.Write(sharedSecret)
+
+	sharedSecretExtended, err := hkdf.Expand(h.Sum(nil), 80, "")
+	if err != nil {
+		return session, fmt.Errorf("hkdf error: %v", err)
+	}
+
+	//login validation
+	checkSecret := make([]byte, 112)
+	copy(checkSecret[:32], decodedSecret[:32])
+	copy(checkSecret[32:], decodedSecret[64:])
+	h2 := hmac.New(hash, sharedSecretExtended[32:64])
+	h2.Write(checkSecret)
+	if !hmac.Equal(h2.Sum(nil), decodedSecret[32:64]) {
+		return session, fmt.Errorf("abort login")
+	}
+
+	keysEncrypted := make([]byte, 96)
+	copy(keysEncrypted[:16], sharedSecretExtended[64:])
+	copy(keysEncrypted[16:], decodedSecret[64:])
+
+	keyDecrypted, err := cbc.Decrypt(sharedSecretExtended[:32], nil, keysEncrypted)
+	if err != nil {
+		return session, fmt.Errorf("error decryptAes: %v", err)
+	}
+
+	session.EncKey = keyDecrypted[:32]
+	session.MacKey = keyDecrypted[32:64]
+	wac.session = &session
+
+	return session, nil
+}
+
+/*
+RestoreSession is the function that restores a given session. It will try to reestablish the connection to the
+WhatsAppWeb servers with the provided session. If it succeeds it will return a new session. This new session has to be
+saved because the Client and Server-Token will change after every login. Logging in with old tokens is possible, but not
+suggested. If so, a challenge has to be resolved which is just another possible point of failure.
+*/
+func (wac *Conn) RestoreSession(session Session) (Session, error) {
+	if wac.session != nil && (wac.session.EncKey != nil || wac.session.MacKey != nil) {
+		return Session{}, fmt.Errorf("already logged in")
+	}
+
+	wac.session = &session
+
+	//listener for Conn or challenge; s1 is not allowed to drop
+	wac.listener["s1"] = make(chan string, 1)
+
+	//admin init
+	init := []interface{}{"admin", "init", []int{0, 3, 225}, []string{wac.longClientName, wac.shortClientName}, session.ClientId, true}
+	initChan, err := wac.write(init)
+	if err != nil {
+		wac.session = nil
+		return Session{}, fmt.Errorf("error writing admin init: %v\n", err)
+	}
+
+	//admin login with takeover
+	login := []interface{}{"admin", "login", session.ClientToken, session.ServerToken, session.ClientId, "takeover"}
+	loginChan, err := wac.write(login)
+	if err != nil {
+		wac.session = nil
+		return Session{}, fmt.Errorf("error writing admin login: %v\n", err)
+	}
+
+	select {
+	case r := <-initChan:
+		var resp map[string]interface{}
+		if err = json.Unmarshal([]byte(r), &resp); err != nil {
+			wac.session = nil
+			return Session{}, fmt.Errorf("error decoding login connResp: %v\n", err)
+		}
+
+		if int(resp["status"].(float64)) != 200 {
+			wac.session = nil
+			return Session{}, fmt.Errorf("init responded with %d", resp["status"])
+		}
+	case <-time.After(wac.msgTimeout):
+		wac.session = nil
+		return Session{}, fmt.Errorf("restore session init timed out")
+	}
+
+	//wait for s1
+	var connResp []interface{}
+	select {
+	case r1 := <-wac.listener["s1"]:
+		if err := json.Unmarshal([]byte(r1), &connResp); err != nil {
+			wac.session = nil
+			return Session{}, fmt.Errorf("error decoding s1 message: %v\n", err)
+		}
+	case <-time.After(wac.msgTimeout):
+		wac.session = nil
+		return Session{}, fmt.Errorf("restore session connection timed out")
+	}
+
+	//check if challenge is present
+	if len(connResp) == 2 && connResp[0] == "Cmd" && connResp[1].(map[string]interface{})["type"] == "challenge" {
+		wac.listener["s2"] = make(chan string, 1)
+
+		if err := wac.resolveChallenge(connResp[1].(map[string]interface{})["challenge"].(string)); err != nil {
+			wac.session = nil
+			return Session{}, fmt.Errorf("error resolving challenge: %v\n", err)
+		}
+
+		select {
+		case r := <-wac.listener["s2"]:
+			if err := json.Unmarshal([]byte(r), &connResp); err != nil {
+				wac.session = nil
+				return Session{}, fmt.Errorf("error decoding s2 message: %v\n", err)
+			}
+		case <-time.After(wac.msgTimeout):
+			wac.session = nil
+			return Session{}, fmt.Errorf("restore session challenge timed out")
+		}
+	}
+
+	//check for login 200 --> login success
+	select {
+	case r := <-loginChan:
+		var resp map[string]interface{}
+		if err = json.Unmarshal([]byte(r), &resp); err != nil {
+			wac.session = nil
+			return Session{}, fmt.Errorf("error decoding login connResp: %v\n", err)
+		}
+
+		if int(resp["status"].(float64)) != 200 {
+			wac.session = nil
+			return Session{}, fmt.Errorf("admin login responded with %d", resp["status"])
+		}
+	case <-time.After(wac.msgTimeout):
+		wac.session = nil
+		return Session{}, fmt.Errorf("restore session login timed out")
+	}
+
+	info := connResp[1].(map[string]interface{})
+
+	wac.Info = newInfoFromReq(info)
+
+	//set new tokens
+	session.ClientToken = info["clientToken"].(string)
+	session.ServerToken = info["serverToken"].(string)
+	session.Wid = info["wid"].(string)
+
+	return *wac.session, nil
+}
+
+func (wac *Conn) resolveChallenge(challenge string) error {
+	decoded, err := base64.StdEncoding.DecodeString(challenge)
+	if err != nil {
+		return err
+	}
+
+	h2 := hmac.New(sha256.New, wac.session.MacKey)
+	h2.Write([]byte(decoded))
+
+	ch := []interface{}{"admin", "challenge", base64.StdEncoding.EncodeToString(h2.Sum(nil)), wac.session.ServerToken, wac.session.ClientId}
+	challengeChan, err := wac.write(ch)
+	if err != nil {
+		return fmt.Errorf("error writing challenge: %v\n", err)
+	}
+
+	select {
+	case r := <-challengeChan:
+		var resp map[string]interface{}
+		if err := json.Unmarshal([]byte(r), &resp); err != nil {
+			return fmt.Errorf("error decoding login resp: %v\n", err)
+		}
+		if int(resp["status"].(float64)) != 200 {
+			return fmt.Errorf("challenge responded with %d\n", resp["status"])
+		}
+	case <-time.After(wac.msgTimeout):
+		return fmt.Errorf("connection timed out")
+	}
+
+	return nil
+}
+
+/*
+Logout is the function to logout from a WhatsApp session. Logging out means invalidating the current session.
+The session can not be resumed and will disappear on your phone in the WhatsAppWeb client list.
+*/
+func (wac *Conn) Logout() error {
+	login := []interface{}{"admin", "Conn", "disconnect"}
+	_, err := wac.write(login)
+	if err != nil {
+		return fmt.Errorf("error writing logout: %v\n", err)
+	}
+
+	return nil
+}