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      1 /*
      2  * "Canonical XML" implementation
      3  * http://www.w3.org/TR/xml-c14n
      4  *
      5  * "Exclusive XML Canonicalization" implementation
      6  * http://www.w3.org/TR/xml-exc-c14n
      7  *
      8  * See Copyright for the status of this software.
      9  *
     10  * Author: Aleksey Sanin <aleksey (at) aleksey.com>
     11  */
     12 #define IN_LIBXML
     13 #include "libxml.h"
     14 #ifdef LIBXML_C14N_ENABLED
     15 #ifdef LIBXML_OUTPUT_ENABLED
     16 
     17 #ifdef HAVE_STDLIB_H
     18 #include <stdlib.h>
     19 #endif
     20 #include <string.h>
     21 
     22 #include <libxml/tree.h>
     23 #include <libxml/parser.h>
     24 #include <libxml/uri.h>
     25 #include <libxml/xmlerror.h>
     26 #include <libxml/globals.h>
     27 #include <libxml/xpathInternals.h>
     28 #include <libxml/c14n.h>
     29 
     30 /************************************************************************
     31  *									*
     32  *		Some declaration better left private ATM		*
     33  *									*
     34  ************************************************************************/
     35 
     36 typedef enum {
     37     XMLC14N_BEFORE_DOCUMENT_ELEMENT = 0,
     38     XMLC14N_INSIDE_DOCUMENT_ELEMENT = 1,
     39     XMLC14N_AFTER_DOCUMENT_ELEMENT = 2
     40 } xmlC14NPosition;
     41 
     42 typedef struct _xmlC14NVisibleNsStack {
     43     int nsCurEnd;           /* number of nodes in the set */
     44     int nsPrevStart;        /* the begginning of the stack for previous visible node */
     45     int nsPrevEnd;          /* the end of the stack for previous visible node */
     46     int nsMax;              /* size of the array as allocated */
     47     xmlNsPtr 	*nsTab;	    /* array of ns in no particular order */
     48     xmlNodePtr	*nodeTab;   /* array of nodes in no particular order */
     49 } xmlC14NVisibleNsStack, *xmlC14NVisibleNsStackPtr;
     50 
     51 typedef struct _xmlC14NCtx {
     52     /* input parameters */
     53     xmlDocPtr doc;
     54     xmlC14NIsVisibleCallback is_visible_callback;
     55     void* user_data;
     56     int with_comments;
     57     xmlOutputBufferPtr buf;
     58 
     59     /* position in the XML document */
     60     xmlC14NPosition pos;
     61     int parent_is_doc;
     62     xmlC14NVisibleNsStackPtr ns_rendered;
     63 
     64     /* C14N mode */
     65     xmlC14NMode mode;
     66 
     67     /* exclusive canonicalization */
     68     xmlChar **inclusive_ns_prefixes;
     69 
     70     /* error number */
     71     int error;
     72 } xmlC14NCtx, *xmlC14NCtxPtr;
     73 
     74 static xmlC14NVisibleNsStackPtr	xmlC14NVisibleNsStackCreate	(void);
     75 static void     xmlC14NVisibleNsStackDestroy	(xmlC14NVisibleNsStackPtr cur);
     76 static void     xmlC14NVisibleNsStackAdd	    (xmlC14NVisibleNsStackPtr cur,
     77                                                  xmlNsPtr ns,
     78                                                  xmlNodePtr node);
     79 static void 			xmlC14NVisibleNsStackSave	(xmlC14NVisibleNsStackPtr cur,
     80 								 xmlC14NVisibleNsStackPtr state);
     81 static void 			xmlC14NVisibleNsStackRestore	(xmlC14NVisibleNsStackPtr cur,
     82 								 xmlC14NVisibleNsStackPtr state);
     83 static void 			xmlC14NVisibleNsStackShift	(xmlC14NVisibleNsStackPtr cur);
     84 static int			xmlC14NVisibleNsStackFind	(xmlC14NVisibleNsStackPtr cur,
     85 								 xmlNsPtr ns);
     86 static int			xmlExcC14NVisibleNsStackFind	(xmlC14NVisibleNsStackPtr cur,
     87 								 xmlNsPtr ns,
     88 								 xmlC14NCtxPtr ctx);
     89 
     90 static int			xmlC14NIsNodeInNodeset		(xmlNodeSetPtr nodes,
     91 								 xmlNodePtr node,
     92 								 xmlNodePtr parent);
     93 
     94 
     95 
     96 static int xmlC14NProcessNode(xmlC14NCtxPtr ctx, xmlNodePtr cur);
     97 static int xmlC14NProcessNodeList(xmlC14NCtxPtr ctx, xmlNodePtr cur);
     98 typedef enum {
     99     XMLC14N_NORMALIZE_ATTR = 0,
    100     XMLC14N_NORMALIZE_COMMENT = 1,
    101     XMLC14N_NORMALIZE_PI = 2,
    102     XMLC14N_NORMALIZE_TEXT = 3
    103 } xmlC14NNormalizationMode;
    104 
    105 static xmlChar *xmlC11NNormalizeString(const xmlChar * input,
    106                                        xmlC14NNormalizationMode mode);
    107 
    108 #define 	xmlC11NNormalizeAttr( a ) \
    109     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_ATTR)
    110 #define 	xmlC11NNormalizeComment( a ) \
    111     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_COMMENT)
    112 #define 	xmlC11NNormalizePI( a )	\
    113     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_PI)
    114 #define 	xmlC11NNormalizeText( a ) \
    115     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_TEXT)
    116 
    117 #define 	xmlC14NIsVisible( ctx, node, parent ) \
    118      (((ctx)->is_visible_callback != NULL) ? \
    119 	(ctx)->is_visible_callback((ctx)->user_data, \
    120 		(xmlNodePtr)(node), (xmlNodePtr)(parent)) : 1)
    121 
    122 #define 	xmlC14NIsExclusive( ctx ) \
    123     ( (ctx)->mode == XML_C14N_EXCLUSIVE_1_0 )
    124 
    125 /************************************************************************
    126  *									*
    127  * 		Some factorized error routines				*
    128  *									*
    129  ************************************************************************/
    130 
    131 /**
    132  * xmlC14NErrMemory:
    133  * @extra:  extra informations
    134  *
    135  * Handle a redefinition of memory error
    136  */
    137 static void
    138 xmlC14NErrMemory(const char *extra)
    139 {
    140     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
    141 		    XML_ERR_NO_MEMORY, XML_ERR_ERROR, NULL, 0, extra,
    142 		    NULL, NULL, 0, 0,
    143 		    "Memory allocation failed : %s\n", extra);
    144 }
    145 
    146 /**
    147  * xmlC14NErrParam:
    148  * @extra:  extra informations
    149  *
    150  * Handle a redefinition of param error
    151  */
    152 static void
    153 xmlC14NErrParam(const char *extra)
    154 {
    155     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
    156 		    XML_ERR_INTERNAL_ERROR, XML_ERR_ERROR, NULL, 0, extra,
    157 		    NULL, NULL, 0, 0,
    158 		    "Invalid parameter : %s\n", extra);
    159 }
    160 
    161 /**
    162  * xmlC14NErrInternal:
    163  * @extra:  extra informations
    164  *
    165  * Handle a redefinition of internal error
    166  */
    167 static void
    168 xmlC14NErrInternal(const char *extra)
    169 {
    170     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
    171 		    XML_ERR_INTERNAL_ERROR, XML_ERR_ERROR, NULL, 0, extra,
    172 		    NULL, NULL, 0, 0,
    173 		    "Internal error : %s\n", extra);
    174 }
    175 
    176 /**
    177  * xmlC14NErrInvalidNode:
    178  * @extra:  extra informations
    179  *
    180  * Handle a redefinition of invalid node error
    181  */
    182 static void
    183 xmlC14NErrInvalidNode(const char *node_type, const char *extra)
    184 {
    185     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
    186 		    XML_C14N_INVALID_NODE, XML_ERR_ERROR, NULL, 0, extra,
    187 		    NULL, NULL, 0, 0,
    188 		    "Node %s is invalid here : %s\n", node_type, extra);
    189 }
    190 
    191 /**
    192  * xmlC14NErrUnknownNode:
    193  * @extra:  extra informations
    194  *
    195  * Handle a redefinition of unknown node error
    196  */
    197 static void
    198 xmlC14NErrUnknownNode(int node_type, const char *extra)
    199 {
    200     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
    201 		    XML_C14N_UNKNOW_NODE, XML_ERR_ERROR, NULL, 0, extra,
    202 		    NULL, NULL, 0, 0,
    203 		    "Unknown node type %d found : %s\n", node_type, extra);
    204 }
    205 
    206 /**
    207  * xmlC14NErrRelativeNamespace:
    208  * @extra:  extra informations
    209  *
    210  * Handle a redefinition of relative namespace error
    211  */
    212 static void
    213 xmlC14NErrRelativeNamespace(const char *ns_uri)
    214 {
    215     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
    216 		    XML_C14N_RELATIVE_NAMESPACE, XML_ERR_ERROR, NULL, 0, NULL,
    217 		    NULL, NULL, 0, 0,
    218 		    "Relative namespace UR is invalid here : %s\n", ns_uri);
    219 }
    220 
    221 
    222 
    223 /**
    224  * xmlC14NErr:
    225  * @ctxt:  a C14N evaluation context
    226  * @node:  the context node
    227  * @error:  the erorr code
    228  * @msg:  the message
    229  * @extra:  extra informations
    230  *
    231  * Handle a redefinition of attribute error
    232  */
    233 static void
    234 xmlC14NErr(xmlC14NCtxPtr ctxt, xmlNodePtr node, int error,
    235            const char * msg)
    236 {
    237     if (ctxt != NULL)
    238         ctxt->error = error;
    239     __xmlRaiseError(NULL, NULL, NULL,
    240 		    ctxt, node, XML_FROM_C14N, error,
    241 		    XML_ERR_ERROR, NULL, 0,
    242 		    NULL, NULL, NULL, 0, 0, "%s", msg);
    243 }
    244 
    245 /************************************************************************
    246  *									*
    247  *		The implementation internals				*
    248  *									*
    249  ************************************************************************/
    250 #define XML_NAMESPACES_DEFAULT		16
    251 
    252 static int
    253 xmlC14NIsNodeInNodeset(xmlNodeSetPtr nodes, xmlNodePtr node, xmlNodePtr parent) {
    254     if((nodes != NULL) && (node != NULL)) {
    255 	if(node->type != XML_NAMESPACE_DECL) {
    256 	    return(xmlXPathNodeSetContains(nodes, node));
    257 	} else {
    258 	    xmlNs ns;
    259 
    260 	    memcpy(&ns, node, sizeof(ns));
    261 
    262 	    /* this is a libxml hack! check xpath.c for details */
    263 	    if((parent != NULL) && (parent->type == XML_ATTRIBUTE_NODE)) {
    264 		ns.next = (xmlNsPtr)parent->parent;
    265 	    } else {
    266 		ns.next = (xmlNsPtr)parent;
    267 	    }
    268 
    269 	    /*
    270 	     * If the input is an XPath node-set, then the node-set must explicitly
    271 	     * contain every node to be rendered to the canonical form.
