Merge branch 'david-loffredo-rand_s-test' (#302, fixes #299)

expat/CMakeLists.txt

@@ -175,7 +175,6 @@ if(WIN32)
 endif(WIN32)
 
 set(expat_SRCS
-    lib/loadlibrary.c
     lib/xmlparse.c
     lib/xmlrole.c
     lib/xmltok.c

expat/Changes

@@ -16,6 +16,9 @@ Release x.x.x xxx xxx xx xxxx
             #265  CMake: Fix linking with MinGW
        #239 #277  CMake: Add argument -DUSE_GETRANDOM=(ON|OFF|AUTO)
        #239 #277  CMake: Add argument -DUSE_SYS_GETRANDOM=(ON|OFF|AUTO)
+       #299 #302  Windows: Replace LoadLibrary hack to access
+                    unofficial API function SystemFunction036 (RtlGenRandom)
+                    by using official API function rand_s (needs WinXP+)
              #14  Drop an OpenVMS support leftover
   #235 #268 #270  Address compiler warnings
     #282 #283 ..
@@ -24,6 +27,7 @@ Release x.x.x xxx xxx xx xxxx
         #24 #293  Mass-apply clang-format 9 (and ensure conformance during CI)
 
         Special thanks to:
+            David Loffredo
             Khajapasha Mohammed
             Kishore Kunche
             Marco Maggi

expat/lib/Makefile.am

@@ -40,7 +40,6 @@ libexpat_la_LDFLAGS = \
     -version-info @LIBCURRENT@:@LIBREVISION@:@LIBAGE@
 
 libexpat_la_SOURCES = \
-    loadlibrary.c \
     xmlparse.c \
     xmltok.c \
     xmlrole.c

expat/lib/expat.vcxproj

@@ -148,7 +148,6 @@
     <CustomBuild Include="libexpat.def" />
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c" />
     <ClCompile Include="xmlparse.c">
       <ExceptionHandling Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
       </ExceptionHandling>

expat/lib/expat.vcxproj.filters

@@ -15,9 +15,6 @@
     </Filter>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="xmlparse.c">
       <Filter>Source Files</Filter>
     </ClCompile>

expat/lib/expat_static.vcxproj

@@ -121,7 +121,6 @@
     </Lib>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c" />
     <ClCompile Include="xmlparse.c" />
     <ClCompile Include="xmlrole.c" />
     <ClCompile Include="xmltok.c" />

expat/lib/expat_static.vcxproj.filters

@@ -11,9 +11,6 @@
     </Filter>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="xmlparse.c">
       <Filter>Source Files</Filter>
     </ClCompile>

expat/lib/expatw.vcxproj

@@ -148,7 +148,6 @@
     <CustomBuild Include="libexpatw.def" />
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c" />
     <ClCompile Include="xmlparse.c">
       <ExceptionHandling Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
       </ExceptionHandling>

expat/lib/expatw.vcxproj.filters

@@ -15,9 +15,6 @@
     </Filter>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="xmlparse.c">
       <Filter>Source Files</Filter>
     </ClCompile>

expat/lib/expatw_static.vcxproj

@@ -121,7 +121,6 @@
     </Lib>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c" />
     <ClCompile Include="xmlparse.c" />
     <ClCompile Include="xmlrole.c" />
     <ClCompile Include="xmltok.c" />

expat/lib/expatw_static.vcxproj.filters

@@ -11,9 +11,6 @@
     </Filter>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="loadlibrary.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="xmlparse.c">
       <Filter>Source Files</Filter>
     </ClCompile>

