eu.europa.esig.dss.tsl.download.XmlDownloadTask Maven / Gradle / Ivy
/**
* DSS - Digital Signature Services
* Copyright (C) 2015 European Commission, provided under the CEF programme
*
* This file is part of the "DSS - Digital Signature Services" project.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package eu.europa.esig.dss.tsl.download;
import eu.europa.esig.dss.xml.utils.XMLCanonicalizer;
import eu.europa.esig.dss.xml.utils.DomUtils;
import eu.europa.esig.dss.enumerations.DigestAlgorithm;
import eu.europa.esig.dss.model.DSSDocument;
import eu.europa.esig.dss.model.DSSException;
import eu.europa.esig.dss.model.Digest;
import eu.europa.esig.dss.spi.DSSUtils;
import eu.europa.esig.dss.spi.client.http.DSSFileLoader;
import org.w3c.dom.Document;
import javax.xml.crypto.dsig.CanonicalizationMethod;
import java.util.Objects;
import java.util.function.Supplier;
/**
* Downloads the document and returns a {@code XmlDownloadResult}
*/
public class XmlDownloadTask implements Supplier {
/** The file loader */
private final DSSFileLoader dssFileLoader;
/** The URL to download the document from */
private final String url;
/**
* Default constructor
*
* @param dssFileLoader {@link DSSFileLoader} to use
* @param url {@link String} to download the document from
*/
public XmlDownloadTask(DSSFileLoader dssFileLoader, String url) {
Objects.requireNonNull(dssFileLoader, "The DSSFileLoader is null");
Objects.requireNonNull(url, "The url is null");
this.dssFileLoader = dssFileLoader;
this.url = url;
}
@Override
public XmlDownloadResult get() {
try {
final DSSDocument dssDocument = dssFileLoader.getDocument(url);
assertDocumentIsValidXML(dssDocument);
final Document dom = DomUtils.buildDOM(dssDocument);
final byte[] canonicalizedContent = XMLCanonicalizer.createInstance(CanonicalizationMethod.EXCLUSIVE).canonicalize(dom);
return new XmlDownloadResult(dssDocument, new Digest(DigestAlgorithm.SHA256, DSSUtils.digest(DigestAlgorithm.SHA256, canonicalizedContent)));
} catch (DSSException e) {
throw e;
} catch (Exception e) {
throw new DSSException(String.format("Unable to retrieve the content for url '%s'. Reason : '%s'", url, e.getMessage()), e);
}
}
private void assertDocumentIsValidXML(DSSDocument document) {
if (document == null) {
throw new NullPointerException(String.format("No document has been retrieved from URL '%s'!", url));
}
if (!DomUtils.isDOM(document)) {
throw new DSSException(String.format("The document obtained from URL '%s' is not a valid XML!", url));
}
}
}