    272 	     */
    273 	    return(xmlXPathNodeSetContains(nodes, (xmlNodePtr)&ns));
    274 	}
    275     }
    276     return(1);
    277 }
    278 
    279 static xmlC14NVisibleNsStackPtr
    280 xmlC14NVisibleNsStackCreate(void) {
    281     xmlC14NVisibleNsStackPtr ret;
    282 
    283     ret = (xmlC14NVisibleNsStackPtr) xmlMalloc(sizeof(xmlC14NVisibleNsStack));
    284     if (ret == NULL) {
    285         xmlC14NErrMemory("creating namespaces stack");
    286 	return(NULL);
    287     }
    288     memset(ret, 0 , (size_t) sizeof(xmlC14NVisibleNsStack));
    289     return(ret);
    290 }
    291 
    292 static void
    293 xmlC14NVisibleNsStackDestroy(xmlC14NVisibleNsStackPtr cur) {
    294     if(cur == NULL) {
    295         xmlC14NErrParam("destroying namespaces stack");
    296         return;
    297     }
    298     if(cur->nsTab != NULL) {
    299 	memset(cur->nsTab, 0, cur->nsMax * sizeof(xmlNsPtr));
    300 	xmlFree(cur->nsTab);
    301     }
    302     if(cur->nodeTab != NULL) {
    303 	memset(cur->nodeTab, 0, cur->nsMax * sizeof(xmlNodePtr));
    304 	xmlFree(cur->nodeTab);
    305     }
    306     memset(cur, 0, sizeof(xmlC14NVisibleNsStack));
    307     xmlFree(cur);
    308 
    309 }
    310 
    311 static void
    312 xmlC14NVisibleNsStackAdd(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns, xmlNodePtr node) {
    313     if((cur == NULL) ||
    314        ((cur->nsTab == NULL) && (cur->nodeTab != NULL)) ||
    315        ((cur->nsTab != NULL) && (cur->nodeTab == NULL))) {
    316         xmlC14NErrParam("adding namespace to stack");
    317 	return;
    318     }
    319 
    320     if ((cur->nsTab == NULL) && (cur->nodeTab == NULL)) {
    321         cur->nsTab = (xmlNsPtr*) xmlMalloc(XML_NAMESPACES_DEFAULT * sizeof(xmlNsPtr));
    322         cur->nodeTab = (xmlNodePtr*) xmlMalloc(XML_NAMESPACES_DEFAULT * sizeof(xmlNodePtr));
    323 	if ((cur->nsTab == NULL) || (cur->nodeTab == NULL)) {
    324 	    xmlC14NErrMemory("adding node to stack");
    325 	    return;
    326 	}
    327 	memset(cur->nsTab, 0 , XML_NAMESPACES_DEFAULT * sizeof(xmlNsPtr));
    328 	memset(cur->nodeTab, 0 , XML_NAMESPACES_DEFAULT * sizeof(xmlNodePtr));
    329         cur->nsMax = XML_NAMESPACES_DEFAULT;
    330     } else if(cur->nsMax == cur->nsCurEnd) {
    331 	void *tmp;
    332 	int tmpSize;
    333 
    334 	tmpSize = 2 * cur->nsMax;
    335 	tmp = xmlRealloc(cur->nsTab, tmpSize * sizeof(xmlNsPtr));
    336 	if (tmp == NULL) {
    337 	    xmlC14NErrMemory("adding node to stack");
    338 	    return;
    339 	}
    340 	cur->nsTab = (xmlNsPtr*)tmp;
    341 
    342 	tmp = xmlRealloc(cur->nodeTab, tmpSize * sizeof(xmlNodePtr));
    343 	if (tmp == NULL) {
    344 	    xmlC14NErrMemory("adding node to stack");
    345 	    return;
    346 	}
    347 	cur->nodeTab = (xmlNodePtr*)tmp;
    348 
    349 	cur->nsMax = tmpSize;
    350     }
    351     cur->nsTab[cur->nsCurEnd] = ns;
    352     cur->nodeTab[cur->nsCurEnd] = node;
    353 
    354     ++cur->nsCurEnd;
    355 }
    356 
    357 static void
    358 xmlC14NVisibleNsStackSave(xmlC14NVisibleNsStackPtr cur, xmlC14NVisibleNsStackPtr state) {
    359     if((cur == NULL) || (state == NULL)) {
    360         xmlC14NErrParam("saving namespaces stack");
    361 	return;
    362     }
    363 
    364     state->nsCurEnd = cur->nsCurEnd;
    365     state->nsPrevStart = cur->nsPrevStart;
    366     state->nsPrevEnd = cur->nsPrevEnd;
    367 }
    368 
    369 static void
    370 xmlC14NVisibleNsStackRestore(xmlC14NVisibleNsStackPtr cur, xmlC14NVisibleNsStackPtr state) {
    371     if((cur == NULL) || (state == NULL)) {
    372         xmlC14NErrParam("restoring namespaces stack");
    373 	return;
    374     }
    375     cur->nsCurEnd = state->nsCurEnd;
    376     cur->nsPrevStart = state->nsPrevStart;
    377     cur->nsPrevEnd = state->nsPrevEnd;
    378 }
    379 
    380 static void
    381 xmlC14NVisibleNsStackShift(xmlC14NVisibleNsStackPtr cur) {
    382     if(cur == NULL) {
    383         xmlC14NErrParam("shifting namespaces stack");
    384 	return;
    385     }
    386     cur->nsPrevStart = cur->nsPrevEnd;
    387     cur->nsPrevEnd = cur->nsCurEnd;
    388 }
    389 
    390 static int
    391 xmlC14NStrEqual(const xmlChar *str1, const xmlChar *str2) {
    392     if (str1 == str2) return(1);
    393     if (str1 == NULL) return((*str2) == '\0');
    394     if (str2 == NULL) return((*str1) == '\0');
    395     do {
    396 	if (*str1++ != *str2) return(0);
    397     } while (*str2++);
    398     return(1);
    399 }
    400 
    401 /**
    402  * xmlC14NVisibleNsStackFind:
    403  * @ctx:		the C14N context
    404  * @ns:			the namespace to check
    405  *
    406  * Checks whether the given namespace was already rendered or not
    407  *
    408  * Returns 1 if we already wrote this namespace or 0 otherwise
    409  */
    410 static int
    411 xmlC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns)
    412 {
    413     int i;
    414     const xmlChar *prefix;
    415     const xmlChar *href;
    416     int has_empty_ns;
    417 
    418     if(cur == NULL) {
    419         xmlC14NErrParam("searching namespaces stack (c14n)");
    420         return (0);
    421     }
    422 
    423     /*
    424      * if the default namespace xmlns="" is not defined yet then
    425      * we do not want to print it out
    426      */
    427     prefix = ((ns == NULL) || (ns->prefix == NULL)) ? BAD_CAST "" : ns->prefix;
    428     href = ((ns == NULL) || (ns->href == NULL)) ? BAD_CAST "" : ns->href;
    429     has_empty_ns = (xmlC14NStrEqual(prefix, NULL) && xmlC14NStrEqual(href, NULL));
    430 
    431     if (cur->nsTab != NULL) {
    432 	int start = (has_empty_ns) ? 0 : cur->nsPrevStart;
    433         for (i = cur->nsCurEnd - 1; i >= start; --i) {
    434             xmlNsPtr ns1 = cur->nsTab[i];
    435 
    436 	    if(xmlC14NStrEqual(prefix, (ns1 != NULL) ? ns1->prefix : NULL)) {
    437 		return(xmlC14NStrEqual(href, (ns1 != NULL) ? ns1->href : NULL));
    438 	    }
    439         }
    440     }
    441     return(has_empty_ns);
    442 }
    443 
    444 static int
    445 xmlExcC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns, xmlC14NCtxPtr ctx) {
    446     int i;
    447     const xmlChar *prefix;
    448     const xmlChar *href;
    449     int has_empty_ns;
    450 
    451     if(cur == NULL) {
    452         xmlC14NErrParam("searching namespaces stack (exc c14n)");
    453         return (0);
    454     }
    455 
    456     /*
    457      * if the default namespace xmlns="" is not defined yet then
    458      * we do not want to print it out
    459      */
    460     prefix = ((ns == NULL) || (ns->prefix == NULL)) ? BAD_CAST "" : ns->prefix;
    461     href = ((ns == NULL) || (ns->href == NULL)) ? BAD_CAST "" : ns->href;
    462     has_empty_ns = (xmlC14NStrEqual(prefix, NULL) && xmlC14NStrEqual(href, NULL));
    463 
    464     if (cur->nsTab != NULL) {
    465 	int start = 0;
    466         for (i = cur->nsCurEnd - 1; i >= start; --i) {
    467             xmlNsPtr ns1 = cur->nsTab[i];
    468 
    469 	    if(xmlC14NStrEqual(prefix, (ns1 != NULL) ? ns1->prefix : NULL)) {
    470 		if(xmlC14NStrEqual(href, (ns1 != NULL) ? ns1->href : NULL)) {
    471 	    	    return(xmlC14NIsVisible(ctx, ns1, cur->nodeTab[i]));
    472 		} else {
    473 		    return(0);
    474 		}
    475 	    }
    476         }
    477     }
    478     return(has_empty_ns);
    479 }
    480 
    481 
    482 
    483 
    484 /**
    485  * xmlC14NIsXmlNs:
    486  * @ns: 		the namespace to check
    487  *
    488  * Checks whether the given namespace is a default "xml:" namespace
    489  * with href="http://www.w3.org/XML/1998/namespace"
    490  *
    491  * Returns 1 if the node is default or 0 otherwise
    492  */
    493 
    494 /* todo: make it a define? */
    495 static int
    496 xmlC14NIsXmlNs(xmlNsPtr ns)
    497 {
    498     return ((ns != NULL) &&
    499             (xmlStrEqual(ns->prefix, BAD_CAST "xml")) &&
    500             (xmlStrEqual(ns->href, XML_XML_NAMESPACE)));
    501 }
    502 
    503 
    504 /**
    505  * xmlC14NNsCompare:
    506  * @ns1:		the pointer to first namespace
    507  * @ns2: 		the pointer to second namespace
    508  *
    509  * Compares the namespaces by names (prefixes).
    510  *
    511  * Returns -1 if ns1 < ns2, 0 if ns1 == ns2 or 1 if ns1 > ns2.
    512  */
    513 static int
    514 xmlC14NNsCompare(xmlNsPtr ns1, xmlNsPtr ns2)
    515 {
    516     if (ns1 == ns2)
    517         return (0);
    518     if (ns1 == NULL)
    519         return (-1);
    520     if (ns2 == NULL)
    521         return (1);
    522 
    523     return (xmlStrcmp(ns1->prefix, ns2->prefix));
    524 }
    525 
    526 
    527 /**
    528  * xmlC14NPrintNamespaces:
    529  * @ns:			the pointer to namespace
    530  * @ctx: 		the C14N context
    531  *
    532  * Prints the given namespace to the output buffer from C14N context.
    533  *
    534  * Returns 1 on success or 0 on fail.