expat/lib/loadlibrary.c

@@ -1,138 +0,0 @@
-/***************************************************************************
- *                                  _   _ ____  _
- *  Project                     ___| | | |  _ \| |
- *                             / __| | | | |_) | |
- *                            | (__| |_| |  _ <| |___
- *                             \___|\___/|_| \_\_____|
- *
- * Copyright (C) 2016 - 2017, Steve Holme, <steve_holme@hotmail.com>.
- * Copyright (C) 2017, Expat development team
- *
- * All rights reserved.
- * Licensed under the MIT license:
- *
- * Permission to  use, copy,  modify, and distribute  this software  for any
- * purpose with  or without fee is  hereby granted, provided that  the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE  SOFTWARE  IS  PROVIDED  "AS  IS",  WITHOUT  WARRANTY  OF  ANY  KIND,
- * EXPRESS  OR IMPLIED,  INCLUDING  BUT  NOT LIMITED  TO  THE WARRANTIES  OF
- * MERCHANTABILITY, FITNESS FOR A  PARTICULAR PURPOSE AND NONINFRINGEMENT OF
- * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
- * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR  OTHERWISE, ARISING FROM, OUT OF OR  IN CONNECTION WITH
- * THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- *
- * Except as contained in this notice,  the name of a copyright holder shall
- * not be used in advertising or otherwise to promote the sale, use or other
- * dealings  in this  Software without  prior written  authorization of  the
- * copyright holder.
- *
- ***************************************************************************/
-
-#if defined(_WIN32)
-
-#  include <windows.h>
-#  include <tchar.h>
-
-HMODULE _Expat_LoadLibrary(LPCTSTR filename);
-
-#  if ! defined(LOAD_WITH_ALTERED_SEARCH_PATH)
-#    define LOAD_WITH_ALTERED_SEARCH_PATH 0x00000008
-#  endif
-
-#  if ! defined(LOAD_LIBRARY_SEARCH_SYSTEM32)
-#    define LOAD_LIBRARY_SEARCH_SYSTEM32 0x00000800
-#  endif
-
-/* We use our own typedef here since some headers might lack these */
-typedef HMODULE(APIENTRY *LOADLIBRARYEX_FN)(LPCTSTR, HANDLE, DWORD);
-
-/* See function definitions in winbase.h */
-#  ifdef UNICODE
-#    ifdef _WIN32_WCE
-#      define LOADLIBARYEX L"LoadLibraryExW"
-#    else
-#      define LOADLIBARYEX "LoadLibraryExW"
-#    endif
-#  else
-#    define LOADLIBARYEX "LoadLibraryExA"
-#  endif
-
-/*
- * _Expat_LoadLibrary()
- *
- * This is used to dynamically load DLLs using the most secure method available
- * for the version of Windows that we are running on.
- *
- * Parameters:
- *
- * filename  [in] - The filename or full path of the DLL to load. If only the
- *                  filename is passed then the DLL will be loaded from the
- *                  Windows system directory.
- *
- * Returns the handle of the module on success; otherwise NULL.
- */
-HMODULE
-_Expat_LoadLibrary(LPCTSTR filename) {
-  HMODULE hModule = NULL;
-  LOADLIBRARYEX_FN pLoadLibraryEx = NULL;
-
-  /* Get a handle to kernel32 so we can access it's functions at runtime */
-  HMODULE hKernel32 = GetModuleHandle(TEXT("kernel32"));
-  if (! hKernel32)
-    return NULL; /* LCOV_EXCL_LINE */
-
-  /* Attempt to find LoadLibraryEx() which is only available on Windows 2000
-     and above */
-  pLoadLibraryEx = (LOADLIBRARYEX_FN)GetProcAddress(hKernel32, LOADLIBARYEX);
-
-  /* Detect if there's already a path in the filename and load the library if
-     there is. Note: Both back slashes and forward slashes have been supported
-     since the earlier days of DOS at an API level although they are not
-     supported by command prompt */
-  if (_tcspbrk(filename, TEXT("\\/"))) {
-    /** !checksrc! disable BANNEDFUNC 1 **/
-    hModule = pLoadLibraryEx ? pLoadLibraryEx(filename, NULL,
-                                              LOAD_WITH_ALTERED_SEARCH_PATH)
-                             : LoadLibrary(filename);
-  }
-  /* Detect if KB2533623 is installed, as LOAD_LIBARY_SEARCH_SYSTEM32 is only
-     supported on Windows Vista, Windows Server 2008, Windows 7 and Windows
-     Server 2008 R2 with this patch or natively on Windows 8 and above */
-  else if (pLoadLibraryEx && GetProcAddress(hKernel32, "AddDllDirectory")) {
-    /* Load the DLL from the Windows system directory */
-    hModule = pLoadLibraryEx(filename, NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
-  } else {
-    /* Attempt to get the Windows system path */
-    UINT systemdirlen = GetSystemDirectory(NULL, 0);
-    if (systemdirlen) {
-      /* Allocate space for the full DLL path (Room for the null terminator
-         is included in systemdirlen) */
-      size_t filenamelen = _tcslen(filename);
-      TCHAR *path = malloc(sizeof(TCHAR) * (systemdirlen + 1 + filenamelen));
-      if (path && GetSystemDirectory(path, systemdirlen)) {
-        /* Calculate the full DLL path */
-        _tcscpy(path + _tcslen(path), TEXT("\\"));
-        _tcscpy(path + _tcslen(path), filename);
-
-        /* Load the DLL from the Windows system directory */
-        /** !checksrc! disable BANNEDFUNC 1 **/
-        hModule = pLoadLibraryEx ? pLoadLibraryEx(path, NULL,
-                                                  LOAD_WITH_ALTERED_SEARCH_PATH)
-                                 : LoadLibrary(path);
-      }
-      free(path);
-    }
-  }
-
-  return hModule;
-}
-
-#else /* defined(_WIN32) */
-
-/* ISO C requires a translation unit to contain at least one declaration
-   [-Wempty-translation-unit] */
-typedef int _TRANSLATION_UNIT_LOAD_LIBRARY_C_NOT_EMTPY;
-
-#endif /* defined(_WIN32) */

