xmlparse.c

/* 8c6b2be7c6281da65ce05218fc15c339f02a811706340824ab596aa86e1fd51a (2.2.4+)
                            __  __            _
                         ___\ \/ /_ __   __ _| |_
                        / _ \\  /| '_ \ / _` | __|
                       |  __//  \| |_) | (_| | |_
                        \___/_/\_\ .__/ \__,_|\__|
                                 |_| XML parser

   Copyright (c) 1997-2000 Thai Open Source Software Center Ltd
   Copyright (c) 2000-2017 Expat development team
   Licensed under the MIT license:

   Permission is  hereby granted,  free of charge,  to any  person obtaining
   a  copy  of  this  software   and  associated  documentation  files  (the
   "Software"),  to  deal in  the  Software  without restriction,  including
   without  limitation the  rights  to use,  copy,  modify, merge,  publish,
   distribute, sublicense, and/or sell copies of the Software, and to permit
   persons  to whom  the Software  is  furnished to  do so,  subject to  the
   following conditions:

   The above copyright  notice and this permission notice  shall be included
   in all copies or substantial portions of the Software.

   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. 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.
*/

#if !defined(_GNU_SOURCE)
# define _GNU_SOURCE 1                  /* syscall prototype */
#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 */

#ifdef _WIN32
#define getpid GetCurrentProcessId
#else
#include <sys/time.h>                   /* gettimeofday() */
#include <sys/types.h>                  /* getpid() */
#include <unistd.h>                     /* getpid() */
#include <fcntl.h>                      /* O_RDONLY */
#include <errno.h>
#endif

#define XML_BUILDING_EXPAT 1

#ifdef _WIN32
#include "winconfig.h"
#elif defined(HAVE_EXPAT_CONFIG_H)
#include <expat_config.h>
#endif /* ndef _WIN32 */

#include "ascii.h"
#include "expat.h"
#include "siphash.h"

#if defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM)
# if defined(HAVE_GETRANDOM)
#  include <sys/random.h>    /* getrandom */
# else
#  include <unistd.h>        /* syscall */
#  include <sys/syscall.h>   /* SYS_getrandom */
# endif
# if ! defined(GRND_NONBLOCK)
#  define GRND_NONBLOCK  0x0001
# endif  /* defined(GRND_NONBLOCK) */
#endif  /* defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM) */

#if defined(HAVE_LIBBSD) \
    && (defined(HAVE_ARC4RANDOM_BUF) || defined(HAVE_ARC4RANDOM))
# include <bsd/stdlib.h>
#endif

#if defined(_WIN32) && !defined(LOAD_LIBRARY_SEARCH_SYSTEM32)
# define LOAD_LIBRARY_SEARCH_SYSTEM32  0x00000800
#endif

#if !defined(HAVE_GETRANDOM) && !defined(HAVE_SYSCALL_GETRANDOM) \
    && !defined(HAVE_ARC4RANDOM_BUF) && !defined(HAVE_ARC4RANDOM) \
    && !defined(XML_DEV_URANDOM) \
    && !defined(_WIN32) \
    && !defined(XML_POOR_ENTROPY)
# error  \
    You do not have support for any sources of high quality entropy \
    enabled.  For end user security, that is probably not what you want. \
    \
    Your options include: \
      * Linux + glibc >=2.25 (getrandom): HAVE_GETRANDOM, \
      * Linux + glibc <2.25 (syscall SYS_getrandom): HAVE_SYSCALL_GETRANDOM, \
      * BSD / macOS >=10.7 (arc4random_buf): HAVE_ARC4RANDOM_BUF, \
      * BSD / macOS <10.7 (arc4random): HAVE_ARC4RANDOM, \
      * 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. \
    \
    If insist on not using any of these, bypass this error by defining \
    XML_POOR_ENTROPY; you have been warned. \
    \
    If you have reasons to patch this detection code away or need changes \
    to the build system, please open a bug.  Thank you!
#endif


#ifdef XML_UNICODE
#define XML_ENCODE_MAX XML_UTF16_ENCODE_MAX
#define XmlConvert XmlUtf16Convert
#define XmlGetInternalEncoding XmlGetUtf16InternalEncoding
#define XmlGetInternalEncodingNS XmlGetUtf16InternalEncodingNS
#define XmlEncode XmlUtf16Encode
/* Using pointer subtraction to convert to integer type. */
#define MUST_CONVERT(enc, s) (!(enc)->isUtf16 || (((char *)(s) - (char *)NULL) & 1))
typedef unsigned short ICHAR;
#else
#define XML_ENCODE_MAX XML_UTF8_ENCODE_MAX
#define XmlConvert XmlUtf8Convert
#define XmlGetInternalEncoding XmlGetUtf8InternalEncoding
#define XmlGetInternalEncodingNS XmlGetUtf8InternalEncodingNS
#define XmlEncode XmlUtf8Encode
#define MUST_CONVERT(enc, s) (!(enc)->isUtf8)
typedef char ICHAR;
#endif


