SevenZipExtractor.java

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/*
 * Autopsy Forensic Browser
 *
 * Copyright 2013-2019 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.embeddedfileextractor;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Level;
import net.sf.sevenzipjbinding.ArchiveFormat;
import static net.sf.sevenzipjbinding.ArchiveFormat.RAR;
import net.sf.sevenzipjbinding.ExtractAskMode;
import net.sf.sevenzipjbinding.ExtractOperationResult;
import net.sf.sevenzipjbinding.IArchiveExtractCallback;
import net.sf.sevenzipjbinding.ICryptoGetTextPassword;
import net.sf.sevenzipjbinding.ISequentialOutStream;
import net.sf.sevenzipjbinding.ISevenZipInArchive;
import net.sf.sevenzipjbinding.PropID;
import net.sf.sevenzipjbinding.SevenZip;
import net.sf.sevenzipjbinding.SevenZipException;
import net.sf.sevenzipjbinding.SevenZipNativeInitializationException;
import org.netbeans.api.progress.ProgressHandle;
import org.openide.util.NbBundle;
import org.openide.util.NbBundle.Messages;
import org.sleuthkit.autopsy.casemodule.Case;
import org.sleuthkit.autopsy.casemodule.NoCurrentCaseException;
import org.sleuthkit.autopsy.casemodule.services.FileManager;
import org.sleuthkit.autopsy.coreutils.FileUtil;
import org.sleuthkit.autopsy.coreutils.Logger;
import org.sleuthkit.autopsy.coreutils.MessageNotifyUtil;
import org.sleuthkit.autopsy.ingest.IngestJobContext;
import org.sleuthkit.autopsy.ingest.IngestMessage;
import org.sleuthkit.autopsy.ingest.IngestMonitor;
import org.sleuthkit.autopsy.ingest.IngestServices;
import org.sleuthkit.autopsy.ingest.ModuleContentEvent;
import org.sleuthkit.autopsy.modules.filetypeid.FileTypeDetector;
import org.sleuthkit.datamodel.AbstractFile;
import org.sleuthkit.datamodel.Blackboard;
import org.sleuthkit.datamodel.BlackboardArtifact;
import static org.sleuthkit.datamodel.BlackboardArtifact.ARTIFACT_TYPE.TSK_INTERESTING_FILE_HIT;
import org.sleuthkit.datamodel.BlackboardAttribute;
import static org.sleuthkit.datamodel.BlackboardAttribute.ATTRIBUTE_TYPE.TSK_COMMENT;
import static org.sleuthkit.datamodel.BlackboardAttribute.ATTRIBUTE_TYPE.TSK_DESCRIPTION;
import static org.sleuthkit.datamodel.BlackboardAttribute.ATTRIBUTE_TYPE.TSK_SET_NAME;
import org.sleuthkit.datamodel.Content;
import org.sleuthkit.datamodel.DerivedFile;
import org.sleuthkit.datamodel.EncodedFileOutputStream;
import org.sleuthkit.datamodel.ReadContentInputStream;
import org.sleuthkit.datamodel.TskCoreException;
import org.sleuthkit.datamodel.TskData;

class SevenZipExtractor {

    private static final Logger logger = Logger.getLogger(SevenZipExtractor.class.getName());
    private static final String MODULE_NAME = EmbeddedFileExtractorModuleFactory.getModuleName();

    //encryption type strings
    private static final String ENCRYPTION_FILE_LEVEL = NbBundle.getMessage(EmbeddedFileExtractorIngestModule.class,
            "EmbeddedFileExtractorIngestModule.ArchiveExtractor.encryptionFileLevel");
    private static final String ENCRYPTION_FULL = NbBundle.getMessage(EmbeddedFileExtractorIngestModule.class,
            "EmbeddedFileExtractorIngestModule.ArchiveExtractor.encryptionFull");

    //zip bomb detection
    private static final int MAX_DEPTH = 4;
    private static final int MAX_COMPRESSION_RATIO = 600;
    private static final long MIN_COMPRESSION_RATIO_SIZE = 500 * 1000000L;
    private static final long MIN_FREE_DISK_SPACE = 1 * 1000 * 1000000L; //1GB

    private IngestServices services = IngestServices.getInstance();
    private final IngestJobContext context;
    private final FileTypeDetector fileTypeDetector;

    private String moduleDirRelative;
    private String moduleDirAbsolute;

    private Blackboard blackboard;

    private ProgressHandle progress;
    private int numItems;
    private String currentArchiveName;

    private String getLocalRootAbsPath(String uniqueArchiveFileName) {
        return moduleDirAbsolute + File.separator + uniqueArchiveFileName;
    }

    private enum SupportedArchiveExtractionFormats {

        ZIP("application/zip"), //NON-NLS
        SEVENZ("application/x-7z-compressed"), //NON-NLS
        GZIP("application/gzip"), //NON-NLS
        XGZIP("application/x-gzip"), //NON-NLS
        XBZIP2("application/x-bzip2"), //NON-NLS
        XTAR("application/x-tar"), //NON-NLS
        XGTAR("application/x-gtar"),
        XRAR("application/x-rar-compressed"); //NON-NLS

        private final String mimeType;

