bpo-30947: Update libexpat from 2.2.1 to 2.2.3 (#3106) (#3145)

* bpo-30947: Update libexpat from 2.2.1 to 2.2.3

* Add NEWS entry

* Add new loadlibrary.c

* expat_external.h: restore include "pyexpatns.h"

* PCbuild: add expat/loadlibrary.c

* Define XML_POOR_ENTROPY to compile expat

Python 2.7 backport: add expat/loadlibrary.c to PC/VS9.0/ project
files (_elementtree and pyexpat).

(cherry picked from commit 93d0cb5)

Author: vstinner

Misc/NEWS.d/next/Security/2017-08-16-16-35-59.bpo-30947.iNMmm4.rst

@@ -0,0 +1,2 @@
+Upgrade libexpat embedded copy from version 2.2.1 to 2.2.3 to get security
+fixes.

Modules/expat/expat.h

@@ -24,7 +24,6 @@ extern "C" {
 struct XML_ParserStruct;
 typedef struct XML_ParserStruct *XML_Parser;
 
-/* Should this be defined using stdbool.h when C99 is available? */
 typedef unsigned char XML_Bool;
 #define XML_TRUE   ((XML_Bool) 1)
 #define XML_FALSE  ((XML_Bool) 0)
@@ -1049,7 +1048,7 @@ XML_GetFeatureList(void);
 */
 #define XML_MAJOR_VERSION 2
 #define XML_MINOR_VERSION 2
-#define XML_MICRO_VERSION 1
+#define XML_MICRO_VERSION 3
 
 #ifdef __cplusplus
 }

Modules/expat/loadlibrary.c

@@ -0,0 +1,141 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2016 - 2017, Steve Holme, <[email protected]>.
+ *
+ * All rights reserved.
+ *
+ * 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;
+
+  /* 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) */

Modules/expat/siphash.h

@@ -2,27 +2,34 @@
  * siphash.h - SipHash-2-4 in a single header file
  * --------------------------------------------------------------------------
  * Derived by William Ahern from the reference implementation[1] published[2]
- * by Jean-Philippe Aumasson and Daniel J. Berstein. Licensed in kind.
  * by Jean-Philippe Aumasson and Daniel J. Berstein.
- * Minimal changes by Sebastian Pipping on top, details below.
+ * Minimal changes by Sebastian Pipping and Victor Stinner on top, see below.
  * Licensed under the CC0 Public Domain Dedication license.
  *
  * 1. https://www.131002.net/siphash/siphash24.c
  * 2. https://www.131002.net/siphash/
  * --------------------------------------------------------------------------
  * HISTORY:
  *
- * 2017-06-18  (Sebastian Pipping)
- *   - Address lack of stdint.h for Visual Studio 2003 to 2008
+ * 2017-07-25  (Vadim Zeitlin)
+ *   - Fix use of SIPHASH_MAIN macro
+ *
+ * 2017-07-05  (Sebastian Pipping)
+ *   - Use _SIP_ULL macro to not require a C++11 compiler if compiled as C++
+ *   - Add const qualifiers at two places
+ *   - Ensure <=80 characters line length (assuming tab width 4)
  *
- * 2017-06-10  (Sebastian Pipping)
+ * 2017-06-23  (Victor Stinner)
+ *   - Address Win64 compile warnings
+ *
+ * 2017-06-18  (Sebastian Pipping)
  *   - Clarify license note in the header
  *   - Address C89 issues:
  *     - Stop using inline keyword (and let compiler decide)
- *     - Turn integer suffix ULL to UL
  *     - Replace _Bool by int
  *     - Turn macro siphash24 into a function
  *     - Address invalid conversion (void pointer) by explicit cast
+ *   - Address lack of stdint.h for Visual Studio 2003 to 2008
  *   - Always expose sip24_valid (for self-tests)
  *
  * 2012-11-04 - Born.  (William Ahern)
@@ -90,6 +97,14 @@
 #endif
 
 
+/*
+ * Workaround to not require a C++11 compiler for using ULL suffix
+ * if this code is included and compiled as C++; related GCC warning is:
+ * warning: use of C++11 long long integer constant [-Wlong-long]
+ */
+#define _SIP_ULL(high, low)  (((uint64_t)high << 32) | low)
+
+
 #define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
 
 #define SIP_U32TO8_LE(p, v) \
@@ -169,11 +184,12 @@ static void sip_round(struct siphash *H, const int rounds) {
 } /* sip_round() */
 
 
-static struct siphash *sip24_init(struct siphash *H, const struct sipkey *key) {
-	H->v0 = 0x736f6d6570736575UL ^ key->k[0];
-	H->v1 = 0x646f72616e646f6dUL ^ key->k[1];
-	H->v2 = 0x6c7967656e657261UL ^ key->k[0];
-	H->v3 = 0x7465646279746573UL ^ key->k[1];
+static struct siphash *sip24_init(struct siphash *H,
+		const struct sipkey *key) {
+	H->v0 = _SIP_ULL(0x736f6d65U, 0x70736575U) ^ key->k[0];
+	H->v1 = _SIP_ULL(0x646f7261U, 0x6e646f6dU) ^ key->k[1];
+	H->v2 = _SIP_ULL(0x6c796765U, 0x6e657261U) ^ key->k[0];
+	H->v3 = _SIP_ULL(0x74656462U, 0x79746573U) ^ key->k[1];
 
 	H->p = H->buf;
 	H->c = 0;
@@ -184,7 +200,8 @@ static struct siphash *sip24_init(struct siphash *H, const struct sipkey *key) {
 
 #define sip_endof(a) (&(a)[sizeof (a) / sizeof *(a)])
 
-static struct siphash *sip24_update(struct siphash *H, const void *src, size_t len) {
+static struct siphash *sip24_update(struct siphash *H, const void *src,
+		size_t len) {
 	const unsigned char *p = (const unsigned char *)src, *pe = p + len;
 	uint64_t m;
 
@@ -209,7 +226,7 @@ static struct siphash *sip24_update(struct siphash *H, const void *src, size_t l
 
 
 static uint64_t sip24_final(struct siphash *H) {
-	char left = H->p - H->buf;
+	const char left = (char)(H->p - H->buf);
 	uint64_t b = (H->c + left) << 56;
 
 	switch (left) {
@@ -233,7 +250,8 @@ static uint64_t sip24_final(struct siphash *H) {
 } /* sip24_final() */
 
 
-static uint64_t siphash24(const void *src, size_t len, const struct sipkey *key) {
+static uint64_t siphash24(const void *src, size_t len,
+		const struct sipkey *key) {
 	struct siphash state = SIPHASH_INITIALIZER;
 	return sip24_final(sip24_update(sip24_init(&state, key), src, len));
 } /* siphash24() */
@@ -321,10 +339,11 @@ static int sip24_valid(void) {
 	struct sipkey k;
 	size_t i;
 
-	sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017");
+	sip_tokey(&k, "\000\001\002\003\004\005\006\007\010\011"
+			"\012\013\014\015\016\017");
 
 	for (i = 0; i < sizeof in; ++i) {
-		in[i] = i;
+		in[i] = (unsigned char)i;
 
 		if (siphash24(in, i, &k) != SIP_U8TO64_LE(vectors[i]))
 			return 0;
@@ -334,12 +353,12 @@ static int sip24_valid(void) {
 } /* sip24_valid() */
 
 
-#if SIPHASH_MAIN
+#ifdef SIPHASH_MAIN
 
 #include <stdio.h>
 
 int main(void) {
-	int ok = sip24_valid();
+	const int ok = sip24_valid();
 
 	if (ok)
 		puts("OK");