From 4588170d1e43db780c551177f5996598fe25bc6e Mon Sep 17 00:00:00 2001
From: Bohdan Horbeshko <bodqhrohro@gmail.com>
Date: Thu, 31 Aug 2023 17:26:35 -0400
Subject: [PATCH] Harden the authorizer access to prevent crashes

---
 Makefile             |  2 +-
 telegabber.go        |  2 +-
 telegram/client.go   |  3 +++
 telegram/commands.go |  6 ++++++
 telegram/connect.go  | 24 ++++++++++++++++++++++++
 5 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 724c73d..e139c00 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 
 COMMIT := $(shell git rev-parse --short HEAD)
 TD_COMMIT := "8517026415e75a8eec567774072cbbbbb52376c1"
-VERSION := "v1.8.0"
+VERSION := "v1.8.1"
 MAKEOPTS := "-j4"
 
 all:
diff --git a/telegabber.go b/telegabber.go
index f409599..85c5fbd 100644
--- a/telegabber.go
+++ b/telegabber.go
@@ -15,7 +15,7 @@ import (
 	goxmpp "gosrc.io/xmpp"
 )
 
-var version string = "1.8.0"
+var version string = "1.8.1"
 var commit string
 
 var sm *goxmpp.StreamManager
diff --git a/telegram/client.go b/telegram/client.go
index e9acd20..6f6d719 100644
--- a/telegram/client.go
+++ b/telegram/client.go
@@ -74,6 +74,9 @@ type clientLocks struct {
 	resourcesLock      sync.Mutex
 	outboxLock         sync.Mutex
 	lastMsgHashesLock  sync.Mutex
+
+	authorizerReadLock  sync.Mutex
+	authorizerWriteLock sync.Mutex
 }
 
 // NewClient instantiates a Telegram App
diff --git a/telegram/commands.go b/telegram/commands.go
index b4920d4..b729973 100644
--- a/telegram/commands.go
+++ b/telegram/commands.go
@@ -244,6 +244,9 @@ func (c *Client) ProcessTransportCommand(cmdline string, resource string) string
 			return notEnoughArguments
 		}
 
+		c.locks.authorizerWriteLock.Lock()
+		defer c.locks.authorizerWriteLock.Unlock()
+
 		if cmd == "login" {
 			err := c.TryLogin(resource, args[0])
 			if err != nil {
@@ -324,10 +327,13 @@ func (c *Client) ProcessTransportCommand(cmdline string, resource string) string
 			lastname = rawCmdArguments(cmdline, 1)
 		}
 
+		c.locks.authorizerWriteLock.Lock()
 		if c.authorizer != nil && !c.authorizer.isClosed {
 			c.authorizer.FirstName <- firstname
 			c.authorizer.LastName <- lastname
+			c.locks.authorizerWriteLock.Unlock()
 		} else {
+			c.locks.authorizerWriteLock.Unlock()
 			if !c.Online() {
 				return notOnline
 			}
diff --git a/telegram/connect.go b/telegram/connect.go
index ab9c19c..6c49aa9 100644
--- a/telegram/connect.go
+++ b/telegram/connect.go
@@ -110,6 +110,7 @@ func (c *Client) Connect(resource string) error {
 
 	log.Warn("Connecting to Telegram network...")
 
+	c.locks.authorizerWriteLock.Lock()
 	c.authorizer = &clientAuthorizer{
 		TdlibParameters: make(chan *client.SetTdlibParametersRequest, 1),
 		PhoneNumber:     make(chan string, 1),
@@ -123,6 +124,7 @@ func (c *Client) Connect(resource string) error {
 	go c.interactor()
 
 	c.authorizer.TdlibParameters <- c.parameters
+	c.locks.authorizerWriteLock.Unlock()
 
 	tdlibClient, err := client.NewClient(c.authorizer, c.options...)
 	if err != nil {
@@ -178,6 +180,9 @@ func (c *Client) TryLogin(resource string, login string) error {
 		time.Sleep(1e5)
 	}
 
+	c.locks.authorizerReadLock.Lock()
+	defer c.locks.authorizerReadLock.Unlock()
+
 	if c.authorizer == nil {
 		return errors.New(TelegramNotInitialized)
 	}
@@ -190,6 +195,9 @@ func (c *Client) TryLogin(resource string, login string) error {
 }
 
 func (c *Client) SetPhoneNumber(login string) error {
+	c.locks.authorizerWriteLock.Lock()
+	defer c.locks.authorizerWriteLock.Unlock()
+
 	if c.authorizer == nil || c.authorizer.isClosed {
 		return errors.New("Authorization not needed")
 	}
@@ -234,9 +242,16 @@ func (c *Client) Disconnect(resource string, quit bool) bool {
 
 func (c *Client) interactor() {
 	for {
+		c.locks.authorizerReadLock.Lock()
+		if c.authorizer == nil {
+			log.Warn("Authorizer is lost, halting the interactor")
+			c.locks.authorizerReadLock.Unlock()
+			return
+		}
 		state, ok := <-c.authorizer.State
 		if !ok {
 			log.Warn("Interactor is disconnected")
+			c.locks.authorizerReadLock.Unlock()
 			return
 		}
 
@@ -266,18 +281,27 @@ func (c *Client) interactor() {
 			log.Warn("Waiting for 2FA password...")
 			gateway.SendServiceMessage(c.jid, "Please, enter 2FA passphrase via /password 12345", c.xmpp)
 		}
+		c.locks.authorizerReadLock.Unlock()
 	}
 }
 
 func (c *Client) forceClose() {
+	c.locks.authorizerReadLock.Lock()
+	c.locks.authorizerWriteLock.Lock()
+	defer c.locks.authorizerReadLock.Unlock()
+	defer c.locks.authorizerWriteLock.Unlock()
+
 	c.online = false
 	c.authorizer = nil
 }
 
 func (c *Client) close() {
+	c.locks.authorizerWriteLock.Lock()
 	if c.authorizer != nil && !c.authorizer.isClosed {
 		c.authorizer.Close()
 	}
+	c.locks.authorizerWriteLock.Unlock()
+
 	if c.client != nil {
 		_, err := c.client.Close()
 		if err != nil {