        SupportedArchiveExtractionFormats(final String mimeType) {
            this.mimeType = mimeType;
        }

        @Override
        public String toString() {
            return this.mimeType;
        }
        // TODO Expand to support more formats after upgrading Tika
    }

    SevenZipExtractor(IngestJobContext context, FileTypeDetector fileTypeDetector, String moduleDirRelative, String moduleDirAbsolute) throws SevenZipNativeInitializationException {
        if (!SevenZip.isInitializedSuccessfully() && (SevenZip.getLastInitializationException() == null)) {
            SevenZip.initSevenZipFromPlatformJAR();
        }
        this.context = context;
        this.fileTypeDetector = fileTypeDetector;
        this.moduleDirRelative = moduleDirRelative;
        this.moduleDirAbsolute = moduleDirAbsolute;
    }

    boolean isSevenZipExtractionSupported(AbstractFile file) {
        String fileMimeType = fileTypeDetector.getMIMEType(file);
        for (SupportedArchiveExtractionFormats mimeType : SupportedArchiveExtractionFormats.values()) {
            if (mimeType.toString().equals(fileMimeType)) {
                return true;
            }
        }
        return false;
    }

    private boolean isZipBombArchiveItemCheck(AbstractFile archiveFile, ISevenZipInArchive inArchive, int inArchiveItemIndex, ConcurrentHashMap<Long, Archive> depthMap, String escapedFilePath) {
        //If a file is corrupted as a result of reconstructing it from unallocated space, then
        //7zip does a poor job estimating the original uncompressed file size. 
        //As a result, many corrupted files have wonky compression ratios and could flood the UI
        //with false zip bomb notifications. The decision was made to skip compression ratio checks 
        //for unallocated zip files. Instead, we let the depth be an indicator of a zip bomb.
        //Gzip archives compress a single file. They may have a sparse file,
        //and that file could be much larger, however it won't be the exponential growth seen with more dangerous zip bombs.
        //In addition a fair number of browser cache files will be gzip archives,
        //and their file sizes are frequently retrieved incorrectly so ignoring gzip files is a reasonable decision.
        if (archiveFile.isMetaFlagSet(TskData.TSK_FS_META_FLAG_ENUM.UNALLOC) || archiveFile.getMIMEType().equalsIgnoreCase(SupportedArchiveExtractionFormats.XGZIP.toString())) {
            return false;
        }

        try {
            final Long archiveItemSize = (Long) inArchive.getProperty(
                    inArchiveItemIndex, PropID.SIZE);

            //skip the check for small files
            if (archiveItemSize == null || archiveItemSize < MIN_COMPRESSION_RATIO_SIZE) {
                return false;
            }

            final Long archiveItemPackedSize = (Long) inArchive.getProperty(
                    inArchiveItemIndex, PropID.PACKED_SIZE);

            if (archiveItemPackedSize == null || archiveItemPackedSize <= 0) {
                logger.log(Level.WARNING, "Cannot getting compression ratio, cannot detect if zipbomb: {0}, item: {1}", //NON-NLS
                        new Object[]{archiveFile.getName(), (String) inArchive.getProperty(inArchiveItemIndex, PropID.PATH)}); //NON-NLS
                return false;
            }

            int cRatio = (int) (archiveItemSize / archiveItemPackedSize);

            if (cRatio >= MAX_COMPRESSION_RATIO) {
                Archive rootArchive = depthMap.get(depthMap.get(archiveFile.getId()).getRootArchiveId());
                String details = NbBundle.getMessage(SevenZipExtractor.class,
                        "EmbeddedFileExtractorIngestModule.ArchiveExtractor.isZipBombCheck.warnDetails",
                        cRatio, FileUtil.escapeFileName(getArchiveFilePath(rootArchive.getArchiveFile())));

                flagRootArchiveAsZipBomb(rootArchive, archiveFile, details, escapedFilePath);
                return true;
            } else {
                return false;
            }

