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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@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 #include "buf.h"
31 
32 /************************************************************************
33  *									*
34  *		Some declaration better left private ATM		*
35  *									*
36  ************************************************************************/
37 
38 typedef enum {
39     XMLC14N_BEFORE_DOCUMENT_ELEMENT = 0,
40     XMLC14N_INSIDE_DOCUMENT_ELEMENT = 1,
41     XMLC14N_AFTER_DOCUMENT_ELEMENT = 2
42 } xmlC14NPosition;
43 
44 typedef struct _xmlC14NVisibleNsStack {
45     int nsCurEnd;           /* number of nodes in the set */
46     int nsPrevStart;        /* the begginning of the stack for previous visible node */
47     int nsPrevEnd;          /* the end of the stack for previous visible node */
48     int nsMax;              /* size of the array as allocated */
49     xmlNsPtr	*nsTab;	    /* array of ns in no particular order */
50     xmlNodePtr	*nodeTab;   /* array of nodes in no particular order */
51 } xmlC14NVisibleNsStack, *xmlC14NVisibleNsStackPtr;
52 
53 typedef struct _xmlC14NCtx {
54     /* input parameters */
55     xmlDocPtr doc;
56     xmlC14NIsVisibleCallback is_visible_callback;
57     void* user_data;
58     int with_comments;
59     xmlOutputBufferPtr buf;
60 
61     /* position in the XML document */
62     xmlC14NPosition pos;
63     int parent_is_doc;
64     xmlC14NVisibleNsStackPtr ns_rendered;
65 
66     /* C14N mode */
67     xmlC14NMode mode;
68 
69     /* exclusive canonicalization */
70     xmlChar **inclusive_ns_prefixes;
71 
72     /* error number */
73     int error;
74 } xmlC14NCtx, *xmlC14NCtxPtr;
75 
76 static xmlC14NVisibleNsStackPtr	xmlC14NVisibleNsStackCreate	(void);
77 static void     xmlC14NVisibleNsStackDestroy	(xmlC14NVisibleNsStackPtr cur);
78 static void     xmlC14NVisibleNsStackAdd	    (xmlC14NVisibleNsStackPtr cur,
79                                                  xmlNsPtr ns,
80                                                  xmlNodePtr node);
81 static void			xmlC14NVisibleNsStackSave	(xmlC14NVisibleNsStackPtr cur,
82 								 xmlC14NVisibleNsStackPtr state);
83 static void			xmlC14NVisibleNsStackRestore	(xmlC14NVisibleNsStackPtr cur,
84 								 xmlC14NVisibleNsStackPtr state);
85 static void			xmlC14NVisibleNsStackShift	(xmlC14NVisibleNsStackPtr cur);
86 static int			xmlC14NVisibleNsStackFind	(xmlC14NVisibleNsStackPtr cur,
87 								 xmlNsPtr ns);
88 static int			xmlExcC14NVisibleNsStackFind	(xmlC14NVisibleNsStackPtr cur,
89 								 xmlNsPtr ns,
90 								 xmlC14NCtxPtr ctx);
91 
92 static int			xmlC14NIsNodeInNodeset		(void *user_data,
93 								 xmlNodePtr node,
94 								 xmlNodePtr parent);
95 
96 
97 
98 static int xmlC14NProcessNode(xmlC14NCtxPtr ctx, xmlNodePtr cur);
99 static int xmlC14NProcessNodeList(xmlC14NCtxPtr ctx, xmlNodePtr cur);
100 typedef enum {
101     XMLC14N_NORMALIZE_ATTR = 0,
102     XMLC14N_NORMALIZE_COMMENT = 1,
103     XMLC14N_NORMALIZE_PI = 2,
104     XMLC14N_NORMALIZE_TEXT = 3
105 } xmlC14NNormalizationMode;
106 
107 static xmlChar *xmlC11NNormalizeString(const xmlChar * input,
108                                        xmlC14NNormalizationMode mode);
109 
110 #define	xmlC11NNormalizeAttr( a ) \
111     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_ATTR)
112 #define	xmlC11NNormalizeComment( a ) \
113     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_COMMENT)
114 #define	xmlC11NNormalizePI( a )	\
115     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_PI)
116 #define	xmlC11NNormalizeText( a ) \
117     xmlC11NNormalizeString((a), XMLC14N_NORMALIZE_TEXT)
118 
119 #define	xmlC14NIsVisible( ctx, node, parent ) \
120      (((ctx)->is_visible_callback != NULL) ? \
121 	(ctx)->is_visible_callback((ctx)->user_data, \
122 		(xmlNodePtr)(node), (xmlNodePtr)(parent)) : 1)
123 
124 #define	xmlC14NIsExclusive( ctx ) \
125     ( (ctx)->mode == XML_C14N_EXCLUSIVE_1_0 )
126 
127 /************************************************************************
128  *									*
129  *		Some factorized error routines				*
130  *									*
131  ************************************************************************/
132 
133 /**
134  * xmlC14NErrMemory:
135  * @extra:  extra informations
136  *
137  * Handle a redefinition of memory error
138  */
139 static void
xmlC14NErrMemory(const char * extra)140 xmlC14NErrMemory(const char *extra)
141 {
142     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
143 		    XML_ERR_NO_MEMORY, XML_ERR_ERROR, NULL, 0, extra,
144 		    NULL, NULL, 0, 0,
145 		    "Memory allocation failed : %s\n", extra);
146 }
147 
148 /**
149  * xmlC14NErrParam:
150  * @extra:  extra informations
151  *
152  * Handle a redefinition of param error
153  */
154 static void
xmlC14NErrParam(const char * extra)155 xmlC14NErrParam(const char *extra)
156 {
157     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
158 		    XML_ERR_INTERNAL_ERROR, XML_ERR_ERROR, NULL, 0, extra,
159 		    NULL, NULL, 0, 0,
160 		    "Invalid parameter : %s\n", extra);
161 }
162 
163 /**
164  * xmlC14NErrInternal:
165  * @extra:  extra informations
166  *
167  * Handle a redefinition of internal error
168  */
169 static void
xmlC14NErrInternal(const char * extra)170 xmlC14NErrInternal(const char *extra)
171 {
172     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
173 		    XML_ERR_INTERNAL_ERROR, XML_ERR_ERROR, NULL, 0, extra,
174 		    NULL, NULL, 0, 0,
175 		    "Internal error : %s\n", extra);
176 }
177 
178 /**
179  * xmlC14NErrInvalidNode:
180  * @extra:  extra informations
181  *
182  * Handle a redefinition of invalid node error
183  */
184 static void
xmlC14NErrInvalidNode(const char * node_type,const char * extra)185 xmlC14NErrInvalidNode(const char *node_type, const char *extra)
186 {
187     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
188 		    XML_C14N_INVALID_NODE, XML_ERR_ERROR, NULL, 0, extra,
189 		    NULL, NULL, 0, 0,
190 		    "Node %s is invalid here : %s\n", node_type, extra);
191 }
192 
193 /**
194  * xmlC14NErrUnknownNode:
195  * @extra:  extra informations
196  *
197  * Handle a redefinition of unknown node error
198  */
199 static void
xmlC14NErrUnknownNode(int node_type,const char * extra)200 xmlC14NErrUnknownNode(int node_type, const char *extra)
201 {
202     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
203 		    XML_C14N_UNKNOW_NODE, XML_ERR_ERROR, NULL, 0, extra,
204 		    NULL, NULL, 0, 0,
205 		    "Unknown node type %d found : %s\n", node_type, extra);
206 }
207 
208 /**
209  * xmlC14NErrRelativeNamespace:
210  * @extra:  extra informations
211  *
212  * Handle a redefinition of relative namespace error
213  */
214 static void
xmlC14NErrRelativeNamespace(const char * ns_uri)215 xmlC14NErrRelativeNamespace(const char *ns_uri)
216 {
217     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
218 		    XML_C14N_RELATIVE_NAMESPACE, XML_ERR_ERROR, NULL, 0, NULL,
219 		    NULL, NULL, 0, 0,
220 		    "Relative namespace UR is invalid here : %s\n", ns_uri);
221 }
222 
223 
224 
225 /**
226  * xmlC14NErr:
227  * @ctxt:  a C14N evaluation context
228  * @node:  the context node
229  * @error:  the erorr code
230  * @msg:  the message
231  * @extra:  extra informations
232  *
233  * Handle a redefinition of attribute error
234  */
235 static void
xmlC14NErr(xmlC14NCtxPtr ctxt,xmlNodePtr node,int error,const char * msg)236 xmlC14NErr(xmlC14NCtxPtr ctxt, xmlNodePtr node, int error,
237            const char * msg)
238 {
239     if (ctxt != NULL)
240         ctxt->error = error;
241     __xmlRaiseError(NULL, NULL, NULL,
242 		    ctxt, node, XML_FROM_C14N, error,
243 		    XML_ERR_ERROR, NULL, 0,
244 		    NULL, NULL, NULL, 0, 0, "%s", msg);
245 }
246 
247 /************************************************************************
248  *									*
249  *		The implementation internals				*
250  *									*
251  ************************************************************************/
252 #define XML_NAMESPACES_DEFAULT		16
253 
254 static int
xmlC14NIsNodeInNodeset(void * user_data,xmlNodePtr node,xmlNodePtr parent)255 xmlC14NIsNodeInNodeset(void *user_data, xmlNodePtr node, xmlNodePtr parent) {
256     xmlNodeSetPtr nodes = (xmlNodeSetPtr) user_data;
257     if((nodes != NULL) && (node != NULL)) {
258 	if(node->type != XML_NAMESPACE_DECL) {
259 	    return(xmlXPathNodeSetContains(nodes, node));
260 	} else {
261 	    xmlNs ns;
262 
263 	    memcpy(&ns, node, sizeof(ns));
264 
265 	    /* this is a libxml hack! check xpath.c for details */
266 	    if((parent != NULL) && (parent->type == XML_ATTRIBUTE_NODE)) {
267 		ns.next = (xmlNsPtr)parent->parent;
268 	    } else {
269 		ns.next = (xmlNsPtr)parent;
270 	    }
271 
272 	    /*
273 	     * If the input is an XPath node-set, then the node-set must explicitly
274 	     * contain every node to be rendered to the canonical form.
