/*

  * This file is part of dependency-check-core.

  *

  * Licensed 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.

  *

  * Copyright (c) 2015 Jeremy Long. All Rights Reserved.

  */

 package org.owasp.dependencycheck.data.update;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileNotFoundException;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.Date;

 import java.util.List;

 import java.util.zip.GZIPInputStream;

 import javax.xml.parsers.ParserConfigurationException;

 import javax.xml.parsers.SAXParser;

 import javax.xml.parsers.SAXParserFactory;

 import org.apache.commons.io.FileUtils;

 import static org.owasp.dependencycheck.data.nvdcve.DatabaseProperties.LAST_CPE_UPDATE;

 import org.owasp.dependencycheck.data.update.cpe.CPEHandler;

 import org.owasp.dependencycheck.data.update.cpe.Cpe;

 import org.owasp.dependencycheck.data.update.exception.UpdateException;

 import org.owasp.dependencycheck.utils.DateUtil;

 import org.owasp.dependencycheck.utils.DownloadFailedException;

 import org.owasp.dependencycheck.utils.Downloader;

 import org.owasp.dependencycheck.utils.Settings;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import org.xml.sax.SAXException;

 /**

  * The CpeUpdater is designed to download the CPE data file from NIST and import the data into the database. However, as this

  * currently adds no beneficial data, compared to what is in the CPE data contained in the CVE data files, this class is not

  * currently used. The code is being kept as a future update may utilize more data from the CPE xml files.

  *

  * @author Jeremy Long

  */

 public class CpeUpdater extends BaseUpdater implements CachedWebDataSource {

     /**

      * Static logger.

      */

     private static final Logger LOGGER = LoggerFactory.getLogger(CpeUpdater.class);

     @Override

     public void update() throws UpdateException {

         try {

             openDataStores();

             if (updateNeeded()) {

                 LOGGER.info("Updating the Common Platform Enumeration (CPE)");

                 final File xml = downloadCpe();

                 final List<Cpe> cpes = processXML(xml);

                 getCveDB().deleteUnusedCpe();

                 for (Cpe cpe : cpes) {

                     getCveDB().addCpe(cpe.getValue(), cpe.getVendor(), cpe.getProduct());

                 }

                 final Date now = new Date();

                 getProperties().save(LAST_CPE_UPDATE, Long.toString(now.getTime()));

                 LOGGER.info("CPE update complete");

             }

         } finally {

             closeDataStores();

         }

     }

     /**

      * Downloads the CPE XML file.

      *

      * @return the file reference to the CPE.xml file

      * @throws UpdateException thrown if there is an issue downloading the XML file

      */

     private File downloadCpe() throws UpdateException {

         File xml;

         final URL url;

         try {

             url = new URL(Settings.getString(Settings.KEYS.CPE_URL));

             xml = File.createTempFile("cpe", ".xml", Settings.getTempDirectory());

             Downloader.fetchFile(url, xml);

             if (url.toExternalForm().endsWith(".xml.gz")) {

                 extractGzip(xml);

             }

         } catch (MalformedURLException ex) {

             throw new UpdateException("Invalid CPE URL", ex);

         } catch (DownloadFailedException ex) {

             throw new UpdateException("Unable to download CPE XML file", ex);

         } catch (IOException ex) {

             throw new UpdateException("Unable to create temporary file to download CPE", ex);

         }

         return xml;

     }

     /**

      * Parses the CPE XML file to return a list of CPE entries.

      *

      * @param xml the CPE data file

      * @return the list of CPE entries

      * @throws UpdateException thrown if there is an issue with parsing the XML file

      */

     private List<Cpe> processXML(final File xml) throws UpdateException {

         try {

             final SAXParserFactory factory = SAXParserFactory.newInstance();

             final SAXParser saxParser = factory.newSAXParser();

             final CPEHandler handler = new CPEHandler();

             saxParser.parse(xml, handler);

             return handler.getData();

         } catch (ParserConfigurationException ex) {

             throw new UpdateException("Unable to parse CPE XML file due to SAX Parser Issue", ex);

         } catch (SAXException ex) {

             throw new UpdateException("Unable to parse CPE XML file due to SAX Parser Exception", ex);

         } catch (IOException ex) {

             throw new UpdateException("Unable to parse CPE XML file due to IO Failure", ex);

         }

     }

     /**

      * Checks to find the last time the CPE data was refreshed and if it needs to be updated.

      *

      * @return true if the CPE data should be refreshed

      */

     private boolean updateNeeded() {

         final Date now = new Date();

         final int days = Settings.getInt(Settings.KEYS.CVE_MODIFIED_VALID_FOR_DAYS, 30);

         long timestamp = 0;

         final String ts = getProperties().getProperty(LAST_CPE_UPDATE);

         if (ts != null && ts.matches("^[0-9]+$")) {

             timestamp = Long.parseLong(ts);

         }

         return !DateUtil.withinDateRange(timestamp, now.getTime(), days);

     }

     /**

      * Extracts the file contained in a gzip archive. The extracted file is placed in the exact same path as the file specified.

      *

      * @param file the archive file

      * @throws FileNotFoundException thrown if the file does not exist

      * @throws IOException thrown if there is an error extracting the file.

      */

     private void extractGzip(File file) throws FileNotFoundException, IOException {

         //TODO - move this to a util class as it is duplicative of (copy of) code in the DownloadTask

         final String originalPath = file.getPath();

         final File gzip = new File(originalPath + ".gz");

         if (gzip.isFile() && !gzip.delete()) {

             gzip.deleteOnExit();

         }

         if (!file.renameTo(gzip)) {

             throw new IOException("Unable to rename '" + file.getPath() + "'");

         }

         final File newfile = new File(originalPath);

         final byte[] buffer = new byte[4096];

         GZIPInputStream cin = null;

         FileOutputStream out = null;

         try {

             cin = new GZIPInputStream(new FileInputStream(gzip));

             out = new FileOutputStream(newfile);

             int len;

             while ((len = cin.read(buffer)) > 0) {

                 out.write(buffer, 0, len);

             }

         } finally {

             if (cin != null) {

                 try {

                     cin.close();

                 } catch (IOException ex) {

                     LOGGER.trace("ignore", ex);

                 }

             }

             if (out != null) {

                 try {

                     out.close();

                 } catch (IOException ex) {

                     LOGGER.trace("ignore", ex);

                 }

             }

             if (gzip.isFile()) {

                 FileUtils.deleteQuietly(gzip);

             }

         }

     }

 }