[gimp] Increase safety on Windows

[Tor Lillqvist <tml src gnome org>]

commit 24386abb3b6c2e509a43a537e35e9600dd25d2ed
Author: Tor Lillqvist <tml iki fi>
Date:   Thu Sep 2 18:38:06 2010 +0300

    Increase safety on Windows
    
    Call SetDllDirectory() to reduce risk of DLL hijacking, and call
    SetProcessDEPPolicy() to reduce risk of rogue code execution.

 app/main.c |   28 ++++++++++++++++++++++++++++
 1 files changed, 28 insertions(+), 0 deletions(-)
---
diff --git a/app/main.c b/app/main.c
index 2fa9c19..aaa8ea7 100644
--- a/app/main.c
+++ b/app/main.c
@@ -60,6 +60,10 @@
 #include "version.h"
 
 #ifdef G_OS_WIN32
+/* To get PROCESS_DEP_* defined we need _WIN32_WINNT at 0x0601. We still
+ * use the API optionally only if present, though.
+ */
+#define _WIN32_WINNT 0x0601
 #include <windows.h>
 #include <conio.h>
 #endif
@@ -279,6 +283,30 @@ main (int    argc,
   argv = __argv;
 #endif
 
+#ifdef G_OS_WIN32
+  /* Reduce risks */
+  {
+    typedef BOOL (WINAPI *t_SetDllDirectoryA) (LPCSTR lpPathName);
+    t_SetDllDirectoryA p_SetDllDirectoryA;
+
+    p_SetDllDirectoryA = GetProcAddress (GetModuleHandle ("kernel32.dll"),
+					 "SetDllDirectoryA");
+    if (p_SetDllDirectoryA)
+      (*p_SetDllDirectoryA) ("");
+  }
+#ifndef _WIN64
+  {
+    typedef BOOL (WINAPI *t_SetProcessDEPPolicy) (DWORD dwFlags);
+    t_SetProcessDEPPolicy p_SetProcessDEPPolicy;
+
+    p_SetProcessDEPPolicy = GetProcAddress (GetModuleHandle ("kernel32.dll"),
+					    "SetProcessDEPPolicy");
+    if (p_SetProcessDEPPolicy)
+      (*p_SetProcessDEPPolicy) (PROCESS_DEP_ENABLE|PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION);
+  }
+#endif
+#endif
+
   g_thread_init (NULL);
 
 #ifdef GIMP_UNSTABLE