275 	     */
276 	    return(xmlXPathNodeSetContains(nodes, (xmlNodePtr)&ns));
277 	}
278     }
279     return(1);
280 }
281 
282 static xmlC14NVisibleNsStackPtr
xmlC14NVisibleNsStackCreate(void)283 xmlC14NVisibleNsStackCreate(void) {
284     xmlC14NVisibleNsStackPtr ret;
285 
286     ret = (xmlC14NVisibleNsStackPtr) xmlMalloc(sizeof(xmlC14NVisibleNsStack));
287     if (ret == NULL) {
288         xmlC14NErrMemory("creating namespaces stack");
289 	return(NULL);
290     }
291     memset(ret, 0 , (size_t) sizeof(xmlC14NVisibleNsStack));
292     return(ret);
293 }
294 
295 static void
xmlC14NVisibleNsStackDestroy(xmlC14NVisibleNsStackPtr cur)296 xmlC14NVisibleNsStackDestroy(xmlC14NVisibleNsStackPtr cur) {
297     if(cur == NULL) {
298         xmlC14NErrParam("destroying namespaces stack");
299         return;
300     }
301     if(cur->nsTab != NULL) {
302 	memset(cur->nsTab, 0, cur->nsMax * sizeof(xmlNsPtr));
303 	xmlFree(cur->nsTab);
304     }
305     if(cur->nodeTab != NULL) {
306 	memset(cur->nodeTab, 0, cur->nsMax * sizeof(xmlNodePtr));
307 	xmlFree(cur->nodeTab);
308     }
309     memset(cur, 0, sizeof(xmlC14NVisibleNsStack));
310     xmlFree(cur);
311 
312 }
313 
314 static void
xmlC14NVisibleNsStackAdd(xmlC14NVisibleNsStackPtr cur,xmlNsPtr ns,xmlNodePtr node)315 xmlC14NVisibleNsStackAdd(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns, xmlNodePtr node) {
316     if((cur == NULL) ||
317        ((cur->nsTab == NULL) && (cur->nodeTab != NULL)) ||
318        ((cur->nsTab != NULL) && (cur->nodeTab == NULL))) {
319         xmlC14NErrParam("adding namespace to stack");
320 	return;
321     }
322 
323     if ((cur->nsTab == NULL) && (cur->nodeTab == NULL)) {
324         cur->nsTab = (xmlNsPtr*) xmlMalloc(XML_NAMESPACES_DEFAULT * sizeof(xmlNsPtr));
325         cur->nodeTab = (xmlNodePtr*) xmlMalloc(XML_NAMESPACES_DEFAULT * sizeof(xmlNodePtr));
326 	if ((cur->nsTab == NULL) || (cur->nodeTab == NULL)) {
327 	    xmlC14NErrMemory("adding node to stack");
328 	    return;
329 	}
330 	memset(cur->nsTab, 0 , XML_NAMESPACES_DEFAULT * sizeof(xmlNsPtr));
331 	memset(cur->nodeTab, 0 , XML_NAMESPACES_DEFAULT * sizeof(xmlNodePtr));
332         cur->nsMax = XML_NAMESPACES_DEFAULT;
333     } else if(cur->nsMax == cur->nsCurEnd) {
334 	void *tmp;
335 	int tmpSize;
336 
337 	tmpSize = 2 * cur->nsMax;
338 	tmp = xmlRealloc(cur->nsTab, tmpSize * sizeof(xmlNsPtr));
339 	if (tmp == NULL) {
340 	    xmlC14NErrMemory("adding node to stack");
341 	    return;
342 	}
343 	cur->nsTab = (xmlNsPtr*)tmp;
344 
345 	tmp = xmlRealloc(cur->nodeTab, tmpSize * sizeof(xmlNodePtr));
346 	if (tmp == NULL) {
347 	    xmlC14NErrMemory("adding node to stack");
348 	    return;
349 	}
350 	cur->nodeTab = (xmlNodePtr*)tmp;
351 
352 	cur->nsMax = tmpSize;
353     }
354     cur->nsTab[cur->nsCurEnd] = ns;
355     cur->nodeTab[cur->nsCurEnd] = node;
356 
357     ++cur->nsCurEnd;
358 }
359 
360 static void
xmlC14NVisibleNsStackSave(xmlC14NVisibleNsStackPtr cur,xmlC14NVisibleNsStackPtr state)361 xmlC14NVisibleNsStackSave(xmlC14NVisibleNsStackPtr cur, xmlC14NVisibleNsStackPtr state) {
362     if((cur == NULL) || (state == NULL)) {
363         xmlC14NErrParam("saving namespaces stack");
364 	return;
365     }
366 
367     state->nsCurEnd = cur->nsCurEnd;
368     state->nsPrevStart = cur->nsPrevStart;
369     state->nsPrevEnd = cur->nsPrevEnd;
370 }
371 
372 static void
xmlC14NVisibleNsStackRestore(xmlC14NVisibleNsStackPtr cur,xmlC14NVisibleNsStackPtr state)373 xmlC14NVisibleNsStackRestore(xmlC14NVisibleNsStackPtr cur, xmlC14NVisibleNsStackPtr state) {
374     if((cur == NULL) || (state == NULL)) {
375         xmlC14NErrParam("restoring namespaces stack");
376 	return;
377     }
378     cur->nsCurEnd = state->nsCurEnd;
379     cur->nsPrevStart = state->nsPrevStart;
380     cur->nsPrevEnd = state->nsPrevEnd;
381 }
382 
383 static void
xmlC14NVisibleNsStackShift(xmlC14NVisibleNsStackPtr cur)384 xmlC14NVisibleNsStackShift(xmlC14NVisibleNsStackPtr cur) {
385     if(cur == NULL) {
386         xmlC14NErrParam("shifting namespaces stack");
387 	return;
388     }
389     cur->nsPrevStart = cur->nsPrevEnd;
390     cur->nsPrevEnd = cur->nsCurEnd;
391 }
392 
393 static int
xmlC14NStrEqual(const xmlChar * str1,const xmlChar * str2)394 xmlC14NStrEqual(const xmlChar *str1, const xmlChar *str2) {
395     if (str1 == str2) return(1);
396     if (str1 == NULL) return((*str2) == '\0');
397     if (str2 == NULL) return((*str1) == '\0');
398     do {
399 	if (*str1++ != *str2) return(0);
400     } while (*str2++);
401     return(1);
402 }
403 
404 /**
405  * xmlC14NVisibleNsStackFind:
406  * @ctx:		the C14N context
407  * @ns:			the namespace to check
408  *
409  * Checks whether the given namespace was already rendered or not
410  *
411  * Returns 1 if we already wrote this namespace or 0 otherwise
412  */
413 static int
xmlC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur,xmlNsPtr ns)414 xmlC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns)
415 {
416     int i;
417     const xmlChar *prefix;
418     const xmlChar *href;
419     int has_empty_ns;
420 
421     if(cur == NULL) {
422         xmlC14NErrParam("searching namespaces stack (c14n)");
423         return (0);
424     }
425 
426     /*
427      * if the default namespace xmlns="" is not defined yet then
428      * we do not want to print it out
429      */
430     prefix = ((ns == NULL) || (ns->prefix == NULL)) ? BAD_CAST "" : ns->prefix;
431     href = ((ns == NULL) || (ns->href == NULL)) ? BAD_CAST "" : ns->href;
432     has_empty_ns = (xmlC14NStrEqual(prefix, NULL) && xmlC14NStrEqual(href, NULL));
433 
434     if (cur->nsTab != NULL) {
435 	int start = (has_empty_ns) ? 0 : cur->nsPrevStart;
436         for (i = cur->nsCurEnd - 1; i >= start; --i) {
437             xmlNsPtr ns1 = cur->nsTab[i];
438 
439 	    if(xmlC14NStrEqual(prefix, (ns1 != NULL) ? ns1->prefix : NULL)) {
440 		return(xmlC14NStrEqual(href, (ns1 != NULL) ? ns1->href : NULL));
441 	    }
442         }
443     }
444     return(has_empty_ns);
445 }
446 
447 static int
xmlExcC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur,xmlNsPtr ns,xmlC14NCtxPtr ctx)448 xmlExcC14NVisibleNsStackFind(xmlC14NVisibleNsStackPtr cur, xmlNsPtr ns, xmlC14NCtxPtr ctx) {
449     int i;
450     const xmlChar *prefix;
451     const xmlChar *href;
452     int has_empty_ns;
453 
454     if(cur == NULL) {
455         xmlC14NErrParam("searching namespaces stack (exc c14n)");
456         return (0);
457     }
458 
459     /*
460      * if the default namespace xmlns="" is not defined yet then
461      * we do not want to print it out
462      */
463     prefix = ((ns == NULL) || (ns->prefix == NULL)) ? BAD_CAST "" : ns->prefix;
464     href = ((ns == NULL) || (ns->href == NULL)) ? BAD_CAST "" : ns->href;
465     has_empty_ns = (xmlC14NStrEqual(prefix, NULL) && xmlC14NStrEqual(href, NULL));
466 
467     if (cur->nsTab != NULL) {
468 	int start = 0;
469         for (i = cur->nsCurEnd - 1; i >= start; --i) {
470             xmlNsPtr ns1 = cur->nsTab[i];
471 
472 	    if(xmlC14NStrEqual(prefix, (ns1 != NULL) ? ns1->prefix : NULL)) {
473 		if(xmlC14NStrEqual(href, (ns1 != NULL) ? ns1->href : NULL)) {
474 		    return(xmlC14NIsVisible(ctx, ns1, cur->nodeTab[i]));
475 		} else {
476 		    return(0);
477 		}
478 	    }
479         }
480     }
481     return(has_empty_ns);
482 }
483 
484 
485 
486 
487 /**
488  * xmlC14NIsXmlNs:
489  * @ns:		the namespace to check
490  *
491  * Checks whether the given namespace is a default "xml:" namespace
492  * with href="http://www.w3.org/XML/1998/namespace"
493  *
494  * Returns 1 if the node is default or 0 otherwise
495  */
496 
497 /* todo: make it a define? */
498 static int
xmlC14NIsXmlNs(xmlNsPtr ns)499 xmlC14NIsXmlNs(xmlNsPtr ns)
500 {
501     return ((ns != NULL) &&
502             (xmlStrEqual(ns->prefix, BAD_CAST "xml")) &&
503             (xmlStrEqual(ns->href, XML_XML_NAMESPACE)));
504 }
505 
506 
507 /**
508  * xmlC14NNsCompare:
509  * @ns1:		the pointer to first namespace
510  * @ns2:		the pointer to second namespace
511  *
512  * Compares the namespaces by names (prefixes).
513  *
514  * Returns -1 if ns1 < ns2, 0 if ns1 == ns2 or 1 if ns1 > ns2.
515  */
516 static int
xmlC14NNsCompare(const void * data1,const void * data2)517 xmlC14NNsCompare(const void *data1, const void *data2)
518 {
519     const xmlNsPtr ns1 = (const xmlNsPtr) data1;
520     const xmlNsPtr ns2 = (const xmlNsPtr) data2;
521     if (ns1 == ns2)
522         return (0);
523     if (ns1 == NULL)
524         return (-1);
525     if (ns2 == NULL)
526         return (1);
527 
528     return (xmlStrcmp(ns1->prefix, ns2->prefix));
529 }
530 
531 
532 /**
533  * xmlC14NPrintNamespaces:
534  * @ns:			the pointer to namespace
535  * @ctx:		the C14N context
536  *
537  * Prints the given namespace to the output buffer from C14N context.
538  *
539  * Returns 1 on success or 0 on fail.
