other-licenses/7zstub/src/C/DllSecur.c

   1 /* DllSecur.c -- DLL loading security
   2 2016-10-04 : Igor Pavlov : Public domain */
   3
   4 #include "Precomp.h"
   5
   6 #ifdef _WIN32
   7
   8 #include <windows.h>
   9
  10 #include "DllSecur.h"
  11
  12 #ifndef UNDER_CE
  13
  14 typedef BOOL (WINAPI *Func_SetDefaultDllDirectories)(DWORD DirectoryFlags);
  15
  16 #define MY_LOAD_LIBRARY_SEARCH_USER_DIRS 0x400
  17 #define MY_LOAD_LIBRARY_SEARCH_SYSTEM32  0x800
  18
  19 static const char * const g_Dlls =
  20   #ifndef _CONSOLE
  21   "UXTHEME\0"
  22   #endif
  23   "USERENV\0"
  24   "SETUPAPI\0"
  25   "APPHELP\0"
  26   "PROPSYS\0"
  27   "DWMAPI\0"
  28   "CRYPTBASE\0"
  29   "OLEACC\0"
  30   "CLBCATQ\0"
  31   ;
  32
  33 #endif
  34
  35 void LoadSecurityDlls()
  36 {
  37   #ifndef UNDER_CE
  38
  39   wchar_t buf[MAX_PATH + 100];
  40
  41   {
  42     // at Vista (ver 6.0) : CoCreateInstance(CLSID_ShellLink, ...) doesn't work after SetDefaultDllDirectories() : Check it ???
  43     OSVERSIONINFO vi;
  44     vi.dwOSVersionInfoSize = sizeof(vi);
  45     if (!GetVersionEx(&vi) || vi.dwMajorVersion != 6 || vi.dwMinorVersion != 0)
  46     {
  47       Func_SetDefaultDllDirectories setDllDirs = (Func_SetDefaultDllDirectories)
  48           GetProcAddress(GetModuleHandle(TEXT("kernel32.dll")), "SetDefaultDllDirectories");
  49       if (setDllDirs)
  50         if (setDllDirs(MY_LOAD_LIBRARY_SEARCH_SYSTEM32 | MY_LOAD_LIBRARY_SEARCH_USER_DIRS))
  51           return;
  52     }
  53   }
  54
  55   {
  56     unsigned len = GetSystemDirectoryW(buf, MAX_PATH + 2);
  57     if (len == 0 || len > MAX_PATH)
  58       return;
  59   }
  60   {
  61     const char *dll;
  62     unsigned pos = (unsigned)lstrlenW(buf);
  63
  64     if (buf[pos - 1] != '\\')
  65       buf[pos++] = '\\';
  66
  67     for (dll = g_Dlls; dll[0] != 0;)
  68     {
  69       unsigned k = 0;
  70       for (;;)
  71       {
  72         char c = *dll++;
  73         buf[pos + k] = c;
  74         k++;
  75         if (c == 0)
  76           break;
  77       }
  78
  79       lstrcatW(buf, L".dll");
  80       LoadLibraryExW(buf, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
  81     }
  82   }
  83
  84   #endif
  85 }
  86
  87 #endif