expat/lib/xmlparse.c

@@ -34,12 +34,17 @@
 #  define _GNU_SOURCE 1 /* syscall prototype */
 #endif
 
+#ifdef _WIN32
+/* force stdlib to define rand_s() */
+#  define _CRT_RAND_S
+#endif
+
 #include <stddef.h>
 #include <string.h> /* memset(), memcpy() */
 #include <assert.h>
 #include <limits.h> /* UINT_MAX */
 #include <stdio.h>  /* fprintf */
-#include <stdlib.h> /* getenv */
+#include <stdlib.h> /* getenv, rand_s */
 
 #ifdef _WIN32
 #  define getpid GetCurrentProcessId
@@ -99,7 +104,7 @@
       * libbsd (arc4random_buf): HAVE_ARC4RANDOM_BUF + HAVE_LIBBSD, \
       * libbsd (arc4random): HAVE_ARC4RANDOM + HAVE_LIBBSD, \
       * Linux / BSD / macOS (/dev/urandom): XML_DEV_URANDOM \
-      * Windows (RtlGenRandom): _WIN32. \
+      * Windows (rand_s): _WIN32. \
     \
     If insist on not using any of these, bypass this error by defining \
     XML_POOR_ENTROPY; you have been warned. \
@@ -729,33 +734,28 @@ writeRandomBytes_arc4random(void *target, size_t count) {
 
 #ifdef _WIN32
 
-typedef BOOLEAN(APIENTRY *RTLGENRANDOM_FUNC)(PVOID, ULONG);
+/* Obtain entropy on Windows using the rand_s() function which
-HMODULE _Expat_LoadLibrary(LPCTSTR filename); /* see loadlibrary.c */
+ * generates cryptographically secure random numbers.  Internally it
-
+ * uses RtlGenRandom API which is present in Windows XP and later.
-/* Obtain entropy on Windows XP / Windows Server 2003 and later.
- * Hint on RtlGenRandom and the following article from libsodium.
- *
- * Michael Howard: Cryptographically Secure Random number on Windows without
- * using CryptoAPI
- * https://blogs.msdn.microsoft.com/michael_howard/2005/01/14/cryptographically-secure-random-number-on-windows-without-using-cryptoapi/
  */
 static int
-writeRandomBytes_RtlGenRandom(void *target, size_t count) {
+writeRandomBytes_rand_s(void *target, size_t count) {
-  int success = 0; /* full count bytes written? */
+  size_t bytesWrittenTotal = 0;
-  const HMODULE advapi32 = _Expat_LoadLibrary(TEXT("ADVAPI32.DLL"));
 
-  if (advapi32) {
+  while (bytesWrittenTotal < count) {
-    const RTLGENRANDOM_FUNC RtlGenRandom
+    unsigned int random32 = 0;
-        = (RTLGENRANDOM_FUNC)GetProcAddress(advapi32, "SystemFunction036");
+    size_t i = 0;
-    if (RtlGenRandom) {
+
-      if (RtlGenRandom((PVOID)target, (ULONG)count) == TRUE) {
+    if (rand_s(&random32))
-        success = 1;
+      return 0; /* failure */
-      }
+
+    for (; (i < sizeof(random32)) && (bytesWrittenTotal < count);
+         i++, bytesWrittenTotal++) {
+      const uint8_t random8 = (uint8_t)(random32 >> (i * 8));
+      ((uint8_t *)target)[bytesWrittenTotal] = random8;
     }
-    FreeLibrary(advapi32);
   }
-
+  return 1; /* success */
-  return success;
 }
 
 #endif /* _WIN32 */
@@ -812,8 +812,8 @@ generate_hash_secret_salt(XML_Parser parser) {
 #else
   /* Try high quality providers first .. */
 #  ifdef _WIN32
-  if (writeRandomBytes_RtlGenRandom((void *)&entropy, sizeof(entropy))) {
+  if (writeRandomBytes_rand_s((void *)&entropy, sizeof(entropy))) {
-    return ENTROPY_DEBUG("RtlGenRandom", entropy);
+    return ENTROPY_DEBUG("rand_s", entropy);
   }
 #  elif defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM)
   if (writeRandomBytes_getrandom_nonblock((void *)&entropy, sizeof(entropy))) {