FileExtMismatchXML.java

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/*
 * Autopsy Forensic Browser
 *
 * Copyright 2011-2014 Basis Technology Corp.
 * Contact: carrier <at> sleuthkit <dot> org
 *
 * 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.
 */
package org.sleuthkit.autopsy.modules.fileextmismatch;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.logging.Level;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.sleuthkit.autopsy.coreutils.Logger;
import org.sleuthkit.autopsy.coreutils.PlatformUtil;
import org.sleuthkit.autopsy.coreutils.XMLUtil;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

class FileExtMismatchXML {

    private static final Logger logger = Logger.getLogger(FileExtMismatchXML.class.getName());
    private static FileExtMismatchXML defaultInstance = null;

    private static final String ENCODING = "UTF-8"; //NON-NLS
    private static final String XSDFILE = "MismatchConfigSchema.xsd"; //NON-NLS

    private static final String ROOT_EL = "mismatch_config"; //NON-NLS
    private static final String SIG_EL = "signature"; //NON-NLS
    private static final String EXT_EL = "ext";     //NON-NLS
    private static final String SIG_MIMETYPE_ATTR = "mimetype"; //NON-NLS

    private static final String DEFAULT_CONFIG_FILE_NAME = "mismatch_config.xml";   //NON-NLS

    protected String filePath;

    FileExtMismatchXML(String filePath) {
        this.filePath = filePath;

        try {
            boolean extracted = PlatformUtil.extractResourceToUserConfigDir(FileExtMismatchXML.class, DEFAULT_CONFIG_FILE_NAME, false);
        } catch (IOException ex) {
            logger.log(Level.SEVERE, "Error copying default mismatch configuration to user dir ", ex); //NON-NLS
        }
    }

    public static synchronized FileExtMismatchXML getDefault() {
        if (defaultInstance == null) {
            final String FILTER_CONFIG_FILE = PlatformUtil.getUserConfigDirectory() + File.separator + DEFAULT_CONFIG_FILE_NAME;
            defaultInstance = new FileExtMismatchXML(FILTER_CONFIG_FILE);
        }
        return defaultInstance;
    }

    public HashMap<String, String[]> load() {
        HashMap<String, String[]> sigTypeToExtMap = new HashMap<>();

        try {
            final Document doc = XMLUtil.loadDoc(FileExtMismatchXML.class, filePath);
            if (doc == null) {
                return null;
            }

            Element root = doc.getDocumentElement();
            if (root == null) {
                logger.log(Level.SEVERE, "Error loading config file: invalid file format (bad root)."); //NON-NLS
                return null;
            }

            NodeList sigNList = root.getElementsByTagName(SIG_EL);
            final int numSigs = sigNList.getLength();

            if (numSigs == 0) {
                return null;
            }

            for (int sigIndex = 0; sigIndex < numSigs; ++sigIndex) {
                Element sigEl = (Element) sigNList.item(sigIndex);
                final String mimetype = sigEl.getAttribute(SIG_MIMETYPE_ATTR);

                NodeList extNList = sigEl.getElementsByTagName(EXT_EL);
                final int numExts = extNList.getLength();

                if (numExts != 0) {
                    List<String> extStrings = new ArrayList<>();
                    for (int extIndex = 0; extIndex < numExts; ++extIndex) {
                        Element extEl = (Element) extNList.item(extIndex);
                        extStrings.add(extEl.getTextContent());
                    }
                    String[] sarray = extStrings.toArray(new String[0]);
                    sigTypeToExtMap.put(mimetype, sarray);
                } else {
                    sigTypeToExtMap.put(mimetype, null); //ok to have an empty type (the ingest module will not use it)
                }
            }

        } catch (Exception e) {
            logger.log(Level.SEVERE, "Error loading config file.", e); //NON-NLS
            return null;
        }
        return sigTypeToExtMap;
    }

    public boolean save(HashMap<String, String[]> sigTypeToExtMap) {
        boolean success;

        DocumentBuilderFactory dbfac = DocumentBuilderFactory.newInstance();

        try {
            DocumentBuilder docBuilder = dbfac.newDocumentBuilder();
            Document doc = docBuilder.newDocument();

            Element rootEl = doc.createElement(ROOT_EL);
            doc.appendChild(rootEl);

            ArrayList<String> mimeTypeList = new ArrayList<>(sigTypeToExtMap.keySet());
            Collections.sort(mimeTypeList);

            for (String mimeType : mimeTypeList) {
                Element sigEl = doc.createElement(SIG_EL);
                sigEl.setAttribute(SIG_MIMETYPE_ATTR, mimeType.toLowerCase());

                String[] extArray = sigTypeToExtMap.get(mimeType);
                if (extArray != null) {
                    ArrayList<String> extList = new ArrayList<>(Arrays.asList(extArray));
                    Collections.sort(extList);
                    for (String ext : extList) {
                        Element extEl = doc.createElement(EXT_EL);
                        extEl.setTextContent(ext.toLowerCase());
                        sigEl.appendChild(extEl);
                    }
                }
                rootEl.appendChild(sigEl);
            }

            success = XMLUtil.saveDoc(FileExtMismatchXML.class, filePath, ENCODING, doc);

        } catch (ParserConfigurationException e) {
            logger.log(Level.SEVERE, "Error saving keyword list: can't initialize parser.", e); //NON-NLS
            success = false;
        }
        return success;
    }

}