540  */
541 static int
xmlC14NPrintNamespaces(const xmlNsPtr ns,xmlC14NCtxPtr ctx)542 xmlC14NPrintNamespaces(const xmlNsPtr ns, xmlC14NCtxPtr ctx)
543 {
544 
545     if ((ns == NULL) || (ctx == NULL)) {
546         xmlC14NErrParam("writing namespaces");
547         return 0;
548     }
549 
550     if (ns->prefix != NULL) {
551         xmlOutputBufferWriteString(ctx->buf, " xmlns:");
552         xmlOutputBufferWriteString(ctx->buf, (const char *) ns->prefix);
553         xmlOutputBufferWriteString(ctx->buf, "=");
554     } else {
555         xmlOutputBufferWriteString(ctx->buf, " xmlns=");
556     }
557     if(ns->href != NULL) {
558 	xmlBufWriteQuotedString(ctx->buf->buffer, ns->href);
559     } else {
560     	xmlOutputBufferWriteString(ctx->buf, "\"\"");
561     }
562     return (1);
563 }
564 
565 static int
xmlC14NPrintNamespacesWalker(const void * ns,void * ctx)566 xmlC14NPrintNamespacesWalker(const void *ns, void *ctx) {
567     return xmlC14NPrintNamespaces((const xmlNsPtr) ns, (xmlC14NCtxPtr) ctx);
568 }
569 
570 /**
571  * xmlC14NProcessNamespacesAxis:
572  * @ctx:		the C14N context
573  * @node:		the current node
574  *
575  * Prints out canonical namespace axis of the current node to the
576  * buffer from C14N context as follows
577  *
578  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
579  *
580  * Namespace Axis
581  * Consider a list L containing only namespace nodes in the
582  * axis and in the node-set in lexicographic order (ascending). To begin
583  * processing L, if the first node is not the default namespace node (a node
584  * with no namespace URI and no local name), then generate a space followed
585  * by xmlns="" if and only if the following conditions are met:
586  *    - the element E that owns the axis is in the node-set
587  *    - The nearest ancestor element of E in the node-set has a default
588  *	    namespace node in the node-set (default namespace nodes always
589  *      have non-empty values in XPath)
590  * The latter condition eliminates unnecessary occurrences of xmlns="" in
591  * the canonical form since an element only receives an xmlns="" if its
592  * default namespace is empty and if it has an immediate parent in the
593  * canonical form that has a non-empty default namespace. To finish
594  * processing  L, simply process every namespace node in L, except omit
595  * namespace node with local name xml, which defines the xml prefix,
596  * if its string value is http://www.w3.org/XML/1998/namespace.
597  *
598  * Exclusive XML Canonicalization v 1.0 (http://www.w3.org/TR/xml-exc-c14n)
599  * Canonical XML applied to a document subset requires the search of the
600  * ancestor nodes of each orphan element node for attributes in the xml
601  * namespace, such as xml:lang and xml:space. These are copied into the
602  * element node except if a declaration of the same attribute is already
603  * in the attribute axis of the element (whether or not it is included in
604  * the document subset). This search and copying are omitted from the
605  * Exclusive XML Canonicalization method.
606  *
607  * Returns 0 on success or -1 on fail.
608  */
609 static int
xmlC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx,xmlNodePtr cur,int visible)610 xmlC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
611 {
612     xmlNodePtr n;
613     xmlNsPtr ns, tmp;
614     xmlListPtr list;
615     int already_rendered;
616     int has_empty_ns = 0;
617 
618     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
619         xmlC14NErrParam("processing namespaces axis (c14n)");
620         return (-1);
621     }
622 
623     /*
624      * Create a sorted list to store element namespaces
625      */
626     list = xmlListCreate(NULL, xmlC14NNsCompare);
627     if (list == NULL) {
628         xmlC14NErrInternal("creating namespaces list (c14n)");
629         return (-1);
630     }
631 
632     /* check all namespaces */
633     for(n = cur; n != NULL; n = n->parent) {
634 	for(ns = n->nsDef; ns != NULL; ns = ns->next) {
635 	    tmp = xmlSearchNs(cur->doc, cur, ns->prefix);
636 
637 	    if((tmp == ns) && !xmlC14NIsXmlNs(ns) && xmlC14NIsVisible(ctx, ns, cur)) {
638 		already_rendered = xmlC14NVisibleNsStackFind(ctx->ns_rendered, ns);
639 		if(visible) {
640 	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
641 		}
642 		if(!already_rendered) {
643 		    xmlListInsert(list, ns);
644 		}
645 		if(xmlStrlen(ns->prefix) == 0) {
646 		    has_empty_ns = 1;
647 		}
648 	    }
649 	}
650     }
651 
652     /**
653      * if the first node is not the default namespace node (a node with no
654      * namespace URI and no local name), then generate a space followed by
655      * xmlns="" if and only if the following conditions are met:
656      *  - the element E that owns the axis is in the node-set
657      *  - the nearest ancestor element of E in the node-set has a default
658      *     namespace node in the node-set (default namespace nodes always
659      *     have non-empty values in XPath)
660      */
661     if(visible && !has_empty_ns) {
662         static xmlNs ns_default;
663 
664         memset(&ns_default, 0, sizeof(ns_default));
665         if(!xmlC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default)) {
666 	    xmlC14NPrintNamespaces(&ns_default, ctx);
667 	}
668     }
669 
670 
671     /*
672      * print out all elements from list
673      */
674     xmlListWalk(list, xmlC14NPrintNamespacesWalker, (void *) ctx);
675 
676     /*
677      * Cleanup
678      */
679     xmlListDelete(list);
680     return (0);
681 }
682 
683 
684 /**
685  * xmlExcC14NProcessNamespacesAxis:
686  * @ctx:		the C14N context
687  * @node:		the current node
688  *
689  * Prints out exclusive canonical namespace axis of the current node to the
690  * buffer from C14N context as follows
691  *
692  * Exclusive XML Canonicalization
693  * http://www.w3.org/TR/xml-exc-c14n
694  *
695  * If the element node is in the XPath subset then output the node in
696  * accordance with Canonical XML except for namespace nodes which are
697  * rendered as follows:
698  *
699  * 1. Render each namespace node iff:
700  *    * it is visibly utilized by the immediate parent element or one of
701  *      its attributes, or is present in InclusiveNamespaces PrefixList, and
702  *    * its prefix and value do not appear in ns_rendered. ns_rendered is
703  *      obtained by popping the state stack in order to obtain a list of
704  *      prefixes and their values which have already been rendered by
705  *      an output ancestor of the namespace node's parent element.
706  * 2. Append the rendered namespace node to the list ns_rendered of namespace
707  * nodes rendered by output ancestors. Push ns_rendered on state stack and
708  * recurse.
709  * 3. After the recursion returns, pop thestate stack.
710  *
711  *
712  * Returns 0 on success or -1 on fail.
713  */
714 static int
xmlExcC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx,xmlNodePtr cur,int visible)715 xmlExcC14NProcessNamespacesAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
716 {
717     xmlNsPtr ns;
718     xmlListPtr list;
719     xmlAttrPtr attr;
720     int already_rendered;
721     int has_empty_ns = 0;
722     int has_visibly_utilized_empty_ns = 0;
723     int has_empty_ns_in_inclusive_list = 0;
724 
725     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
726         xmlC14NErrParam("processing namespaces axis (exc c14n)");
727         return (-1);
728     }
729 
730     if(!xmlC14NIsExclusive(ctx)) {
731         xmlC14NErrParam("processing namespaces axis (exc c14n)");
732         return (-1);
733 
734     }
735 
736     /*
737      * Create a sorted list to store element namespaces
738      */
739     list = xmlListCreate(NULL, xmlC14NNsCompare);
740     if (list == NULL) {
741         xmlC14NErrInternal("creating namespaces list (exc c14n)");
742         return (-1);
743     }
744 
745     /*
746      * process inclusive namespaces:
747      * All namespace nodes appearing on inclusive ns list are
748      * handled as provided in Canonical XML
749      */
750     if(ctx->inclusive_ns_prefixes != NULL) {
751 	xmlChar *prefix;
752 	int i;
753 
754 	for (i = 0; ctx->inclusive_ns_prefixes[i] != NULL; ++i) {
755 	    prefix = ctx->inclusive_ns_prefixes[i];
756 	    /*
757 	     * Special values for namespace with empty prefix
758 	     */
759             if (xmlStrEqual(prefix, BAD_CAST "#default")
760                 || xmlStrEqual(prefix, BAD_CAST "")) {
761                 prefix = NULL;
762 		has_empty_ns_in_inclusive_list = 1;
763             }
764 
765 	    ns = xmlSearchNs(cur->doc, cur, prefix);
766 	    if((ns != NULL) && !xmlC14NIsXmlNs(ns) && xmlC14NIsVisible(ctx, ns, cur)) {
767 		already_rendered = xmlC14NVisibleNsStackFind(ctx->ns_rendered, ns);
768 		if(visible) {
769 		    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
770 		}
771 		if(!already_rendered) {
772 		    xmlListInsert(list, ns);
773 		}
774 		if(xmlStrlen(ns->prefix) == 0) {
775 		    has_empty_ns = 1;
776 		}
777 	    }
778 	}
779     }
780 
781     /* add node namespace */
782     if(cur->ns != NULL) {
783 	ns = cur->ns;
784     } else {
785         ns = xmlSearchNs(cur->doc, cur, NULL);
786 	has_visibly_utilized_empty_ns = 1;
787     }
788     if((ns != NULL) && !xmlC14NIsXmlNs(ns)) {
789 	if(visible && xmlC14NIsVisible(ctx, ns, cur)) {
790 	    if(!xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, ns, ctx)) {
791 		xmlListInsert(list, ns);
792 	    }
793 	}
794 	if(visible) {
795 	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, ns, cur);
796 	}
797 	if(xmlStrlen(ns->prefix) == 0) {
798 	    has_empty_ns = 1;
799 	}
800     }
801 
802 
803     /* add attributes */
804     for(attr = cur->properties; attr != NULL; attr = attr->next) {
805         /*
806          * we need to check that attribute is visible and has non
807          * default namespace (XML Namespaces: "default namespaces
808 	 * do not apply directly to attributes")
809          */
810 	if((attr->ns != NULL) && !xmlC14NIsXmlNs(attr->ns) && xmlC14NIsVisible(ctx, attr, cur)) {
811 	    already_rendered = xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, attr->ns, ctx);
812 	    xmlC14NVisibleNsStackAdd(ctx->ns_rendered, attr->ns, cur);
813 	    if(!already_rendered && visible) {
814 		xmlListInsert(list, attr->ns);
815 	    }
816 	    if(xmlStrlen(attr->ns->prefix) == 0) {
817 		has_empty_ns = 1;
818 	    }
819 	} else if((attr->ns != NULL) && (xmlStrlen(attr->ns->prefix) == 0) && (xmlStrlen(attr->ns->href) == 0)) {
820 	    has_visibly_utilized_empty_ns = 1;
821 	}
822     }
823 
824     /*
825      * Process xmlns=""
826      */
827     if(visible && has_visibly_utilized_empty_ns &&
828 	    !has_empty_ns && !has_empty_ns_in_inclusive_list) {
829         static xmlNs ns_default;
830 
831         memset(&ns_default, 0, sizeof(ns_default));
832 
833         already_rendered = xmlExcC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default, ctx);
834 	if(!already_rendered) {
835 	    xmlC14NPrintNamespaces(&ns_default, ctx);
836 	}
837     } else if(visible && !has_empty_ns && has_empty_ns_in_inclusive_list) {
838         static xmlNs ns_default;
839 
840         memset(&ns_default, 0, sizeof(ns_default));
841         if(!xmlC14NVisibleNsStackFind(ctx->ns_rendered, &ns_default)) {
842 	    xmlC14NPrintNamespaces(&ns_default, ctx);
843 	}
844     }
845 
846 
847 
848     /*
849      * print out all elements from list
850      */
851     xmlListWalk(list, xmlC14NPrintNamespacesWalker, (void *) ctx);
852 
853     /*
854      * Cleanup
855      */
856     xmlListDelete(list);
857     return (0);
858 }
859 
860 
861 /**
862  * xmlC14NIsXmlAttr:
863  * @attr:		the attr to check
864  *
865  * Checks whether the given attribute is a default "xml:" namespace
866  * with href="http://www.w3.org/XML/1998/namespace"
867  *
868  * Returns 1 if the node is default or 0 otherwise
869  */
870 
871 /* todo: make it a define? */
872 static int
xmlC14NIsXmlAttr(xmlAttrPtr attr)873 xmlC14NIsXmlAttr(xmlAttrPtr attr)
874 {
875     return ((attr->ns != NULL) &&
876            (xmlC14NIsXmlNs(attr->ns) != 0));
877 }
878 
879 
880 /**
881  * xmlC14NAttrsCompare:
882  * @attr1:		the pointer tls o first attr
883  * @attr2:		the pointer to second attr
884  *
885  * Prints the given attribute to the output buffer from C14N context.