        } catch (SevenZipException ex) {
            logger.log(Level.WARNING, "Error getting archive item size and cannot detect if zipbomb. ", ex); //NON-NLS
            return false;
        }
    }

    private void flagRootArchiveAsZipBomb(Archive rootArchive, AbstractFile archiveFile, String details, String escapedFilePath) {
        rootArchive.flagAsZipBomb();
        logger.log(Level.INFO, details);
        try {
            Collection<BlackboardAttribute> attributes = Arrays.asList(
                    new BlackboardAttribute(
                            TSK_SET_NAME, MODULE_NAME,
                            "Possible Zip Bomb"),
                    new BlackboardAttribute(
                            TSK_DESCRIPTION, MODULE_NAME,
                            Bundle.SevenZipExtractor_zipBombArtifactCreation_text(archiveFile.getName())),
                    new BlackboardAttribute(
                            TSK_COMMENT, MODULE_NAME,
                            details));

            if (!blackboard.artifactExists(archiveFile, TSK_INTERESTING_FILE_HIT, attributes)) {
                BlackboardArtifact artifact = rootArchive.getArchiveFile().newArtifact(TSK_INTERESTING_FILE_HIT);
                artifact.addAttributes(attributes);
                try {
                    /*
                     * post the artifact which will index the artifact for
                     * keyword search, and fire an event to notify UI of this
                     * new artifact
                     */
                    blackboard.postArtifact(artifact, MODULE_NAME);

                    String msg = NbBundle.getMessage(SevenZipExtractor.class,
                            "EmbeddedFileExtractorIngestModule.ArchiveExtractor.isZipBombCheck.warnMsg", archiveFile.getName(), escapedFilePath);//NON-NLS

                    services.postMessage(IngestMessage.createWarningMessage(MODULE_NAME, msg, details));

                } catch (Blackboard.BlackboardException ex) {
                    logger.log(Level.SEVERE, "Unable to index blackboard artifact " + artifact.getArtifactID(), ex); //NON-NLS
                    MessageNotifyUtil.Notify.error(
                            Bundle.SevenZipExtractor_indexError_message(), artifact.getDisplayName());
                }
            }
        } catch (TskCoreException ex) {
            logger.log(Level.SEVERE, "Error creating blackboard artifact for Zip Bomb Detection for file: " + escapedFilePath, ex); //NON-NLS
        }
    }

    private ArchiveFormat get7ZipOptions(AbstractFile archiveFile) {
        // try to get the file type from the BB
        String detectedFormat;
        detectedFormat = archiveFile.getMIMEType();

        if (detectedFormat == null) {
            logger.log(Level.WARNING, "Could not detect format for file: {0}", archiveFile); //NON-NLS

            // if we don't have attribute info then use file extension
            String extension = archiveFile.getNameExtension();
            if ("rar".equals(extension)) //NON-NLS
            {
                // for RAR files we need to open them explicitly as RAR. Otherwise, if there is a ZIP archive inside RAR archive
                // it will be opened incorrectly when using 7zip's built-in auto-detect functionality
                return RAR;
            }

            // Otherwise open the archive using 7zip's built-in auto-detect functionality
            return null;
        } else if (detectedFormat.contains("application/x-rar-compressed")) //NON-NLS
        {
            // for RAR files we need to open them explicitly as RAR. Otherwise, if there is a ZIP archive inside RAR archive
            // it will be opened incorrectly when using 7zip's built-in auto-detect functionality
            return RAR;
        }

        // Otherwise open the archive using 7zip's built-in auto-detect functionality
        return null;
    }

    private long getRootArchiveId(AbstractFile file) throws TskCoreException {
        long id = file.getId();
        Content parentContent = file.getParent();
        while (parentContent != null) {
            id = parentContent.getId();
            parentContent = parentContent.getParent();
        }
        return id;
    }

    private List<AbstractFile> getAlreadyExtractedFiles(AbstractFile archiveFile, String archiveFilePath) throws TskCoreException, NoCurrentCaseException {
        //check if already has derived files, skip
        //check if local unpacked dir exists 
        if (archiveFile.hasChildren() && new File(moduleDirAbsolute, EmbeddedFileExtractorIngestModule.getUniqueName(archiveFile)).exists()) {
            return Case.getCurrentCaseThrows().getServices().getFileManager().findFilesByParentPath(getRootArchiveId(archiveFile), archiveFilePath);
        }
        return new ArrayList<>();
    }