    535  */
    536 static int
    537 xmlC14NPrintNamespaces(const xmlNsPtr ns, xmlC14NCtxPtr ctx)
    538 {
    539 
    540     if ((ns == NULL) || (ctx == NULL)) {
    541         xmlC14NErrParam("writing namespaces");
    542         return 0;
    543     }
    544 
    545     if (ns->prefix != NULL) {
    546         xmlOutputBufferWriteString(ctx->buf, " xmlns:");
    547         xmlOutputBufferWriteString(ctx->buf, (const char *) ns->prefix);
    548         xmlOutputBufferWriteString(ctx->buf, "=\"");
    549     } else {
    550         xmlOutputBufferWriteString(ctx->buf, " xmlns=\"");
    551     }
    552     if(ns->href != NULL) {
    553 	xmlOutputBufferWriteString(ctx->buf, (const char *) ns->href);
    554     }
    555     xmlOutputBufferWriteString(ctx->buf, "\"");
    556     return (1);
    557 }
    558 
    559 /**
    560  * xmlC14NProcessNamespacesAxis:
    561  * @ctx: 		the C14N context
    562  * @node:		the current node
    563  *
    564  * Prints out canonical namespace axis of the current node to the
    565  * buffer from C14N context as follows
    566  *
    567  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
    568  *
    569  * Namespace Axis
    570  * Consider a list L containing only namespace nodes in the
    571  * axis and in the node-set in lexicographic order (ascending). To begin
    572  * processing L, if the first node is not the default namespace node (a node
    573  * with no namespace URI and no local name), then generate a space followed
    574  * by xmlns="" if and only if the following conditions are met:
    575  *    - the element E that owns the axis is in the node-set
    576  *    - The nearest ancestor element of E in the node-set has a default
    577  *	    namespace node in the node-set (default namespace nodes always
    578  *      have non-empty values in XPath)
    579  * The latter condition eliminates unnecessary occurrences of xmlns="" in
    580  * the canonical form since an element only receives an xmlns="" if its
    581  * default namespace is empty and if it has an immediate parent in the
    582  * canonical form that has a non-empty default namespace. To finish
    583  * processing  L, simply process every namespace node in L, except omit
    584  * namespace node with local name xml, which defines the xml prefix,
    585  * if its string value is http://www.w3.org/XML/1998/namespace.
    586  *
    587  * Exclusive XML Canonicalization v 1.0 (http://www.w3.org/TR/xml-exc-c14n)
    588  * Canonical XML applied to a document subset requires the search of the
    589  * ancestor nodes of each orphan element node for attributes in the xml
    590  * namespace, such as xml:lang and xml:space. These are copied into the
    591  * element node except if a declaration of the same attribute is already
    592  * in the attribute axis of the element (whether or not it is included in
    593  * the document subset). This search and copying are omitted from the
    594  * Exclusive XML Canonicalization method.
    595  *
    596  * Returns 0 on success or -1 on fail.
    597  */
    598 static int
    599 xmlC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
    600 {
    601     xmlNodePtr n;
    602     xmlNsPtr ns, tmp;
    603     xmlListPtr list;
    604     int already_rendered;
    605     int has_empty_ns = 0;
    606 
    607     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
    608         xmlC14NErrParam("processing namespaces axis (c14n)");
    609         return (-1);
    610     }
    611 
    612     /*
    613      * Create a sorted list to store element namespaces
    614      */
    615     list = xmlListCreate(NULL, (xmlListDataCompare) xmlC14NNsCompare);
    616     if (list == NULL) {
    617         xmlC14NErrInternal("creating namespaces list (c14n)");
    618         return (-1);
    619     }
    620 
    621     /* check all namespaces */
    622     for(n = cur; n != NULL; n = n->parent) {
    623 	for(ns = n->nsDef; ns != NULL; ns = ns->next) {
    624 	    tmp = xmlSearchNs(cur->doc, cur, ns->prefix);
    625 
    626 	    if((tmp == ns) && !xmlC14NIsXmlNs(ns) && xmlC14NIsVisible(ctx, ns, cur)) {
    627 		already_rendered = xmlC14NVisibleNsStackFind(ctx->ns_rendered, ns);
    628 		if(visible) {
    629         	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
    630 		}
    631 		if(!already_rendered) {
    632 		    xmlListInsert(list, ns);
    633 		}
    634     		if(xmlStrlen(ns->prefix) == 0) {
    635 		    has_empty_ns = 1;
    636 		}
    637 	    }
    638 	}
    639     }
    640 
    641     /**
    642      * if the first node is not the default namespace node (a node with no
    643      * namespace URI and no local name), then generate a space followed by
    644      * xmlns="" if and only if the following conditions are met:
    645      *  - the element E that owns the axis is in the node-set
    646      *  - the nearest ancestor element of E in the node-set has a default
    647      *     namespace node in the node-set (default namespace nodes always
    648      *     have non-empty values in XPath)
    649      */
    650     if(visible && !has_empty_ns) {
    651         static xmlNs ns_default;
    652 
    653         memset(&ns_default, 0, sizeof(ns_default));
    654         if(!xmlC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default)) {
    655     	    xmlC14NPrintNamespaces(&ns_default, ctx);
    656 	}
    657     }
    658 
    659 
    660     /*
    661      * print out all elements from list
    662      */
    663     xmlListWalk(list, (xmlListWalker) xmlC14NPrintNamespaces, (const void *) ctx);
    664 
    665     /*
    666      * Cleanup
    667      */
    668     xmlListDelete(list);
    669     return (0);
    670 }
    671 
    672 
    673 /**
    674  * xmlExcC14NProcessNamespacesAxis:
    675  * @ctx: 		the C14N context
    676  * @node:		the current node
    677  *
    678  * Prints out exclusive canonical namespace axis of the current node to the
    679  * buffer from C14N context as follows
    680  *
    681  * Exclusive XML Canonicalization
    682  * http://www.w3.org/TR/xml-exc-c14n
    683  *
    684  * If the element node is in the XPath subset then output the node in
    685  * accordance with Canonical XML except for namespace nodes which are
    686  * rendered as follows:
    687  *
    688  * 1. Render each namespace node iff:
    689  *    * it is visibly utilized by the immediate parent element or one of
    690  *      its attributes, or is present in InclusiveNamespaces PrefixList, and
    691  *    * its prefix and value do not appear in ns_rendered. ns_rendered is
    692  *      obtained by popping the state stack in order to obtain a list of
    693  *      prefixes and their values which have already been rendered by
    694  *      an output ancestor of the namespace node's parent element.
    695  * 2. Append the rendered namespace node to the list ns_rendered of namespace
    696  * nodes rendered by output ancestors. Push ns_rendered on state stack and
    697  * recurse.
    698  * 3. After the recursion returns, pop thestate stack.
    699  *
    700  *
    701  * Returns 0 on success or -1 on fail.
    702  */
    703 static int
    704 xmlExcC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
    705 {
    706     xmlNsPtr ns;
    707     xmlListPtr list;
    708     xmlAttrPtr attr;
    709     int already_rendered;
    710     int has_empty_ns = 0;
    711     int has_visibly_utilized_empty_ns = 0;
    712     int has_empty_ns_in_inclusive_list = 0;
    713 
    714     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
    715         xmlC14NErrParam("processing namespaces axis (exc c14n)");
    716         return (-1);
    717     }
    718 
    719     if(!xmlC14NIsExclusive(ctx)) {
    720         xmlC14NErrParam("processing namespaces axis (exc c14n)");
    721         return (-1);
    722 
    723     }
    724 
    725     /*
    726      * Create a sorted list to store element namespaces
    727      */
    728     list = xmlListCreate(NULL, (xmlListDataCompare) xmlC14NNsCompare);
    729     if (list == NULL) {
    730         xmlC14NErrInternal("creating namespaces list (exc c14n)");
    731         return (-1);
    732     }
    733 
    734     /*
    735      * process inclusive namespaces:
    736      * All namespace nodes appearing on inclusive ns list are
    737      * handled as provided in Canonical XML
    738      */
    739     if(ctx->inclusive_ns_prefixes != NULL) {
    740 	xmlChar *prefix;
    741 	int i;
    742 
    743 	for (i = 0; ctx->inclusive_ns_prefixes[i] != NULL; ++i) {
    744 	    prefix = ctx->inclusive_ns_prefixes[i];
    745 	    /*
    746 	     * Special values for namespace with empty prefix
    747 	     */
    748             if (xmlStrEqual(prefix, BAD_CAST "#default")
    749                 || xmlStrEqual(prefix, BAD_CAST "")) {
    750                 prefix = NULL;
    751 		has_empty_ns_in_inclusive_list = 1;
    752             }
    753 
    754 	    ns = xmlSearchNs(cur->doc, cur, prefix);
    755 	    if((ns != NULL) && !xmlC14NIsXmlNs(ns) && xmlC14NIsVisible(ctx, ns, cur)) {
    756 		already_rendered = xmlC14NVisibleNsStackFind(ctx->ns_rendered, ns);
    757 		if(visible) {
    758     	    	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
    759 		}
    760 		if(!already_rendered) {
    761 	    	    xmlListInsert(list, ns);
    762 		}
    763     		if(xmlStrlen(ns->prefix) == 0) {
    764 		    has_empty_ns = 1;
    765 		}
    766 	    }
    767 	}
    768     }
    769 
    770     /* add node namespace */
    771     if(cur->ns != NULL) {
    772 	ns = cur->ns;
    773     } else {
    774         ns = xmlSearchNs(cur->doc, cur, NULL);
    775 	has_visibly_utilized_empty_ns = 1;
    776     }
    777     if((ns != NULL) && !xmlC14NIsXmlNs(ns)) {
    778 	if(visible && xmlC14NIsVisible(ctx, ns, cur)) {
    779 	    if(!xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, ns, ctx)) {
    780 		xmlListInsert(list, ns);
    781 	    }
    782 	}
    783 	if(visible) {
    784     	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
    785 	}
    786 	if(xmlStrlen(ns->prefix) == 0) {
    787 	    has_empty_ns = 1;
    788 	}
    789     }
    790 
    791 
    792     /* add attributes */
    793     for(attr = cur->properties; attr != NULL; attr = attr->next) {
    794         /*
    795          * we need to check that attribute is visible and has non
    796          * default namespace (XML Namespaces: "default namespaces
    797     	 * do not apply directly to attributes")
    798          */
    799 	if((attr->ns != NULL) && !xmlC14NIsXmlNs(attr->ns) && xmlC14NIsVisible(ctx, attr, cur)) {
    800 	    already_rendered = xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, attr->ns, ctx);
    801 	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, attr->ns, cur);
    802 	    if(!already_rendered && visible) {
    803 		xmlListInsert(list, attr->ns);
    804 	    }
    805 	    if(xmlStrlen(attr->ns->prefix) == 0) {
    806 		has_empty_ns = 1;
    807 	    }
    808 	} else if((attr->ns != NULL) && (xmlStrlen(attr->ns->prefix) == 0) && (xmlStrlen(attr->ns->href) == 0)) {
    809 	    has_visibly_utilized_empty_ns = 1;
    810 	}
    811     }
    812 
    813     /*
    814      * Process xmlns=""
    815      */
    816     if(visible && has_visibly_utilized_empty_ns &&
    817 	    !has_empty_ns && !has_empty_ns_in_inclusive_list) {
    818         static xmlNs ns_default;
    819 
    820         memset(&ns_default, 0, sizeof(ns_default));
    821 
    822         already_rendered = xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default, ctx);
    823 	if(!already_rendered) {
    824     	    xmlC14NPrintNamespaces(&ns_default, ctx);
    825 	}
    826     } else if(visible && !has_empty_ns && has_empty_ns_in_inclusive_list) {
    827         static xmlNs ns_default;
    828 
    829         memset(&ns_default, 0, sizeof(ns_default));
    830         if(!xmlC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default)) {
    831     	    xmlC14NPrintNamespaces(&ns_default, ctx);
    832 	}
    833     }
    834 
    835 
    836 
    837     /*
    838      * print out all elements from list
    839      */
    840     xmlListWalk(list, (xmlListWalker) xmlC14NPrintNamespaces, (const void *) ctx);
    841 
    842     /*
    843      * Cleanup
    844      */
    845     xmlListDelete(list);
    846     return (0);
    847 }
    848 
    849 
    850 /**
    851  * xmlC14NIsXmlAttr:
    852  * @attr: 		the attr to check
    853  *
    854  * Checks whether the given attribute is a default "xml:" namespace
    855  * with href="http://www.w3.org/XML/1998/namespace"
    856  *
    857  * Returns 1 if the node is default or 0 otherwise
    858  */
    859 
    860 /* todo: make it a define? */
    861 static int
    862 xmlC14NIsXmlAttr(xmlAttrPtr attr)
    863 {
    864     return ((attr->ns != NULL) &&
    865            (xmlC14NIsXmlNs(attr->ns) != 0));
    866 }
    867 
    868 
    869 /**
    870  * xmlC14NAttrsCompare:
    871  * @attr1:		the pointer tls o first attr
    872  * @attr2: 		the pointer to second attr
    873  *
    874  * Prints the given attribute to the output buffer from C14N context.
