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* DO NOT REMOVE OR ALTER!
*/
/*
* 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.
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package com.sun.org.apache.xml.internal.security.utils;
import java.lang.ref.WeakReference;
import java.util.Arrays;
import java.util.WeakHashMap;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
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...
The problem is that if you do not validate a document, you cannot use the
getElementByID 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 @Id attributes in an Element from the XML
Signature namespace are of type ID.
Author: $Author: mullan $ See Also:
/**
* 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: mullan $
* @see <A HREF="http://www.xml.com/lpt/a/2001/11/07/id.html">"Identity Crisis" on xml.com</A>
*/
public class IdResolver {
logging logging facility /** {@link java.util.logging} logging facility */
private static java.util.logging.Logger log =
java.util.logging.Logger.getLogger(IdResolver.class.getName());
private static WeakHashMap docMap = new WeakHashMap();
Constructor IdResolver
/**
* Constructor IdResolver
*
*/
private IdResolver() {
// we don't allow instantiation
}
Method registerElementById
Params: - element – the element to register
- idValue – the value of the ID attribute
/**
* Method registerElementById
*
* @param element the element to register
* @param idValue the value of the ID attribute
*/
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
Params: - element – the element to register
- id – the ID attribute
/**
* Method registerElementById
*
* @param element the element to register
* @param id the ID attribute
*/
public static void registerElementById(Element element, Attr id) {
IdResolver.registerElementById(element, id.getNodeValue());
}
Method getElementById
Params: - doc – the document
- id – the value of the ID
Returns: the element obtained by the id, or null if it is not found.
/**
* Method getElementById
*
* @param doc the document
* @param id the value of the 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 = IdResolver.getElementByIdType(doc, id);
if (result != null) {
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) {
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
Params: - doc – the document
- id – the value of the ID
Returns: the element obtained by the id, or null if it is not found.
/**
* Method getElementByIdUsingDOM
*
* @param doc the document
* @param id the value of the ID
* @return the element obtained by the id, or null if it is not found.
*/
private static Element getElementByIdUsingDOM(Document doc, String id) {
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
Params: - doc – the document
- id – the value of the ID
Returns: the element obtained by the id, or null if it is not found.
/**
* Method getElementByIdType
*
* @param doc the document
* @param id the value of the ID
* @return the element obtained by the id, or null if it is not found.
*/
private static Element getElementByIdType(Document doc, String id) {
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;
}
private static java.util.List names;
private static int namesLength;
static {
String namespaces[]={
Constants.SignatureSpecNS,
EncryptionConstants.EncryptionSpecNS,
"http://schemas.xmlsoap.org/soap/security/2000-12",
"http://www.w3.org/2002/03/xkms#",
"urn:oasis:names:tc:SAML:1.0:assertion",
"urn:oasis:names:tc:SAML:1.0:protocol"
};
names = Arrays.asList(namespaces);
namesLength = names.size();
}
private static Element getElementBySearching(Node root,String id) {
Element []els=new Element[namesLength + 1];
getEl(root,id,els);
for (int i=0;i<els.length;i++) {
if (els[i]!=null) {
return els[i];
}
}
return null;
}
private static int getEl(Node currentNode,String id,Element []els) {
Node sibling=null;
Node parentNode=null;
do {
switch (currentNode.getNodeType()) {
case Node.DOCUMENT_FRAGMENT_NODE :
case Node.DOCUMENT_NODE :
sibling= currentNode.getFirstChild();
break;
case Node.ELEMENT_NODE :
Element currentElement = (Element) currentNode;
if (isElement(currentElement, id, els)==1)
return 1;
sibling= currentNode.getFirstChild();
if (sibling==null) {
if (parentNode != null) {
sibling= currentNode.getNextSibling();
}
} else {
parentNode=currentElement;
}
break;
} while (sibling==null && parentNode!=null) {
sibling=parentNode.getNextSibling();
parentNode=parentNode.getParentNode();
if (parentNode != null && parentNode.getNodeType() != Node.ELEMENT_NODE) {
parentNode=null;
}
}
if (sibling==null)
return 1;
currentNode=sibling;
sibling=currentNode.getNextSibling();
} while(true);
}
public static int isElement(Element el, String id,Element[] els) {
if (!el.hasAttributes()) {
return 0;
}
NamedNodeMap ns=el.getAttributes();
int elementIndex=names.indexOf(el.getNamespaceURI());
elementIndex=(elementIndex<0) ? namesLength : elementIndex;
for (int length=ns.getLength(), i=0; i<length; i++) {
Attr n=(Attr)ns.item(i);
String s=n.getNamespaceURI();
int index=s==null ? elementIndex : names.indexOf(n.getNamespaceURI());
index=(index<0) ? namesLength : index;
String name=n.getLocalName();
if (name.length()>2)
continue;
String value=n.getNodeValue();
if (name.charAt(0)=='I') {
char ch=name.charAt(1);
if (ch=='d' && value.equals(id)) {
els[index]=el;
if (index==0) {
return 1;
}
} else if (ch=='D' &&value.endsWith(id)) {
if (index!=3) {
index=namesLength;
}
els[index]=el;
}
} else if ( "id".equals(name) && value.equals(id) ) {
if (index!=2) {
index=namesLength;
}
els[index]=el;
}
}
//For an element namespace search for importants
if ((elementIndex==3)&&(
el.getAttribute("OriginalRequestID").equals(id) ||
el.getAttribute("RequestID").equals(id) ||
el.getAttribute("ResponseID").equals(id))) {
els[3]=el;
} else if ((elementIndex==4)&&(
el.getAttribute("AssertionID").equals(id))) {
els[4]=el;
} else if ((elementIndex==5)&&(
el.getAttribute("RequestID").equals(id) ||
el.getAttribute("ResponseID").equals(id))) {
els[5]=el;
}
return 0;
}
}