src/lib/llharden/winprocess_sys.c

   1 /* Copyright (c) 2018-2021, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 /**
   5  * \file winprocess_sys.c
   6  * \brief Subsystem object for windows process setup.
   7  **/
   8
   9 #include "orconfig.h"
  10 #include "lib/subsys/subsys.h"
  11 #include "lib/llharden/winprocess_sys.h"
  12
  13 #include <stdbool.h>
  14 #include <stddef.h>
  15
  16 #ifdef _WIN32
  17 #include <windows.h>
  18
  19 #define WINPROCESS_SYS_ENABLED true
  20
  21 static int
  22 subsys_winprocess_initialize(void)
  23 {
  24 #ifndef HeapEnableTerminationOnCorruption
  25 #define HeapEnableTerminationOnCorruption 1
  26 #endif
  27
  28   /* On heap corruption, just give up; don't try to play along. */
  29   HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
  30
  31   /* SetProcessDEPPolicy is only supported on 32-bit Windows.
  32    * (On 64-bit Windows it always fails, and some compilers don't like the
  33    * PSETDEP cast.)
  34    * 32-bit Windows defines _WIN32.
  35    * 64-bit Windows defines _WIN32 and _WIN64. */
  36 #ifndef _WIN64
  37   /* Call SetProcessDEPPolicy to permanently enable DEP.
  38      The function will not resolve on earlier versions of Windows,
  39      and failure is not dangerous. */
  40   HMODULE hMod = GetModuleHandleA("Kernel32.dll");
  41   if (hMod) {
  42     typedef BOOL (WINAPI *PSETDEP)(DWORD);
  43     PSETDEP setdeppolicy = (PSETDEP)GetProcAddress(hMod,
  44                            "SetProcessDEPPolicy");
  45     if (setdeppolicy) {
  46       /* PROCESS_DEP_ENABLE | PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION */
  47       setdeppolicy(3);
  48     }
  49   }
  50 #endif /* !defined(_WIN64) */
  51
  52   return 0;
  53 }
  54 #else /* !defined(_WIN32) */
  55 #define WINPROCESS_SYS_ENABLED false
  56 #define subsys_winprocess_initialize NULL
  57 #endif /* defined(_WIN32) */
  58
  59 const subsys_fns_t sys_winprocess = {
  60   .name = "winprocess",
  61   SUBSYS_DECLARE_LOCATION(),
  62   /* HeapEnableTerminationOnCorruption and setdeppolicy() are security
  63    * features, we want them to run first. */
  64   .level = -100,
  65   .supported = WINPROCESS_SYS_ENABLED,
  66   .initialize = subsys_winprocess_initialize,
  67 };