886  *
887  * Returns -1 if attr1 < attr2, 0 if attr1 == attr2 or 1 if attr1 > attr2.
888  */
889 static int
xmlC14NAttrsCompare(const void * data1,const void * data2)890 xmlC14NAttrsCompare(const void *data1, const void *data2)
891 {
892     const xmlAttrPtr attr1 = (const xmlAttrPtr) data1;
893     const xmlAttrPtr attr2 = (const xmlAttrPtr) data2;
894     int ret = 0;
895 
896     /*
897      * Simple cases
898      */
899     if (attr1 == attr2)
900         return (0);
901     if (attr1 == NULL)
902         return (-1);
903     if (attr2 == NULL)
904         return (1);
905     if (attr1->ns == attr2->ns) {
906         return (xmlStrcmp(attr1->name, attr2->name));
907     }
908 
909     /*
910      * Attributes in the default namespace are first
911      * because the default namespace is not applied to
912      * unqualified attributes
913      */
914     if (attr1->ns == NULL)
915         return (-1);
916     if (attr2->ns == NULL)
917         return (1);
918     if (attr1->ns->prefix == NULL)
919         return (-1);
920     if (attr2->ns->prefix == NULL)
921         return (1);
922 
923     ret = xmlStrcmp(attr1->ns->href, attr2->ns->href);
924     if (ret == 0) {
925         ret = xmlStrcmp(attr1->name, attr2->name);
926     }
927     return (ret);
928 }
929 
930 
931 /**
932  * xmlC14NPrintAttrs:
933  * @attr:		the pointer to attr
934  * @ctx:		the C14N context
935  *
936  * Prints out canonical attribute urrent node to the
937  * buffer from C14N context as follows
938  *
939  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
940  *
941  * Returns 1 on success or 0 on fail.
942  */
943 static int
xmlC14NPrintAttrs(const void * data,void * user)944 xmlC14NPrintAttrs(const void *data, void *user)
945 {
946     const xmlAttrPtr attr = (const xmlAttrPtr) data;
947     xmlC14NCtxPtr ctx = (xmlC14NCtxPtr) user;
948     xmlChar *value;
949     xmlChar *buffer;
950 
951     if ((attr == NULL) || (ctx == NULL)) {
952         xmlC14NErrParam("writing attributes");
953         return (0);
954     }
955 
956     xmlOutputBufferWriteString(ctx->buf, " ");
957     if (attr->ns != NULL && xmlStrlen(attr->ns->prefix) > 0) {
958         xmlOutputBufferWriteString(ctx->buf,
959                                    (const char *) attr->ns->prefix);
960         xmlOutputBufferWriteString(ctx->buf, ":");
961     }
962     xmlOutputBufferWriteString(ctx->buf, (const char *) attr->name);
963     xmlOutputBufferWriteString(ctx->buf, "=\"");
964 
965     value = xmlNodeListGetString(ctx->doc, attr->children, 1);
966     /* todo: should we log an error if value==NULL ? */
967     if (value != NULL) {
968         buffer = xmlC11NNormalizeAttr(value);
969         xmlFree(value);
970         if (buffer != NULL) {
971             xmlOutputBufferWriteString(ctx->buf, (const char *) buffer);
972             xmlFree(buffer);
973         } else {
974             xmlC14NErrInternal("normalizing attributes axis");
975             return (0);
976         }
977     }
978     xmlOutputBufferWriteString(ctx->buf, "\"");
979     return (1);
980 }
981 
982 /**
983  * xmlC14NFindHiddenParentAttr:
984  *
985  * Finds an attribute in a hidden parent node.
986  *
987  * Returns a pointer to the attribute node (if found) or NULL otherwise.
988  */
989 static xmlAttrPtr
xmlC14NFindHiddenParentAttr(xmlC14NCtxPtr ctx,xmlNodePtr cur,const xmlChar * name,const xmlChar * ns)990 xmlC14NFindHiddenParentAttr(xmlC14NCtxPtr ctx, xmlNodePtr cur, const xmlChar * name, const xmlChar * ns)
991 {
992     xmlAttrPtr res;
993     while((cur != NULL) && (!xmlC14NIsVisible(ctx, cur, cur->parent))) {
994         res = xmlHasNsProp(cur, name, ns);
995         if(res != NULL) {
996             return res;
997         }
998 
999         cur = cur->parent;
1000     }
1001 
1002     return NULL;
1003 }
1004 
1005 /**
1006  * xmlC14NFixupBaseAttr:
1007  *
1008  * Fixes up the xml:base attribute
1009  *
1010  * Returns the newly created attribute or NULL
1011  */
1012 static xmlAttrPtr
xmlC14NFixupBaseAttr(xmlC14NCtxPtr ctx,xmlAttrPtr xml_base_attr)1013 xmlC14NFixupBaseAttr(xmlC14NCtxPtr ctx, xmlAttrPtr xml_base_attr)
1014 {
1015     xmlChar * res = NULL;
1016     xmlNodePtr cur;
1017     xmlAttrPtr attr;
1018     xmlChar * tmp_str;
1019     xmlChar * tmp_str2;
1020     int tmp_str_len;
1021 
1022     if ((ctx == NULL) || (xml_base_attr == NULL) || (xml_base_attr->parent == NULL)) {
1023         xmlC14NErrParam("processing xml:base attribute");
1024         return (NULL);
1025     }
1026 
1027     /* start from current value */
1028     res = xmlNodeListGetString(ctx->doc, xml_base_attr->children, 1);
1029     if(res == NULL) {
1030         xmlC14NErrInternal("processing xml:base attribute - can't get attr value");
1031         return (NULL);
1032     }
1033 
1034     /* go up the stack until we find a node that we rendered already */
1035     cur = xml_base_attr->parent->parent;
1036     while((cur != NULL) && (!xmlC14NIsVisible(ctx, cur, cur->parent))) {
1037         attr = xmlHasNsProp(cur, BAD_CAST "base", XML_XML_NAMESPACE);
1038         if(attr != NULL) {
1039             /* get attr value */
1040             tmp_str = xmlNodeListGetString(ctx->doc, attr->children, 1);
1041             if(tmp_str == NULL) {
1042                 xmlFree(res);
1043 
1044                 xmlC14NErrInternal("processing xml:base attribute - can't get attr value");
1045                 return (NULL);
1046             }
1047 
1048             /* we need to add '/' if our current base uri ends with '..' or '.'
1049             to ensure that we are forced to go "up" all the time */
1050             tmp_str_len = xmlStrlen(tmp_str);
1051             if(tmp_str_len > 1 && tmp_str[tmp_str_len - 2] == '.') {
1052                 tmp_str2 = xmlStrcat(tmp_str, BAD_CAST "/");
1053                 if(tmp_str2 == NULL) {
1054                     xmlFree(tmp_str);
1055                     xmlFree(res);
1056 
1057                     xmlC14NErrInternal("processing xml:base attribute - can't modify uri");
1058                     return (NULL);
1059                 }
1060 
1061                 tmp_str = tmp_str2;
1062             }
1063 
1064             /* build uri */
1065             tmp_str2 = xmlBuildURI(res, tmp_str);
1066             if(tmp_str2 == NULL) {
1067                 xmlFree(tmp_str);
1068                 xmlFree(res);
1069 
1070                 xmlC14NErrInternal("processing xml:base attribute - can't construct uri");
1071                 return (NULL);
1072             }
1073 
1074             /* cleanup and set the new res */
1075             xmlFree(tmp_str);
1076             xmlFree(res);
1077             res = tmp_str2;
1078         }
1079 
1080         /* next */
1081         cur = cur->parent;
1082     }
1083 
1084     /* check if result uri is empty or not */
1085     if((res == NULL) || xmlStrEqual(res, BAD_CAST "")) {
1086         xmlFree(res);
1087         return (NULL);
1088     }
1089 
1090     /* create and return the new attribute node */
1091     attr = xmlNewNsProp(NULL, xml_base_attr->ns, BAD_CAST "base", res);
1092     if(attr == NULL) {
1093         xmlFree(res);
1094 
1095         xmlC14NErrInternal("processing xml:base attribute - can't construct attribute");
1096         return (NULL);
1097     }
1098 
1099     /* done */
1100     xmlFree(res);
1101     return (attr);
1102 }
1103 
1104 /**
1105  * xmlC14NProcessAttrsAxis:
1106  * @ctx:		the C14N context
1107  * @cur:		the current node
1108  * @parent_visible:	the visibility of parent node
1109  * @all_parents_visible: the visibility of all parent nodes
1110  *
1111  * Prints out canonical attribute axis of the current node to the
1112  * buffer from C14N context as follows
1113  *
1114  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
1115  *
1116  * Attribute Axis
1117  * In lexicographic order (ascending), process each node that
1118  * is in the element's attribute axis and in the node-set.
1119  *
1120  * The processing of an element node E MUST be modified slightly
1121  * when an XPath node-set is given as input and the element's
1122  * parent is omitted from the node-set.
1123  *
1124  *
1125  * Exclusive XML Canonicalization v 1.0 (http://www.w3.org/TR/xml-exc-c14n)
1126  *
1127  * Canonical XML applied to a document subset requires the search of the
1128  * ancestor nodes of each orphan element node for attributes in the xml
1129  * namespace, such as xml:lang and xml:space. These are copied into the
1130  * element node except if a declaration of the same attribute is already
1131  * in the attribute axis of the element (whether or not it is included in
1132  * the document subset). This search and copying are omitted from the
1133  * Exclusive XML Canonicalization method.
1134  *
1135  * Returns 0 on success or -1 on fail.
