[3.4] bpo-29591, bpo-30694: Upgrade Modules/expat to libexpat 2.2.1 (#2164) (#2203)

* bpo-29591: Upgrade Modules/expat to libexpat 2.2 (#2164)

* bpo-29591: Upgrade Modules/expat to libexpat 2.2

* bpo-29591: Restore Python changes on expat

* bpo-29591: Remove expat config of unsupported platforms

Remove the configuration (Modules/expat/*config.h) of unsupported
platforms:

* Amiga
* MacOS Classic on PPC32
* Open Watcom

* bpo-29591: Remove useless XML_HAS_SET_HASH_SALT

The XML_HAS_SET_HASH_SALT define of Modules/expat/expat.h became
useless since our local expat copy was upgrade to expat 2.1 (it's now
expat 2.2.0).

(cherry picked from commit 23ec4b5)

* bpo-30694: Upgrade Modules/expat/ to libexpat 2.2.1 (#2300)

New file: Modules/expat/siphash.h.
(cherry picked from commit 5ff7132)

* bpo-30726: PCbuild _elementtree: remove duplicate defines (#2348)

bpo-30726, bpo-29591: libexpat 2.2.1 of Modules/expat/ now uses
a winconfig.h configuration file which already defines:

* XML_NS
* XML_DTD
* BYTEORDER=1234
* XML_CONTEXT_BYTES=1024
* HAVE_MEMMOVE

Remove these defines from PCbuild/_elementtree.vcxproj to prevent
compiler warnings.

Co-Authored-By: Jeremy Kloth <[email protected]>
(cherry picked from commit c8fb58b)

* bpo-30726: Fix elementtree warnings on Windows due to expat upgrade (#2319)

* bpo-30726: Fix elementtree warnings on Windows

Caused by usage of `getenv` which should be safe. And a few integer
truncations which should also be ok.

* bpo-30726: Don't ignore libexpat warnings which haypo intends to fix upstream

(cherry picked from commit 87c6555)

Author: vstinner

Misc/NEWS.d/next/Security/2017-07-11-22-25-24.bpo-30694.oOf3Er.rst

@@ -0,0 +1,8 @@
+Upgrade expat copy from 2.2.0 to 2.2.1 to get fixes of multiple security
+vulnerabilities including: CVE-2017-9233 (External entity infinite loop
+DoS), CVE-2016-9063 (Integer overflow, re-fix), CVE-2016-0718 (Fix
+regression bugs from 2.2.0's fix to CVE-2016-0718) and CVE-2012-0876
+(Counter hash flooding with SipHash).  Note: the CVE-2016-5300 (Use os-
+specific entropy sources like getrandom) doesn't impact Python, since Python
+already gets entropy from the OS to set the expat secret using
+``XML_SetHashSalt()``.

Misc/NEWS.d/next/Security/2017-07-11-22-26-48.bpo-29591.cOeMX-.rst

@@ -0,0 +1,3 @@
+Update expat copy from 2.1.1 to 2.2.0 to get fixes of CVE-2016-0718 and
+CVE-2016-4472. See https://sourceforge.net/p/expat/bugs/537/ for more
+information.

Modules/expat/COPYING

@@ -1,6 +1,5 @@
-Copyright (c) 1998, 1999, 2000 Thai Open Source Software Center Ltd
-                               and Clark Cooper
-Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006 Expat maintainers.
+Copyright (c) 1998-2000 Thai Open Source Software Center Ltd and Clark Cooper
+Copyright (c) 2001-2017 Expat maintainers
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

Modules/expat/amigaconfig.h

@@ -95,7 +95,9 @@ enum XML_Error {
   /* Added in 2.0. */
   XML_ERROR_RESERVED_PREFIX_XML,
   XML_ERROR_RESERVED_PREFIX_XMLNS,
-  XML_ERROR_RESERVED_NAMESPACE_URI
+  XML_ERROR_RESERVED_NAMESPACE_URI,
+  /* Added in 2.2.1. */
+  XML_ERROR_INVALID_ARGUMENT
 };
 
 enum XML_Content_Type {
@@ -342,7 +344,7 @@ XML_SetEntityDeclHandler(XML_Parser parser,
                          XML_EntityDeclHandler handler);
 
 /* OBSOLETE -- OBSOLETE -- OBSOLETE
-   This handler has been superceded by the EntityDeclHandler above.
+   This handler has been superseded by the EntityDeclHandler above.
    It is provided here for backward compatibility.
 
    This is called for a declaration of an unparsed (NDATA) entity.
@@ -706,6 +708,7 @@ XML_UseParserAsHandlerArg(XML_Parser parser);
      be called, despite an external subset being parsed.
    Note: If XML_DTD is not defined when Expat is compiled, returns
      XML_ERROR_FEATURE_REQUIRES_XML_DTD.
+   Note: If parser == NULL, returns XML_ERROR_INVALID_ARGUMENT.
 */
 XMLPARSEAPI(enum XML_Error)
 XML_UseForeignDTD(XML_Parser parser, XML_Bool useDTD);
@@ -729,15 +732,16 @@ XML_GetBase(XML_Parser parser);
    to the XML_StartElementHandler that were specified in the start-tag
    rather than defaulted. Each attribute/value pair counts as 2; thus
    this correspondds to an index into the atts array passed to the
-   XML_StartElementHandler.
+   XML_StartElementHandler.  Returns -1 if parser == NULL.
 */
 XMLPARSEAPI(int)
 XML_GetSpecifiedAttributeCount(XML_Parser parser);
 
