org.apache.xml.security.c14n.implementations.CanonicalizerPhysical Maven / Gradle / Ivy
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/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.xml.security.c14n.implementations;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.xml.security.c14n.CanonicalizationException;
import org.apache.xml.security.c14n.Canonicalizer;
import org.apache.xml.security.signature.XMLSignatureInput;
import org.w3c.dom.Attr;
import org.w3c.dom.Comment;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.ProcessingInstruction;
import org.xml.sax.SAXException;
/**
* Serializes the physical representation of the subtree. All the attributes
* present in the subtree are emitted. The attributes are sorted within an element,
* with the namespace declarations appearing before the regular attributes.
* This algorithm is not a true canonicalization since equivalent subtrees
* may produce different output. It is therefore unsuitable for digital signatures.
* This same property makes it ideal for XML Encryption Syntax and Processing,
* because the decrypted XML content will share the same physical representation
* as the original XML content that was encrypted.
*/
public class CanonicalizerPhysical extends CanonicalizerBase {
private final SortedSet result = new TreeSet(COMPARE);
/**
* Constructor Canonicalizer20010315
*/
public CanonicalizerPhysical() {
super(true);
}
/**
* Always throws a CanonicalizationException.
*
* @param xpathNodeSet
* @param inclusiveNamespaces
* @return none it always fails
* @throws CanonicalizationException always
*/
public byte[] engineCanonicalizeXPathNodeSet(Set xpathNodeSet, String inclusiveNamespaces)
throws CanonicalizationException {
/** $todo$ well, should we throw UnsupportedOperationException ? */
throw new CanonicalizationException("c14n.Canonicalizer.UnsupportedOperation");
}
/**
* Always throws a CanonicalizationException.
*
* @param rootNode
* @param inclusiveNamespaces
* @return none it always fails
* @throws CanonicalizationException
*/
public byte[] engineCanonicalizeSubTree(Node rootNode, String inclusiveNamespaces)
throws CanonicalizationException {
/** $todo$ well, should we throw UnsupportedOperationException ? */
throw new CanonicalizationException("c14n.Canonicalizer.UnsupportedOperation");
}
/**
* Returns the Attr[]s to be output for the given element.
*
* The code of this method is a copy of {@link #handleAttributes(Element,
* NameSpaceSymbTable)},
* whereas it takes into account that subtree-c14n is -- well -- subtree-based.
* So if the element in question isRoot of c14n, it's parent is not in the
* node set, as well as all other ancestors.
*
* @param element
* @param ns
* @return the Attr[]s to be output
* @throws CanonicalizationException
*/
@Override
protected Iterator handleAttributesSubtree(Element element, NameSpaceSymbTable ns)
throws CanonicalizationException {
if (!element.hasAttributes()) {
return null;
}
// result will contain all the attrs declared directly on that element
final SortedSet result = this.result;
result.clear();
if (element.hasAttributes()) {
NamedNodeMap attrs = element.getAttributes();
int attrsLength = attrs.getLength();
for (int i = 0; i < attrsLength; i++) {
Attr attribute = (Attr) attrs.item(i);
result.add(attribute);
}
}
return result.iterator();
}
/**
* Returns the Attr[]s to be output for the given element.
*
* @param element
* @param ns
* @return the Attr[]s to be output
* @throws CanonicalizationException
*/
@Override
protected Iterator handleAttributes(Element element, NameSpaceSymbTable ns)
throws CanonicalizationException {
/** $todo$ well, should we throw UnsupportedOperationException ? */
throw new CanonicalizationException("c14n.Canonicalizer.UnsupportedOperation");
}
protected void circumventBugIfNeeded(XMLSignatureInput input)
throws CanonicalizationException, ParserConfigurationException, IOException, SAXException {
// nothing to do
}
@Override
protected void handleParent(Element e, NameSpaceSymbTable ns) {
// nothing to do
}
/** @inheritDoc */
public final String engineGetURI() {
return Canonicalizer.ALGO_ID_C14N_PHYSICAL;
}
/** @inheritDoc */
public final boolean engineGetIncludeComments() {
return true;
}
@Override
protected void outputPItoWriter(ProcessingInstruction currentPI,
OutputStream writer, int position) throws IOException {
// Processing Instructions before or after the document element are not treated specially
super.outputPItoWriter(currentPI, writer, NODE_NOT_BEFORE_OR_AFTER_DOCUMENT_ELEMENT);
}
@Override
protected void outputCommentToWriter(Comment currentComment,
OutputStream writer, int position) throws IOException {
// Comments before or after the document element are not treated specially
super.outputCommentToWriter(currentComment, writer, NODE_NOT_BEFORE_OR_AFTER_DOCUMENT_ELEMENT);
}
}