    875  *
    876  * Returns -1 if attr1 < attr2, 0 if attr1 == attr2 or 1 if attr1 > attr2.
    877  */
    878 static int
    879 xmlC14NAttrsCompare(xmlAttrPtr attr1, xmlAttrPtr attr2)
    880 {
    881     int ret = 0;
    882 
    883     /*
    884      * Simple cases
    885      */
    886     if (attr1 == attr2)
    887         return (0);
    888     if (attr1 == NULL)
    889         return (-1);
    890     if (attr2 == NULL)
    891         return (1);
    892     if (attr1->ns == attr2->ns) {
    893         return (xmlStrcmp(attr1->name, attr2->name));
    894     }
    895 
    896     /*
    897      * Attributes in the default namespace are first
    898      * because the default namespace is not applied to
    899      * unqualified attributes
    900      */
    901     if (attr1->ns == NULL)
    902         return (-1);
    903     if (attr2->ns == NULL)
    904         return (1);
    905     if (attr1->ns->prefix == NULL)
    906         return (-1);
    907     if (attr2->ns->prefix == NULL)
    908         return (1);
    909 
    910     ret = xmlStrcmp(attr1->ns->href, attr2->ns->href);
    911     if (ret == 0) {
    912         ret = xmlStrcmp(attr1->name, attr2->name);
    913     }
    914     return (ret);
    915 }
    916 
    917 
    918 /**
    919  * xmlC14NPrintAttrs:
    920  * @attr:		the pointer to attr
    921  * @ctx: 		the C14N context
    922  *
    923  * Prints out canonical attribute urrent node to the
    924  * buffer from C14N context as follows
    925  *
    926  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
    927  *
    928  * Returns 1 on success or 0 on fail.
    929  */
    930 static int
    931 xmlC14NPrintAttrs(const xmlAttrPtr attr, xmlC14NCtxPtr ctx)
    932 {
    933     xmlChar *value;
    934     xmlChar *buffer;
    935 
    936     if ((attr == NULL) || (ctx == NULL)) {
    937         xmlC14NErrParam("writing attributes");
    938         return (0);
    939     }
    940 
    941     xmlOutputBufferWriteString(ctx->buf, " ");
    942     if (attr->ns != NULL && xmlStrlen(attr->ns->prefix) > 0) {
    943         xmlOutputBufferWriteString(ctx->buf,
    944                                    (const char *) attr->ns->prefix);
    945         xmlOutputBufferWriteString(ctx->buf, ":");
    946     }
    947     xmlOutputBufferWriteString(ctx->buf, (const char *) attr->name);
    948     xmlOutputBufferWriteString(ctx->buf, "=\"");
    949 
    950     value = xmlNodeListGetString(ctx->doc, attr->children, 1);
    951     /* todo: should we log an error if value==NULL ? */
    952     if (value != NULL) {
    953         buffer = xmlC11NNormalizeAttr(value);
    954         xmlFree(value);
    955         if (buffer != NULL) {
    956             xmlOutputBufferWriteString(ctx->buf, (const char *) buffer);
    957             xmlFree(buffer);
    958         } else {
    959             xmlC14NErrInternal("normalizing attributes axis");
    960             return (0);
    961         }
    962     }
    963     xmlOutputBufferWriteString(ctx->buf, "\"");
    964     return (1);
    965 }
    966 
    967 /**
    968  * xmlC14NFindHiddenParentAttr:
    969  *
    970  * Finds an attribute in a hidden parent node.
    971  *
    972  * Returns a pointer to the attribute node (if found) or NULL otherwise.
    973  */
    974 static xmlAttrPtr
    975 xmlC14NFindHiddenParentAttr(xmlC14NCtxPtr ctx, xmlNodePtr cur, const xmlChar * name, const xmlChar * ns)
    976 {
    977     xmlAttrPtr res;
    978     while((cur != NULL) && (!xmlC14NIsVisible(ctx, cur, cur->parent))) {
    979         res = xmlHasNsProp(cur, name, ns);
    980         if(res != NULL) {
    981             return res;
    982         }
    983 
    984         cur = cur->parent;
    985     }
    986 
    987     return NULL;
    988 }
    989 
    990 /**
    991  * xmlC14NFixupBaseAttr:
    992  *
    993  * Fixes up the xml:base attribute
    994  *
    995  * Returns the newly created attribute or NULL
    996  */
    997 static xmlAttrPtr
    998 xmlC14NFixupBaseAttr(xmlC14NCtxPtr ctx, xmlAttrPtr xml_base_attr)
    999 {
   1000     xmlChar * res = NULL;
   1001     xmlNodePtr cur;
   1002     xmlAttrPtr attr;
   1003     xmlChar * tmp_str;
   1004     xmlChar * tmp_str2;
   1005     int tmp_str_len;
   1006 
   1007     if ((ctx == NULL) || (xml_base_attr == NULL) || (xml_base_attr->parent == NULL)) {
   1008         xmlC14NErrParam("processing xml:base attribute");
   1009         return (NULL);
   1010     }
   1011 
   1012     /* start from current value */
   1013     res = xmlNodeListGetString(ctx->doc, xml_base_attr->children, 1);
   1014     if(res == NULL) {
   1015         xmlC14NErrInternal("processing xml:base attribute - can't get attr value");
   1016         return (NULL);
   1017     }
   1018 
   1019     /* go up the stack until we find a node that we rendered already */
   1020     cur = xml_base_attr->parent->parent;
   1021     while((cur != NULL) && (!xmlC14NIsVisible(ctx, cur, cur->parent))) {
   1022         attr = xmlHasNsProp(cur, BAD_CAST "base", XML_XML_NAMESPACE);
   1023         if(attr != NULL) {
   1024             /* get attr value */
   1025             tmp_str = xmlNodeListGetString(ctx->doc, attr->children, 1);
   1026             if(tmp_str == NULL) {
   1027                 xmlFree(res);
   1028 
   1029                 xmlC14NErrInternal("processing xml:base attribute - can't get attr value");
   1030                 return (NULL);
   1031             }
   1032 
   1033             /* we need to add '/' if our current base uri ends with '..' or '.'
   1034             to ensure that we are forced to go "up" all the time */
   1035             tmp_str_len = xmlStrlen(tmp_str);
   1036             if(tmp_str_len > 1 && tmp_str[tmp_str_len - 2] == '.') {
   1037                 tmp_str2 = xmlStrcat(tmp_str, BAD_CAST "/");
   1038                 if(tmp_str2 == NULL) {
   1039                     xmlFree(tmp_str);
   1040                     xmlFree(res);
   1041 
   1042                     xmlC14NErrInternal("processing xml:base attribute - can't modify uri");
   1043                     return (NULL);
   1044                 }
   1045 
   1046                 tmp_str = tmp_str2;
   1047             }
   1048 
   1049             /* build uri */
   1050             tmp_str2 = xmlBuildURI(res, tmp_str);
   1051             if(tmp_str2 == NULL) {
   1052                 xmlFree(tmp_str);
   1053                 xmlFree(res);
   1054 
   1055                 xmlC14NErrInternal("processing xml:base attribute - can't construct uri");
   1056                 return (NULL);
   1057             }
   1058 
   1059             /* cleanup and set the new res */
   1060             xmlFree(tmp_str);
   1061             xmlFree(res);
   1062             res = tmp_str2;
   1063         }
   1064 
   1065         /* next */
   1066         cur = cur->parent;
   1067     }
   1068 
   1069     /* check if result uri is empty or not */
   1070     if((res == NULL) || xmlStrEqual(res, BAD_CAST "")) {
   1071         xmlFree(res);
   1072         return (NULL);
   1073     }
   1074 
   1075     /* create and return the new attribute node */
   1076     attr = xmlNewNsProp(NULL, xml_base_attr->ns, BAD_CAST "base", res);
   1077     if(attr == NULL) {
   1078         xmlFree(res);
   1079 
   1080         xmlC14NErrInternal("processing xml:base attribute - can't construct attribute");
   1081         return (NULL);
   1082     }
   1083 
   1084     /* done */
   1085     xmlFree(res);
   1086     return (attr);
   1087 }
   1088 
   1089 /**
   1090  * xmlC14NProcessAttrsAxis:
   1091  * @ctx: 		the C14N context
   1092  * @cur:		the current node
   1093  * @parent_visible:	the visibility of parent node
   1094  * @all_parents_visible: the visibility of all parent nodes
   1095  *
   1096  * Prints out canonical attribute axis of the current node to the
   1097  * buffer from C14N context as follows
   1098  *
   1099  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
   1100  *
   1101  * Attribute Axis
   1102  * In lexicographic order (ascending), process each node that
   1103  * is in the element's attribute axis and in the node-set.
   1104  *
   1105  * The processing of an element node E MUST be modified slightly
   1106  * when an XPath node-set is given as input and the element's
   1107  * parent is omitted from the node-set.
   1108  *
   1109  *
   1110  * Exclusive XML Canonicalization v 1.0 (http://www.w3.org/TR/xml-exc-c14n)
   1111  *
   1112  * Canonical XML applied to a document subset requires the search of the
   1113  * ancestor nodes of each orphan element node for attributes in the xml
   1114  * namespace, such as xml:lang and xml:space. These are copied into the
   1115  * element node except if a declaration of the same attribute is already
   1116  * in the attribute axis of the element (whether or not it is included in
   1117  * the document subset). This search and copying are omitted from the
   1118  * Exclusive XML Canonicalization method.
   1119  *
   1120  * Returns 0 on success or -1 on fail.
