AbstractXMLDigestReader.java

/*
 * GovWay - A customizable API Gateway 
 * https://govway.org
 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package org.openspcoop2.utils.digest;

import org.slf4j.Logger;
import org.openspcoop2.utils.LoggerWrapperFactory;
import org.openspcoop2.utils.UtilsException;
import org.openspcoop2.utils.xml.AbstractXMLUtils;
import org.openspcoop2.utils.xml.AbstractXPathExpressionEngine;
import org.openspcoop2.utils.xml.DynamicNamespaceContext;
import org.openspcoop2.utils.xml.XPathNotFoundException;
import org.openspcoop2.utils.xml.XPathReturnType;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

/**
 * AbstractXMLDigestReader
 *
 * @author Andrea Poli (apoli@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public abstract class AbstractXMLDigestReader implements IDigestReader {

    private Logger log;
    private AbstractXPathExpressionEngine xpathEngine;
    private AbstractXMLUtils xmlUtils;

    public AbstractXMLDigestReader(AbstractXMLUtils xmlUtils,AbstractXPathExpressionEngine xpathEngine) {
        this(LoggerWrapperFactory.getLogger(AbstractXMLDigestReader.class),xmlUtils,xpathEngine);
    }
    public AbstractXMLDigestReader(Logger log,AbstractXMLUtils xmlUtils,AbstractXPathExpressionEngine xpathEngine) {
        this.log = log;
        this.xmlUtils = xmlUtils;
        this.xpathEngine = xpathEngine;
    }

    @Override
    public String getDigest(Element element,String referenceId,DynamicNamespaceContext dnc) throws UtilsException{

        try {

            // Search ReferenceElement
            String xPathReferenceElement = 
                    "//{"+Constants.DS_NAMESPACE+"}"+
                            Constants.DS_REFERENCE_ELEMENT+
                            "[@"+Constants.DS_REFERENCE_ATTRIBUTE_URI+"='"+referenceId+"']";
            Node n = null;
            try{
                this.log.debug("Search referenceId con xpath ["+xPathReferenceElement+"] ...");
                n = (Node) this.xpathEngine.getMatchPattern(element, dnc, xPathReferenceElement , XPathReturnType.NODE);
            }catch(XPathNotFoundException notFound){
                xPathReferenceElement = 
                        "//"+Constants.DS_REFERENCE_ELEMENT+
                        "[@"+Constants.DS_REFERENCE_ATTRIBUTE_URI+"='"+referenceId+"']";
                this.log.debug("Search(2) referenceId con xpath ["+xPathReferenceElement+"] ...");
                try{
                    n = (Node) this.xpathEngine.getMatchPattern(element, dnc, xPathReferenceElement , XPathReturnType.NODE);
                }catch(XPathNotFoundException notFoundInternal){
                    this.log.debug("Reference id ["+referenceId+"] non troavata");
                    return null;
                }
            }
            byte [] nBytes= this.xmlUtils.toByteArray(n);
            this.log.debug("Found Reference Element ["+this.xmlUtils.toString(n)+"]");

            // Search DigestValue
            String xPathDigestValue = "//{"+Constants.DS_NAMESPACE+"}"+Constants.DS_REFERENCE_DIGEST_VALUE_ELEMENT+"/text()";
            String digest = null;
            try{
                this.log.debug("Search digestValue con xpath ["+xPathDigestValue+"] ...");
                digest = (String) this.xpathEngine.getMatchPattern(this.xmlUtils.newDocument(nBytes), dnc, xPathDigestValue , XPathReturnType.STRING);
            }catch(XPathNotFoundException notFound){
                xPathDigestValue = "//"+Constants.DS_REFERENCE_DIGEST_VALUE_ELEMENT+"/text()";
                this.log.debug("Search(2) digestValue con xpath ["+xPathDigestValue+"] ...");
                digest = (String) this.xpathEngine.getMatchPattern(element, dnc, xPathReferenceElement , XPathReturnType.STRING);
            }
            this.log.debug("Found DigestValue ["+digest+"]");

            return digest;
        } catch (Exception e) {
            this.log.error("Errore durante la getDigest", e);
            throw new UtilsException(e.getMessage(),e);
        } 
    

    }

}