    private String getArchiveFilePath(AbstractFile archiveFile) {
        return archiveFile.getParentPath() + archiveFile.getName();
    }

    private void makeLocalDirectories(String uniqueArchiveFileName) {
        final String localRootAbsPath = getLocalRootAbsPath(uniqueArchiveFileName);
        final File localRoot = new File(localRootAbsPath);
        if (!localRoot.exists()) {
            localRoot.mkdirs();
        }
    }

    private String getPathInArchive(ISevenZipInArchive archive, int inArchiveItemIndex, AbstractFile archiveFile) throws SevenZipException {
        String pathInArchive = (String) archive.getProperty(
                inArchiveItemIndex, PropID.PATH);

        if (pathInArchive == null || pathInArchive.isEmpty()) {
            //some formats (.tar.gz) may not be handled correctly -- file in archive has no name/path
            //handle this for .tar.gz and tgz but assuming the child is tar,
            //otherwise, unpack using itemNumber as name

            //TODO this should really be signature based, not extension based
            String archName = archiveFile.getName();
            int dotI = archName.lastIndexOf(".");
            String useName = null;
            if (dotI != -1) {
                String base = archName.substring(0, dotI);
                String ext = archName.substring(dotI);
                int colonIndex = ext.lastIndexOf(":");
                if (colonIndex != -1) {
                    // If alternate data stream is found, fix the name 
                    // so Windows doesn't choke on the colon character.
                    ext = ext.substring(0, colonIndex);
                }
                switch (ext) {
                    case ".gz": //NON-NLS
                        useName = base;
                        break;
                    case ".tgz": //NON-NLS
                        useName = base + ".tar"; //NON-NLS
                        break;
                    case ".bz2": //NON-NLS
                        useName = base;
                        break;
                }
            }
            if (useName == null) {
                pathInArchive = "/" + archName + "/" + Integer.toString(inArchiveItemIndex);
            } else {
                pathInArchive = "/" + useName;
            }
            String msg = NbBundle.getMessage(SevenZipExtractor.class,
                    "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.unknownPath.msg",
                    getArchiveFilePath(archiveFile), pathInArchive);
            logger.log(Level.WARNING, msg);
        }
        return pathInArchive;
    }

    /*
     * Get the String that will represent the key for the hashmap which keeps
     * track of existing files from an AbstractFile
     */
    private String getKeyAbstractFile(AbstractFile fileInDatabase) {
        return fileInDatabase == null ? null : fileInDatabase.getParentPath() + fileInDatabase.getName();
    }

    /*
     * Get the String that will represent the key for the hashmap which keeps
     * track of existing files from an unpacked node and the archiveFilePath
     */
    private String getKeyFromUnpackedNode(UnpackedTree.UnpackedNode node, String archiveFilePath) {
        return node == null ? null : archiveFilePath + "/" + node.getFileName();
    }

    void unpack(AbstractFile archiveFile, ConcurrentHashMap<Long, Archive> depthMap) {
        unpack(archiveFile, depthMap, null);
    }

    @Messages({"SevenZipExtractor.indexError.message=Failed to index encryption detected artifact for keyword search.",
        "# {0} -  rootArchive",
        "SevenZipExtractor.zipBombArtifactCreation.text=Zip Bomb Detected {0}"})
    boolean unpack(AbstractFile archiveFile, ConcurrentHashMap<Long, Archive> depthMap, String password) {
        boolean unpackSuccessful = true; //initialized to true change to false if any files fail to extract and
        boolean hasEncrypted = false;
        boolean fullEncryption = true;
        boolean progressStarted = false;
        final String archiveFilePath = getArchiveFilePath(archiveFile);
        final String escapedArchiveFilePath = FileUtil.escapeFileName(archiveFilePath);
        HashMap<String, ZipFileStatusWrapper> statusMap = new HashMap<>();
        List<AbstractFile> unpackedFiles = Collections.<AbstractFile>emptyList();
        ISevenZipInArchive inArchive = null;
        currentArchiveName = archiveFile.getName();

        SevenZipContentReadStream stream = null;
        progress = ProgressHandle.createHandle(Bundle.EmbeddedFileExtractorIngestModule_ArchiveExtractor_moduleName());
        //recursion depth check for zip bomb
        Archive parentAr;
        try {
            blackboard = Case.getCurrentCaseThrows().getSleuthkitCase().getBlackboard();
        } catch (NoCurrentCaseException ex) {
            logger.log(Level.INFO, "Exception while getting open case.", ex); //NON-NLS
            unpackSuccessful = false;
            return unpackSuccessful;
        }
        try {