   1121  */
   1122 static int
   1123 xmlC14NProcessAttrsAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int parent_visible)
   1124 {
   1125     xmlAttrPtr attr;
   1126     xmlListPtr list;
   1127     xmlAttrPtr attrs_to_delete = NULL;
   1128 
   1129     /* special processing for 1.1 spec */
   1130     xmlAttrPtr xml_base_attr = NULL;
   1131     xmlAttrPtr xml_lang_attr = NULL;
   1132     xmlAttrPtr xml_space_attr = NULL;
   1133 
   1134     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
   1135         xmlC14NErrParam("processing attributes axis");
   1136         return (-1);
   1137     }
   1138 
   1139     /*
   1140      * Create a sorted list to store element attributes
   1141      */
   1142     list = xmlListCreate(NULL, (xmlListDataCompare) xmlC14NAttrsCompare);
   1143     if (list == NULL) {
   1144         xmlC14NErrInternal("creating attributes list");
   1145         return (-1);
   1146     }
   1147 
   1148     switch(ctx->mode) {
   1149     case XML_C14N_1_0:
   1150         /* The processing of an element node E MUST be modified slightly when an XPath node-set is
   1151          * given as input and the element's parent is omitted from the node-set. The method for processing
   1152          * the attribute axis of an element E in the node-set is enhanced. All element nodes along E's
   1153          * ancestor axis are examined for nearest occurrences of attributes in the xml namespace, such
   1154          * as xml:lang and xml:space (whether or not they are in the node-set). From this list of attributes,
   1155          * remove any that are in E's attribute axis (whether or not they are in the node-set). Then,
   1156          * lexicographically merge this attribute list with the nodes of E's attribute axis that are in
   1157          * the node-set. The result of visiting the attribute axis is computed by processing the attribute
   1158          * nodes in this merged attribute list.
   1159          */
   1160 
   1161         /*
   1162          * Add all visible attributes from current node.
   1163          */
   1164         attr = cur->properties;
   1165         while (attr != NULL) {
   1166             /* check that attribute is visible */
   1167             if (xmlC14NIsVisible(ctx, attr, cur)) {
   1168                 xmlListInsert(list, attr);
   1169             }
   1170             attr = attr->next;
   1171         }
   1172 
   1173         /*
   1174          * Handle xml attributes
   1175          */
   1176         if (parent_visible && (cur->parent != NULL) &&
   1177             (!xmlC14NIsVisible(ctx, cur->parent, cur->parent->parent)))
   1178         {
   1179             xmlNodePtr tmp;
   1180 
   1181             /*
   1182              * If XPath node-set is not specified then the parent is always
   1183              * visible!
   1184              */
   1185             tmp = cur->parent;
   1186             while (tmp != NULL) {
   1187                 attr = tmp->properties;
   1188                 while (attr != NULL) {
   1189                     if (xmlC14NIsXmlAttr(attr) != 0) {
   1190                         if (xmlListSearch(list, attr) == NULL) {
   1191                             xmlListInsert(list, attr);
   1192                         }
   1193                     }
   1194                     attr = attr->next;
   1195                 }
   1196                 tmp = tmp->parent;
   1197             }
   1198         }
   1199 
   1200         /* done */
   1201         break;
   1202     case XML_C14N_EXCLUSIVE_1_0:
   1203         /* attributes in the XML namespace, such as xml:lang and xml:space
   1204          * are not imported into orphan nodes of the document subset
   1205          */
   1206 
   1207         /*
   1208          * Add all visible attributes from current node.
   1209          */
   1210         attr = cur->properties;
   1211         while (attr != NULL) {
   1212             /* check that attribute is visible */
   1213             if (xmlC14NIsVisible(ctx, attr, cur)) {
   1214                 xmlListInsert(list, attr);
   1215             }
   1216             attr = attr->next;
   1217         }
   1218 
   1219         /* do nothing special for xml attributes */
   1220         break;
   1221     case XML_C14N_1_1:
   1222         /* The processing of an element node E MUST be modified slightly when an XPath node-set is
   1223          * given as input and some of the element's ancestors are omitted from the node-set.
   1224          *
   1225          * Simple inheritable attributes are attributes that have a value that requires at most a simple
   1226          * redeclaration. This redeclaration is done by supplying a new value in the child axis. The
   1227          * redeclaration of a simple inheritable attribute A contained in one of E's ancestors is done
   1228          * by supplying a value to an attribute Ae inside E with the same name. Simple inheritable attributes
   1229          * are xml:lang and xml:space.
   1230          *
   1231          * The method for processing the attribute axis of an element E in the node-set is hence enhanced.
   1232          * All element nodes along E's ancestor axis are examined for the nearest occurrences of simple
   1233          * inheritable attributes in the xml namespace, such as xml:lang and xml:space (whether or not they
   1234          * are in the node-set). From this list of attributes, any simple inheritable attributes that are
   1235          * already in E's attribute axis (whether or not they are in the node-set) are removed. Then,
   1236          * lexicographically merge this attribute list with the nodes of E's attribute axis that are in
   1237          * the node-set. The result of visiting the attribute axis is computed by processing the attribute
   1238          * nodes in this merged attribute list.
   1239          *
   1240          * The xml:id attribute is not a simple inheritable attribute and no processing of these attributes is
   1241          * performed.
   1242          *
   1243          * The xml:base attribute is not a simple inheritable attribute and requires special processing beyond
   1244          * a simple redeclaration.
   1245          *
   1246          * Attributes in the XML namespace other than xml:base, xml:id, xml:lang, and xml:space MUST be processed
   1247          * as ordinary attributes.
   1248          */
   1249 
   1250         /*
   1251          * Add all visible attributes from current node.
   1252          */
   1253         attr = cur->properties;
   1254         while (attr != NULL) {
   1255             /* special processing for XML attribute kiks in only when we have invisible parents */
   1256             if ((!parent_visible) || (xmlC14NIsXmlAttr(attr) == 0)) {
   1257                 /* check that attribute is visible */
   1258                 if (xmlC14NIsVisible(ctx, attr, cur)) {
   1259                     xmlListInsert(list, attr);
   1260                 }
   1261             } else {
   1262                 int matched = 0;
   1263 
   1264                 /* check for simple inheritance attributes */
   1265                 if((!matched) && (xml_lang_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "lang")) {
   1266                     xml_lang_attr = attr;
   1267                     matched = 1;
   1268                 }
   1269                 if((!matched) && (xml_space_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "space")) {
   1270                     xml_space_attr = attr;
   1271                     matched = 1;
   1272                 }
   1273 
   1274                 /* check for base attr */
   1275                 if((!matched) && (xml_base_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "base")) {
   1276                     xml_base_attr = attr;
   1277                     matched = 1;
   1278                 }
   1279 
   1280                 /* otherwise, it is a normal attribute, so just check if it is visible */
   1281                 if((!matched) && xmlC14NIsVisible(ctx, attr, cur)) {
   1282                     xmlListInsert(list, attr);
   1283                 }
   1284             }
   1285 
   1286             /* move to the next one */
   1287             attr = attr->next;
   1288         }
   1289 
   1290         /* special processing for XML attribute kiks in only when we have invisible parents */
   1291         if ((parent_visible)) {
   1292 
   1293             /* simple inheritance attributes - copy */
   1294             if(xml_lang_attr == NULL) {
   1295                 xml_lang_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "lang", XML_XML_NAMESPACE);
   1296             }
   1297             if(xml_lang_attr != NULL) {
   1298                 xmlListInsert(list, xml_lang_attr);
   1299             }
   1300             if(xml_space_attr == NULL) {
   1301                 xml_space_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "space", XML_XML_NAMESPACE);
   1302             }
   1303             if(xml_space_attr != NULL) {
   1304                 xmlListInsert(list, xml_space_attr);
   1305             }
   1306 
   1307             /* base uri attribute - fix up */
   1308             if(xml_base_attr == NULL) {
   1309                 /* if we don't have base uri attribute, check if we have a "hidden" one above */
   1310                 xml_base_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "base", XML_XML_NAMESPACE);
   1311             }
   1312             if(xml_base_attr != NULL) {
   1313                 xml_base_attr = xmlC14NFixupBaseAttr(ctx, xml_base_attr);
   1314                 if(xml_base_attr != NULL) {
   1315                     xmlListInsert(list, xml_base_attr);
   1316 
   1317                     /* note that we MUST delete returned attr node ourselves! */
   1318                     xml_base_attr->next = attrs_to_delete;
   1319                     attrs_to_delete = xml_base_attr;
   1320                 }
   1321             }
   1322         }
   1323 
   1324         /* done */
   1325         break;
   1326     }
   1327 
   1328     /*
   1329      * print out all elements from list
   1330      */
   1331     xmlListWalk(list, (xmlListWalker) xmlC14NPrintAttrs, (const void *) ctx);
   1332 
   1333     /*
   1334      * Cleanup
   1335      */
   1336     xmlFreePropList(attrs_to_delete);
   1337     xmlListDelete(list);
   1338     return (0);
   1339 }
   1340 
   1341 /**
   1342  * xmlC14NCheckForRelativeNamespaces:
   1343  * @ctx:		the C14N context
   1344  * @cur:		the current element node
   1345  *
   1346  * Checks that current element node has no relative namespaces defined
   1347  *
   1348  * Returns 0 if the node has no relative namespaces or -1 otherwise.
   1349  */
   1350 static int
   1351 xmlC14NCheckForRelativeNamespaces(xmlC14NCtxPtr ctx, xmlNodePtr cur)
   1352 {
   1353     xmlNsPtr ns;
   1354 
   1355     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
   1356         xmlC14NErrParam("checking for relative namespaces");
   1357         return (-1);
   1358     }
   1359 
   1360     ns = cur->nsDef;
   1361     while (ns != NULL) {
   1362         if (xmlStrlen(ns->href) > 0) {
   1363             xmlURIPtr uri;
   1364 
   1365             uri = xmlParseURI((const char *) ns->href);
   1366             if (uri == NULL) {
   1367                 xmlC14NErrInternal("parsing namespace uri");
   1368                 return (-1);
   1369             }
   1370             if (xmlStrlen((const xmlChar *) uri->scheme) == 0) {
   1371                 xmlC14NErrRelativeNamespace(uri->scheme);
   1372                 xmlFreeURI(uri);
   1373                 return (-1);
   1374             }
   1375             if ((xmlStrcasecmp((const xmlChar *) uri->scheme, BAD_CAST "urn") != 0)
   1376                 && (xmlStrcasecmp((const xmlChar *) uri->scheme, BAD_CAST "dav") !=0)
   1377                 && (xmlStrlen((const xmlChar *) uri->server) == 0)) {
   1378                 xmlC14NErrRelativeNamespace(uri->scheme);
   1379                 xmlFreeURI(uri);
   1380                 return (-1);
   1381             }
   1382             xmlFreeURI(uri);
   1383         }
   1384         ns = ns->next;
   1385     }
   1386     return (0);
   1387 }
   1388 
   1389 /**
   1390  * xmlC14NProcessElementNode:
   1391  * @ctx: 		the pointer to C14N context object
   1392  * @cur:		the node to process
   1393  * @visible:    this node is visible
   1394  * @all_parents_visible: whether all the parents of this node are visible
   1395  *
   1396  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
   1397  *
   1398  * Element Nodes
   1399  * If the element is not in the node-set, then the result is obtained
   1400  * by processing the namespace axis, then the attribute axis, then
   1401  * processing the child nodes of the element that are in the node-set
   1402  * (in document order). If the element is in the node-set, then the result
   1403  * is an open angle bracket (<), the element QName, the result of
   1404  * processing the namespace axis, the result of processing the attribute
   1405  * axis, a close angle bracket (>), the result of processing the child
   1406  * nodes of the element that are in the node-set (in document order), an
   1407  * open angle bracket, a forward slash (/), the element QName, and a close
   1408  * angle bracket.