#ifndef XML_NS

#define XmlInitEncodingNS XmlInitEncoding
#define XmlInitUnknownEncodingNS XmlInitUnknownEncoding
#undef XmlGetInternalEncodingNS
#define XmlGetInternalEncodingNS XmlGetInternalEncoding
#define XmlParseXmlDeclNS XmlParseXmlDecl

#endif

#ifdef XML_UNICODE

#ifdef XML_UNICODE_WCHAR_T
#define XML_T(x) (const wchar_t)x
#define XML_L(x) L ## x
#else
#define XML_T(x) (const unsigned short)x
#define XML_L(x) x
#endif

#else

#define XML_T(x) x
#define XML_L(x) x

#endif

/* Round up n to be a multiple of sz, where sz is a power of 2. */
#define ROUND_UP(n, sz) (((n) + ((sz) - 1)) & ~((sz) - 1))

/* Handle the case where memmove() doesn't exist. */
#ifndef HAVE_MEMMOVE
#ifdef HAVE_BCOPY
#define memmove(d,s,l) bcopy((s),(d),(l))
#else
#error memmove does not exist on this platform, nor is a substitute available
#endif /* HAVE_BCOPY */
#endif /* HAVE_MEMMOVE */

#include "internal.h"
#include "xmltok.h"
#include "xmlrole.h"

typedef const XML_Char *KEY;

typedef struct {
  KEY name;
} NAMED;

typedef struct {
  NAMED **v;
  unsigned char power;
  size_t size;
  size_t used;
  const XML_Memory_Handling_Suite *mem;
} HASH_TABLE;

static size_t
keylen(KEY s);

static void
copy_salt_to_sipkey(XML_Parser parser, struct sipkey * key);

/* For probing (after a collision) we need a step size relative prime
   to the hash table size, which is a power of 2. We use double-hashing,
   since we can calculate a second hash value cheaply by taking those bits
   of the first hash value that were discarded (masked out) when the table
   index was calculated: index = hash & mask, where mask = table->size - 1.
   We limit the maximum step size to table->size / 4 (mask >> 2) and make
   it odd, since odd numbers are always relative prime to a power of 2.
*/
#define SECOND_HASH(hash, mask, power) \
  ((((hash) & ~(mask)) >> ((power) - 1)) & ((mask) >> 2))
#define PROBE_STEP(hash, mask, power) \
  ((unsigned char)((SECOND_HASH(hash, mask, power)) | 1))

typedef struct {
  NAMED **p;
  NAMED **end;
} HASH_TABLE_ITER;

#define INIT_TAG_BUF_SIZE 32  /* must be a multiple of sizeof(XML_Char) */
#define INIT_DATA_BUF_SIZE 1024
#define INIT_ATTS_SIZE 16
#define INIT_ATTS_VERSION 0xFFFFFFFF
#define INIT_BLOCK_SIZE 1024
#define INIT_BUFFER_SIZE 1024

#define EXPAND_SPARE 24

typedef struct binding {
  struct prefix *prefix;
  struct binding *nextTagBinding;
  struct binding *prevPrefixBinding;
  const struct attribute_id *attId;
  XML_Char *uri;
  int uriLen;
  int uriAlloc;
} BINDING;

typedef struct prefix {
  const XML_Char *name;
  BINDING *binding;
} PREFIX;

typedef struct {
  const XML_Char *str;
  const XML_Char *localPart;
  const XML_Char *prefix;
  int strLen;
  int uriLen;
  int prefixLen;
} TAG_NAME;

/* TAG represents an open element.
   The name of the element is stored in both the document and API
   encodings.  The memory buffer 'buf' is a separately-allocated
   memory area which stores the name.  During the XML_Parse()/
   XMLParseBuffer() when the element is open, the memory for the 'raw'
   version of the name (in the document encoding) is shared with the
   document buffer.  If the element is open across calls to
   XML_Parse()/XML_ParseBuffer(), the buffer is re-allocated to
   contain the 'raw' name as well.

   A parser re-uses these structures, maintaining a list of allocated
   TAG objects in a free list.
*/
typedef struct tag {
  struct tag *parent;           /* parent of this element */
  const char *rawName;          /* tagName in the original encoding */
  int rawNameLength;
  TAG_NAME name;                /* tagName in the API encoding */
  char *buf;                    /* buffer for name components */
  char *bufEnd;                 /* end of the buffer */
  BINDING *bindings;
} TAG;

typedef struct {
  const XML_Char *name;
  const XML_Char *textPtr;
  int textLen;                  /* length in XML_Chars */
  int processed;                /* # of processed bytes - when suspended */
  const XML_Char *systemId;
  const XML_Char *base;
  const XML_Char *publicId;
  const XML_Char *notation;
  XML_Bool open;
  XML_Bool is_param;
  XML_Bool is_internal; /* true if declared in internal subset outside PE */
} ENTITY;

typedef struct {
  enum XML_Content_Type         type;
  enum XML_Content_Quant        quant;
  const XML_Char *              name;
  int                           firstchild;
  int                           lastchild;
  int                           childcnt;
  int                           nextsib;
} CONTENT_SCAFFOLD;

