In-Band Registration (XEP-0077)

telegram/commands.go

@@ -15,7 +15,8 @@ import (
 )
 
 const notEnoughArguments string = "Not enough arguments"
-const telegramNotInitialized string = "Telegram connection is not initialized yet"
+const TelegramNotInitialized string = "Telegram connection is not initialized yet"
+const TelegramAuthDone string = "Authorization is done already"
 const notOnline string = "Not online"
 
 var permissionsAdmin = client.ChatAdministratorRights{
@@ -244,40 +245,29 @@ func (c *Client) ProcessTransportCommand(cmdline string, resource string) string
 		}
 
 		if cmd == "login" {
-			wasSessionLoginEmpty := c.Session.Login == ""
-			c.Session.Login = args[0]
-
-			if wasSessionLoginEmpty && c.authorizer == nil {
-				go func() {
-					err := c.Connect(resource)
-					if err != nil {
-						log.Error(errors.Wrap(err, "TDlib connection failure"))
-					}
-				}()
-				// a quirk for authorizer to become ready. If it's still not,
-				// nothing bad: the command just needs to be resent again
-				time.Sleep(1e5)
+			err := c.TryLogin(resource, args[0])
+			if err != nil {
+				return err.Error()
 			}
-		}
 
-		if c.authorizer == nil {
-			return telegramNotInitialized
-		}
-
-		if c.authorizer.isClosed {
-			return "Authorization is done already"
-		}
-
-		switch cmd {
-		// sign in
-		case "login":
 			c.authorizer.PhoneNumber <- args[0]
-		// check auth code
-		case "code":
-			c.authorizer.Code <- args[0]
-		// check auth password
-		case "password":
-			c.authorizer.Password <- args[0]
+		} else {
+			if c.authorizer == nil {
+				return TelegramNotInitialized
+			}
+
+			if c.authorizer.isClosed {
+				return TelegramAuthDone
+			}
+
+			switch cmd {
+			// check auth code
+			case "code":
+				c.authorizer.Code <- args[0]
+			// check auth password
+			case "password":
+				c.authorizer.Password <- args[0]
+			}
 		}
 	// sign out
 	case "logout":

telegram/connect.go

@@ -3,6 +3,7 @@ package telegram
 import (
 	"github.com/pkg/errors"
 	"strconv"
+	"time"
 
 	"dev.narayana.im/narayana/telegabber/xmpp/gateway"
 
@@ -154,14 +155,49 @@ func (c *Client) Connect(resource string) error {
 			log.Errorf("Could not retrieve chats: %v", err)
 		}
 
-		gateway.SendPresence(c.xmpp, c.jid, gateway.SPType("subscribe"))
-		gateway.SendPresence(c.xmpp, c.jid, gateway.SPType("subscribed"))
+		gateway.SubscribeToTransport(c.xmpp, c.jid)
 		gateway.SendPresence(c.xmpp, c.jid, gateway.SPStatus("Logged in as: "+c.Session.Login))
 	}()
 
 	return nil
 }
 
+func (c *Client) TryLogin(resource string, login string) error {
+	wasSessionLoginEmpty := c.Session.Login == ""
+	c.Session.Login = login
+
+	if wasSessionLoginEmpty && c.authorizer == nil {
+		go func() {
+			err := c.Connect(resource)
+			if err != nil {
+				log.Error(errors.Wrap(err, "TDlib connection failure"))
+			}
+		}()
+		// a quirk for authorizer to become ready. If it's still not,
+		// nothing bad: just re-login again
+		time.Sleep(1e5)
+	}
+
+	if c.authorizer == nil {
+		return errors.New(TelegramNotInitialized)
+	}
+
+	if c.authorizer.isClosed {
+		return errors.New(TelegramAuthDone)
+	}
+
+	return nil
+}
+
+func (c *Client) SetPhoneNumber(login string) error {
+	if c.authorizer == nil || c.authorizer.isClosed {
+		return errors.New("Authorization not needed")
+	}
+
+	c.authorizer.PhoneNumber <- login
+	return nil
+}
+
 // Disconnect drops TDlib connection and
 // returns the flag indicating if disconnecting is permitted
 func (c *Client) Disconnect(resource string, quit bool) bool {

xmpp/extensions/extensions.go

@@ -193,6 +193,26 @@ type Replace struct {
 	Id      string   `xml:"id,attr"`
 }
 
+// QueryRegister is from XEP-0077
+type QueryRegister struct {
+	XMLName      xml.Name                 `xml:"jabber:iq:register query"`
+	Instructions string                   `xml:"instructions"`
+	Username     string                   `xml:"username"`
+	Registered   *QueryRegisterRegistered `xml:"registered"`
+	Remove       *QueryRegisterRemove     `xml:"remove"`
+	ResultSet    *stanza.ResultSet        `xml:"set,omitempty"`
+}
+
+// QueryRegisterRegistered is a child element from XEP-0077
+type QueryRegisterRegistered struct {
+	XMLName xml.Name `xml:"registered"`
+}
+
+// QueryRegisterRemove is a child element from XEP-0077
+type QueryRegisterRemove struct {
+	XMLName xml.Name `xml:"remove"`
+}
+
 // Namespace is a namespace!
 func (c PresenceNickExtension) Namespace() string {
 	return c.XMLName.Space
@@ -248,6 +268,16 @@ func (c Replace) Namespace() string {
 	return c.XMLName.Space
 }
 