1136  */
1137 static int
xmlC14NProcessAttrsAxis(xmlC14NCtxPtr ctx,xmlNodePtr cur,int parent_visible)1138 xmlC14NProcessAttrsAxis(xmlC14NCtxPtr ctx, xmlNodePtr cur, int parent_visible)
1139 {
1140     xmlAttrPtr attr;
1141     xmlListPtr list;
1142     xmlAttrPtr attrs_to_delete = NULL;
1143 
1144     /* special processing for 1.1 spec */
1145     xmlAttrPtr xml_base_attr = NULL;
1146     xmlAttrPtr xml_lang_attr = NULL;
1147     xmlAttrPtr xml_space_attr = NULL;
1148 
1149     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
1150         xmlC14NErrParam("processing attributes axis");
1151         return (-1);
1152     }
1153 
1154     /*
1155      * Create a sorted list to store element attributes
1156      */
1157     list = xmlListCreate(NULL, xmlC14NAttrsCompare);
1158     if (list == NULL) {
1159         xmlC14NErrInternal("creating attributes list");
1160         return (-1);
1161     }
1162 
1163     switch(ctx->mode) {
1164     case XML_C14N_1_0:
1165         /* The processing of an element node E MUST be modified slightly when an XPath node-set is
1166          * given as input and the element's parent is omitted from the node-set. The method for processing
1167          * the attribute axis of an element E in the node-set is enhanced. All element nodes along E's
1168          * ancestor axis are examined for nearest occurrences of attributes in the xml namespace, such
1169          * as xml:lang and xml:space (whether or not they are in the node-set). From this list of attributes,
1170          * remove any that are in E's attribute axis (whether or not they are in the node-set). Then,
1171          * lexicographically merge this attribute list with the nodes of E's attribute axis that are in
1172          * the node-set. The result of visiting the attribute axis is computed by processing the attribute
1173          * nodes in this merged attribute list.
1174          */
1175 
1176         /*
1177          * Add all visible attributes from current node.
1178          */
1179         attr = cur->properties;
1180         while (attr != NULL) {
1181             /* check that attribute is visible */
1182             if (xmlC14NIsVisible(ctx, attr, cur)) {
1183                 xmlListInsert(list, attr);
1184             }
1185             attr = attr->next;
1186         }
1187 
1188         /*
1189          * Handle xml attributes
1190          */
1191         if (parent_visible && (cur->parent != NULL) &&
1192             (!xmlC14NIsVisible(ctx, cur->parent, cur->parent->parent)))
1193         {
1194             xmlNodePtr tmp;
1195 
1196             /*
1197              * If XPath node-set is not specified then the parent is always
1198              * visible!
1199              */
1200             tmp = cur->parent;
1201             while (tmp != NULL) {
1202                 attr = tmp->properties;
1203                 while (attr != NULL) {
1204                     if (xmlC14NIsXmlAttr(attr) != 0) {
1205                         if (xmlListSearch(list, attr) == NULL) {
1206                             xmlListInsert(list, attr);
1207                         }
1208                     }
1209                     attr = attr->next;
1210                 }
1211                 tmp = tmp->parent;
1212             }
1213         }
1214 
1215         /* done */
1216         break;
1217     case XML_C14N_EXCLUSIVE_1_0:
1218         /* attributes in the XML namespace, such as xml:lang and xml:space
1219          * are not imported into orphan nodes of the document subset
1220          */
1221 
1222         /*
1223          * Add all visible attributes from current node.
1224          */
1225         attr = cur->properties;
1226         while (attr != NULL) {
1227             /* check that attribute is visible */
1228             if (xmlC14NIsVisible(ctx, attr, cur)) {
1229                 xmlListInsert(list, attr);
1230             }
1231             attr = attr->next;
1232         }
1233 
1234         /* do nothing special for xml attributes */
1235         break;
1236     case XML_C14N_1_1:
1237         /* The processing of an element node E MUST be modified slightly when an XPath node-set is
1238          * given as input and some of the element's ancestors are omitted from the node-set.
1239          *
1240          * Simple inheritable attributes are attributes that have a value that requires at most a simple
1241          * redeclaration. This redeclaration is done by supplying a new value in the child axis. The
1242          * redeclaration of a simple inheritable attribute A contained in one of E's ancestors is done
1243          * by supplying a value to an attribute Ae inside E with the same name. Simple inheritable attributes
1244          * are xml:lang and xml:space.
1245          *
1246          * The method for processing the attribute axis of an element E in the node-set is hence enhanced.
1247          * All element nodes along E's ancestor axis are examined for the nearest occurrences of simple
1248          * inheritable attributes in the xml namespace, such as xml:lang and xml:space (whether or not they
1249          * are in the node-set). From this list of attributes, any simple inheritable attributes that are
1250          * already in E's attribute axis (whether or not they are in the node-set) are removed. Then,
1251          * lexicographically merge this attribute list with the nodes of E's attribute axis that are in
1252          * the node-set. The result of visiting the attribute axis is computed by processing the attribute
1253          * nodes in this merged attribute list.
1254          *
1255          * The xml:id attribute is not a simple inheritable attribute and no processing of these attributes is
1256          * performed.
1257          *
1258          * The xml:base attribute is not a simple inheritable attribute and requires special processing beyond
1259          * a simple redeclaration.
1260          *
1261          * Attributes in the XML namespace other than xml:base, xml:id, xml:lang, and xml:space MUST be processed
1262          * as ordinary attributes.
1263          */
1264 
1265         /*
1266          * Add all visible attributes from current node.
1267          */
1268         attr = cur->properties;
1269         while (attr != NULL) {
1270             /* special processing for XML attribute kiks in only when we have invisible parents */
1271             if ((!parent_visible) || (xmlC14NIsXmlAttr(attr) == 0)) {
1272                 /* check that attribute is visible */
1273                 if (xmlC14NIsVisible(ctx, attr, cur)) {
1274                     xmlListInsert(list, attr);
1275                 }
1276             } else {
1277                 int matched = 0;
1278 
1279                 /* check for simple inheritance attributes */
1280                 if((!matched) && (xml_lang_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "lang")) {
1281                     xml_lang_attr = attr;
1282                     matched = 1;
1283                 }
1284                 if((!matched) && (xml_space_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "space")) {
1285                     xml_space_attr = attr;
1286                     matched = 1;
1287                 }
1288 
1289                 /* check for base attr */
1290                 if((!matched) && (xml_base_attr == NULL) && xmlStrEqual(attr->name, BAD_CAST "base")) {
1291                     xml_base_attr = attr;
1292                     matched = 1;
1293                 }
1294 
1295                 /* otherwise, it is a normal attribute, so just check if it is visible */
1296                 if((!matched) && xmlC14NIsVisible(ctx, attr, cur)) {
1297                     xmlListInsert(list, attr);
1298                 }
1299             }
1300 
1301             /* move to the next one */
1302             attr = attr->next;
1303         }
1304 
1305         /* special processing for XML attribute kiks in only when we have invisible parents */
1306         if ((parent_visible)) {
1307 
1308             /* simple inheritance attributes - copy */
1309             if(xml_lang_attr == NULL) {
1310                 xml_lang_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "lang", XML_XML_NAMESPACE);
1311             }
1312             if(xml_lang_attr != NULL) {
1313                 xmlListInsert(list, xml_lang_attr);
1314             }
1315             if(xml_space_attr == NULL) {
1316                 xml_space_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "space", XML_XML_NAMESPACE);
1317             }
1318             if(xml_space_attr != NULL) {
1319                 xmlListInsert(list, xml_space_attr);
1320             }
1321 
1322             /* base uri attribute - fix up */
1323             if(xml_base_attr == NULL) {
1324                 /* if we don't have base uri attribute, check if we have a "hidden" one above */
1325                 xml_base_attr = xmlC14NFindHiddenParentAttr(ctx, cur->parent, BAD_CAST "base", XML_XML_NAMESPACE);
1326             }
1327             if(xml_base_attr != NULL) {
1328                 xml_base_attr = xmlC14NFixupBaseAttr(ctx, xml_base_attr);
1329                 if(xml_base_attr != NULL) {
1330                     xmlListInsert(list, xml_base_attr);
1331 
1332                     /* note that we MUST delete returned attr node ourselves! */
1333                     xml_base_attr->next = attrs_to_delete;
1334                     attrs_to_delete = xml_base_attr;
1335                 }
1336             }
1337         }
1338 
1339         /* done */
1340         break;
1341     }
1342 
1343     /*
1344      * print out all elements from list
1345      */
1346     xmlListWalk(list, xmlC14NPrintAttrs, (void *) ctx);
1347 
1348     /*
1349      * Cleanup
1350      */
1351     xmlFreePropList(attrs_to_delete);
1352     xmlListDelete(list);
1353     return (0);
1354 }
1355 
1356 /**
1357  * xmlC14NCheckForRelativeNamespaces:
1358  * @ctx:		the C14N context
1359  * @cur:		the current element node
1360  *
1361  * Checks that current element node has no relative namespaces defined
1362  *
1363  * Returns 0 if the node has no relative namespaces or -1 otherwise.
1364  */
1365 static int
xmlC14NCheckForRelativeNamespaces(xmlC14NCtxPtr ctx,xmlNodePtr cur)1366 xmlC14NCheckForRelativeNamespaces(xmlC14NCtxPtr ctx, xmlNodePtr cur)
1367 {
1368     xmlNsPtr ns;
1369 
1370     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
1371         xmlC14NErrParam("checking for relative namespaces");
1372         return (-1);
1373     }
1374 
1375     ns = cur->nsDef;
1376     while (ns != NULL) {
1377         if (xmlStrlen(ns->href) > 0) {
1378             xmlURIPtr uri;
1379 
1380             uri = xmlParseURI((const char *) ns->href);
1381             if (uri == NULL) {
1382                 xmlC14NErrInternal("parsing namespace uri");
1383                 return (-1);
1384             }
1385             if (xmlStrlen((const xmlChar *) uri->scheme) == 0) {
1386                 xmlC14NErrRelativeNamespace(uri->scheme);
1387                 xmlFreeURI(uri);
1388                 return (-1);
1389             }
1390             xmlFreeURI(uri);
1391         }
1392         ns = ns->next;
1393     }
1394     return (0);
1395 }
1396 
1397 /**
1398  * xmlC14NProcessElementNode:
1399  * @ctx:		the pointer to C14N context object
1400  * @cur:		the node to process
1401  * @visible:    this node is visible
1402  * @all_parents_visible: whether all the parents of this node are visible
1403  *
1404  * Canonical XML v 1.0 (http://www.w3.org/TR/xml-c14n)
1405  *
1406  * Element Nodes
1407  * If the element is not in the node-set, then the result is obtained
1408  * by processing the namespace axis, then the attribute axis, then
1409  * processing the child nodes of the element that are in the node-set
1410  * (in document order). If the element is in the node-set, then the result
1411  * is an open angle bracket (<), the element QName, the result of
1412  * processing the namespace axis, the result of processing the attribute
1413  * axis, a close angle bracket (>), the result of processing the child
1414  * nodes of the element that are in the node-set (in document order), an
1415  * open angle bracket, a forward slash (/), the element QName, and a close
1416  * angle bracket.