   1409  *
   1410  * Returns non-negative value on success or negative value on fail
   1411  */
   1412 static int
   1413 xmlC14NProcessElementNode(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
   1414 {
   1415     int ret;
   1416     xmlC14NVisibleNsStack state;
   1417     int parent_is_doc = 0;
   1418 
   1419     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
   1420         xmlC14NErrParam("processing element node");
   1421         return (-1);
   1422     }
   1423 
   1424     /*
   1425      * Check relative relative namespaces:
   1426      * implementations of XML canonicalization MUST report an operation
   1427      * failure on documents containing relative namespace URIs.
   1428      */
   1429     if (xmlC14NCheckForRelativeNamespaces(ctx, cur) < 0) {
   1430         xmlC14NErrInternal("checking for relative namespaces");
   1431         return (-1);
   1432     }
   1433 
   1434 
   1435     /*
   1436      * Save ns_rendered stack position
   1437      */
   1438     memset(&state, 0, sizeof(state));
   1439     xmlC14NVisibleNsStackSave(ctx->ns_rendered, &state);
   1440 
   1441     if (visible) {
   1442         if (ctx->parent_is_doc) {
   1443 	    /* save this flag into the stack */
   1444 	    parent_is_doc = ctx->parent_is_doc;
   1445 	    ctx->parent_is_doc = 0;
   1446             ctx->pos = XMLC14N_INSIDE_DOCUMENT_ELEMENT;
   1447         }
   1448         xmlOutputBufferWriteString(ctx->buf, "<");
   1449 
   1450         if ((cur->ns != NULL) && (xmlStrlen(cur->ns->prefix) > 0)) {
   1451             xmlOutputBufferWriteString(ctx->buf,
   1452                                        (const char *) cur->ns->prefix);
   1453             xmlOutputBufferWriteString(ctx->buf, ":");
   1454         }
   1455         xmlOutputBufferWriteString(ctx->buf, (const char *) cur->name);
   1456     }
   1457 
   1458     if (!xmlC14NIsExclusive(ctx)) {
   1459         ret = xmlC14NProcessNamespacesAxis(ctx, cur, visible);
   1460     } else {
   1461         ret = xmlExcC14NProcessNamespacesAxis(ctx, cur, visible);
   1462     }
   1463     if (ret < 0) {
   1464         xmlC14NErrInternal("processing namespaces axis");
   1465         return (-1);
   1466     }
   1467     /* todo: shouldn't this go to "visible only"? */
   1468     if(visible) {
   1469 	xmlC14NVisibleNsStackShift(ctx->ns_rendered);
   1470     }
   1471 
   1472     ret = xmlC14NProcessAttrsAxis(ctx, cur, visible);
   1473     if (ret < 0) {
   1474 	xmlC14NErrInternal("processing attributes axis");
   1475     	return (-1);
   1476     }
   1477 
   1478     if (visible) {
   1479         xmlOutputBufferWriteString(ctx->buf, ">");
   1480     }
   1481     if (cur->children != NULL) {
   1482         ret = xmlC14NProcessNodeList(ctx, cur->children);
   1483         if (ret < 0) {
   1484             xmlC14NErrInternal("processing childrens list");
   1485             return (-1);
   1486         }
   1487     }
   1488     if (visible) {
   1489         xmlOutputBufferWriteString(ctx->buf, "</");
   1490         if ((cur->ns != NULL) && (xmlStrlen(cur->ns->prefix) > 0)) {
   1491             xmlOutputBufferWriteString(ctx->buf,
   1492                                        (const char *) cur->ns->prefix);
   1493             xmlOutputBufferWriteString(ctx->buf, ":");
   1494         }
   1495         xmlOutputBufferWriteString(ctx->buf, (const char *) cur->name);
   1496         xmlOutputBufferWriteString(ctx->buf, ">");
   1497         if (parent_is_doc) {
   1498 	    /* restore this flag from the stack for next node */
   1499             ctx->parent_is_doc = parent_is_doc;
   1500 	    ctx->pos = XMLC14N_AFTER_DOCUMENT_ELEMENT;
   1501         }
   1502     }
   1503 
   1504     /*
   1505      * Restore ns_rendered stack position
   1506      */
   1507     xmlC14NVisibleNsStackRestore(ctx->ns_rendered, &state);
   1508     return (0);
   1509 }
   1510 
   1511 /**
   1512  * xmlC14NProcessNode:
   1513  * @ctx: 		the pointer to C14N context object
   1514  * @cur:		the node to process
   1515  *
   1516  * Processes the given node
   1517  *
   1518  * Returns non-negative value on success or negative value on fail
   1519  */
   1520 static int
   1521 xmlC14NProcessNode(xmlC14NCtxPtr ctx, xmlNodePtr cur)
   1522 {
   1523     int ret = 0;
   1524     int visible;
   1525 
   1526     if ((ctx == NULL) || (cur == NULL)) {
   1527         xmlC14NErrParam("processing node");
   1528         return (-1);
   1529     }
   1530 
   1531     visible = xmlC14NIsVisible(ctx, cur, cur->parent);
   1532     switch (cur->type) {
   1533         case XML_ELEMENT_NODE:
   1534             ret = xmlC14NProcessElementNode(ctx, cur, visible);
   1535             break;
   1536         case XML_CDATA_SECTION_NODE:
   1537         case XML_TEXT_NODE:
   1538             /*
   1539              * Text Nodes
   1540              * the string value, except all ampersands are replaced
   1541              * by &amp;, all open angle brackets (<) are replaced by &lt;, all closing
   1542              * angle brackets (>) are replaced by &gt;, and all #xD characters are
   1543              * replaced by &#xD;.
   1544              */
   1545             /* cdata sections are processed as text nodes */
   1546             /* todo: verify that cdata sections are included in XPath nodes set */
   1547             if ((visible) && (cur->content != NULL)) {
   1548                 xmlChar *buffer;
   1549 
   1550                 buffer = xmlC11NNormalizeText(cur->content);
   1551                 if (buffer != NULL) {
   1552                     xmlOutputBufferWriteString(ctx->buf,
   1553                                                (const char *) buffer);
   1554                     xmlFree(buffer);
   1555                 } else {
   1556                     xmlC14NErrInternal("normalizing text node");
   1557                     return (-1);
   1558                 }
   1559             }
   1560             break;
   1561         case XML_PI_NODE:
   1562             /*
   1563              * Processing Instruction (PI) Nodes-
   1564              * The opening PI symbol (<?), the PI target name of the node,
   1565              * a leading space and the string value if it is not empty, and
   1566              * the closing PI symbol (?>). If the string value is empty,
   1567              * then the leading space is not added. Also, a trailing #xA is
   1568              * rendered after the closing PI symbol for PI children of the
   1569              * root node with a lesser document order than the document
   1570              * element, and a leading #xA is rendered before the opening PI
   1571              * symbol of PI children of the root node with a greater document
   1572              * order than the document element.
   1573              */
   1574             if (visible) {
   1575                 if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
   1576                     xmlOutputBufferWriteString(ctx->buf, "\x0A<?");
   1577                 } else {
   1578                     xmlOutputBufferWriteString(ctx->buf, "<?");
   1579                 }
   1580 
   1581                 xmlOutputBufferWriteString(ctx->buf,
   1582                                            (const char *) cur->name);
   1583                 if ((cur->content != NULL) && (*(cur->content) != '\0')) {
   1584                     xmlChar *buffer;
   1585 
   1586                     xmlOutputBufferWriteString(ctx->buf, " ");
   1587 
   1588                     /* todo: do we need to normalize pi? */
   1589                     buffer = xmlC11NNormalizePI(cur->content);
   1590                     if (buffer != NULL) {
   1591                         xmlOutputBufferWriteString(ctx->buf,
   1592                                                    (const char *) buffer);
   1593                         xmlFree(buffer);
   1594                     } else {
   1595                         xmlC14NErrInternal("normalizing pi node");
   1596                         return (-1);
   1597                     }
   1598                 }
   1599 
   1600                 if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
   1601                     xmlOutputBufferWriteString(ctx->buf, "?>\x0A");
   1602                 } else {
   1603                     xmlOutputBufferWriteString(ctx->buf, "?>");
   1604                 }
   1605             }
   1606             break;
   1607         case XML_COMMENT_NODE:
   1608             /*
   1609              * Comment Nodes
   1610              * Nothing if generating canonical XML without  comments. For
   1611              * canonical XML with comments, generate the opening comment
   1612              * symbol (<!--), the string value of the node, and the
   1613              * closing comment symbol (-->). Also, a trailing #xA is rendered
   1614              * after the closing comment symbol for comment children of the
   1615              * root node with a lesser document order than the document
   1616              * element, and a leading #xA is rendered before the opening
   1617              * comment symbol of comment children of the root node with a
   1618              * greater document order than the document element. (Comment
   1619              * children of the root node represent comments outside of the
   1620              * top-level document element and outside of the document type
   1621              * declaration).
   1622              */
   1623             if (visible && ctx->with_comments) {
   1624                 if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
   1625                     xmlOutputBufferWriteString(ctx->buf, "\x0A<!--");
   1626                 } else {
   1627                     xmlOutputBufferWriteString(ctx->buf, "<!--");
   1628                 }
   1629 
   1630                 if (cur->content != NULL) {
   1631                     xmlChar *buffer;
   1632 
   1633                     /* todo: do we need to normalize comment? */
   1634                     buffer = xmlC11NNormalizeComment(cur->content);
   1635                     if (buffer != NULL) {
   1636                         xmlOutputBufferWriteString(ctx->buf,
   1637                                                    (const char *) buffer);
   1638                         xmlFree(buffer);
   1639                     } else {
   1640                         xmlC14NErrInternal("normalizing comment node");
   1641                         return (-1);
   1642                     }
   1643                 }
   1644 
   1645                 if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
   1646                     xmlOutputBufferWriteString(ctx->buf, "-->\x0A");
   1647                 } else {
   1648                     xmlOutputBufferWriteString(ctx->buf, "-->");
   1649                 }
   1650             }
   1651             break;
   1652         case XML_DOCUMENT_NODE:
   1653         case XML_DOCUMENT_FRAG_NODE:   /* should be processed as document? */
   1654 #ifdef LIBXML_DOCB_ENABLED
   1655         case XML_DOCB_DOCUMENT_NODE:   /* should be processed as document? */
   1656 #endif
   1657 #ifdef LIBXML_HTML_ENABLED
   1658         case XML_HTML_DOCUMENT_NODE:   /* should be processed as document? */
   1659 #endif
   1660             if (cur->children != NULL) {
   1661                 ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
   1662                 ctx->parent_is_doc = 1;
   1663                 ret = xmlC14NProcessNodeList(ctx, cur->children);
   1664             }
   1665             break;
   1666 
   1667         case XML_ATTRIBUTE_NODE:
   1668             xmlC14NErrInvalidNode("XML_ATTRIBUTE_NODE", "processing node");
   1669             return (-1);
   1670         case XML_NAMESPACE_DECL:
   1671             xmlC14NErrInvalidNode("XML_NAMESPACE_DECL", "processing node");
   1672             return (-1);
   1673         case XML_ENTITY_REF_NODE:
   1674             xmlC14NErrInvalidNode("XML_ENTITY_REF_NODE", "processing node");
   1675             return (-1);
   1676         case XML_ENTITY_NODE:
   1677             xmlC14NErrInvalidNode("XML_ENTITY_NODE", "processing node");
   1678             return (-1);
   1679 
   1680         case XML_DOCUMENT_TYPE_NODE:
   1681         case XML_NOTATION_NODE:
   1682         case XML_DTD_NODE:
   1683         case XML_ELEMENT_DECL:
   1684         case XML_ATTRIBUTE_DECL:
   1685         case XML_ENTITY_DECL:
   1686 #ifdef LIBXML_XINCLUDE_ENABLED
   1687         case XML_XINCLUDE_START:
   1688         case XML_XINCLUDE_END:
   1689 #endif
   1690             /*
   1691              * should be ignored according to "W3C Canonical XML"
   1692              */
   1693             break;
   1694         default:
   1695             xmlC14NErrUnknownNode(cur->type, "processing node");
   1696             return (-1);
   1697     }
   1698 
   1699     return (ret);
   1700 }
   1701 
   1702 /**
   1703  * xmlC14NProcessNodeList:
   1704  * @ctx: 		the pointer to C14N context object
   1705  * @cur:		the node to start from
   1706  *
   1707  * Processes all nodes in the row starting from cur.