+// Namespace is a namespace!
+func (c QueryRegister) Namespace() string {
+	return c.XMLName.Space
+}
+
+// GetSet getsets!
+func (c QueryRegister) GetSet() *stanza.ResultSet {
+	return c.ResultSet
+}
+
 // Name is a packet name
 func (ClientMessage) Name() string {
 	return "message"
@@ -326,4 +356,10 @@ func init() {
 		"urn:xmpp:message-correct:0",
 		"replace",
 	}, Replace{})
+
+	// register query
+	stanza.TypeRegistry.MapExtension(stanza.PKTIQ, xml.Name{
+		"jabber:iq:register",
+		"query",
+	}, QueryRegister{})
 }

xmpp/gateway/gateway.go

@@ -360,6 +360,12 @@ func ResumableSend(component *xmpp.Component, packet stanza.Packet) error {
 	return err
 }
 
+// SubscribeToTransport ensures a two-way subscription to the transport
+func SubscribeToTransport(component *xmpp.Component, jid string) {
+	SendPresence(component, jid, SPType("subscribe"))
+	SendPresence(component, jid, SPType("subscribed"))
+}
+
 // SplitJID tokenizes a JID string to bare JID and resource
 func SplitJID(from string) (string, string, bool) {
 	fromJid, err := stanza.NewJid(from)

xmpp/handlers.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/base64"
 	"encoding/xml"
+	"fmt"
 	"github.com/pkg/errors"
 	"io"
 	"strconv"
@@ -57,6 +58,22 @@ func HandleIq(s xmpp.Sender, p stanza.Packet) {
 			go handleGetDiscoInfo(s, iq)
 			return
 		}
+		_, ok = iq.Payload.(*stanza.DiscoItems)
+		if ok {
+			go handleGetDiscoItems(s, iq)
+			return
+		}
+		_, ok = iq.Payload.(*extensions.QueryRegister)
+		if ok {
+			go handleGetQueryRegister(s, iq)
+			return
+		}
+	} else if iq.Type == "set" {
+		query, ok := iq.Payload.(*extensions.QueryRegister)
+		if ok {
+			go handleSetQueryRegister(s, iq, query)
+			return
+		}
 	}
 }
 
@@ -91,8 +108,7 @@ func HandleMessage(s xmpp.Sender, p stanza.Packet) {
 		session, ok := sessions[bare]
 		if !ok {
 			if msg.To == gatewayJid {
-				gateway.SendPresence(component, msg.From, gateway.SPType("subscribe"))
-				gateway.SendPresence(component, msg.From, gateway.SPType("subscribed"))
+				gateway.SubscribeToTransport(component, msg.From)
 			} else {
 				log.Error("Message from stranger")
 			}
@@ -444,6 +460,7 @@ func handleGetDiscoInfo(s xmpp.Sender, iq *stanza.IQ) {
 		disco.AddIdentity("", "account", "registered")
 	} else {
 		disco.AddIdentity("Telegram Gateway", "gateway", "telegram")
+		disco.AddFeatures("jabber:iq:register")
 	}
 	answer.Payload = disco
 
@@ -458,6 +475,189 @@ func handleGetDiscoInfo(s xmpp.Sender, iq *stanza.IQ) {
 	_ = gateway.ResumableSend(component, answer)
 }
 
