/** 

 * XML Security Library (http://www.aleksey.com/xmlsec).

 *

 * XPath transform

 *

 * This is free software; see Copyright file in the source

 * distribution for preciese wording.

 * 

 * Copyright (C) 2002-2003 Aleksey Sanin <aleksey@aleksey.com>

 * Portion Copyright © 2009 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.

 */

#include "xmlsec_globals.h"

#include <stdlib.h>

#include <string.h>

#include <libxml2_tree.h>

#include <libxml2_xpath.h>

#include <libxml2_xpathinternals.h>

#include <libxml2_xpointer.h>

#include <libxml2_valid.h>

#include <libxml2_globals.h>

#include "xmlsec_xmlsec.h"

#include "xmlsec_xmltree.h"

#include "xmlsec_keys.h"

#include "xmlsec_list.h"

#include "xmlsec_transforms.h"

#include "xmlsec_errors.h"

/**************************************************************************

 *

 * xmlSecXPathHereFunction:

 * @ctxt:		the ponter to XPath context.

 * @nargs:		the arguments nubmer.

 *

 * The implementation of XPath "here()" function.

 * See xmlXPtrHereFunction() in xpointer.c. the only change is that 

 * we return NodeSet instead of NodeInterval.

 *

 *****************************************************************************/

static void 

xmlSecXPathHereFunction(xmlXPathParserContextPtr ctxt, int nargs) {

    CHECK_ARITY(0);

    if((ctxt == NULL) || (ctxt->context == NULL) || (ctxt->context->here == NULL)) {

	XP_ERROR(XPTR_SYNTAX_ERROR);

    }

    valuePush(ctxt, xmlXPathNewNodeSet(ctxt->context->here));

}

/**************************************************************************

 *

 * XPath/XPointer data

 *

 *****************************************************************************/

typedef struct _xmlSecXPathData			xmlSecXPathData,

						*xmlSecXPathDataPtr;

typedef enum {

    xmlSecXPathDataTypeXPath,

    xmlSecXPathDataTypeXPath2,

    xmlSecXPathDataTypeXPointer

} xmlSecXPathDataType;

struct _xmlSecXPathData {

    xmlSecXPathDataType			type;

    xmlXPathContextPtr			ctx;

    xmlChar*				expr;

    xmlSecNodeSetOp			nodeSetOp;

    xmlSecNodeSetType			nodeSetType;    

};

static xmlSecXPathDataPtr 	xmlSecXPathDataCreate		(xmlSecXPathDataType type);

static void		  	xmlSecXPathDataDestroy		(xmlSecXPathDataPtr data);

static int		  	xmlSecXPathDataSetExpr		(xmlSecXPathDataPtr data,

								 const xmlChar* expr);

static int 			xmlSecXPathDataRegisterNamespaces(xmlSecXPathDataPtr data, 

								 xmlNodePtr node);

static int		  	xmlSecXPathDataNodeRead		(xmlSecXPathDataPtr data,

								 xmlNodePtr node);

static xmlSecNodeSetPtr		xmlSecXPathDataExecute		(xmlSecXPathDataPtr data,

								 xmlDocPtr doc,

								 xmlNodePtr hereNode);

static xmlSecXPathDataPtr  

xmlSecXPathDataCreate(xmlSecXPathDataType type) {

    xmlSecXPathDataPtr data;

    data = (xmlSecXPathDataPtr) xmlMalloc(sizeof(xmlSecXPathData));

    if(data == NULL) {

	xmlSecError(XMLSEC_ERRORS_HERE,

		    NULL,

		    NULL,

		    XMLSEC_ERRORS_R_MALLOC_FAILED,

		    "sizeof(xmlSecXPathData)=%d",

		    sizeof(xmlSecXPathData));

	return(NULL);

    }

    memset(data, 0, sizeof(xmlSecXPathData)); 

    data->type = type;

    data->nodeSetType = xmlSecNodeSetTree;

    /* create xpath or xpointer context */

    switch(data->type) {

    case xmlSecXPathDataTypeXPath:    

    case xmlSecXPathDataTypeXPath2:    

	data->ctx = xmlXPathNewContext(NULL); /* we'll set doc in the context later */

	if(data->ctx == NULL) {

	    xmlSecError(XMLSEC_ERRORS_HERE,

			NULL,

			"xmlXPathNewContext",

			XMLSEC_ERRORS_R_XML_FAILED,

			XMLSEC_ERRORS_NO_MESSAGE);

	    xmlSecXPathDataDestroy(data);

	    return(NULL);