   1708  *
   1709  * Returns non-negative value on success or negative value on fail
   1710  */
   1711 static int
   1712 xmlC14NProcessNodeList(xmlC14NCtxPtr ctx, xmlNodePtr cur)
   1713 {
   1714     int ret;
   1715 
   1716     if (ctx == NULL) {
   1717         xmlC14NErrParam("processing node list");
   1718         return (-1);
   1719     }
   1720 
   1721     for (ret = 0; cur != NULL && ret >= 0; cur = cur->next) {
   1722         ret = xmlC14NProcessNode(ctx, cur);
   1723     }
   1724     return (ret);
   1725 }
   1726 
   1727 
   1728 /**
   1729  * xmlC14NFreeCtx:
   1730  * @ctx: the pointer to C14N context object
   1731  *
   1732  * Cleanups the C14N context object.
   1733  */
   1734 
   1735 static void
   1736 xmlC14NFreeCtx(xmlC14NCtxPtr ctx)
   1737 {
   1738     if (ctx == NULL) {
   1739         xmlC14NErrParam("freeing context");
   1740         return;
   1741     }
   1742 
   1743     if (ctx->ns_rendered != NULL) {
   1744         xmlC14NVisibleNsStackDestroy(ctx->ns_rendered);
   1745     }
   1746     xmlFree(ctx);
   1747 }
   1748 
   1749 /**
   1750  * xmlC14NNewCtx:
   1751  * @doc: 		the XML document for canonization
   1752  * @is_visible_callback:the function to use to determine is node visible
   1753  *			or not
   1754  * @user_data: 		the first parameter for @is_visible_callback function
   1755  *			(in most cases, it is nodes set)
   1756  * @mode:   the c14n mode (see @xmlC14NMode)
   1757  * @inclusive_ns_prefixe the list of inclusive namespace prefixes
   1758  *			ended with a NULL or NULL if there is no
   1759  *			inclusive namespaces (only for `
   1760  *			canonicalization)
   1761  * @with_comments: 	include comments in the result (!=0) or not (==0)
   1762  * @buf: 		the output buffer to store canonical XML; this
   1763  *			buffer MUST have encoder==NULL because C14N requires
   1764  *			UTF-8 output
   1765  *
   1766  * Creates new C14N context object to store C14N parameters.
   1767  *
   1768  * Returns pointer to newly created object (success) or NULL (fail)
   1769  */
   1770 static xmlC14NCtxPtr
   1771 xmlC14NNewCtx(xmlDocPtr doc,
   1772 	      xmlC14NIsVisibleCallback is_visible_callback, void* user_data,
   1773               xmlC14NMode mode, xmlChar ** inclusive_ns_prefixes,
   1774               int with_comments, xmlOutputBufferPtr buf)
   1775 {
   1776     xmlC14NCtxPtr ctx = NULL;
   1777 
   1778     if ((doc == NULL) || (buf == NULL)) {
   1779         xmlC14NErrParam("creating new context");
   1780         return (NULL);
   1781     }
   1782 
   1783     /*
   1784      *  Validate the encoding output buffer encoding
   1785      */
   1786     if (buf->encoder != NULL) {
   1787         xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
   1788 "xmlC14NNewCtx: output buffer encoder != NULL but C14N requires UTF8 output\n");
   1789         return (NULL);
   1790     }
   1791 
   1792     /*
   1793      *  Validate the XML document encoding value, if provided.
   1794      */
   1795     if (doc->charset != XML_CHAR_ENCODING_UTF8) {
   1796         xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
   1797 		   "xmlC14NNewCtx: source document not in UTF8\n");
   1798         return (NULL);
   1799     }
   1800 
   1801     /*
   1802      * Allocate a new xmlC14NCtxPtr and fill the fields.
   1803      */
   1804     ctx = (xmlC14NCtxPtr) xmlMalloc(sizeof(xmlC14NCtx));
   1805     if (ctx == NULL) {
   1806 	xmlC14NErrMemory("creating context");
   1807         return (NULL);
   1808     }
   1809     memset(ctx, 0, sizeof(xmlC14NCtx));
   1810 
   1811     /*
   1812      * initialize C14N context
   1813      */
   1814     ctx->doc = doc;
   1815     ctx->with_comments = with_comments;
   1816     ctx->is_visible_callback = is_visible_callback;
   1817     ctx->user_data = user_data;
   1818     ctx->buf = buf;
   1819     ctx->parent_is_doc = 1;
   1820     ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
   1821     ctx->ns_rendered = xmlC14NVisibleNsStackCreate();
   1822 
   1823     if(ctx->ns_rendered == NULL) {
   1824         xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_CREATE_STACK,
   1825 		   "xmlC14NNewCtx: xmlC14NVisibleNsStackCreate failed\n");
   1826 	xmlC14NFreeCtx(ctx);
   1827         return (NULL);
   1828     }
   1829 
   1830     /*
   1831      * Set "mode" flag and remember list of incluseve prefixes
   1832      * for exclusive c14n
   1833      */
   1834     ctx->mode = mode;
   1835     if(xmlC14NIsExclusive(ctx)) {
   1836         ctx->inclusive_ns_prefixes = inclusive_ns_prefixes;
   1837     }
   1838     return (ctx);
   1839 }
   1840 
   1841 /**
   1842  * xmlC14NExecute:
   1843  * @doc: 		the XML document for canonization
   1844  * @is_visible_callback:the function to use to determine is node visible
   1845  *			or not
   1846  * @user_data: 		the first parameter for @is_visible_callback function
   1847  *			(in most cases, it is nodes set)
   1848  * @mode:	the c14n mode (see @xmlC14NMode)
   1849  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
   1850  *			ended with a NULL or NULL if there is no
   1851  *			inclusive namespaces (only for exclusive
   1852  *			canonicalization, ignored otherwise)
   1853  * @with_comments: 	include comments in the result (!=0) or not (==0)
   1854  * @buf: 		the output buffer to store canonical XML; this
   1855  *			buffer MUST have encoder==NULL because C14N requires
   1856  *			UTF-8 output
   1857  *
   1858  * Dumps the canonized image of given XML document into the provided buffer.
   1859  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
   1860  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
   1861  *
   1862  * Returns non-negative value on success or a negative value on fail
   1863  */
   1864 int
   1865 xmlC14NExecute(xmlDocPtr doc, xmlC14NIsVisibleCallback is_visible_callback,
   1866 	 void* user_data, int mode, xmlChar **inclusive_ns_prefixes,
   1867 	 int with_comments, xmlOutputBufferPtr buf) {
   1868 
   1869     xmlC14NCtxPtr ctx;
   1870     xmlC14NMode c14n_mode = XML_C14N_1_0;
   1871     int ret;
   1872 
   1873     if ((buf == NULL) || (doc == NULL)) {
   1874         xmlC14NErrParam("executing c14n");
   1875         return (-1);
   1876     }
   1877 
   1878     /* for backward compatibility, we have to have "mode" as "int"
   1879        and here we check that user gives valid value */
   1880     switch(mode) {
   1881     case XML_C14N_1_0:
   1882     case XML_C14N_EXCLUSIVE_1_0:
   1883     case XML_C14N_1_1:
   1884          c14n_mode = (xmlC14NMode)mode;
   1885          break;
   1886     default:
   1887         xmlC14NErrParam("invalid mode for executing c14n");
   1888         return (-1);
   1889     }
   1890 
   1891     /*
   1892      *  Validate the encoding output buffer encoding
   1893      */
   1894     if (buf->encoder != NULL) {
   1895         xmlC14NErr(NULL, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
   1896 "xmlC14NExecute: output buffer encoder != NULL but C14N requires UTF8 output\n");
   1897         return (-1);
   1898     }
   1899 
   1900     ctx = xmlC14NNewCtx(doc, is_visible_callback, user_data,
   1901 	            c14n_mode, inclusive_ns_prefixes,
   1902                     with_comments, buf);
   1903     if (ctx == NULL) {
   1904         xmlC14NErr(NULL, (xmlNodePtr) doc, XML_C14N_CREATE_CTXT,
   1905 		   "xmlC14NExecute: unable to create C14N context\n");
   1906         return (-1);
   1907     }
   1908 
   1909 
   1910 
   1911     /*
   1912      * Root Node
   1913      * The root node is the parent of the top-level document element. The
   1914      * result of processing each of its child nodes that is in the node-set
   1915      * in document order. The root node does not generate a byte order mark,
   1916      * XML declaration, nor anything from within the document type
   1917      * declaration.
   1918      */
   1919     if (doc->children != NULL) {
   1920         ret = xmlC14NProcessNodeList(ctx, doc->children);
   1921         if (ret < 0) {
   1922             xmlC14NErrInternal("processing docs children list");
   1923             xmlC14NFreeCtx(ctx);
   1924             return (-1);
   1925         }
   1926     }
   1927 
   1928     /*
   1929      * Flush buffer to get number of bytes written
   1930      */
   1931     ret = xmlOutputBufferFlush(buf);
   1932     if (ret < 0) {
   1933         xmlC14NErrInternal("flushing output buffer");
   1934         xmlC14NFreeCtx(ctx);
   1935         return (-1);
   1936     }
   1937 
   1938     /*
   1939      * Cleanup
   1940      */
   1941     xmlC14NFreeCtx(ctx);
   1942     return (ret);
   1943 }
   1944 
   1945 /**
   1946  * xmlC14NDocSaveTo:
   1947  * @doc: 		the XML document for canonization
   1948  * @nodes: 		the nodes set to be included in the canonized image
   1949  *      		or NULL if all document nodes should be included
   1950  * @mode:		the c14n mode (see @xmlC14NMode)
   1951  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
   1952  *			ended with a NULL or NULL if there is no
   1953  *			inclusive namespaces (only for exclusive
   1954  *			canonicalization, ignored otherwise)
   1955  * @with_comments: 	include comments in the result (!=0) or not (==0)
   1956  * @buf: 		the output buffer to store canonical XML; this
   1957  *			buffer MUST have encoder==NULL because C14N requires
   1958  *			UTF-8 output
   1959  *
   1960  * Dumps the canonized image of given XML document into the provided buffer.
