/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.sun.org.apache.xml.internal.security.utils;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import java.util.Arrays;
import java.util.WeakHashMap;
import java.lang.ref.WeakReference;
/**
* Purpose of this class is to enable the XML Parser to keep track of ID
* attributes. This is done by 'registering' attributes of type ID at the
* IdResolver. This is necessary if we create a document from scratch and we
* sign some resources with a URI using a fragent identifier...
* <BR />
* The problem is that if you do not validate a document, you cannot use the
* <CODE>getElementByID</CODE> functionality. So this modules uses some implicit
* knowledge on selected Schemas and DTDs to pick the right Element for a given
* ID: We know that all <CODE>@Id</CODE> attributes in an Element from the XML
* Signature namespace are of type <CODE>ID</CODE>.
*
* @author $Author: raul $
* @see <A HREF="http://www.xml.com/lpt/a/2001/11/07/id.html">"Identity Crisis" on xml.com</A>
*/
public class IdResolver {
/** {@link java.util.logging} logging facility */
static java.util.logging.Logger log =
java.util.logging.Logger.getLogger(IdResolver.class.getName());
static WeakHashMap docMap = new WeakHashMap();
/**
* Constructor IdResolver
*
*/
private IdResolver() {
// we don't allow instantiation
}
/**
* Method registerElementById
*
* @param element
* @param idValue
*/
public static void registerElementById(Element element, String idValue) {
Document doc = element.getOwnerDocument();
WeakHashMap elementMap = (WeakHashMap) docMap.get(doc);
if(elementMap == null) {
elementMap = new WeakHashMap();
docMap.put(doc, elementMap);
}
elementMap.put(idValue, new WeakReference(element));
}
/**
* Method registerElementById
*
* @param element
* @param id
*/
public static void registerElementById(Element element, Attr id) {
IdResolver.registerElementById(element, id.getNodeValue());
}
/**
* Method getElementById
*
* @param doc
* @param id
* @return the element obtained by the Id, or null if it is not found.
*/
public static Element getElementById(Document doc, String id) {
Element result = null;
result = IdResolver.getElementByIdType(doc, id);
if (result != null) {
if (log.isLoggable(java.util.logging.Level.FINE)) log.log(java.util.logging.Level.FINE,
"I could find an Element using the simple getElementByIdType method: "
+ result.getTagName());
return result;
}
result = IdResolver.getElementByIdUsingDOM(doc, id);
if (result != null) {
if (log.isLoggable(java.util.logging.Level.FINE)) log.log(java.util.logging.Level.FINE,
"I could find an Element using the simple getElementByIdUsingDOM method: "
+ result.getTagName());
return result;
}
// this must be done so that Xalan can catch ALL namespaces
//XMLUtils.circumventBug2650(doc);
result = IdResolver.getElementBySearching(doc, id);
if (result != null) {
IdResolver.registerElementById(result, id);
return result;
}
return null;
}
/**
* Method getElementByIdUsingDOM
*
* @param doc
* @param id
* @return the element obtained by the Id, or null if it is not found.
*/
private static Element getElementByIdUsingDOM(Document doc, String id) {
if (true)
if (log.isLoggable(java.util.logging.Level.FINE)) log.log(java.util.logging.Level.FINE, "getElementByIdUsingDOM() Search for ID " + id);
return doc.getElementById(id);
}
/**
* Method getElementByIdType
*
* @param doc
* @param id
* @return the element obtained by the Id, or null if it is not found.
*/
private static Element getElementByIdType(Document doc, String id) {
if (true)
if (log.isLoggable(java.util.logging.Level.FINE)) log.log(java.util.logging.Level.FINE, "getElementByIdType() Search for ID " + id);
WeakHashMap elementMap = (WeakHashMap) docMap.get(doc);
if (elementMap != null) {
WeakReference weakReference = (WeakReference) elementMap.get(id);
if (weakReference != null)
{
return (Element) weakReference.get();
}
}
return null;
}
static java.util.List names;
static {
String namespaces[]={ Constants.SignatureSpecNS,
EncryptionConstants.EncryptionSpecNS,
"http://schemas.xmlsoap.org/soap/security/2000-12",
"http://www.w3.org/2002/03/xkms#"
};
names=Arrays.asList(namespaces);
}
private static Element getElementBySearching(Node root,String id) {
Element []els=new Element[5];
getElementBySearching(root,id,els);
for (int i=0;i<els.length;i++) {
if (els[i]!=null) {
return els[i];
}
}
return null;
}
private static int getElementBySearching(Node root,String id,Element []els) {
switch (root.getNodeType()) {
case Node.ELEMENT_NODE:
Element el=(Element)root;
if (el.hasAttributes()) {
int index=names.indexOf(el.getNamespaceURI());
if (index<0) {
index=4;
}
if (el.getAttribute("Id").equals(id)) {
els[index]=el;
if (index==0) {
return 1;
}
} else if ( el.getAttribute("id").equals(id) ) {
if (index!=2) {
index=4;
}
els[index]=el;
} else if ( el.getAttribute("ID").equals(id) ) {
if (index!=3) {
index=4;
}
els[index]=el;
} else if ((index==3)&&(
el.getAttribute("OriginalRequestID").equals(id) ||
el.getAttribute("RequestID").equals(id) ||
el.getAttribute("ResponseID" ).equals(id))) {
els[3]=el;
}
}
case Node.DOCUMENT_NODE:
Node sibling=root.getFirstChild();
while (sibling!=null) {
if (getElementBySearching(sibling,id,els)==1)
return 1;
sibling=sibling.getNextSibling();
}
}
return 0;
}
}
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