#define INIT_SCAFFOLD_ELEMENTS 32

typedef struct block {
  struct block *next;
  int size;
  XML_Char s[1];
} BLOCK;

typedef struct {
  BLOCK *blocks;
  BLOCK *freeBlocks;
  const XML_Char *end;
  XML_Char *ptr;
  XML_Char *start;
  const XML_Memory_Handling_Suite *mem;
} STRING_POOL;

/* The XML_Char before the name is used to determine whether
   an attribute has been specified. */
typedef struct attribute_id {
  XML_Char *name;
  PREFIX *prefix;
  XML_Bool maybeTokenized;
  XML_Bool xmlns;
} ATTRIBUTE_ID;

typedef struct {
  const ATTRIBUTE_ID *id;
  XML_Bool isCdata;
  const XML_Char *value;
} DEFAULT_ATTRIBUTE;

typedef struct {
  unsigned long version;
  unsigned long hash;
  const XML_Char *uriName;
} NS_ATT;

typedef struct {
  const XML_Char *name;
  PREFIX *prefix;
  const ATTRIBUTE_ID *idAtt;
  int nDefaultAtts;
  int allocDefaultAtts;
  DEFAULT_ATTRIBUTE *defaultAtts;
} ELEMENT_TYPE;

typedef struct {
  HASH_TABLE generalEntities;
  HASH_TABLE elementTypes;
  HASH_TABLE attributeIds;
  HASH_TABLE prefixes;
  STRING_POOL pool;
  STRING_POOL entityValuePool;
  /* false once a parameter entity reference has been skipped */
  XML_Bool keepProcessing;
  /* true once an internal or external PE reference has been encountered;
     this includes the reference to an external subset */
  XML_Bool hasParamEntityRefs;
  XML_Bool standalone;
#ifdef XML_DTD
  /* indicates if external PE has been read */
  XML_Bool paramEntityRead;
  HASH_TABLE paramEntities;
#endif /* XML_DTD */
  PREFIX defaultPrefix;
  /* === scaffolding for building content model === */
  XML_Bool in_eldecl;
  CONTENT_SCAFFOLD *scaffold;
  unsigned contentStringLen;
  unsigned scaffSize;
  unsigned scaffCount;
  int scaffLevel;
  int *scaffIndex;
} DTD;

typedef struct open_internal_entity {
  const char *internalEventPtr;
  const char *internalEventEndPtr;
  struct open_internal_entity *next;
  ENTITY *entity;
  int startTagLevel;
  XML_Bool betweenDecl; /* WFC: PE Between Declarations */
} OPEN_INTERNAL_ENTITY;

typedef enum XML_Error PTRCALL Processor(XML_Parser parser,
                                         const char *start,
                                         const char *end,
                                         const char **endPtr);

static Processor prologProcessor;
static Processor prologInitProcessor;
static Processor contentProcessor;
static Processor cdataSectionProcessor;
#ifdef XML_DTD
static Processor ignoreSectionProcessor;
static Processor externalParEntProcessor;
static Processor externalParEntInitProcessor;
static Processor entityValueProcessor;
static Processor entityValueInitProcessor;
#endif /* XML_DTD */
static Processor epilogProcessor;
static Processor errorProcessor;
static Processor externalEntityInitProcessor;
static Processor externalEntityInitProcessor2;
static Processor externalEntityInitProcessor3;
static Processor externalEntityContentProcessor;
static Processor internalEntityProcessor;

static enum XML_Error
handleUnknownEncoding(XML_Parser parser, const XML_Char *encodingName);
static enum XML_Error
processXmlDecl(XML_Parser parser, int isGeneralTextEntity,
               const char *s, const char *next);
static enum XML_Error
initializeEncoding(XML_Parser parser);
static enum XML_Error
doProlog(XML_Parser parser, const ENCODING *enc, const char *s,
         const char *end, int tok, const char *next, const char **nextPtr,
         XML_Bool haveMore);
static enum XML_Error
processInternalEntity(XML_Parser parser, ENTITY *entity,
                      XML_Bool betweenDecl);
static enum XML_Error
doContent(XML_Parser parser, int startTagLevel, const ENCODING *enc,
          const char *start, const char *end, const char **endPtr,
          XML_Bool haveMore);
static enum XML_Error
doCdataSection(XML_Parser parser, const ENCODING *, const char **startPtr,
               const char *end, const char **nextPtr, XML_Bool haveMore);
#ifdef XML_DTD
static enum XML_Error
doIgnoreSection(XML_Parser parser, const ENCODING *, const char **startPtr,
                const char *end, const char **nextPtr, XML_Bool haveMore);
#endif /* XML_DTD */