	}

	break;

    case xmlSecXPathDataTypeXPointer:    

	data->ctx = xmlXPtrNewContext(NULL, NULL, NULL); /* we'll set doc in the context later */

	if(data->ctx == NULL) {

	    xmlSecError(XMLSEC_ERRORS_HERE,

			NULL,

			"xmlXPtrNewContext",

			XMLSEC_ERRORS_R_XML_FAILED,

			XMLSEC_ERRORS_NO_MESSAGE);

	    xmlSecXPathDataDestroy(data);

	    return(NULL);

	}

	break;

    }

    return(data);

}

static void				

xmlSecXPathDataDestroy(xmlSecXPathDataPtr data) {

    xmlSecAssert(data != NULL);    

    if(data->expr != NULL) {

	xmlFree(data->expr);

    }

    if(data->ctx != NULL) {

	xmlXPathFreeContext(data->ctx);

    }

    memset(data, 0, sizeof(xmlSecXPathData));  

    xmlFree(data);

}

static int 

xmlSecXPathDataSetExpr(xmlSecXPathDataPtr data, const xmlChar* expr) {

    xmlSecAssert2(data != NULL, -1);    

    xmlSecAssert2(data->expr == NULL, -1);

    xmlSecAssert2(data->ctx != NULL, -1);

    xmlSecAssert2(expr != NULL, -1);    

    data->expr = xmlStrdup(expr);

    if(data->expr == NULL) {

	xmlSecError(XMLSEC_ERRORS_HERE,

		    NULL,

		    NULL,

		    XMLSEC_ERRORS_R_STRDUP_FAILED,

		    XMLSEC_ERRORS_NO_MESSAGE);

        return(-1);

    }

    return(0);

}

static int 

xmlSecXPathDataRegisterNamespaces(xmlSecXPathDataPtr data, xmlNodePtr node) {

    xmlNodePtr cur;

    xmlNsPtr ns;

    int ret;

    xmlSecAssert2(data != NULL, -1);    

    xmlSecAssert2(data->ctx != NULL, -1);

    xmlSecAssert2(node != NULL, -1);

    /* register namespaces */

    for(cur = node; cur != NULL; cur = cur->parent) {

	for(ns = cur->nsDef; ns != NULL; ns = ns->next) {

	    /* check that we have no other namespace with same prefix already */

	    if((ns->prefix != NULL) && (xmlXPathNsLookup(data->ctx, ns->prefix) == NULL)){

	        ret = xmlXPathRegisterNs(data->ctx, ns->prefix, ns->href);

		if(ret != 0) {

		    xmlSecError(XMLSEC_ERRORS_HERE,

				NULL,

			        "xmlXPathRegisterNs",

				XMLSEC_ERRORS_R_XML_FAILED,

			        "href=%s;prefix=%s",

			        xmlSecErrorsSafeString(ns->href),

				xmlSecErrorsSafeString(ns->prefix)); 

		    return(-1);

		}

	    }

	}

    }

    return(0);

}

static int 

xmlSecXPathDataNodeRead(xmlSecXPathDataPtr data, xmlNodePtr node) {

    int ret;

    xmlSecAssert2(data != NULL, -1);    

    xmlSecAssert2(data->expr == NULL, -1);

    xmlSecAssert2(data->ctx != NULL, -1);

    xmlSecAssert2(node != NULL, -1);

    ret = xmlSecXPathDataRegisterNamespaces (data, node);

    if(ret < 0) {

	xmlSecError(XMLSEC_ERRORS_HERE,

		    NULL,

		    "xmlSecXPathDataRegisterNamespaces",

		    XMLSEC_ERRORS_R_XMLSEC_FAILED,

		    XMLSEC_ERRORS_NO_MESSAGE);

        return(-1);

    }

    /* read node content and set expr */

    data->expr = xmlNodeGetContent(node);

    if(data->expr == NULL) {

	xmlSecError(XMLSEC_ERRORS_HERE,

		    NULL,

		    xmlSecErrorsSafeString(xmlSecNodeGetName(node)),

		    XMLSEC_ERRORS_R_INVALID_NODE_CONTENT,

		    XMLSEC_ERRORS_NO_MESSAGE);

        return(-1);

