org.apache.xml.security.encryption.AbstractSerializer Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of xmlsec Show documentation

Apache XML Security for Java supports XML-Signature Syntax and Processing, W3C Recommendation 12 February 2002, and XML Encryption Syntax and Processing, W3C Recommendation 10 December 2002. As of version 1.4, the library supports the standard Java API JSR-105: XML Digital Signature APIs.

There is a newer version: 4.0.3

Show newest version

/**
 * 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.encryption;

import java.io.ByteArrayOutputStream;
import java.util.HashMap;
import java.util.Map;

import org.apache.xml.security.c14n.Canonicalizer;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Converts Strings into Nodes and visa versa.
 * 
 * An abstract class for common Serializer functionality
 */
public abstract class AbstractSerializer implements Serializer {
    
    protected Canonicalizer canon;
    
    public void setCanonicalizer(Canonicalizer canon) {
        this.canon = canon;
    }
    
    /**
     * Returns a String representation of the specified
     * Element.
     * 
     * Refer also to comments about setup of format.
     *
     * @param element the Element to serialize.
     * @return the String representation of the serilaized
     *   Element.
     * @throws Exception
     */
    public String serialize(Element element) throws Exception {
        return canonSerialize(element);
    }

    /**
     * Returns a String representation of the specified
     * NodeList.
     * 

     * This is a special case because the NodeList may represent a
     * DocumentFragment. A document fragment may be a
     * non-valid XML document (refer to appropriate description of
     * W3C) because it my start with a non-element node, e.g. a text
     * node.
     * 

     * The methods first converts the node list into a document fragment.
     * Special care is taken to not destroy the current document, thus
     * the method clones the nodes (deep cloning) before it appends
     * them to the document fragment.
     * 
     * Refer also to comments about setup of format.
     * 
     * @param content the NodeList to serialize.
     * @return the String representation of the serialized
     *   NodeList.
     * @throws Exception
     */
    public String serialize(NodeList content) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        canon.setWriter(baos);
        canon.notReset();
        for (int i = 0; i < content.getLength(); i++) {                
            canon.canonicalizeSubtree(content.item(i));                
        }
        String ret = baos.toString("UTF-8");
        baos.reset();
        return ret;
    }

    /**
     * Use the Canonicalizer to serialize the node
     * @param node
     * @return the canonicalization of the node
     * @throws Exception
     */ 
    public String canonSerialize(Node node) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        canon.setWriter(baos);                      
        canon.notReset();
        canon.canonicalizeSubtree(node);                    
        String ret = baos.toString("UTF-8");
        baos.reset();
        return ret;
    }

    /**
     * @param source
     * @param ctx
     * @return the Node resulting from the parse of the source
     * @throws XMLEncryptionException
     */
    public abstract Node deserialize(String source, Node ctx) throws XMLEncryptionException;
    
    protected static String createContext(String source, Node ctx) {
        // Create the context to parse the document against
        StringBuilder sb = new StringBuilder();
        sb.append(" storedNamespaces = new HashMap();
        Node wk = ctx;
        while (wk != null) {
            NamedNodeMap atts = wk.getAttributes();
            if (atts != null) {
                for (int i = 0; i < atts.getLength(); ++i) {
                    Node att = atts.item(i);
                    String nodeName = att.getNodeName();
                    if ((nodeName.equals("xmlns") || nodeName.startsWith("xmlns:"))
                        && !storedNamespaces.containsKey(att.getNodeName())) {
                        sb.append(" " + nodeName + "=\"" + att.getNodeValue() + "\"");
                        storedNamespaces.put(nodeName, att.getNodeValue());
                    }
                }
            }
            wk = wk.getParentNode();
        }
        sb.append(">" + source + "");
        return sb.toString();
    }
    
}