+func handleGetDiscoItems(s xmpp.Sender, iq *stanza.IQ) {
+	answer, err := stanza.NewIQ(stanza.Attrs{
+		Type: stanza.IQTypeResult,
+		From: iq.To,
+		To:   iq.From,
+		Id:   iq.Id,
+		Lang: "en",
+	})
+	if err != nil {
+		log.Errorf("Failed to create answer IQ: %v", err)
+		return
+	}
+
+	answer.Payload = answer.DiscoItems()
+
+	component, ok := s.(*xmpp.Component)
+	if !ok {
+		log.Error("Not a component")
+		return
+	}
+
+	_ = gateway.ResumableSend(component, answer)
+}
+
+func handleGetQueryRegister(s xmpp.Sender, iq *stanza.IQ) {
+	component, ok := s.(*xmpp.Component)
+	if !ok {
+		log.Error("Not a component")
+		return
+	}
+
+	answer, err := stanza.NewIQ(stanza.Attrs{
+		Type: stanza.IQTypeResult,
+		From: iq.To,
+		To:   iq.From,
+		Id:   iq.Id,
+		Lang: "en",
+	})
+	if err != nil {
+		log.Errorf("Failed to create answer IQ: %v", err)
+		return
+	}
+
+	var login string
+	bare, _, ok := gateway.SplitJID(iq.From)
+	if ok {
+		session, ok := sessions[bare]
+		if ok {
+			login = session.Session.Login
+		}
+	}
+
+	var query stanza.IQPayload
+	if login == "" {
+		query = extensions.QueryRegister{
+			Instructions: fmt.Sprintf("Authorization in Telegram is a multi-step process, so please accept %v to your contacts and follow further instructions (provide the authentication code there, etc.).\nFor now, please provide your login.", iq.To),
+		}
+	} else {
+		query = extensions.QueryRegister{
+			Instructions: "Already logged in",
+			Username:     login,
+			Registered:   &extensions.QueryRegisterRegistered{},
+		}
+	}
+	answer.Payload = query
+
+	log.Debugf("%#v", query)
+
+	_ = gateway.ResumableSend(component, answer)
+
+	if login == "" {
+		gateway.SubscribeToTransport(component, iq.From)
+	}
+}
+
+func handleSetQueryRegister(s xmpp.Sender, iq *stanza.IQ, query *extensions.QueryRegister) {
+	component, ok := s.(*xmpp.Component)
+	if !ok {
+		log.Error("Not a component")
+		return
+	}
+
+	answer, err := stanza.NewIQ(stanza.Attrs{
+		Type: stanza.IQTypeResult,
+		From: iq.To,
+		To:   iq.From,
+		Id:   iq.Id,
+		Lang: "en",
+	})
+	if err != nil {
+		log.Errorf("Failed to create answer IQ: %v", err)
+		return
+	}
+
+	defer gateway.ResumableSend(component, answer)
+
+	if query.Remove != nil {
+		iqAnswerSetError(answer, query, 405)
+		return
+	}
+
+	var login string
+	var session *telegram.Client
+	bare, resource, ok := gateway.SplitJID(iq.From)
+	if ok {
+		session, ok = sessions[bare]
+		if ok {
+			login = session.Session.Login
+		}
+	}
+
+	if login == "" {
+		if !ok {
+			session, ok = getTelegramInstance(bare, &persistence.Session{}, component)
+			if !ok {
+				iqAnswerSetError(answer, query, 500)
+				return
+			}
+		}
+
+		err := session.TryLogin(resource, query.Username)
+		if err != nil {
+			if err.Error() == telegram.TelegramAuthDone {
+				iqAnswerSetError(answer, query, 406)
+			} else {
+				iqAnswerSetError(answer, query, 500)
+			}
+			return
+		}
+
+		err = session.SetPhoneNumber(query.Username)
+		if err != nil {
+			iqAnswerSetError(answer, query, 500)
+			return
+		}
+
+		// everything okay, the response should be empty with no payload/error at this point
+		gateway.SubscribeToTransport(component, iq.From)
+	} else {
+		iqAnswerSetError(answer, query, 406)
+	}
+}
+
+func iqAnswerSetError(answer *stanza.IQ, payload *extensions.QueryRegister, code int) {
+	answer.Type = stanza.IQTypeError
+	answer.Payload = *payload
+	switch code {
+	case 400:
+		answer.Error = &stanza.Err{
+			Code: code,
+			Type: stanza.ErrorTypeModify,
+			Reason: "bad-request",
+		}
+	case 405:
+		answer.Error = &stanza.Err{
+			Code: code,
+			Type: stanza.ErrorTypeCancel,
+			Reason: "not-allowed",
+			Text: "Logging out is dangerous. If you are sure you would be able to receive the authentication code again, issue the /logout command to the transport",
+		}
+	case 406:
+		answer.Error = &stanza.Err{
+			Code: code,
+			Type: stanza.ErrorTypeModify,
+			Reason: "not-acceptable",
+			Text: "Phone number already provided, chat with the transport for further instruction",
+		}
+	case 500:
+		answer.Error = &stanza.Err{
+			Code: code,
+			Type: stanza.ErrorTypeWait,
+			Reason: "internal-server-error",
+		}
+	default:
+		log.Error("Unknown error code, falling back with empty reason")
+		answer.Error = &stanza.Err{
+			Code: code,
+			Type: stanza.ErrorTypeCancel,
+			Reason: "undefined-condition",
+		}
+	}
+}
+
 func toToID(to string) (int64, bool) {
 	toParts := strings.Split(to, "@")
 	if len(toParts) < 2 {