1417  *
1418  * Returns non-negative value on success or negative value on fail
1419  */
1420 static int
xmlC14NProcessElementNode(xmlC14NCtxPtr ctx,xmlNodePtr cur,int visible)1421 xmlC14NProcessElementNode(xmlC14NCtxPtr ctx, xmlNodePtr cur, int visible)
1422 {
1423     int ret;
1424     xmlC14NVisibleNsStack state;
1425     int parent_is_doc = 0;
1426 
1427     if ((ctx == NULL) || (cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {
1428         xmlC14NErrParam("processing element node");
1429         return (-1);
1430     }
1431 
1432     /*
1433      * Check relative relative namespaces:
1434      * implementations of XML canonicalization MUST report an operation
1435      * failure on documents containing relative namespace URIs.
1436      */
1437     if (xmlC14NCheckForRelativeNamespaces(ctx, cur) < 0) {
1438         xmlC14NErrInternal("checking for relative namespaces");
1439         return (-1);
1440     }
1441 
1442 
1443     /*
1444      * Save ns_rendered stack position
1445      */
1446     memset(&state, 0, sizeof(state));
1447     xmlC14NVisibleNsStackSave(ctx->ns_rendered, &state);
1448 
1449     if (visible) {
1450         if (ctx->parent_is_doc) {
1451 	    /* save this flag into the stack */
1452 	    parent_is_doc = ctx->parent_is_doc;
1453 	    ctx->parent_is_doc = 0;
1454             ctx->pos = XMLC14N_INSIDE_DOCUMENT_ELEMENT;
1455         }
1456         xmlOutputBufferWriteString(ctx->buf, "<");
1457 
1458         if ((cur->ns != NULL) && (xmlStrlen(cur->ns->prefix) > 0)) {
1459             xmlOutputBufferWriteString(ctx->buf,
1460                                        (const char *) cur->ns->prefix);
1461             xmlOutputBufferWriteString(ctx->buf, ":");
1462         }
1463         xmlOutputBufferWriteString(ctx->buf, (const char *) cur->name);
1464     }
1465 
1466     if (!xmlC14NIsExclusive(ctx)) {
1467         ret = xmlC14NProcessNamespacesAxis(ctx, cur, visible);
1468     } else {
1469         ret = xmlExcC14NProcessNamespacesAxis(ctx, cur, visible);
1470     }
1471     if (ret < 0) {
1472         xmlC14NErrInternal("processing namespaces axis");
1473         return (-1);
1474     }
1475     /* todo: shouldn't this go to "visible only"? */
1476     if(visible) {
1477 	xmlC14NVisibleNsStackShift(ctx->ns_rendered);
1478     }
1479 
1480     ret = xmlC14NProcessAttrsAxis(ctx, cur, visible);
1481     if (ret < 0) {
1482 	xmlC14NErrInternal("processing attributes axis");
1483 	return (-1);
1484     }
1485 
1486     if (visible) {
1487         xmlOutputBufferWriteString(ctx->buf, ">");
1488     }
1489     if (cur->children != NULL) {
1490         ret = xmlC14NProcessNodeList(ctx, cur->children);
1491         if (ret < 0) {
1492             xmlC14NErrInternal("processing childrens list");
1493             return (-1);
1494         }
1495     }
1496     if (visible) {
1497         xmlOutputBufferWriteString(ctx->buf, "</");
1498         if ((cur->ns != NULL) && (xmlStrlen(cur->ns->prefix) > 0)) {
1499             xmlOutputBufferWriteString(ctx->buf,
1500                                        (const char *) cur->ns->prefix);
1501             xmlOutputBufferWriteString(ctx->buf, ":");
1502         }
1503         xmlOutputBufferWriteString(ctx->buf, (const char *) cur->name);
1504         xmlOutputBufferWriteString(ctx->buf, ">");
1505         if (parent_is_doc) {
1506 	    /* restore this flag from the stack for next node */
1507             ctx->parent_is_doc = parent_is_doc;
1508 	    ctx->pos = XMLC14N_AFTER_DOCUMENT_ELEMENT;
1509         }
1510     }
1511 
1512     /*
1513      * Restore ns_rendered stack position
1514      */
1515     xmlC14NVisibleNsStackRestore(ctx->ns_rendered, &state);
1516     return (0);
1517 }
1518 
1519 /**
1520  * xmlC14NProcessNode:
1521  * @ctx:		the pointer to C14N context object
1522  * @cur:		the node to process
1523  *
1524  * Processes the given node
1525  *
1526  * Returns non-negative value on success or negative value on fail
1527  */
1528 static int
xmlC14NProcessNode(xmlC14NCtxPtr ctx,xmlNodePtr cur)1529 xmlC14NProcessNode(xmlC14NCtxPtr ctx, xmlNodePtr cur)
1530 {
1531     int ret = 0;
1532     int visible;
1533 
1534     if ((ctx == NULL) || (cur == NULL)) {
1535         xmlC14NErrParam("processing node");
1536         return (-1);
1537     }
1538 
1539     visible = xmlC14NIsVisible(ctx, cur, cur->parent);
1540     switch (cur->type) {
1541         case XML_ELEMENT_NODE:
1542             ret = xmlC14NProcessElementNode(ctx, cur, visible);
1543             break;
1544         case XML_CDATA_SECTION_NODE:
1545         case XML_TEXT_NODE:
1546             /*
1547              * Text Nodes
1548              * the string value, except all ampersands are replaced
1549              * by &amp;, all open angle brackets (<) are replaced by &lt;, all closing
1550              * angle brackets (>) are replaced by &gt;, and all #xD characters are
1551              * replaced by &#xD;.
1552              */
1553             /* cdata sections are processed as text nodes */
1554             /* todo: verify that cdata sections are included in XPath nodes set */
1555             if ((visible) && (cur->content != NULL)) {
1556                 xmlChar *buffer;
1557 
1558                 buffer = xmlC11NNormalizeText(cur->content);
1559                 if (buffer != NULL) {
1560                     xmlOutputBufferWriteString(ctx->buf,
1561                                                (const char *) buffer);
1562                     xmlFree(buffer);
1563                 } else {
1564                     xmlC14NErrInternal("normalizing text node");
1565                     return (-1);
1566                 }
1567             }
1568             break;
1569         case XML_PI_NODE:
1570             /*
1571              * Processing Instruction (PI) Nodes-
1572              * The opening PI symbol (<?), the PI target name of the node,
1573              * a leading space and the string value if it is not empty, and
1574              * the closing PI symbol (?>). If the string value is empty,
1575              * then the leading space is not added. Also, a trailing #xA is
1576              * rendered after the closing PI symbol for PI children of the
1577              * root node with a lesser document order than the document
1578              * element, and a leading #xA is rendered before the opening PI
1579              * symbol of PI children of the root node with a greater document
1580              * order than the document element.
1581              */
1582             if (visible) {
1583                 if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
1584                     xmlOutputBufferWriteString(ctx->buf, "\x0A<?");
1585                 } else {
1586                     xmlOutputBufferWriteString(ctx->buf, "<?");
1587                 }
1588 
1589                 xmlOutputBufferWriteString(ctx->buf,
1590                                            (const char *) cur->name);
1591                 if ((cur->content != NULL) && (*(cur->content) != '\0')) {
1592                     xmlChar *buffer;
1593 
1594                     xmlOutputBufferWriteString(ctx->buf, " ");
1595 
1596                     /* todo: do we need to normalize pi? */
1597                     buffer = xmlC11NNormalizePI(cur->content);
1598                     if (buffer != NULL) {
1599                         xmlOutputBufferWriteString(ctx->buf,
1600                                                    (const char *) buffer);
1601                         xmlFree(buffer);
1602                     } else {
1603                         xmlC14NErrInternal("normalizing pi node");
1604                         return (-1);
1605                     }
1606                 }
1607 
1608                 if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
1609                     xmlOutputBufferWriteString(ctx->buf, "?>\x0A");
1610                 } else {
1611                     xmlOutputBufferWriteString(ctx->buf, "?>");
1612                 }
1613             }
1614             break;
1615         case XML_COMMENT_NODE:
1616             /*
1617              * Comment Nodes
1618              * Nothing if generating canonical XML without  comments. For
1619              * canonical XML with comments, generate the opening comment
1620              * symbol (<!--), the string value of the node, and the
1621              * closing comment symbol (-->). Also, a trailing #xA is rendered
1622              * after the closing comment symbol for comment children of the
1623              * root node with a lesser document order than the document
1624              * element, and a leading #xA is rendered before the opening
1625              * comment symbol of comment children of the root node with a
1626              * greater document order than the document element. (Comment
1627              * children of the root node represent comments outside of the
1628              * top-level document element and outside of the document type
1629              * declaration).
1630              */
1631             if (visible && ctx->with_comments) {
1632                 if (ctx->pos == XMLC14N_AFTER_DOCUMENT_ELEMENT) {
1633                     xmlOutputBufferWriteString(ctx->buf, "\x0A<!--");
1634                 } else {
1635                     xmlOutputBufferWriteString(ctx->buf, "<!--");
1636                 }
1637 
1638                 if (cur->content != NULL) {
1639                     xmlChar *buffer;
1640 
1641                     /* todo: do we need to normalize comment? */
1642                     buffer = xmlC11NNormalizeComment(cur->content);
1643                     if (buffer != NULL) {
1644                         xmlOutputBufferWriteString(ctx->buf,
1645                                                    (const char *) buffer);
1646                         xmlFree(buffer);
1647                     } else {
1648                         xmlC14NErrInternal("normalizing comment node");
1649                         return (-1);
1650                     }
1651                 }
1652 
1653                 if (ctx->pos == XMLC14N_BEFORE_DOCUMENT_ELEMENT) {
1654                     xmlOutputBufferWriteString(ctx->buf, "-->\x0A");
1655                 } else {
1656                     xmlOutputBufferWriteString(ctx->buf, "-->");
1657                 }
1658             }
1659             break;
1660         case XML_DOCUMENT_NODE:
1661         case XML_DOCUMENT_FRAG_NODE:   /* should be processed as document? */
1662 #ifdef LIBXML_DOCB_ENABLED
1663         case XML_DOCB_DOCUMENT_NODE:   /* should be processed as document? */
1664 #endif
1665 #ifdef LIBXML_HTML_ENABLED
1666         case XML_HTML_DOCUMENT_NODE:   /* should be processed as document? */
1667 #endif
1668             if (cur->children != NULL) {
1669                 ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
1670                 ctx->parent_is_doc = 1;
1671                 ret = xmlC14NProcessNodeList(ctx, cur->children);
1672             }
1673             break;
1674 
1675         case XML_ATTRIBUTE_NODE:
1676             xmlC14NErrInvalidNode("XML_ATTRIBUTE_NODE", "processing node");
1677             return (-1);
1678         case XML_NAMESPACE_DECL:
1679             xmlC14NErrInvalidNode("XML_NAMESPACE_DECL", "processing node");
1680             return (-1);
1681         case XML_ENTITY_REF_NODE:
1682             xmlC14NErrInvalidNode("XML_ENTITY_REF_NODE", "processing node");
1683             return (-1);
1684         case XML_ENTITY_NODE:
1685             xmlC14NErrInvalidNode("XML_ENTITY_NODE", "processing node");
1686             return (-1);
1687 
1688         case XML_DOCUMENT_TYPE_NODE:
1689         case XML_NOTATION_NODE:
1690         case XML_DTD_NODE:
1691         case XML_ELEMENT_DECL:
1692         case XML_ATTRIBUTE_DECL:
1693         case XML_ENTITY_DECL:
1694 #ifdef LIBXML_XINCLUDE_ENABLED
1695         case XML_XINCLUDE_START:
1696         case XML_XINCLUDE_END:
1697 #endif
1698             /*
1699              * should be ignored according to "W3C Canonical XML"
1700              */
1701             break;
1702         default:
1703             xmlC14NErrUnknownNode(cur->type, "processing node");
1704             return (-1);
1705     }
1706 
1707     return (ret);
1708 }
1709 
1710 /**
1711  * xmlC14NProcessNodeList:
1712  * @ctx:		the pointer to C14N context object
1713  * @cur:		the node to start from
1714  *
1715  * Processes all nodes in the row starting from cur.