            List<AbstractFile> existingFiles = getAlreadyExtractedFiles(archiveFile, archiveFilePath);
            for (AbstractFile file : existingFiles) {
                statusMap.put(getKeyAbstractFile(file), new ZipFileStatusWrapper(file, ZipFileStatus.EXISTS));
            }
        } catch (TskCoreException e) {
            logger.log(Level.INFO, "Error checking if file already has been processed, skipping: {0}", escapedArchiveFilePath); //NON-NLS
            unpackSuccessful = false;
            return unpackSuccessful;
        } catch (NoCurrentCaseException ex) {
            logger.log(Level.INFO, "No open case was found while trying to unpack the archive file {0}", escapedArchiveFilePath); //NON-NLS
            unpackSuccessful = false;
            return unpackSuccessful;
        }
        parentAr = depthMap.get(archiveFile.getId());
        if (parentAr == null) {
            parentAr = new Archive(0, archiveFile.getId(), archiveFile);
            depthMap.put(archiveFile.getId(), parentAr);
        } else {
            Archive rootArchive = depthMap.get(parentAr.getRootArchiveId());
            if (rootArchive.isFlaggedAsZipBomb()) {
                //skip this archive as the root archive has already been determined to contain a zip bomb     
                unpackSuccessful = false;
                return unpackSuccessful;
            } else if (parentAr.getDepth() == MAX_DEPTH) {
                String details = NbBundle.getMessage(SevenZipExtractor.class,
                        "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.warnDetails.zipBomb",
                        parentAr.getDepth(), FileUtil.escapeFileName(getArchiveFilePath(rootArchive.getArchiveFile())));
                flagRootArchiveAsZipBomb(rootArchive, archiveFile, details, escapedArchiveFilePath);
                unpackSuccessful = false;
                return unpackSuccessful;
            }
        }
        try {
            stream = new SevenZipContentReadStream(new ReadContentInputStream(archiveFile));
            // for RAR files we need to open them explicitly as RAR. Otherwise, if there is a ZIP archive inside RAR archive
            // it will be opened incorrectly when using 7zip's built-in auto-detect functionality.
            // All other archive formats are still opened using 7zip built-in auto-detect functionality.
            ArchiveFormat options = get7ZipOptions(archiveFile);
            if (password == null) {
                inArchive = SevenZip.openInArchive(options, stream);
            } else {
                inArchive = SevenZip.openInArchive(options, stream, password);
            }
            numItems = inArchive.getNumberOfItems();
            progress.start(numItems);
            progressStarted = true;

            //setup the archive local root folder
            final String uniqueArchiveFileName = FileUtil.escapeFileName(EmbeddedFileExtractorIngestModule.getUniqueName(archiveFile));
            try {
                makeLocalDirectories(uniqueArchiveFileName);
            } catch (SecurityException e) {
                logger.log(Level.SEVERE, "Error setting up output path for archive root: {0}", getLocalRootAbsPath(uniqueArchiveFileName)); //NON-NLS
                //bail
                unpackSuccessful = false;
                return unpackSuccessful;
            }

            //initialize tree hierarchy to keep track of unpacked file structure
            SevenZipExtractor.UnpackedTree unpackedTree = new SevenZipExtractor.UnpackedTree(moduleDirRelative + "/" + uniqueArchiveFileName, archiveFile);

            long freeDiskSpace;
            try {
                freeDiskSpace = services.getFreeDiskSpace();
            } catch (NullPointerException ex) {
                //If ingest has not been run at least once getFreeDiskSpace() will throw a null pointer exception
                //currently getFreeDiskSpace always returns DISK_FREE_SPACE_UNKNOWN
                freeDiskSpace = IngestMonitor.DISK_FREE_SPACE_UNKNOWN;
            }

            Map<Integer, InArchiveItemDetails> archiveDetailsMap = new HashMap<>();
            for (int inArchiveItemIndex = 0; inArchiveItemIndex < numItems; inArchiveItemIndex++) {
                progress.progress(String.format("%s: Analyzing archive metadata and creating local files (%d of %d)", currentArchiveName, inArchiveItemIndex + 1, numItems), 0);
                if (isZipBombArchiveItemCheck(archiveFile, inArchive, inArchiveItemIndex, depthMap, escapedArchiveFilePath)) {
                    unpackSuccessful = false;
                    return unpackSuccessful;
                }

