From 50b10ba0bf61fc5d30f033e239b5a81ac478ec78 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Sun, 14 Aug 2016 21:55:59 +0300
Subject: [PATCH] Dll hijacking fixes: Windows version check +
 SetDllDirectory("").

---
 .../SourceFiles/platform/win/windows_dlls.cpp | 46 ++++++++++++++-----
 .../SourceFiles/platform/win/windows_dlls.h   |  6 +++
 Telegram/SourceFiles/pspecific_win.cpp        |  1 +
 3 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/Telegram/SourceFiles/platform/win/windows_dlls.cpp b/Telegram/SourceFiles/platform/win/windows_dlls.cpp
index 048aed9291..299136f315 100644
--- a/Telegram/SourceFiles/platform/win/windows_dlls.cpp
+++ b/Telegram/SourceFiles/platform/win/windows_dlls.cpp
@@ -24,6 +24,23 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 namespace Platform {
 namespace Dlls {
 
+f_SetDllDirectory SetDllDirectory;
+
+HINSTANCE LibKernel32;
+
+void init() {
+	static bool inited = false;
+	if (inited) return;
+	inited = true;
+
+	LibKernel32 = LoadLibrary(L"KERNEL32.DLL");
+	load(LibKernel32, "SetDllDirectoryW", SetDllDirectory);
+	if (SetDllDirectory) {
+		// Remove the current directory from the DLL search order.
+		SetDllDirectory(L"");
+	}
+}
+
 f_SetWindowTheme SetWindowTheme;
 f_OpenAs_RunDLL OpenAs_RunDLL;
 f_SHOpenWithDialog SHOpenWithDialog;
@@ -45,8 +62,7 @@ HINSTANCE LibPropSys;
 HINSTANCE LibComBase;
 
 void start() {
-	LibUxTheme = LoadLibrary(L"UXTHEME.DLL");
-	load(LibUxTheme, "SetWindowTheme", SetWindowTheme);
+	init();
 
 	LibShell32 = LoadLibrary(L"SHELL32.DLL");
 	load(LibShell32, "SHAssocEnumHandlers", SHAssocEnumHandlers);
@@ -56,17 +72,25 @@ void start() {
 	load(LibShell32, "SHQueryUserNotificationState", SHQueryUserNotificationState);
 	load(LibShell32, "SetCurrentProcessExplicitAppUserModelID", SetCurrentProcessExplicitAppUserModelID);
 
-	LibWtsApi32 = LoadLibrary(L"WTSAPI32.DLL");
-	load(LibWtsApi32, "WTSRegisterSessionNotification", WTSRegisterSessionNotification);
-	load(LibWtsApi32, "WTSUnRegisterSessionNotification", WTSUnRegisterSessionNotification);
+	auto version = QSysInfo::windowsVersion();
+	if (version >= QSysInfo::WV_VISTA) {
+		LibUxTheme = LoadLibrary(L"UXTHEME.DLL");
+		load(LibUxTheme, "SetWindowTheme", SetWindowTheme);
 
-	LibPropSys = LoadLibrary(L"PROPSYS.DLL");
-	load(LibPropSys, "PropVariantToString", PropVariantToString);
+		LibWtsApi32 = LoadLibrary(L"WTSAPI32.DLL");
+		load(LibWtsApi32, "WTSRegisterSessionNotification", WTSRegisterSessionNotification);
+		load(LibWtsApi32, "WTSUnRegisterSessionNotification", WTSUnRegisterSessionNotification);
 
-	LibComBase = LoadLibrary(L"COMBASE.DLL");
-	load(LibComBase, "RoGetActivationFactory", RoGetActivationFactory);
-	load(LibComBase, "WindowsCreateStringReference", WindowsCreateStringReference);
-	load(LibComBase, "WindowsDeleteString", WindowsDeleteString);
+		LibPropSys = LoadLibrary(L"PROPSYS.DLL");
+		load(LibPropSys, "PropVariantToString", PropVariantToString);
+
+		if (version >= QSysInfo::WV_WINDOWS8) {
+			LibComBase = LoadLibrary(L"COMBASE.DLL");
+			load(LibComBase, "RoGetActivationFactory", RoGetActivationFactory);
+			load(LibComBase, "WindowsCreateStringReference", WindowsCreateStringReference);
+			load(LibComBase, "WindowsDeleteString", WindowsDeleteString);
+		}
+	}
 }
 
 } // namespace Dlls
diff --git a/Telegram/SourceFiles/platform/win/windows_dlls.h b/Telegram/SourceFiles/platform/win/windows_dlls.h
index 0e684d46c3..27a82d5029 100644
--- a/Telegram/SourceFiles/platform/win/windows_dlls.h
+++ b/Telegram/SourceFiles/platform/win/windows_dlls.h
@@ -27,6 +27,12 @@ Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
 namespace Platform {
 namespace Dlls {
 
+void init();
+
+// KERNEL32.DLL
+typedef BOOL (FAR STDAPICALLTYPE *f_SetDllDirectory)(LPCWSTR lpPathName);
+extern f_SetDllDirectory SetDllDirectory;
+
 void start();
 
 template <typename Function>
diff --git a/Telegram/SourceFiles/pspecific_win.cpp b/Telegram/SourceFiles/pspecific_win.cpp
index c1215a59e6..636db7fddc 100644
--- a/Telegram/SourceFiles/pspecific_win.cpp
+++ b/Telegram/SourceFiles/pspecific_win.cpp
@@ -737,6 +737,7 @@ void psShowInFolder(const QString &name) {
 namespace Platform {
 
 void start() {
+	Dlls::init();
 }
 
 void finish() {