1716  *
1717  * Returns non-negative value on success or negative value on fail
1718  */
1719 static int
xmlC14NProcessNodeList(xmlC14NCtxPtr ctx,xmlNodePtr cur)1720 xmlC14NProcessNodeList(xmlC14NCtxPtr ctx, xmlNodePtr cur)
1721 {
1722     int ret;
1723 
1724     if (ctx == NULL) {
1725         xmlC14NErrParam("processing node list");
1726         return (-1);
1727     }
1728 
1729     for (ret = 0; cur != NULL && ret >= 0; cur = cur->next) {
1730         ret = xmlC14NProcessNode(ctx, cur);
1731     }
1732     return (ret);
1733 }
1734 
1735 
1736 /**
1737  * xmlC14NFreeCtx:
1738  * @ctx: the pointer to C14N context object
1739  *
1740  * Cleanups the C14N context object.
1741  */
1742 
1743 static void
xmlC14NFreeCtx(xmlC14NCtxPtr ctx)1744 xmlC14NFreeCtx(xmlC14NCtxPtr ctx)
1745 {
1746     if (ctx == NULL) {
1747         xmlC14NErrParam("freeing context");
1748         return;
1749     }
1750 
1751     if (ctx->ns_rendered != NULL) {
1752         xmlC14NVisibleNsStackDestroy(ctx->ns_rendered);
1753     }
1754     xmlFree(ctx);
1755 }
1756 
1757 /**
1758  * xmlC14NNewCtx:
1759  * @doc:		the XML document for canonization
1760  * @is_visible_callback:the function to use to determine is node visible
1761  *			or not
1762  * @user_data:		the first parameter for @is_visible_callback function
1763  *			(in most cases, it is nodes set)
1764  * @mode:   the c14n mode (see @xmlC14NMode)
1765  * @inclusive_ns_prefixe the list of inclusive namespace prefixes
1766  *			ended with a NULL or NULL if there is no
1767  *			inclusive namespaces (only for `
1768  *			canonicalization)
1769  * @with_comments:	include comments in the result (!=0) or not (==0)
1770  * @buf:		the output buffer to store canonical XML; this
1771  *			buffer MUST have encoder==NULL because C14N requires
1772  *			UTF-8 output
1773  *
1774  * Creates new C14N context object to store C14N parameters.
1775  *
1776  * Returns pointer to newly created object (success) or NULL (fail)
1777  */
1778 static xmlC14NCtxPtr
xmlC14NNewCtx(xmlDocPtr doc,xmlC14NIsVisibleCallback is_visible_callback,void * user_data,xmlC14NMode mode,xmlChar ** inclusive_ns_prefixes,int with_comments,xmlOutputBufferPtr buf)1779 xmlC14NNewCtx(xmlDocPtr doc,
1780 	      xmlC14NIsVisibleCallback is_visible_callback, void* user_data,
1781               xmlC14NMode mode, xmlChar ** inclusive_ns_prefixes,
1782               int with_comments, xmlOutputBufferPtr buf)
1783 {
1784     xmlC14NCtxPtr ctx = NULL;
1785 
1786     if ((doc == NULL) || (buf == NULL)) {
1787         xmlC14NErrParam("creating new context");
1788         return (NULL);
1789     }
1790 
1791     /*
1792      *  Validate the encoding output buffer encoding
1793      */
1794     if (buf->encoder != NULL) {
1795         xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
1796 "xmlC14NNewCtx: output buffer encoder != NULL but C14N requires UTF8 output\n");
1797         return (NULL);
1798     }
1799 
1800     /*
1801      *  Validate the XML document encoding value, if provided.
1802      */
1803     if (doc->charset != XML_CHAR_ENCODING_UTF8) {
1804         xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
1805 		   "xmlC14NNewCtx: source document not in UTF8\n");
1806         return (NULL);
1807     }
1808 
1809     /*
1810      * Allocate a new xmlC14NCtxPtr and fill the fields.
1811      */
1812     ctx = (xmlC14NCtxPtr) xmlMalloc(sizeof(xmlC14NCtx));
1813     if (ctx == NULL) {
1814 	xmlC14NErrMemory("creating context");
1815         return (NULL);
1816     }
1817     memset(ctx, 0, sizeof(xmlC14NCtx));
1818 
1819     /*
1820      * initialize C14N context
1821      */
1822     ctx->doc = doc;
1823     ctx->with_comments = with_comments;
1824     ctx->is_visible_callback = is_visible_callback;
1825     ctx->user_data = user_data;
1826     ctx->buf = buf;
1827     ctx->parent_is_doc = 1;
1828     ctx->pos = XMLC14N_BEFORE_DOCUMENT_ELEMENT;
1829     ctx->ns_rendered = xmlC14NVisibleNsStackCreate();
1830 
1831     if(ctx->ns_rendered == NULL) {
1832         xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_CREATE_STACK,
1833 		   "xmlC14NNewCtx: xmlC14NVisibleNsStackCreate failed\n");
1834 	xmlC14NFreeCtx(ctx);
1835         return (NULL);
1836     }
1837 
1838     /*
1839      * Set "mode" flag and remember list of incluseve prefixes
1840      * for exclusive c14n
1841      */
1842     ctx->mode = mode;
1843     if(xmlC14NIsExclusive(ctx)) {
1844         ctx->inclusive_ns_prefixes = inclusive_ns_prefixes;
1845     }
1846     return (ctx);
1847 }
1848 
1849 /**
1850  * xmlC14NExecute:
1851  * @doc:		the XML document for canonization
1852  * @is_visible_callback:the function to use to determine is node visible
1853  *			or not
1854  * @user_data:		the first parameter for @is_visible_callback function
1855  *			(in most cases, it is nodes set)
1856  * @mode:	the c14n mode (see @xmlC14NMode)
1857  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
1858  *			ended with a NULL or NULL if there is no
1859  *			inclusive namespaces (only for exclusive
1860  *			canonicalization, ignored otherwise)
1861  * @with_comments:	include comments in the result (!=0) or not (==0)
1862  * @buf:		the output buffer to store canonical XML; this
1863  *			buffer MUST have encoder==NULL because C14N requires
1864  *			UTF-8 output
1865  *
1866  * Dumps the canonized image of given XML document into the provided buffer.
1867  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
1868  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
1869  *
1870  * Returns non-negative value on success or a negative value on fail
1871  */
1872 int
xmlC14NExecute(xmlDocPtr doc,xmlC14NIsVisibleCallback is_visible_callback,void * user_data,int mode,xmlChar ** inclusive_ns_prefixes,int with_comments,xmlOutputBufferPtr buf)1873 xmlC14NExecute(xmlDocPtr doc, xmlC14NIsVisibleCallback is_visible_callback,
1874 	 void* user_data, int mode, xmlChar **inclusive_ns_prefixes,
1875 	 int with_comments, xmlOutputBufferPtr buf) {
1876 
1877     xmlC14NCtxPtr ctx;
1878     xmlC14NMode c14n_mode = XML_C14N_1_0;
1879     int ret;
1880 
1881     if ((buf == NULL) || (doc == NULL)) {
1882         xmlC14NErrParam("executing c14n");
1883         return (-1);
1884     }
1885 
1886     /* for backward compatibility, we have to have "mode" as "int"
1887        and here we check that user gives valid value */
1888     switch(mode) {
1889     case XML_C14N_1_0:
1890     case XML_C14N_EXCLUSIVE_1_0:
1891     case XML_C14N_1_1:
1892          c14n_mode = (xmlC14NMode)mode;
1893          break;
1894     default:
1895         xmlC14NErrParam("invalid mode for executing c14n");
1896         return (-1);
1897     }
1898 
1899     /*
1900      *  Validate the encoding output buffer encoding
1901      */
1902     if (buf->encoder != NULL) {
1903         xmlC14NErr(NULL, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
1904 "xmlC14NExecute: output buffer encoder != NULL but C14N requires UTF8 output\n");
1905         return (-1);
1906     }
1907 
1908     ctx = xmlC14NNewCtx(doc, is_visible_callback, user_data,
1909 	            c14n_mode, inclusive_ns_prefixes,
1910                     with_comments, buf);
1911     if (ctx == NULL) {
1912         xmlC14NErr(NULL, (xmlNodePtr) doc, XML_C14N_CREATE_CTXT,
1913 		   "xmlC14NExecute: unable to create C14N context\n");
1914         return (-1);
1915     }
1916 
1917 
1918 
1919     /*
1920      * Root Node
1921      * The root node is the parent of the top-level document element. The
1922      * result of processing each of its child nodes that is in the node-set
1923      * in document order. The root node does not generate a byte order mark,
1924      * XML declaration, nor anything from within the document type
1925      * declaration.
1926      */
1927     if (doc->children != NULL) {
1928         ret = xmlC14NProcessNodeList(ctx, doc->children);
1929         if (ret < 0) {
1930             xmlC14NErrInternal("processing docs children list");
1931             xmlC14NFreeCtx(ctx);
1932             return (-1);
1933         }
1934     }
1935 
1936     /*
1937      * Flush buffer to get number of bytes written
1938      */
1939     ret = xmlOutputBufferFlush(buf);
1940     if (ret < 0) {
1941         xmlC14NErrInternal("flushing output buffer");
1942         xmlC14NFreeCtx(ctx);
1943         return (-1);
1944     }
1945 
1946     /*
1947      * Cleanup
1948      */
1949     xmlC14NFreeCtx(ctx);
1950     return (ret);
1951 }
1952 
1953 /**
1954  * xmlC14NDocSaveTo:
1955  * @doc:		the XML document for canonization
1956  * @nodes:		the nodes set to be included in the canonized image
1957  *		or NULL if all document nodes should be included
1958  * @mode:		the c14n mode (see @xmlC14NMode)
1959  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
1960  *			ended with a NULL or NULL if there is no
1961  *			inclusive namespaces (only for exclusive
1962  *			canonicalization, ignored otherwise)
1963  * @with_comments:	include comments in the result (!=0) or not (==0)
1964  * @buf:		the output buffer to store canonical XML; this
1965  *			buffer MUST have encoder==NULL because C14N requires
1966  *			UTF-8 output
1967  *
1968  * Dumps the canonized image of given XML document into the provided buffer.