                String pathInArchive = getPathInArchive(inArchive, inArchiveItemIndex, archiveFile);
                UnpackedTree.UnpackedNode unpackedNode = unpackedTree.addNode(pathInArchive);

                final boolean isEncrypted = (Boolean) inArchive.getProperty(inArchiveItemIndex, PropID.ENCRYPTED);

                if (isEncrypted && password == null) {
                    logger.log(Level.WARNING, "Skipping encrypted file in archive: {0}", pathInArchive); //NON-NLS
                    hasEncrypted = true;
                    unpackSuccessful = false;
                    continue;
                } else {
                    fullEncryption = false;
                }

                // NOTE: item size may return null in case of certain
                // archiving formats. Eg: BZ2
                //check if unpacking this file will result in out of disk space
                //this is additional to zip bomb prevention mechanism
                Long archiveItemSize = (Long) inArchive.getProperty(
                        inArchiveItemIndex, PropID.SIZE);
                if (freeDiskSpace != IngestMonitor.DISK_FREE_SPACE_UNKNOWN && archiveItemSize != null && archiveItemSize > 0) { //if free space is known and file is not empty.
                    String archiveItemPath = (String) inArchive.getProperty(
                            inArchiveItemIndex, PropID.PATH);
                    long newDiskSpace = freeDiskSpace - archiveItemSize;
                    if (newDiskSpace < MIN_FREE_DISK_SPACE) {
                        String msg = NbBundle.getMessage(SevenZipExtractor.class,
                                "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.notEnoughDiskSpace.msg",
                                escapedArchiveFilePath, archiveItemPath);
                        String details = NbBundle.getMessage(SevenZipExtractor.class,
                                "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.notEnoughDiskSpace.details");
                        services.postMessage(IngestMessage.createErrorMessage(MODULE_NAME, msg, details));
                        logger.log(Level.INFO, "Skipping archive item due to insufficient disk space: {0}, {1}", new String[]{escapedArchiveFilePath, archiveItemPath}); //NON-NLS
                        logger.log(Level.INFO, "Available disk space: {0}", new Object[]{freeDiskSpace}); //NON-NLS
                        unpackSuccessful = false;
                        continue; //skip this file
                    } else {
                        //update est. disk space during this archive, so we don't need to poll for every file extracted
                        freeDiskSpace = newDiskSpace;
                    }
                }
                final String uniqueExtractedName = FileUtil.escapeFileName(uniqueArchiveFileName + File.separator + (inArchiveItemIndex / 1000) + File.separator + inArchiveItemIndex + "_" + new File(pathInArchive).getName());
                final String localAbsPath = moduleDirAbsolute + File.separator + uniqueExtractedName;
                final String localRelPath = moduleDirRelative + File.separator + uniqueExtractedName;

                //create local dirs and empty files before extracted
                File localFile = new java.io.File(localAbsPath);
                //cannot rely on files in top-bottom order
                if (!localFile.exists()) {
                    try {
                        if ((Boolean) inArchive.getProperty(
                                inArchiveItemIndex, PropID.IS_FOLDER)) {
                            localFile.mkdirs();
                        } else {
                            localFile.getParentFile().mkdirs();
                            try {
                                localFile.createNewFile();
                            } catch (IOException e) {
                                logger.log(Level.SEVERE, "Error creating extracted file: "//NON-NLS
                                                         + localFile.getAbsolutePath(), e);
                            }
                        }
                    } catch (SecurityException e) {
                        logger.log(Level.SEVERE, "Error setting up output path for unpacked file: {0}", //NON-NLS
                                pathInArchive); //NON-NLS
                        //TODO consider bail out / msg to the user
                    }
                }
                // skip the rest of this loop if we couldn't create the file
                //continue will skip details from being added to the map
                if (localFile.exists() == false) {
                    continue;
                }

                //Store archiveItemIndex with local paths and unpackedNode reference.
                //Necessary for the extract call back to write the current archive
                //file to the correct disk location and to correctly update it's 
                //corresponding unpackedNode
                archiveDetailsMap.put(inArchiveItemIndex, new InArchiveItemDetails(
                        unpackedNode, localAbsPath, localRelPath));
            }

            int[] extractionIndices = getExtractableFilesFromDetailsMap(archiveDetailsMap);

            StandardIArchiveExtractCallback archiveCallBack
                    = new StandardIArchiveExtractCallback(
                            inArchive, archiveFile, progress,
                            archiveDetailsMap, password, freeDiskSpace);

            //According to the documentation, indices in sorted order are optimal 
            //for efficiency. Hence, the HashMap and linear processing of 
            //inArchiveItemIndex. False indicates non-test mode
            inArchive.extract(extractionIndices, false, archiveCallBack);

            unpackSuccessful &= archiveCallBack.wasSuccessful();

            archiveDetailsMap = null;