    }

    return(0);

}

static xmlSecNodeSetPtr

xmlSecXPathDataExecute(xmlSecXPathDataPtr data, xmlDocPtr doc, xmlNodePtr hereNode) {

    xmlXPathObjectPtr xpathObj = NULL; 

    xmlSecNodeSetPtr nodes = NULL;

    xmlSecAssert2(data != NULL, NULL);    

    xmlSecAssert2(data->expr != NULL, NULL);

    xmlSecAssert2(data->ctx != NULL, NULL);

    xmlSecAssert2(doc != NULL, NULL);

    xmlSecAssert2(hereNode != NULL, NULL);

    /* do not forget to set the doc */

    data->ctx->doc = doc;

    /* here function works only on the same document */

    if(hereNode->doc == doc) {

	xmlXPathRegisterFunc(data->ctx, (xmlChar *)"here", xmlSecXPathHereFunction);

	data->ctx->here = hereNode;

	data->ctx->xptr = 1;

    }

    /* execute xpath or xpointer expression */

    switch(data->type) {

    case xmlSecXPathDataTypeXPath:    

    case xmlSecXPathDataTypeXPath2:    

	xpathObj = xmlXPathEvalExpression(data->expr, data->ctx);

	if(xpathObj == NULL) {

	    xmlSecError(XMLSEC_ERRORS_HERE,

			NULL,

			"xmlXPathEvalExpression",

			XMLSEC_ERRORS_R_XML_FAILED,

			"expr=%s", 

			xmlSecErrorsSafeString(data->expr));

	    return(NULL);

	}

	break;

    case xmlSecXPathDataTypeXPointer:    

	xpathObj = xmlXPtrEval(data->expr, data->ctx);

	if(xpathObj == NULL) {

	    xmlSecError(XMLSEC_ERRORS_HERE,

			NULL,

			"xmlXPtrEval",

			XMLSEC_ERRORS_R_XML_FAILED,

			"expr=%s", 

			xmlSecErrorsSafeString(data->expr));

	    return(NULL);

	}

	break;

    }

    if (xpathObj != NULL) {

        nodes = xmlSecNodeSetCreate(doc, xpathObj->nodesetval, data->nodeSetType);

    }

    if(nodes == NULL) {

	xmlSecError(XMLSEC_ERRORS_HERE,

		    NULL,

		    "xmlSecNodeSetCreate",

		    XMLSEC_ERRORS_R_XMLSEC_FAILED,

		    "type=%d", data->nodeSetType);

	xmlXPathFreeObject(xpathObj);     

	return(NULL);

    }

    xpathObj->nodesetval = NULL;

    xmlXPathFreeObject(xpathObj); 

    return(nodes);

}

/**************************************************************************

 *

 * XPath data list

 *

 *****************************************************************************/

#define xmlSecXPathDataListId	\

	xmlSecXPathDataListGetKlass()

static xmlSecPtrListId 	xmlSecXPathDataListGetKlass		(void);

static xmlSecNodeSetPtr	xmlSecXPathDataListExecute		(xmlSecPtrListPtr dataList,

								 xmlDocPtr doc,

								 xmlNodePtr hereNode,

								 xmlSecNodeSetPtr nodes);

static xmlSecPtrListKlass xmlSecXPathDataListKlass = {

    BAD_CAST "xpath-data-list",

    NULL,						/* xmlSecPtrDuplicateItemMethod duplicateItem; */

    (xmlSecPtrDestroyItemMethod)xmlSecXPathDataDestroy,	/* xmlSecPtrDestroyItemMethod destroyItem; */

    NULL,						/* xmlSecPtrDebugDumpItemMethod debugDumpItem; */

    NULL,						/* xmlSecPtrDebugDumpItemMethod debugXmlDumpItem; */

};

static xmlSecPtrListId 

xmlSecXPathDataListGetKlass(void) {

    return(&xmlSecXPathDataListKlass);

