From f2687a31dcba201fb4f02cb76f7e88bc2fd186a1 Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Thu, 7 Mar 2024 20:59:06 +0300
Subject: [PATCH] Check chat identifier along with business connection
 identifier.

---
 td/telegram/BusinessConnectionManager.cpp | 18 +++++++++++++++---
 td/telegram/BusinessConnectionManager.h   |  3 ++-
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/td/telegram/BusinessConnectionManager.cpp b/td/telegram/BusinessConnectionManager.cpp
index 1c59240db..c7fc1f85a 100644
--- a/td/telegram/BusinessConnectionManager.cpp
+++ b/td/telegram/BusinessConnectionManager.cpp
@@ -90,11 +90,23 @@ void BusinessConnectionManager::tear_down() {
   parent_.reset();
 }
 
-Status BusinessConnectionManager::check_business_connection_id(const BusinessConnectionId &connection_id) const {
-  if (connection_id.is_empty() || business_connections_.count(connection_id) != 0) {
+Status BusinessConnectionManager::check_business_connection(const BusinessConnectionId &connection_id,
+                                                            DialogId dialog_id) const {
+  if (connection_id.is_empty()) {
     return Status::OK();
   }
-  return Status::Error(400, "Business connection not found");
+  auto connection = business_connections_.get_pointer(connection_id);
+  if (connection == nullptr) {
+    return Status::Error(400, "Business connection not found");
+  }
+  if (dialog_id.get_type() != DialogType::User) {
+    return Status::Error(400, "Chat must be a private chat");
+  }
+  if (dialog_id == DialogId(connection->user_id_)) {
+    return Status::Error(400, "Messages must not be sent to self");
+  }
+  // no need to check connection->can_reply_ and connection->is_disabled_
+  return Status::OK();
 }
 
 void BusinessConnectionManager::on_update_bot_business_connect(
diff --git a/td/telegram/BusinessConnectionManager.h b/td/telegram/BusinessConnectionManager.h
index 3be9e4611..4ddf26b32 100644
--- a/td/telegram/BusinessConnectionManager.h
+++ b/td/telegram/BusinessConnectionManager.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include "td/telegram/BusinessConnectionId.h"
+#include "td/telegram/DialogId.h"
 #include "td/telegram/td_api.h"
 #include "td/telegram/telegram_api.h"
 
@@ -30,7 +31,7 @@ class BusinessConnectionManager final : public Actor {
   BusinessConnectionManager &operator=(BusinessConnectionManager &&) = delete;
   ~BusinessConnectionManager() final;
 
-  Status check_business_connection_id(const BusinessConnectionId &connection_id) const;
+  Status check_business_connection(const BusinessConnectionId &connection_id, DialogId dialog_id) const;
 
   void on_update_bot_business_connect(telegram_api::object_ptr<telegram_api::botBusinessConnection> &&connection);