            // add them to the DB. We wait until the end so that we have the metadata on all of the
            // intermediate nodes since the order is not guaranteed
            try {
                unpackedTree.updateOrAddFileToCaseRec(statusMap, archiveFilePath);
                unpackedFiles = unpackedTree.getAllFileObjects();
                //check if children are archives, update archive depth tracking
                for (int i = 0; i < unpackedFiles.size(); i++) {
                    progress.progress(String.format("%s: Searching for nested archives (%d of %d)", currentArchiveName, i + 1, unpackedFiles.size()));
                    AbstractFile unpackedFile = unpackedFiles.get(i);
                    if (unpackedFile == null) {
                        continue;
                    }
                    if (isSevenZipExtractionSupported(unpackedFile)) {
                        Archive child = new Archive(parentAr.getDepth() + 1, parentAr.getRootArchiveId(), archiveFile);
                        parentAr.addChild(child);
                        depthMap.put(unpackedFile.getId(), child);
                    }
                    unpackedFile.close();
                }

            } catch (TskCoreException | NoCurrentCaseException e) {
                logger.log(Level.SEVERE, "Error populating complete derived file hierarchy from the unpacked dir structure", e); //NON-NLS
                //TODO decide if anything to cleanup, for now bailing
            }

        } catch (SevenZipException ex) {
            logger.log(Level.WARNING, "Error unpacking file: " + archiveFile, ex); //NON-NLS
            //inbox message

            // print a message if the file is allocated
            if (archiveFile.isMetaFlagSet(TskData.TSK_FS_META_FLAG_ENUM.ALLOC)) {
                String msg = NbBundle.getMessage(SevenZipExtractor.class,
                        "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.errUnpacking.msg",
                        currentArchiveName);
                String details = NbBundle.getMessage(SevenZipExtractor.class,
                        "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.errUnpacking.details",
                        escapedArchiveFilePath, ex.getMessage());
                services.postMessage(IngestMessage.createErrorMessage(MODULE_NAME, msg, details));
            }
        } finally {
            if (inArchive != null) {
                try {
                    inArchive.close();
                } catch (SevenZipException e) {
                    logger.log(Level.SEVERE, "Error closing archive: " + archiveFile, e); //NON-NLS
                }
            }

            if (stream != null) {
                try {
                    stream.close();
                } catch (IOException ex) {
                    logger.log(Level.SEVERE, "Error closing stream after unpacking archive: " + archiveFile, ex); //NON-NLS
                }
            }

            //close progress bar
            if (progressStarted) {
                progress.finish();
            }
        }

        //create artifact and send user message
        if (hasEncrypted) {
            String encryptionType = fullEncryption ? ENCRYPTION_FULL : ENCRYPTION_FILE_LEVEL;
            try {
                BlackboardArtifact artifact = archiveFile.newArtifact(BlackboardArtifact.ARTIFACT_TYPE.TSK_ENCRYPTION_DETECTED);
                artifact.addAttribute(new BlackboardAttribute(BlackboardAttribute.ATTRIBUTE_TYPE.TSK_COMMENT, MODULE_NAME, encryptionType));

                try {
                    /*
                     * post the artifact which will index the artifact for
                     * keyword search, and fire an event to notify UI of this
                     * new artifact
                     */
                    blackboard.postArtifact(artifact, MODULE_NAME);
                } catch (Blackboard.BlackboardException ex) {
                    logger.log(Level.SEVERE, "Unable to post blackboard artifact " + artifact.getArtifactID(), ex); //NON-NLS
                    MessageNotifyUtil.Notify.error(
                            Bundle.SevenZipExtractor_indexError_message(), artifact.getDisplayName());
                }

            } catch (TskCoreException ex) {
                logger.log(Level.SEVERE, "Error creating blackboard artifact for encryption detected for file: " + escapedArchiveFilePath, ex); //NON-NLS
            }

            String msg = NbBundle.getMessage(SevenZipExtractor.class,
                    "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.encrFileDetected.msg");
            String details = NbBundle.getMessage(SevenZipExtractor.class,
                    "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.encrFileDetected.details",
                    currentArchiveName, MODULE_NAME);
            services.postMessage(IngestMessage.createWarningMessage(MODULE_NAME, msg, details));
        }