 /* Returns the index of the ID attribute passed in the last call to
-   XML_StartElementHandler, or -1 if there is no ID attribute.  Each
-   attribute/value pair counts as 2; thus this correspondds to an
-   index into the atts array passed to the XML_StartElementHandler.
+   XML_StartElementHandler, or -1 if there is no ID attribute or
+   parser == NULL.  Each attribute/value pair counts as 2; thus this
+   correspondds to an index into the atts array passed to the
+   XML_StartElementHandler.
 */
 XMLPARSEAPI(int)
 XML_GetIdAttributeIndex(XML_Parser parser);
@@ -901,6 +905,7 @@ enum XML_ParamEntityParsing {
    entities is requested; otherwise it will return non-zero.
    Note: If XML_SetParamEntityParsing is called after XML_Parse or
       XML_ParseBuffer, then it has no effect and will always return 0.
+   Note: If parser == NULL, the function will do nothing and return 0.
 */
 XMLPARSEAPI(int)
 XML_SetParamEntityParsing(XML_Parser parser,
@@ -910,13 +915,12 @@ XML_SetParamEntityParsing(XML_Parser parser,
    Helps in preventing DoS attacks based on predicting hash
    function behavior. This must be called before parsing is started.
    Returns 1 if successful, 0 when called after parsing has started.
+   Note: If parser == NULL, the function will do nothing and return 0.
 */
 XMLPARSEAPI(int)
 XML_SetHashSalt(XML_Parser parser,
                 unsigned long hash_salt);
 
-#define XML_HAS_SET_HASH_SALT  /* Python Only: Defined for pyexpat.c. */
-
 /* If XML_Parse or XML_ParseBuffer have returned XML_STATUS_ERROR, then
    XML_GetErrorCode returns information about the error.
 */
@@ -938,6 +942,10 @@ XML_GetErrorCode(XML_Parser parser);
    the location is the location of the character at which the error
    was detected; otherwise the location is the location of the last
    parse event, as described above.
+
+   Note: XML_GetCurrentLineNumber and XML_GetCurrentColumnNumber
+   return 0 to indicate an error.
+   Note: XML_GetCurrentByteIndex returns -1 to indicate an error.
 */
 XMLPARSEAPI(XML_Size) XML_GetCurrentLineNumber(XML_Parser parser);
 XMLPARSEAPI(XML_Size) XML_GetCurrentColumnNumber(XML_Parser parser);
@@ -975,9 +983,12 @@ XML_FreeContentModel(XML_Parser parser, XML_Content *model);
 
 /* Exposing the memory handling functions used in Expat */
 XMLPARSEAPI(void *)
+XML_ATTR_MALLOC
+XML_ATTR_ALLOC_SIZE(2)
 XML_MemMalloc(XML_Parser parser, size_t size);
 
 XMLPARSEAPI(void *)
+XML_ATTR_ALLOC_SIZE(3)
 XML_MemRealloc(XML_Parser parser, void *ptr, size_t size);
 
 XMLPARSEAPI(void)
@@ -1033,13 +1044,11 @@ XMLPARSEAPI(const XML_Feature *)
 XML_GetFeatureList(void);
 
 
-/* Expat follows the GNU/Linux convention of odd number minor version for
-   beta/development releases and even number minor version for stable
-   releases. Micro is bumped with each release, and set to 0 with each
-   change to major or minor version.
+/* Expat follows the semantic versioning convention.
+   See http://semver.org.
 */
 #define XML_MAJOR_VERSION 2
-#define XML_MINOR_VERSION 1
+#define XML_MINOR_VERSION 2
 #define XML_MICRO_VERSION 1
 
 #ifdef __cplusplus

Modules/expat/expat.h

@@ -69,12 +69,26 @@
 #endif
 #endif  /* not defined XML_STATIC */
 
+#if !defined(XMLIMPORT) && defined(__GNUC__) && (__GNUC__ >= 4)
+#define XMLIMPORT __attribute__ ((visibility ("default")))
+#endif
 
 /* If we didn't define it above, define it away: */
 #ifndef XMLIMPORT
 #define XMLIMPORT
 #endif
 
+#if defined(__GNUC__) && (__GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96))
+#define XML_ATTR_MALLOC __attribute__((__malloc__))
+#else
+#define XML_ATTR_MALLOC
+#endif
+
+#if defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
+#define XML_ATTR_ALLOC_SIZE(x)  __attribute__((__alloc_size__(x)))
+#else
+#define XML_ATTR_ALLOC_SIZE(x)
+#endif
 
 #define XMLPARSEAPI(type) XMLIMPORT type XMLCALL
 
@@ -83,7 +97,10 @@ extern "C" {
 #endif
 
 #ifdef XML_UNICODE_WCHAR_T
-#define XML_UNICODE
+# define XML_UNICODE
+# if defined(__SIZEOF_WCHAR_T__) && (__SIZEOF_WCHAR_T__ != 2)
+#  error "sizeof(wchar_t) != 2; Need -fshort-wchar for both Expat and libc"
+# endif
 #endif
 
 #ifdef XML_UNICODE     /* Information is UTF-16 encoded. */

Modules/expat/expat_external.h

@@ -71,3 +71,25 @@
 #define inline
 #endif
 #endif
+
+#ifndef UNUSED_P
+# ifdef __GNUC__
+#  define UNUSED_P(p) UNUSED_ ## p __attribute__((__unused__))
+# else
+#  define UNUSED_P(p) UNUSED_ ## p
+# endif
+#endif
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+void
+align_limit_to_full_utf8_characters(const char * from, const char ** fromLimRef);
+
+
+#ifdef __cplusplus
+}
+#endif