1969  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
1970  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
1971  *
1972  * Returns non-negative value on success or a negative value on fail
1973  */
1974 int
xmlC14NDocSaveTo(xmlDocPtr doc,xmlNodeSetPtr nodes,int mode,xmlChar ** inclusive_ns_prefixes,int with_comments,xmlOutputBufferPtr buf)1975 xmlC14NDocSaveTo(xmlDocPtr doc, xmlNodeSetPtr nodes,
1976                  int mode, xmlChar ** inclusive_ns_prefixes,
1977                  int with_comments, xmlOutputBufferPtr buf) {
1978     return(xmlC14NExecute(doc,
1979 			xmlC14NIsNodeInNodeset,
1980 			nodes,
1981 			mode,
1982 			inclusive_ns_prefixes,
1983 			with_comments,
1984 			buf));
1985 }
1986 
1987 
1988 /**
1989  * xmlC14NDocDumpMemory:
1990  * @doc:		the XML document for canonization
1991  * @nodes:		the nodes set to be included in the canonized image
1992  *		or NULL if all document nodes should be included
1993  * @mode:		the c14n mode (see @xmlC14NMode)
1994  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
1995  *			ended with a NULL or NULL if there is no
1996  *			inclusive namespaces (only for exclusive
1997  *			canonicalization, ignored otherwise)
1998  * @with_comments:	include comments in the result (!=0) or not (==0)
1999  * @doc_txt_ptr:	the memory pointer for allocated canonical XML text;
2000  *			the caller of this functions is responsible for calling
2001  *			xmlFree() to free allocated memory
2002  *
2003  * Dumps the canonized image of given XML document into memory.
2004  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
2005  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
2006  *
2007  * Returns the number of bytes written on success or a negative value on fail
2008  */
2009 int
xmlC14NDocDumpMemory(xmlDocPtr doc,xmlNodeSetPtr nodes,int mode,xmlChar ** inclusive_ns_prefixes,int with_comments,xmlChar ** doc_txt_ptr)2010 xmlC14NDocDumpMemory(xmlDocPtr doc, xmlNodeSetPtr nodes,
2011                      int mode, xmlChar ** inclusive_ns_prefixes,
2012                      int with_comments, xmlChar ** doc_txt_ptr)
2013 {
2014     int ret;
2015     xmlOutputBufferPtr buf;
2016 
2017     if (doc_txt_ptr == NULL) {
2018         xmlC14NErrParam("dumping doc to memory");
2019         return (-1);
2020     }
2021 
2022     *doc_txt_ptr = NULL;
2023 
2024     /*
2025      * create memory buffer with UTF8 (default) encoding
2026      */
2027     buf = xmlAllocOutputBuffer(NULL);
2028     if (buf == NULL) {
2029         xmlC14NErrMemory("creating output buffer");
2030         return (-1);
2031     }
2032 
2033     /*
2034      * canonize document and write to buffer
2035      */
2036     ret = xmlC14NDocSaveTo(doc, nodes, mode, inclusive_ns_prefixes,
2037                            with_comments, buf);
2038     if (ret < 0) {
2039         xmlC14NErrInternal("saving doc to output buffer");
2040         (void) xmlOutputBufferClose(buf);
2041         return (-1);
2042     }
2043 
2044     ret = xmlBufUse(buf->buffer);
2045     if (ret > 0) {
2046         *doc_txt_ptr = xmlStrndup(xmlBufContent(buf->buffer), ret);
2047     }
2048     (void) xmlOutputBufferClose(buf);
2049 
2050     if ((*doc_txt_ptr == NULL) && (ret > 0)) {
2051         xmlC14NErrMemory("coping canonicanized document");
2052         return (-1);
2053     }
2054     return (ret);
2055 }
2056 
2057 /**
2058  * xmlC14NDocSave:
2059  * @doc:		the XML document for canonization
2060  * @nodes:		the nodes set to be included in the canonized image
2061  *		or NULL if all document nodes should be included
2062  * @mode:		the c14n mode (see @xmlC14NMode)
2063  * @inclusive_ns_prefixes: the list of inclusive namespace prefixes
2064  *			ended with a NULL or NULL if there is no
2065  *			inclusive namespaces (only for exclusive
2066  *			canonicalization, ignored otherwise)
2067  * @with_comments:	include comments in the result (!=0) or not (==0)
2068  * @filename:		the filename to store canonical XML image
2069  * @compression:	the compression level (zlib requred):
2070  *				-1 - libxml default,
2071  *				 0 - uncompressed,
2072  *				>0 - compression level
2073  *
2074  * Dumps the canonized image of given XML document into the file.
2075  * For details see "Canonical XML" (http://www.w3.org/TR/xml-c14n) or
2076  * "Exclusive XML Canonicalization" (http://www.w3.org/TR/xml-exc-c14n)
2077  *
2078  * Returns the number of bytes written success or a negative value on fail
2079  */
2080 int
xmlC14NDocSave(xmlDocPtr doc,xmlNodeSetPtr nodes,int mode,xmlChar ** inclusive_ns_prefixes,int with_comments,const char * filename,int compression)2081 xmlC14NDocSave(xmlDocPtr doc, xmlNodeSetPtr nodes,
2082                int mode, xmlChar ** inclusive_ns_prefixes,
2083                int with_comments, const char *filename, int compression)
2084 {
2085     xmlOutputBufferPtr buf;
2086     int ret;
2087 
2088     if (filename == NULL) {
2089         xmlC14NErrParam("saving doc");
2090         return (-1);
2091     }
2092 #ifdef LIBXML_ZLIB_ENABLED
2093     if (compression < 0)
2094         compression = xmlGetCompressMode();
2095 #endif
2096 
2097     /*
2098      * save the content to a temp buffer, use default UTF8 encoding.
2099      */
2100     buf = xmlOutputBufferCreateFilename(filename, NULL, compression);
2101     if (buf == NULL) {
2102         xmlC14NErrInternal("creating temporary filename");
2103         return (-1);
2104     }
2105 
2106     /*
2107      * canonize document and write to buffer
2108      */
2109     ret = xmlC14NDocSaveTo(doc, nodes, mode, inclusive_ns_prefixes,
2110                            with_comments, buf);
2111     if (ret < 0) {
2112         xmlC14NErrInternal("cannicanize document to buffer");
2113         (void) xmlOutputBufferClose(buf);
2114         return (-1);
2115     }
2116 
2117     /*
2118      * get the numbers of bytes written
2119      */
2120     ret = xmlOutputBufferClose(buf);
2121     return (ret);
2122 }
2123 
2124 
2125 
2126 /*
2127  * Macro used to grow the current buffer.
2128  */
2129 #define growBufferReentrant() {						\
2130     buffer_size *= 2;							\
2131     buffer = (xmlChar *)						\
2132 		xmlRealloc(buffer, buffer_size * sizeof(xmlChar));	\
2133     if (buffer == NULL) {						\
2134 	xmlC14NErrMemory("growing buffer");				\
2135 	return(NULL);							\
2136     }									\
2137 }
2138 
2139 /**
2140  * xmlC11NNormalizeString:
2141  * @input:		the input string
2142  * @mode:		the normalization mode (attribute, comment, PI or text)
2143  *
2144  * Converts a string to a canonical (normalized) format. The code is stolen
2145  * from xmlEncodeEntitiesReentrant(). Added normalization of \x09, \x0a, \x0A
2146  * and the @mode parameter
2147  *
2148  * Returns a normalized string (caller is responsible for calling xmlFree())
2149  * or NULL if an error occurs
2150  */
2151 static xmlChar *
xmlC11NNormalizeString(const xmlChar * input,xmlC14NNormalizationMode mode)2152 xmlC11NNormalizeString(const xmlChar * input,
2153                        xmlC14NNormalizationMode mode)
2154 {
2155     const xmlChar *cur = input;
2156     xmlChar *buffer = NULL;
2157     xmlChar *out = NULL;
2158     int buffer_size = 0;
2159 
2160     if (input == NULL)
2161         return (NULL);
2162 
2163     /*
2164      * allocate an translation buffer.
2165      */
2166     buffer_size = 1000;
2167     buffer = (xmlChar *) xmlMallocAtomic(buffer_size * sizeof(xmlChar));
2168     if (buffer == NULL) {
2169 	xmlC14NErrMemory("allocating buffer");
2170         return (NULL);
2171     }
2172     out = buffer;
2173 
2174     while (*cur != '\0') {
2175         if ((out - buffer) > (buffer_size - 10)) {
2176             int indx = out - buffer;
2177 
2178             growBufferReentrant();
2179             out = &buffer[indx];
2180         }
2181 
2182         if ((*cur == '<') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
2183                               (mode == XMLC14N_NORMALIZE_TEXT))) {
2184             *out++ = '&';
2185             *out++ = 'l';
2186             *out++ = 't';
2187             *out++ = ';';
2188         } else if ((*cur == '>') && (mode == XMLC14N_NORMALIZE_TEXT)) {
2189             *out++ = '&';
2190             *out++ = 'g';
2191             *out++ = 't';
2192             *out++ = ';';
2193         } else if ((*cur == '&') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
2194                                      (mode == XMLC14N_NORMALIZE_TEXT))) {
2195             *out++ = '&';
2196             *out++ = 'a';
2197             *out++ = 'm';
2198             *out++ = 'p';
2199             *out++ = ';';
2200         } else if ((*cur == '"') && (mode == XMLC14N_NORMALIZE_ATTR)) {
2201             *out++ = '&';
2202             *out++ = 'q';
2203             *out++ = 'u';
2204             *out++ = 'o';
2205             *out++ = 't';
2206             *out++ = ';';
2207         } else if ((*cur == '\x09') && (mode == XMLC14N_NORMALIZE_ATTR)) {
2208             *out++ = '&';
2209             *out++ = '#';
2210             *out++ = 'x';
2211             *out++ = '9';
2212             *out++ = ';';
2213         } else if ((*cur == '\x0A') && (mode == XMLC14N_NORMALIZE_ATTR)) {
2214             *out++ = '&';
2215             *out++ = '#';
2216             *out++ = 'x';
2217             *out++ = 'A';
2218             *out++ = ';';
2219         } else if ((*cur == '\x0D') && ((mode == XMLC14N_NORMALIZE_ATTR) ||
2220                                         (mode == XMLC14N_NORMALIZE_TEXT) ||
2221                                         (mode == XMLC14N_NORMALIZE_COMMENT) ||
2222 					(mode == XMLC14N_NORMALIZE_PI))) {
2223             *out++ = '&';
2224             *out++ = '#';
2225             *out++ = 'x';
2226             *out++ = 'D';
2227             *out++ = ';';
2228         } else {
2229             /*
2230              * Works because on UTF-8, all extended sequences cannot
2231              * result in bytes in the ASCII range.
2232              */
2233             *out++ = *cur;
2234         }
2235         cur++;
2236     }
2237     *out = 0;
2238     return (buffer);
2239 }
2240 #endif /* LIBXML_OUTPUT_ENABLED */
2241 #define bottom_c14n
2242 #include "elfgcchack.h"
2243 #endif /* LIBXML_C14N_ENABLED */
2244