static void
freeBindings(XML_Parser parser, BINDING *bindings);
static enum XML_Error
storeAtts(XML_Parser parser, const ENCODING *, const char *s,
          TAG_NAME *tagNamePtr, BINDING **bindingsPtr);
static enum XML_Error
addBinding(XML_Parser parser, PREFIX *prefix, const ATTRIBUTE_ID *attId,
           const XML_Char *uri, BINDING **bindingsPtr);
static int
defineAttribute(ELEMENT_TYPE *type, ATTRIBUTE_ID *, XML_Bool isCdata,
                XML_Bool isId, const XML_Char *dfltValue, XML_Parser parser);
static enum XML_Error
storeAttributeValue(XML_Parser parser, const ENCODING *, XML_Bool isCdata,
                    const char *, const char *, STRING_POOL *);
static enum XML_Error
appendAttributeValue(XML_Parser parser, const ENCODING *, XML_Bool isCdata,
                     const char *, const char *, STRING_POOL *);
static ATTRIBUTE_ID *
getAttributeId(XML_Parser parser, const ENCODING *enc, const char *start,
               const char *end);
static int
setElementTypePrefix(XML_Parser parser, ELEMENT_TYPE *);
static enum XML_Error
storeEntityValue(XML_Parser parser, const ENCODING *enc, const char *start,
                 const char *end);
static int
reportProcessingInstruction(XML_Parser parser, const ENCODING *enc,
                            const char *start, const char *end);
static int
reportComment(XML_Parser parser, const ENCODING *enc, const char *start,
              const char *end);
static void
reportDefault(XML_Parser parser, const ENCODING *enc, const char *start,
              const char *end);

static const XML_Char * getContext(XML_Parser parser);
static XML_Bool
setContext(XML_Parser parser, const XML_Char *context);

static void FASTCALL normalizePublicId(XML_Char *s);

static DTD * dtdCreate(const XML_Memory_Handling_Suite *ms);
/* do not call if parentParser != NULL */
static void dtdReset(DTD *p, const XML_Memory_Handling_Suite *ms);
static void
dtdDestroy(DTD *p, XML_Bool isDocEntity, const XML_Memory_Handling_Suite *ms);
static int
dtdCopy(XML_Parser oldParser,
        DTD *newDtd, const DTD *oldDtd, const XML_Memory_Handling_Suite *ms);
static int
copyEntityTable(XML_Parser oldParser,
                HASH_TABLE *, STRING_POOL *, const HASH_TABLE *);
static NAMED *
lookup(XML_Parser parser, HASH_TABLE *table, KEY name, size_t createSize);
static void FASTCALL
hashTableInit(HASH_TABLE *, const XML_Memory_Handling_Suite *ms);
static void FASTCALL hashTableClear(HASH_TABLE *);
static void FASTCALL hashTableDestroy(HASH_TABLE *);
static void FASTCALL
hashTableIterInit(HASH_TABLE_ITER *, const HASH_TABLE *);
static NAMED * FASTCALL hashTableIterNext(HASH_TABLE_ITER *);

static void FASTCALL
poolInit(STRING_POOL *, const XML_Memory_Handling_Suite *ms);
static void FASTCALL poolClear(STRING_POOL *);
static void FASTCALL poolDestroy(STRING_POOL *);
static XML_Char *
poolAppend(STRING_POOL *pool, const ENCODING *enc,
           const char *ptr, const char *end);
static XML_Char *
poolStoreString(STRING_POOL *pool, const ENCODING *enc,
                const char *ptr, const char *end);
static XML_Bool FASTCALL poolGrow(STRING_POOL *pool);
static const XML_Char * FASTCALL
poolCopyString(STRING_POOL *pool, const XML_Char *s);
static const XML_Char *
poolCopyStringN(STRING_POOL *pool, const XML_Char *s, int n);
static const XML_Char * FASTCALL
poolAppendString(STRING_POOL *pool, const XML_Char *s);

static int FASTCALL nextScaffoldPart(XML_Parser parser);
static XML_Content * build_model(XML_Parser parser);
static ELEMENT_TYPE *
getElementType(XML_Parser parser, const ENCODING *enc,
               const char *ptr, const char *end);

static XML_Char *copyString(const XML_Char *s,
                            const XML_Memory_Handling_Suite *memsuite);

static unsigned long generate_hash_secret_salt(XML_Parser parser);
static XML_Bool startParsing(XML_Parser parser);

static XML_Parser
parserCreate(const XML_Char *encodingName,
             const XML_Memory_Handling_Suite *memsuite,
             const XML_Char *nameSep,
             DTD *dtd);

static void
parserInit(XML_Parser parser, const XML_Char *encodingName);

