1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 /*
6 * Copyright 1999-2004 The Apache Software Foundation.
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 *
20 */
21 package com.sun.org.apache.xml.internal.security.utils;
22
23 import java.lang.ref.WeakReference;
24 import java.util.Arrays;
25 import java.util.WeakHashMap;
26 import java.util.Map;
27
28 import org.w3c.dom.Attr;
29 import org.w3c.dom.Document;
30 import org.w3c.dom.Element;
31 import org.w3c.dom.NamedNodeMap;
32 import org.w3c.dom.Node;
33
34
35 /**
36 * Purpose of this class is to enable the XML Parser to keep track of ID
37 * attributes. This is done by 'registering' attributes of type ID at the
38 * IdResolver. This is necessary if we create a document from scratch and we
39 * sign some resources with a URI using a fragent identifier...
40 * <BR />
41 * The problem is that if you do not validate a document, you cannot use the
42 * <CODE>getElementByID</CODE> functionality. So this modules uses some implicit
43 * knowledge on selected Schemas and DTDs to pick the right Element for a given
44 * ID: We know that all <CODE>@Id</CODE> attributes in an Element from the XML
45 * Signature namespace are of type <CODE>ID</CODE>.
46 *
47 * @author $Author: mullan $
48 * @see <A HREF="http://www.xml.com/lpt/a/2001/11/07/id.html">"Identity Crisis" on xml.com</A>
49 */
50 public class IdResolver {
51
52 /** {@link java.util.logging} logging facility */
53 private static java.util.logging.Logger log =
54 java.util.logging.Logger.getLogger(IdResolver.class.getName());
55
56 private static Map<Document, Map<String, WeakReference<Element>>> docMap =
57 new WeakHashMap<Document, Map<String, WeakReference<Element>>>();
58
59 /**
60 * Constructor IdResolver
61 *
62 */
63 private IdResolver() {
64 // we don't allow instantiation
65 }
66
67 /**
68 * Method registerElementById
69 *
70 * @param element the element to register
71 * @param idValue the value of the ID attribute
72 */
73 public static void registerElementById(Element element, String idValue) {
74 Document doc = element.getOwnerDocument();
75 Map<String, WeakReference<Element>> elementMap;
76 synchronized (docMap) {
77 elementMap = docMap.get(doc);
78 if (elementMap == null) {
79 elementMap = new WeakHashMap<String, WeakReference<Element>>();
80 docMap.put(doc, elementMap);
81 }
82 }
83 elementMap.put(idValue, new WeakReference<Element>(element));
84 }
85
86 /**
87 * Method registerElementById
88 *
89 * @param element the element to register
90 * @param id the ID attribute
91 */
92 public static void registerElementById(Element element, Attr id) {
93 IdResolver.registerElementById(element, id.getNodeValue());
94 }
95
96 /**
97 * Method getElementById
98 *
99 * @param doc the document
100 * @param id the value of the ID
101 * @return the element obtained by the id, or null if it is not found.
102 */
103 public static Element getElementById(Document doc, String id) {
104
105 Element result = IdResolver.getElementByIdType(doc, id);
106
107 if (result != null) {
108 log.log(java.util.logging.Level.FINE,
109 "I could find an Element using the simple getElementByIdType method: "
110 + result.getTagName());
111
112 return result;
113 }
114
115 result = IdResolver.getElementByIdUsingDOM(doc, id);
116
117 if (result != null) {
118 log.log(java.util.logging.Level.FINE,
119 "I could find an Element using the simple getElementByIdUsingDOM method: "
120 + result.getTagName());
121
122 return result;
123 }
124 // this must be done so that Xalan can catch ALL namespaces
125 //XMLUtils.circumventBug2650(doc);
126 result = IdResolver.getElementBySearching(doc, id);
127
128 if (result != null) {
129 IdResolver.registerElementById(result, id);
130
131 return result;
132 }
133
134 return null;
135 }
136
137
138 /**
139 * Method getElementByIdUsingDOM
140 *
141 * @param doc the document
142 * @param id the value of the ID
143 * @return the element obtained by the id, or null if it is not found.
144 */
145 private static Element getElementByIdUsingDOM(Document doc, String id) {
146 if (log.isLoggable(java.util.logging.Level.FINE))
147 log.log(java.util.logging.Level.FINE, "getElementByIdUsingDOM() Search for ID " + id);
148 return doc.getElementById(id);
149 }
150
151 /**
152 * Method getElementByIdType
153 *
154 * @param doc the document
155 * @param id the value of the ID
156 * @return the element obtained by the id, or null if it is not found.
