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