#define poolStart(pool) ((pool)->start)
#define poolEnd(pool) ((pool)->ptr)
#define poolLength(pool) ((pool)->ptr - (pool)->start)
#define poolChop(pool) ((void)--(pool->ptr))
#define poolLastChar(pool) (((pool)->ptr)[-1])
#define poolDiscard(pool) ((pool)->ptr = (pool)->start)
#define poolFinish(pool) ((pool)->start = (pool)->ptr)
#define poolAppendChar(pool, c) \
  (((pool)->ptr == (pool)->end && !poolGrow(pool)) \
   ? 0 \
   : ((*((pool)->ptr)++ = c), 1))

struct XML_ParserStruct {
  /* The first member must be userData so that the XML_GetUserData
     macro works. */
  void *m_userData;
  void *m_handlerArg;
  char *m_buffer;
  const XML_Memory_Handling_Suite m_mem;
  /* first character to be parsed */
  const char *m_bufferPtr;
  /* past last character to be parsed */
  char *m_bufferEnd;
  /* allocated end of buffer */
  const char *m_bufferLim;
  XML_Index m_parseEndByteIndex;
  const char *m_parseEndPtr;
  XML_Char *m_dataBuf;
  XML_Char *m_dataBufEnd;
  XML_StartElementHandler m_startElementHandler;
  XML_EndElementHandler m_endElementHandler;
  XML_CharacterDataHandler m_characterDataHandler;
  XML_ProcessingInstructionHandler m_processingInstructionHandler;
  XML_CommentHandler m_commentHandler;
  XML_StartCdataSectionHandler m_startCdataSectionHandler;
  XML_EndCdataSectionHandler m_endCdataSectionHandler;
  XML_DefaultHandler m_defaultHandler;
  XML_StartDoctypeDeclHandler m_startDoctypeDeclHandler;
  XML_EndDoctypeDeclHandler m_endDoctypeDeclHandler;
  XML_UnparsedEntityDeclHandler m_unparsedEntityDeclHandler;
  XML_NotationDeclHandler m_notationDeclHandler;
  XML_StartNamespaceDeclHandler m_startNamespaceDeclHandler;
  XML_EndNamespaceDeclHandler m_endNamespaceDeclHandler;
  XML_NotStandaloneHandler m_notStandaloneHandler;
  XML_ExternalEntityRefHandler m_externalEntityRefHandler;
  XML_Parser m_externalEntityRefHandlerArg;
  XML_SkippedEntityHandler m_skippedEntityHandler;
  XML_UnknownEncodingHandler m_unknownEncodingHandler;
  XML_ElementDeclHandler m_elementDeclHandler;
  XML_AttlistDeclHandler m_attlistDeclHandler;
  XML_EntityDeclHandler m_entityDeclHandler;
  XML_XmlDeclHandler m_xmlDeclHandler;
  const ENCODING *m_encoding;
  INIT_ENCODING m_initEncoding;
  const ENCODING *m_internalEncoding;
  const XML_Char *m_protocolEncodingName;
  XML_Bool m_ns;
  XML_Bool m_ns_triplets;
  void *m_unknownEncodingMem;
  void *m_unknownEncodingData;
  void *m_unknownEncodingHandlerData;
  void (XMLCALL *m_unknownEncodingRelease)(void *);
  PROLOG_STATE m_prologState;
  Processor *m_processor;
  enum XML_Error m_errorCode;
  const char *m_eventPtr;
  const char *m_eventEndPtr;
  const char *m_positionPtr;
  OPEN_INTERNAL_ENTITY *m_openInternalEntities;
  OPEN_INTERNAL_ENTITY *m_freeInternalEntities;
  XML_Bool m_defaultExpandInternalEntities;
  int m_tagLevel;
  ENTITY *m_declEntity;
  const XML_Char *m_doctypeName;
  const XML_Char *m_doctypeSysid;
  const XML_Char *m_doctypePubid;
  const XML_Char *m_declAttributeType;
  const XML_Char *m_declNotationName;
  const XML_Char *m_declNotationPublicId;
  ELEMENT_TYPE *m_declElementType;
  ATTRIBUTE_ID *m_declAttributeId;
  XML_Bool m_declAttributeIsCdata;
  XML_Bool m_declAttributeIsId;
  DTD *m_dtd;
  const XML_Char *m_curBase;
  TAG *m_tagStack;
  TAG *m_freeTagList;
  BINDING *m_inheritedBindings;
  BINDING *m_freeBindingList;
  int m_attsSize;
  int m_nSpecifiedAtts;
  int m_idAttIndex;
  ATTRIBUTE *m_atts;
  NS_ATT *m_nsAtts;
  unsigned long m_nsAttsVersion;
  unsigned char m_nsAttsPower;
#ifdef XML_ATTR_INFO
  XML_AttrInfo *m_attInfo;
#endif
  POSITION m_position;
  STRING_POOL m_tempPool;
  STRING_POOL m_temp2Pool;
  char *m_groupConnector;
  unsigned int m_groupSize;
  XML_Char m_namespaceSeparator;
  XML_Parser m_parentParser;
  XML_ParsingStatus m_parsingStatus;
#ifdef XML_DTD
  XML_Bool m_isParamEntity;
  XML_Bool m_useForeignDTD;
  enum XML_ParamEntityParsing m_paramEntityParsing;
#endif
  unsigned long m_hash_secret_salt;
};