}

static xmlSecNodeSetPtr	

xmlSecXPathDataListExecute(xmlSecPtrListPtr dataList, xmlDocPtr doc, 

		    	   xmlNodePtr hereNode, xmlSecNodeSetPtr nodes) {

    xmlSecXPathDataPtr data;

    xmlSecNodeSetPtr res, tmp, tmp2;

    xmlSecSize pos;

    xmlSecAssert2(xmlSecPtrListCheckId(dataList, xmlSecXPathDataListId), NULL);

    xmlSecAssert2(xmlSecPtrListGetSize(dataList) > 0, NULL);

    xmlSecAssert2(doc != NULL, NULL);

    xmlSecAssert2(hereNode != NULL, NULL);

    res = nodes;

    for(pos = 0; pos < xmlSecPtrListGetSize(dataList); ++pos) {

        data = (xmlSecXPathDataPtr)xmlSecPtrListGetItem(dataList, pos);

	if(data == NULL) {

	    xmlSecError(XMLSEC_ERRORS_HERE,

		        NULL,

			"xmlSecPtrListGetItem",

		        XMLSEC_ERRORS_R_XMLSEC_FAILED,

			"pos=%d", pos);

	    if((res != NULL) && (res != nodes)) {

		xmlSecNodeSetDestroy(res);

	    }

	    return(NULL);

	}

	tmp = xmlSecXPathDataExecute(data, doc, hereNode);

	if(tmp == NULL) {

	    xmlSecError(XMLSEC_ERRORS_HERE,

			NULL,

			"xmlSecXPathDataExecute",

			XMLSEC_ERRORS_R_XMLSEC_FAILED,

			XMLSEC_ERRORS_NO_MESSAGE);

	    if((res != NULL) && (res != nodes)) {

		xmlSecNodeSetDestroy(res);

	    }

	    return(NULL);

	}    

	tmp2 = xmlSecNodeSetAdd(res, tmp, data->nodeSetOp);

	if(tmp2 == NULL) {

	    xmlSecError(XMLSEC_ERRORS_HERE,

			NULL,

			"xmlSecNodeSetAdd",

		        XMLSEC_ERRORS_R_XMLSEC_FAILED,

			"xmlSecNodeSetIntersection");

	    if((res != NULL) && (res != nodes)) {

		xmlSecNodeSetDestroy(res);

	    }

	    xmlSecNodeSetDestroy(tmp);

	    return(NULL);

	}

	res = tmp2;

    }

    return(res);

}

/******************************************************************************

 *

 * XPath/XPointer transforms

 *

 * xmlSecXPathDataList is located after xmlSecTransform structure

 * 

 *****************************************************************************/

#define xmlSecXPathTransformSize	\

    (sizeof(xmlSecTransform) + sizeof(xmlSecPtrList))

#define xmlSecXPathTransformGetDataList(transform) \

    ((xmlSecTransformCheckSize((transform), xmlSecXPathTransformSize)) ? \

	(xmlSecPtrListPtr)(((xmlSecByte*)(transform)) + sizeof(xmlSecTransform)) : \

	(xmlSecPtrListPtr)NULL)

#define xmlSecTransformXPathCheckId(transform) \

    (xmlSecTransformCheckId((transform), xmlSecTransformXPathId) || \

     xmlSecTransformCheckId((transform), xmlSecTransformXPath2Id) || \

     xmlSecTransformCheckId((transform), xmlSecTransformXPointerId))

static int 		xmlSecTransformXPathInitialize	(xmlSecTransformPtr transform);

static void		xmlSecTransformXPathFinalize	(xmlSecTransformPtr transform);

static int 		xmlSecTransformXPathExecute	(xmlSecTransformPtr transform,

							 int last, 

							 xmlSecTransformCtxPtr transformCtx);

static int

xmlSecTransformXPathInitialize(xmlSecTransformPtr transform) {	

    xmlSecPtrListPtr dataList;

    int ret;

    xmlSecAssert2(xmlSecTransformXPathCheckId(transform), -1);

    dataList = xmlSecXPathTransformGetDataList(transform);

    xmlSecAssert2(dataList != NULL, -1);

    ret = xmlSecPtrListInitialize(dataList, xmlSecXPathDataListId);

    if(ret < 0) {

	xmlSecError(XMLSEC_ERRORS_HERE,

		    xmlSecErrorsSafeString(xmlSecTransformGetName(transform)),

		    "xmlSecPtrListInitialize",

		    XMLSEC_ERRORS_R_XMLSEC_FAILED,

		    XMLSEC_ERRORS_NO_MESSAGE);

	return(-1);

    }

    return(0);

