be.fedict.eid.applet.service.signer.odf.ODFURIDereferencer.java Source code

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Here is the source code for be.fedict.eid.applet.service.signer.odf.ODFURIDereferencer.java

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/*
 * eID Applet Project.
 * Copyright (C) 2009 FedICT.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version
 * 3.0 as published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, see 
 * http://www.gnu.org/licenses/.
 */
package be.fedict.eid.applet.service.signer.odf;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLDecoder;

import javax.xml.crypto.Data;
import javax.xml.crypto.OctetStreamData;
import javax.xml.crypto.URIDereferencer;
import javax.xml.crypto.URIReference;
import javax.xml.crypto.URIReferenceException;
import javax.xml.crypto.XMLCryptoContext;
import javax.xml.crypto.dsig.XMLSignatureFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.xml.security.signature.XMLSignatureInput;
import org.w3c.dom.Document;
import org.xml.sax.EntityResolver;
import org.xml.sax.SAXException;

/**
 * JSR105 URI dereferencer implementation using an ODF file as resource
 * repository.
 * 
 * @author fcorneli
 * 
 */
public class ODFURIDereferencer implements URIDereferencer {

    private static final Log LOG = LogFactory.getLog(ODFURIDereferencer.class);
    private final URL odfUrl;
    private final byte[] odfData;
    private final URIDereferencer baseUriDereferener;
    private final DocumentBuilder documentBuilder;

    public ODFURIDereferencer(URL odfUrl) {
        this(odfUrl, null);
    }

    public ODFURIDereferencer(byte[] odfData) {
        this(null, odfData);
    }

    private ODFURIDereferencer(URL odfUrl, byte[] odfData) {
        if (null == odfUrl && null == odfData) {
            throw new IllegalArgumentException("odfUrl and odfData are null");
        }
        if (null != odfUrl && null != odfData) {
            throw new IllegalArgumentException("odfUrl and odfData are both not null");
        }
        this.odfUrl = odfUrl;
        this.odfData = odfData;
        XMLSignatureFactory xmlSignatureFactory = XMLSignatureFactory.getInstance();
        this.baseUriDereferener = xmlSignatureFactory.getURIDereferencer();

        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        documentBuilderFactory.setNamespaceAware(true);

        try {
            this.documentBuilder = documentBuilderFactory.newDocumentBuilder();
        } catch (ParserConfigurationException e) {
            throw new RuntimeException("parser config error: " + e.getMessage(), e);
        }
        EntityResolver entityResolver = new ODFEntityResolver();
        this.documentBuilder.setEntityResolver(entityResolver);
    }

    public Data dereference(URIReference uriReference, XMLCryptoContext context) throws URIReferenceException {
        if (null == uriReference) {
            throw new NullPointerException("URIReference cannot be null");
        }
        if (null == context) {
            throw new NullPointerException("XMLCrytoContext cannot be null");
        }

        String uri = uriReference.getURI();
        try {
            uri = URLDecoder.decode(uri, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            LOG.warn("could not URL decode the uri: " + uri);
        }
        LOG.debug("dereference: " + uri);
        try {
            InputStream dataInputStream = findDataInputStream(uri);
            if (null == dataInputStream) {
                LOG.debug("cannot resolve, delegating to base DOM URI dereferener: " + uri);
                return this.baseUriDereferener.dereference(uriReference, context);
            }
            if (uri.endsWith(".xml")) {
                /*
                 * We parse the XML ourselves as we might need to resolve MathML
                 * DTD.
                 */
                byte[] data = IOUtils.toByteArray(dataInputStream);
                if (0 == data.length) {
                    return new OctetStreamData(dataInputStream, uri, null);
                }
                Document document = documentBuilder.parse(new ByteArrayInputStream(data));
                XMLSignatureInput xmlSignatureInput = new XMLSignatureInput(document);
                ApacheNodeSetData apacheNodeSetData = new ApacheNodeSetData(xmlSignatureInput);
                return apacheNodeSetData;
            }
            return new OctetStreamData(dataInputStream, uri, null);
        } catch (IOException e) {
            throw new URIReferenceException("I/O error: " + e.getMessage(), e);
        } catch (SAXException e) {
            throw new URIReferenceException("SAX error: " + e.getMessage(), e);
        }
    }

    /**
     * Find a given file / zip entry in the ODF package
     * 
     * @param uri
     * @return inputstream of the file
     * @throws IOException
     */
    private InputStream findDataInputStream(String uri) throws IOException {
        InputStream odfInputStream;
        if (null != this.odfUrl) {
            odfInputStream = this.odfUrl.openStream();
        } else {
            odfInputStream = new ByteArrayInputStream(this.odfData);
        }
        return ODFUtil.findDataInputStream(odfInputStream, uri);
    }
}