#define MALLOC(s) (parser->m_mem.malloc_fcn((s)))
#define REALLOC(p,s) (parser->m_mem.realloc_fcn((p),(s)))
#define FREE(p) (parser->m_mem.free_fcn((p)))

#define userData (parser->m_userData)
#define handlerArg (parser->m_handlerArg)
#define startElementHandler (parser->m_startElementHandler)
#define endElementHandler (parser->m_endElementHandler)
#define characterDataHandler (parser->m_characterDataHandler)
#define processingInstructionHandler \
        (parser->m_processingInstructionHandler)
#define commentHandler (parser->m_commentHandler)
#define startCdataSectionHandler \
        (parser->m_startCdataSectionHandler)
#define endCdataSectionHandler (parser->m_endCdataSectionHandler)
#define defaultHandler (parser->m_defaultHandler)
#define startDoctypeDeclHandler (parser->m_startDoctypeDeclHandler)
#define endDoctypeDeclHandler (parser->m_endDoctypeDeclHandler)
#define unparsedEntityDeclHandler \
        (parser->m_unparsedEntityDeclHandler)
#define notationDeclHandler (parser->m_notationDeclHandler)
#define startNamespaceDeclHandler \
        (parser->m_startNamespaceDeclHandler)
#define endNamespaceDeclHandler (parser->m_endNamespaceDeclHandler)
#define notStandaloneHandler (parser->m_notStandaloneHandler)
#define externalEntityRefHandler \
        (parser->m_externalEntityRefHandler)
#define externalEntityRefHandlerArg \
        (parser->m_externalEntityRefHandlerArg)
#define internalEntityRefHandler \
        (parser->m_internalEntityRefHandler)
#define skippedEntityHandler (parser->m_skippedEntityHandler)
#define unknownEncodingHandler (parser->m_unknownEncodingHandler)
#define elementDeclHandler (parser->m_elementDeclHandler)
#define attlistDeclHandler (parser->m_attlistDeclHandler)
#define entityDeclHandler (parser->m_entityDeclHandler)
#define xmlDeclHandler (parser->m_xmlDeclHandler)
#define encoding (parser->m_encoding)
#define initEncoding (parser->m_initEncoding)
#define internalEncoding (parser->m_internalEncoding)
#define unknownEncodingMem (parser->m_unknownEncodingMem)
#define unknownEncodingData (parser->m_unknownEncodingData)
#define unknownEncodingHandlerData \
  (parser->m_unknownEncodingHandlerData)
#define unknownEncodingRelease (parser->m_unknownEncodingRelease)
#define protocolEncodingName (parser->m_protocolEncodingName)
#define ns (parser->m_ns)
#define ns_triplets (parser->m_ns_triplets)
#define prologState (parser->m_prologState)
#define processor (parser->m_processor)
#define errorCode (parser->m_errorCode)
#define eventPtr (parser->m_eventPtr)
#define eventEndPtr (parser->m_eventEndPtr)
#define positionPtr (parser->m_positionPtr)
#define position (parser->m_position)
#define openInternalEntities (parser->m_openInternalEntities)
#define freeInternalEntities (parser->m_freeInternalEntities)
#define defaultExpandInternalEntities \
        (parser->m_defaultExpandInternalEntities)
#define tagLevel (parser->m_tagLevel)
#define buffer (parser->m_buffer)
#define bufferPtr (parser->m_bufferPtr)
#define bufferEnd (parser->m_bufferEnd)
#define parseEndByteIndex (parser->m_parseEndByteIndex)
#define parseEndPtr (parser->m_parseEndPtr)
#define bufferLim (parser->m_bufferLim)
#define dataBuf (parser->m_dataBuf)
#define dataBufEnd (parser->m_dataBufEnd)
#define _dtd (parser->m_dtd)
#define curBase (parser->m_curBase)
#define declEntity (parser->m_declEntity)
#define doctypeName (parser->m_doctypeName)
#define doctypeSysid (parser->m_doctypeSysid)
#define doctypePubid (parser->m_doctypePubid)
#define declAttributeType (parser->m_declAttributeType)
#define declNotationName (parser->m_declNotationName)
#define declNotationPublicId (parser->m_declNotationPublicId)
#define declElementType (parser->m_declElementType)
#define declAttributeId (parser->m_declAttributeId)
#define declAttributeIsCdata (parser->m_declAttributeIsCdata)
#define declAttributeIsId (parser->m_declAttributeIsId)
#define freeTagList (parser->m_freeTagList)
#define freeBindingList (parser->m_freeBindingList)
#define inheritedBindings (parser->m_inheritedBindings)
#define tagStack (parser->m_tagStack)
#define atts (parser->m_atts)
#define attsSize (parser->m_attsSize)
#define nSpecifiedAtts (parser->m_nSpecifiedAtts)
#define idAttIndex (parser->m_idAttIndex)
#define nsAtts (parser->m_nsAtts)
#define nsAttsVersion (parser->m_nsAttsVersion)
#define nsAttsPower (parser->m_nsAttsPower)
#define attInfo (parser->m_attInfo)
#define tempPool (parser->m_tempPool)
#define temp2Pool (parser->m_temp2Pool)
#define groupConnector (parser->m_groupConnector)
#define groupSize (parser->m_groupSize)
#define namespaceSeparator (parser->m_namespaceSeparator)
#define parentParser (parser->m_parentParser)
#define ps_parsing (parser->m_parsingStatus.parsing)
#define ps_finalBuffer (parser->m_parsingStatus.finalBuffer)
#ifdef XML_DTD
#define isParamEntity (parser->m_isParamEntity)
#define useForeignDTD (parser->m_useForeignDTD)
#define paramEntityParsing (parser->m_paramEntityParsing)
#endif /* XML_DTD */
#define hash_secret_salt (parser->m_hash_secret_salt)