157 */
158 private static Element getElementByIdType(Document doc, String id) {
159 if (log.isLoggable(java.util.logging.Level.FINE))
160 log.log(java.util.logging.Level.FINE, "getElementByIdType() Search for ID " + id);
161 Map<String, WeakReference<Element>> elementMap;
162 synchronized (docMap) {
163 elementMap = docMap.get(doc);
164 }
165 if (elementMap != null) {
166 WeakReference<Element> weakReference = elementMap.get(id);
167 if (weakReference != null) {
168 return weakReference.get();
169 }
170 }
171 return null;
172 }
173
174 private static java.util.List<String> names;
175 private static int namesLength;
176 static {
177 String namespaces[]={
178 Constants.SignatureSpecNS,
179 EncryptionConstants.EncryptionSpecNS,
180 "http://schemas.xmlsoap.org/soap/security/2000-12",
181 "http://www.w3.org/2002/03/xkms#",
182 "urn:oasis:names:tc:SAML:1.0:assertion",
183 "urn:oasis:names:tc:SAML:1.0:protocol"
184 };
185 names = Arrays.asList(namespaces);
186 namesLength = names.size();
187 }
188
189
190 private static Element getElementBySearching(Node root,String id) {
191 Element []els=new Element[namesLength + 1];
192 getEl(root,id,els);
193 for (int i=0;i<els.length;i++) {
194 if (els[i]!=null) {
195 return els[i];
196 }
197 }
198 return null;
199 }
200
201 private static int getEl(Node currentNode,String id,Element []els) {
202 Node sibling=null;
203 Node parentNode=null;
204 do {
205 switch (currentNode.getNodeType()) {
206 case Node.DOCUMENT_FRAGMENT_NODE :
207 case Node.DOCUMENT_NODE :
208 sibling= currentNode.getFirstChild();
209 break;
210
211
212 case Node.ELEMENT_NODE :
213 Element currentElement = (Element) currentNode;
214 if (isElement(currentElement, id, els)==1)
215 return 1;
216 sibling= currentNode.getFirstChild();
217 if (sibling==null) {
218 if (parentNode != null) {
219 sibling= currentNode.getNextSibling();
220 }
221 } else {
222 parentNode=currentElement;
223 }
224 break;
225 } while (sibling==null && parentNode!=null) {
226 sibling=parentNode.getNextSibling();
227 parentNode=parentNode.getParentNode();
228 if (parentNode != null && parentNode.getNodeType() != Node.ELEMENT_NODE) {
229 parentNode=null;
230 }
231 }
232 if (sibling==null)
233 return 1;
234 currentNode=sibling;
235 sibling=currentNode.getNextSibling();
236 } while(true);
237
238 }
239 public static int isElement(Element el, String id,Element[] els) {
240 if (!el.hasAttributes()) {
241 return 0;
242 }
243 NamedNodeMap ns=el.getAttributes();
244 int elementIndex=names.indexOf(el.getNamespaceURI());
245 elementIndex=(elementIndex<0) ? namesLength : elementIndex;
246 for (int length=ns.getLength(), i=0; i<length; i++) {
247 Attr n=(Attr)ns.item(i);
248 String s=n.getNamespaceURI();
249
250 int index=s==null ? elementIndex : names.indexOf(n.getNamespaceURI());
251 index=(index<0) ? namesLength : index;
252 String name=n.getLocalName();
253 if (name == null)
254 name = n.getName();
255 if (name.length()>2)
256 continue;
257 String value=n.getNodeValue();
258 if (name.charAt(0)=='I') {
259 char ch=name.charAt(1);
260 if (ch=='d' && value.equals(id)) {
261 els[index]=el;
262 if (index==0) {
263 return 1;
264 }
265 } else if (ch=='D' &&value.endsWith(id)) {
266 if (index!=3) {
267 index=namesLength;
268 }
269 els[index]=el;
270 }
271 } else if ( "id".equals(name) && value.equals(id) ) {
272 if (index!=2) {
273 index=namesLength;
274 }
275 els[index]=el;
276 }
277 }
278 //For an element namespace search for importants
279 if ((elementIndex==3)&&(
280 el.getAttribute("OriginalRequestID").equals(id) ||
281 el.getAttribute("RequestID").equals(id) ||
282 el.getAttribute("ResponseID").equals(id))) {
283 els[3]=el;
284 } else if ((elementIndex==4)&&(
285 el.getAttribute("AssertionID").equals(id))) {
286 els[4]=el;
287 } else if ((elementIndex==5)&&(
288 el.getAttribute("RequestID").equals(id) ||
289 el.getAttribute("ResponseID").equals(id))) {
290 els[5]=el;
291 }
292 return 0;
293 }
294 }