   1961  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
   1962  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
   1963  *
   1964  * Returns non-negative value on success or a negative value on fail
   1965  */
   1966 int
   1967 xmlC14NDocSaveTo(xmlDocPtr doc, xmlNodeSetPtr nodes,
   1968                  int mode, xmlChar ** inclusive_ns_prefixes,
   1969                  int with_comments, xmlOutputBufferPtr buf) {
   1970     return(xmlC14NExecute(doc,
   1971 			(xmlC14NIsVisibleCallback)xmlC14NIsNodeInNodeset,
   1972 			nodes,
   1973 			mode,
   1974 			inclusive_ns_prefixes,
   1975 			with_comments,
   1976 			buf));
   1977 }
   1978 
   1979 
   1980 /**
   1981  * xmlC14NDocDumpMemory:
   1982  * @doc: 		the XML document for canonization
   1983  * @nodes: 		the nodes set to be included in the canonized image
   1984  *      		or NULL if all document nodes should be included
   1985  * @mode:		the c14n mode (see @xmlC14NMode)
   1986  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
   1987  *			ended with a NULL or NULL if there is no
   1988  *			inclusive namespaces (only for exclusive
   1989  *			canonicalization, ignored otherwise)
   1990  * @with_comments: 	include comments in the result (!=0) or not (==0)
   1991  * @doc_txt_ptr: 	the memory pointer for allocated canonical XML text;
   1992  *			the caller of this functions is responsible for calling
   1993  *			xmlFree() to free allocated memory
   1994  *
   1995  * Dumps the canonized image of given XML document into memory.
   1996  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
   1997  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
   1998  *
   1999  * Returns the number of bytes written on success or a negative value on fail
   2000  */
   2001 int
   2002 xmlC14NDocDumpMemory(xmlDocPtr doc, xmlNodeSetPtr nodes,
   2003                      int mode, xmlChar ** inclusive_ns_prefixes,
   2004                      int with_comments, xmlChar ** doc_txt_ptr)
   2005 {
   2006     int ret;
   2007     xmlOutputBufferPtr buf;
   2008 
   2009     if (doc_txt_ptr == NULL) {
   2010         xmlC14NErrParam("dumping doc to memory");
   2011         return (-1);
   2012     }
   2013 
   2014     *doc_txt_ptr = NULL;
   2015 
   2016     /*
   2017      * create memory buffer with UTF8 (default) encoding
   2018      */
   2019     buf = xmlAllocOutputBuffer(NULL);
   2020     if (buf == NULL) {
   2021         xmlC14NErrMemory("creating output buffer");
   2022         return (-1);
   2023     }
   2024 
   2025     /*
   2026      * canonize document and write to buffer
   2027      */
   2028     ret = xmlC14NDocSaveTo(doc, nodes, mode, inclusive_ns_prefixes,
   2029                            with_comments, buf);
   2030     if (ret < 0) {
   2031         xmlC14NErrInternal("saving doc to output buffer");
   2032         (void) xmlOutputBufferClose(buf);
   2033         return (-1);
   2034     }
   2035 
   2036     ret = buf->buffer->use;
   2037     if (ret > 0) {
   2038         *doc_txt_ptr = xmlStrndup(buf->buffer->content, ret);
   2039     }
   2040     (void) xmlOutputBufferClose(buf);
   2041 
   2042     if ((*doc_txt_ptr == NULL) && (ret > 0)) {
   2043         xmlC14NErrMemory("coping canonicanized document");
   2044         return (-1);
   2045     }
   2046     return (ret);
   2047 }
   2048 
   2049 /**
   2050  * xmlC14NDocSave:
   2051  * @doc: 		the XML document for canonization
   2052  * @nodes: 		the nodes set to be included in the canonized image
   2053  *      		or NULL if all document nodes should be included
   2054  * @mode:		the c14n mode (see @xmlC14NMode)
   2055  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
   2056  *			ended with a NULL or NULL if there is no
   2057  *			inclusive namespaces (only for exclusive
   2058  *			canonicalization, ignored otherwise)
   2059  * @with_comments: 	include comments in the result (!=0) or not (==0)
   2060  * @filename: 		the filename to store canonical XML image
   2061  * @compression:	the compression level (zlib requred):
   2062  *				-1 - libxml default,
   2063  *				 0 - uncompressed,
   2064  *				>0 - compression level
   2065  *
   2066  * Dumps the canonized image of given XML document into the file.
   2067  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
   2068  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
   2069  *
   2070  * Returns the number of bytes written success or a negative value on fail
   2071  */
   2072 int
   2073 xmlC14NDocSave(xmlDocPtr doc, xmlNodeSetPtr nodes,
   2074                int mode, xmlChar ** inclusive_ns_prefixes,
   2075                int with_comments, const char *filename, int compression)
   2076 {
   2077     xmlOutputBufferPtr buf;
   2078     int ret;
   2079 
   2080     if (filename == NULL) {
   2081         xmlC14NErrParam("saving doc");
   2082         return (-1);
   2083     }
   2084 #ifdef HAVE_ZLIB_H
   2085     if (compression < 0)
   2086         compression = xmlGetCompressMode();
   2087 #endif
   2088 
   2089     /*
   2090      * save the content to a temp buffer, use default UTF8 encoding.
   2091      */
   2092     buf = xmlOutputBufferCreateFilename(filename, NULL, compression);
   2093     if (buf == NULL) {
   2094         xmlC14NErrInternal("creating temporary filename");
   2095         return (-1);
   2096     }
   2097 
   2098     /*
   2099      * canonize document and write to buffer
   2100      */
   2101     ret = xmlC14NDocSaveTo(doc, nodes, mode, inclusive_ns_prefixes,
   2102                            with_comments, buf);
   2103     if (ret < 0) {
   2104         xmlC14NErrInternal("cannicanize document to buffer");
   2105         (void) xmlOutputBufferClose(buf);
   2106         return (-1);
   2107     }
   2108 
   2109     /*
   2110      * get the numbers of bytes written
   2111      */
   2112     ret = xmlOutputBufferClose(buf);
   2113     return (ret);
   2114 }
   2115 
   2116 
   2117 
   2118 /*
   2119  * Macro used to grow the current buffer.
   2120  */
   2121 #define growBufferReentrant() {						\
   2122     buffer_size *= 2;							\
   2123     buffer = (xmlChar *)						\
   2124     		xmlRealloc(buffer, buffer_size * sizeof(xmlChar));	\
   2125     if (buffer == NULL) {						\
   2126 	xmlC14NErrMemory("growing buffer");				\
   2127 	return(NULL);							\
   2128     }									\
   2129 }
   2130 
   2131 /**
   2132  * xmlC11NNormalizeString:
   2133  * @input:		the input string
   2134  * @mode:		the normalization mode (attribute, comment, PI or text)
   2135  *
   2136  * Converts a string to a canonical (normalized) format. The code is stolen
   2137  * from xmlEncodeEntitiesReentrant(). Added normalization of \x09, \x0a, \x0A
   2138  * and the @mode parameter
   2139  *
   2140  * Returns a normalized string (caller is responsible for calling xmlFree())
   2141  * or NULL if an error occurs
   2142  */
   2143 static xmlChar *
   2144 xmlC11NNormalizeString(const xmlChar * input,
   2145                        xmlC14NNormalizationMode mode)
   2146 {
   2147     const xmlChar *cur = input;
   2148     xmlChar *buffer = NULL;
   2149     xmlChar *out = NULL;
   2150     int buffer_size = 0;
   2151 
   2152     if (input == NULL)
   2153         return (NULL);
   2154 
   2155     /*
   2156      * allocate an translation buffer.
   2157      */
   2158     buffer_size = 1000;
   2159     buffer = (xmlChar *) xmlMallocAtomic(buffer_size * sizeof(xmlChar));
   2160     if (buffer == NULL) {
   2161 	xmlC14NErrMemory("allocating buffer");
   2162         return (NULL);
   2163     }
   2164     out = buffer;
   2165 
   2166     while (*cur != '\0') {
   2167         if ((out - buffer) > (buffer_size - 10)) {
   2168             int indx = out - buffer;
   2169 
   2170             growBufferReentrant();
   2171             out = &buffer[indx];
   2172         }
   2173 
   2174         if ((*cur == '<') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
   2175                               (mode == XMLC14N_NORMALIZE_TEXT))) {
   2176             *out++ = '&';
   2177             *out++ = 'l';
   2178             *out++ = 't';
   2179             *out++ = ';';
   2180         } else if ((*cur == '>') && (mode == XMLC14N_NORMALIZE_TEXT)) {
   2181             *out++ = '&';
   2182             *out++ = 'g';
   2183             *out++ = 't';
   2184             *out++ = ';';
   2185         } else if ((*cur == '&') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
   2186                                      (mode == XMLC14N_NORMALIZE_TEXT))) {
   2187             *out++ = '&';
   2188             *out++ = 'a';
   2189             *out++ = 'm';
   2190             *out++ = 'p';
   2191             *out++ = ';';
   2192         } else if ((*cur == '"') && (mode == XMLC14N_NORMALIZE_ATTR)) {
   2193             *out++ = '&';
   2194             *out++ = 'q';
   2195             *out++ = 'u';
   2196             *out++ = 'o';
   2197             *out++ = 't';
   2198             *out++ = ';';
   2199         } else if ((*cur == '\x09') && (mode == XMLC14N_NORMALIZE_ATTR)) {
   2200             *out++ = '&';
   2201             *out++ = '#';
   2202             *out++ = 'x';
   2203             *out++ = '9';
   2204             *out++ = ';';
   2205         } else if ((*cur == '\x0A') && (mode == XMLC14N_NORMALIZE_ATTR)) {
   2206             *out++ = '&';
   2207             *out++ = '#';
   2208             *out++ = 'x';
   2209             *out++ = 'A';
   2210             *out++ = ';';
   2211         } else if ((*cur == '\x0D') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
   2212                                         (mode == XMLC14N_NORMALIZE_TEXT) ||
   2213                                         (mode == XMLC14N_NORMALIZE_COMMENT) ||
   2214 					(mode == XMLC14N_NORMALIZE_PI))) {
   2215             *out++ = '&';
   2216             *out++ = '#';
   2217             *out++ = 'x';
   2218             *out++ = 'D';
   2219             *out++ = ';';
   2220         } else {
   2221             /*
   2222              * Works because on UTF-8, all extended sequences cannot
   2223              * result in bytes in the ASCII range.
   2224              */
   2225             *out++ = *cur;
   2226         }
   2227         cur++;
   2228     }
   2229     *out = 0;
   2230     return (buffer);
   2231 }
   2232 #endif /* LIBXML_OUTPUT_ENABLED */
   2233 #define bottom_c14n
   2234 #include "elfgcchack.h"
   2235 #endif /* LIBXML_C14N_ENABLED */
   2236