}

static void

xmlSecTransformXPathFinalize(xmlSecTransformPtr transform) {

    xmlSecPtrListPtr dataList;

    xmlSecAssert(xmlSecTransformXPathCheckId(transform));

    dataList = xmlSecXPathTransformGetDataList(transform);

    xmlSecAssert(xmlSecPtrListCheckId(dataList, xmlSecXPathDataListId));

    xmlSecPtrListFinalize(dataList);

}

static int

xmlSecTransformXPathExecute(xmlSecTransformPtr transform, int last,

			    xmlSecTransformCtxPtr transformCtx) {

    xmlSecPtrListPtr dataList;

    xmlDocPtr doc;

    xmlSecAssert2(xmlSecTransformXPathCheckId(transform), -1);

    xmlSecAssert2(transform->hereNode != NULL, -1);

    xmlSecAssert2(transform->outNodes == NULL, -1);

    xmlSecAssert2(last != 0, -1);

    xmlSecAssert2(transformCtx != NULL, -1);

    dataList = xmlSecXPathTransformGetDataList(transform);

    xmlSecAssert2(xmlSecPtrListCheckId(dataList, xmlSecXPathDataListId), -1);

    xmlSecAssert2(xmlSecPtrListGetSize(dataList) > 0, -1);

    doc = (transform->inNodes != NULL) ? transform->inNodes->doc : transform->hereNode->doc;

    xmlSecAssert2(doc != NULL, -1);

    transform->outNodes = xmlSecXPathDataListExecute(dataList, doc, 

				transform->hereNode, transform->inNodes);

    if(transform->outNodes == NULL) {

	xmlSecError(XMLSEC_ERRORS_HERE,

		    xmlSecErrorsSafeString(xmlSecTransformGetName(transform)),

		    "xmlSecXPathDataExecute",

		    XMLSEC_ERRORS_R_XMLSEC_FAILED,

		    XMLSEC_ERRORS_NO_MESSAGE);

	return(-1);

    }    

    return(0);

}

/******************************************************************************

 *

 * XPath transform

 * 

 *****************************************************************************/

static int 		xmlSecTransformXPathNodeRead	(xmlSecTransformPtr transform,

							 xmlNodePtr node,

							 xmlSecTransformCtxPtr transformCtx);

static xmlSecTransformKlass xmlSecTransformXPathKlass = {

    /* klass/object sizes */

    sizeof(xmlSecTransformKlass),		/* xmlSecSize klassSize */

    xmlSecXPathTransformSize,			/* xmlSecSize objSize */

    xmlSecNameXPath,				/* const xmlChar* name; */

    xmlSecXPathNs, 				/* const xmlChar* href; */

    xmlSecTransformUsageDSigTransform,		/* xmlSecTransformUsage	usage; */

    xmlSecTransformXPathInitialize,		/* xmlSecTransformInitializeMethod initialize; */

    xmlSecTransformXPathFinalize,		/* xmlSecTransformFinalizeMethod finalize; */

    xmlSecTransformXPathNodeRead,		/* xmlSecTransformNodeReadMethod readNode; */

    NULL,					/* xmlSecTransformNodeWriteMethod writeNode; */

    NULL,					/* xmlSecTransformSetKeyReqMethod setKeyReq; */

    NULL,					/* xmlSecTransformSetKeyMethod setKey; */

    NULL,					/* xmlSecTransformValidateMethod validate; */

    xmlSecTransformDefaultGetDataType,		/* xmlSecTransformGetDataTypeMethod getDataType; */

    NULL,					/* xmlSecTransformPushBinMethod pushBin; */

    NULL,					/* xmlSecTransformPopBinMethod popBin; */

    xmlSecTransformDefaultPushXml,		/* xmlSecTransformPushXmlMethod pushXml; */

    xmlSecTransformDefaultPopXml,		/* xmlSecTransformPopXmlMethod popXml; */

    xmlSecTransformXPathExecute,		/* xmlSecTransformExecuteMethod execute; */

    NULL,					/* void* reserved0; */

    NULL,					/* void* reserved1; */

};

/**

 * xmlSecTransformXPathGetKlass:

 *

 * The XPath transform evaluates given XPath expression and 

 * intersects the result with the previous nodes set. See 

 * http://www.w3.org/TR/xmldsig-core/#sec-XPath for more details.

 *

 * Returns XPath transform id.

 */

EXPORT_C

xmlSecTransformId 

xmlSecTransformXPathGetKlass(void) {