XML_Parser XMLCALL
XML_ParserCreate(const XML_Char *encodingName)
{
  return XML_ParserCreate_MM(encodingName, NULL, NULL);
}

XML_Parser XMLCALL
XML_ParserCreateNS(const XML_Char *encodingName, XML_Char nsSep)
{
  XML_Char tmp[2];
  *tmp = nsSep;
  return XML_ParserCreate_MM(encodingName, NULL, tmp);
}

static const XML_Char implicitContext[] = {
  ASCII_x, ASCII_m, ASCII_l, ASCII_EQUALS, ASCII_h, ASCII_t, ASCII_t, ASCII_p,
  ASCII_COLON, ASCII_SLASH, ASCII_SLASH, ASCII_w, ASCII_w, ASCII_w,
  ASCII_PERIOD, ASCII_w, ASCII_3, ASCII_PERIOD, ASCII_o, ASCII_r, ASCII_g,
  ASCII_SLASH, ASCII_X, ASCII_M, ASCII_L, ASCII_SLASH, ASCII_1, ASCII_9,
  ASCII_9, ASCII_8, ASCII_SLASH, ASCII_n, ASCII_a, ASCII_m, ASCII_e,
  ASCII_s, ASCII_p, ASCII_a, ASCII_c, ASCII_e, '\0'
};


#if defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM)

/* Obtain entropy on Linux 3.17+ */
static int
writeRandomBytes_getrandom_nonblock(void * target, size_t count) {
  int success = 0;  /* full count bytes written? */
  size_t bytesWrittenTotal = 0;
  const unsigned int getrandomFlags = GRND_NONBLOCK;

  do {
    void * const currentTarget = (void*)((char*)target + bytesWrittenTotal);
    const size_t bytesToWrite = count - bytesWrittenTotal;

    const int bytesWrittenMore =
#if defined(HAVE_GETRANDOM)
        getrandom(currentTarget, bytesToWrite, getrandomFlags);
#else
        syscall(SYS_getrandom, currentTarget, bytesToWrite, getrandomFlags);
#endif

    if (bytesWrittenMore > 0) {
      bytesWrittenTotal += bytesWrittenMore;
      if (bytesWrittenTotal >= count)
        success = 1;
    }
  } while (! success && (errno == EINTR));

  return success;
}

#endif  /* defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM) */


#if ! defined(_WIN32) && defined(XML_DEV_URANDOM)

/* Extract entropy from /dev/urandom */
static int
writeRandomBytes_dev_urandom(void * target, size_t count) {
  int success = 0;  /* full count bytes written? */
  size_t bytesWrittenTotal = 0;

  const int fd = open("/dev/urandom", O_RDONLY);
  if (fd < 0) {
    return 0;
  }

  do {
    void * const currentTarget = (void*)((char*)target + bytesWrittenTotal);
    const size_t bytesToWrite = count - bytesWrittenTotal;

    const ssize_t bytesWrittenMore = read(fd, currentTarget, bytesToWrite);

    if (bytesWrittenMore > 0) {
      bytesWrittenTotal += bytesWrittenMore;
      if (bytesWrittenTotal >= count)
        success = 1;
    }
  } while (! success && (errno == EINTR));

  close(fd);
  return success;
}

#endif  /* ! defined(_WIN32) && defined(XML_DEV_URANDOM) */


#if defined(HAVE_ARC4RANDOM)

static void
writeRandomBytes_arc4random(void * target, size_t count) {
  size_t bytesWrittenTotal = 0;

  while (bytesWrittenTotal < count) {
    const uint32_t random32 = arc4random();
    size_t i = 0;

    for (; (i < sizeof(random32)) && (bytesWrittenTotal < count);
        i++, bytesWrittenTotal++) {
      const uint8_t random8 = (uint8_t)(random32 >> (i * 8));
      ((uint8_t *)target)[bytesWrittenTotal] = random8;
    }
  }
}

#endif  /* defined(HAVE_ARC4RANDOM) */


#ifdef _WIN32

typedef BOOLEAN (APIENTRY *RTLGENRANDOM_FUNC)(PVOID, ULONG);
HMODULE _Expat_LoadLibrary(LPCTSTR filename);  /* see loadlibrary.c */

/* 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) {
  int success = 0;  /* full count bytes written? */
  const HMODULE advapi32 = _Expat_LoadLibrary(TEXT("ADVAPI32.DLL"));

  if (advapi32) {
    const RTLGENRANDOM_FUNC RtlGenRandom
        = (RTLGENRANDOM_FUNC)GetProcAddress(advapi32, "SystemFunction036");
    if (RtlGenRandom) {
      if (RtlGenRandom((PVOID)target, (ULONG)count) == TRUE) {
        success = 1;
      }
    }
    FreeLibrary(advapi32);
  }

  return success;
}

#endif /* _WIN32 */


#if ! defined(HAVE_ARC4RANDOM_BUF) && ! defined(HAVE_ARC4RANDOM)

static unsigned long
gather_time_entropy(void)
{
#ifdef _WIN32
  FILETIME ft;
  GetSystemTimeAsFileTime(&ft); /* never fails */
  return ft.dwHighDateTime ^ ft.dwLowDateTime;
#else
  struct timeval tv;
  int gettimeofday_res;

  gettimeofday_res = gettimeofday(&tv, NULL);

#if defined(NDEBUG)
  (void)gettimeofday_res;
#else
  assert (gettimeofday_res == 0);
#endif  /* defined(NDEBUG) */

  /* Microseconds time is <20 bits entropy */
  return tv.tv_usec;
#endif
}

#endif  /* ! defined(HAVE_ARC4RANDOM_BUF) && ! defined(HAVE_ARC4RANDOM) */


static unsigned long
ENTROPY_DEBUG(const char * label, unsigned long entropy) {
  const char * const EXPAT_ENTROPY_DEBUG = getenv("EXPAT_ENTROPY_DEBUG");
  if (EXPAT_ENTROPY_DEBUG && ! strcmp(EXPAT_ENTROPY_DEBUG, "1")) {
    fprintf(stderr, "Entropy: %s --> 0x%0*lx (%lu bytes)\n",
        label,
        (int)sizeof(entropy) * 2, entropy,
        (unsigned long)sizeof(entropy));
  }
  return entropy;
}

static unsigned long
generate_hash_secret_salt(XML_Parser parser)
{
  unsigned long entropy;
  (void)parser;
#if defined(HAVE_ARC4RANDOM_BUF)
  arc4random_buf(&entropy, sizeof(entropy));
  return ENTROPY_DEBUG("arc4random_buf", entropy);
#elif defined(HAVE_ARC4RANDOM)
  writeRandomBytes_arc4random((void *)&entropy, sizeof(entropy));
  return ENTROPY_DEBUG("arc4random", entropy);
#else
  /* Try high quality providers first .. */
#ifdef _WIN32
  if (writeRandomBytes_RtlGenRandom((void *)&entropy, sizeof(entropy))) {
    return ENTROPY_DEBUG("RtlGenRandom", entropy);
  }
#elif defined(HAVE_GETRANDOM) || defined(HAVE_SYSCALL_GETRANDOM)
  if (writeRandomBytes_getrandom_nonblock((void *)&entropy, sizeof(entropy))) {
    return ENTROPY_DEBUG("getrandom", entropy);
  }
#endif
#if ! defined(_WIN32) && defined(XML_DEV_URANDOM)
  if (writeRandomBytes_dev_urandom((void *)&entropy, sizeof(entropy))) {
    return ENTROPY_DEBUG("/dev/urandom", entropy);
  }
#endif  /* ! defined(_WIN32) && defined(XML_DEV_URANDOM) */
  /* .. and self-made low quality for backup: */

  /* Process ID is 0 bits entropy if attacker has local access */
  entropy = gather_time_entropy() ^ getpid();

  /* Factors are 2^31-1 and 2^61-1 (Mersenne primes M31 and M61) */
  if (sizeof(unsigned long) == 4) {
    return ENTROPY_DEBUG("fallback(4)", entropy * 2147483647);
  } else {
    return ENTROPY_DEBUG("fallback(8)",
        entropy * (unsigned long)2305843009213693951ULL);
  }
#endif
}

static unsigned long
get_hash_secret_salt(XML_Parser parser) {
  if (parser->m_parentParser != NULL)
    return get_hash_secret_salt(parser->m_parentParser);
  return parser->m_hash_secret_salt;
}

static XML_Bool  /* only valid for root parser */
startParsing(XML_Parser parser)
{
    /* hash functions must be initialized before setContext() is called */
    if (hash_secret_salt == 0)
      hash_secret_salt = generate_hash_secret_salt(parser);
    if (ns) {
      /* implicit context only set for root parser, since child
         parsers (i.e. external entity parsers) will inherit it
      */
      return setContext(parser, implicitContext);
    }