        // adding unpacked extracted derived files to the job after closing relevant resources.
        if (!unpackedFiles.isEmpty()) {
            //currently sending a single event for all new files
            services.fireModuleContentEvent(new ModuleContentEvent(archiveFile));
            if (context != null) {
                context.addFilesToJob(unpackedFiles);
            }
        }
        return unpackSuccessful;
    }

    private int[] getExtractableFilesFromDetailsMap(
            Map<Integer, InArchiveItemDetails> archiveDetailsMap) {

        Integer[] wrappedExtractionIndices = archiveDetailsMap.keySet()
                .toArray(new Integer[archiveDetailsMap.size()]);

        return Arrays.stream(wrappedExtractionIndices)
                .mapToInt(Integer::intValue)
                .toArray();
    }

    private final static class UnpackStream implements ISequentialOutStream {

        private EncodedFileOutputStream output;
        private String localAbsPath;
        private int bytesWritten;

        UnpackStream(String localAbsPath) throws IOException {
            this.output = new EncodedFileOutputStream(new FileOutputStream(localAbsPath), TskData.EncodingType.XOR1);
            this.localAbsPath = localAbsPath;
            this.bytesWritten = 0;
        }

        public void setNewOutputStream(String localAbsPath) throws IOException {
            this.output.close();
            this.output = new EncodedFileOutputStream(new FileOutputStream(localAbsPath), TskData.EncodingType.XOR1);
            this.localAbsPath = localAbsPath;
            this.bytesWritten = 0;
        }

        public int getSize() {
            return bytesWritten;
        }

        @Override
        public int write(byte[] bytes) throws SevenZipException {
            try {
                output.write(bytes);
                this.bytesWritten += bytes.length;
            } catch (IOException ex) {
                throw new SevenZipException(
                        NbBundle.getMessage(SevenZipExtractor.class,
                                "EmbeddedFileExtractorIngestModule.ArchiveExtractor.UnpackStream.write.exception.msg",
                                localAbsPath), ex);
            }
            return bytes.length;
        }

        public void close() throws IOException {
            try (EncodedFileOutputStream out = output) {
                out.flush();
            }
        }

    }

    private static class InArchiveItemDetails {

        private final SevenZipExtractor.UnpackedTree.UnpackedNode unpackedNode;
        private final String localAbsPath;
        private final String localRelPath;

        InArchiveItemDetails(
                SevenZipExtractor.UnpackedTree.UnpackedNode unpackedNode,
                String localAbsPath, String localRelPath) {
            this.unpackedNode = unpackedNode;
            this.localAbsPath = localAbsPath;
            this.localRelPath = localRelPath;
        }

        public SevenZipExtractor.UnpackedTree.UnpackedNode getUnpackedNode() {
            return unpackedNode;
        }

        public String getLocalAbsPath() {
            return localAbsPath;
        }

        public String getLocalRelPath() {
            return localRelPath;
        }
    }

    private static class StandardIArchiveExtractCallback
            implements IArchiveExtractCallback, ICryptoGetTextPassword {

        private final AbstractFile archiveFile;
        private final ISevenZipInArchive inArchive;
        private UnpackStream unpackStream = null;
        private final Map<Integer, InArchiveItemDetails> archiveDetailsMap;
        private final ProgressHandle progressHandle;

        private int inArchiveItemIndex;

        private long createTimeInSeconds;
        private long modTimeInSeconds;
        private long accessTimeInSeconds;

        private boolean isFolder;
        private final String password;

        private boolean unpackSuccessful = true;

        StandardIArchiveExtractCallback(ISevenZipInArchive inArchive,
                                        AbstractFile archiveFile, ProgressHandle progressHandle,
                                        Map<Integer, InArchiveItemDetails> archiveDetailsMap,
                                        String password, long freeDiskSpace) {

            this.inArchive = inArchive;
            this.progressHandle = progressHandle;
            this.archiveFile = archiveFile;
            this.archiveDetailsMap = archiveDetailsMap;
            this.password = password;
        }

        @Override
        public ISequentialOutStream getStream(int inArchiveItemIndex,
                                              ExtractAskMode mode) throws SevenZipException {

            this.inArchiveItemIndex = inArchiveItemIndex;

            isFolder = (Boolean) inArchive
                    .getProperty(inArchiveItemIndex, PropID.IS_FOLDER);
            if (isFolder || mode != ExtractAskMode.EXTRACT) {
                return null;
            }

            final String localAbsPath = archiveDetailsMap.get(
                    inArchiveItemIndex).getLocalAbsPath();

            //If the Unpackstream has been allocated, then set the Outputstream 
            //to another file rather than creating a new unpack stream. The 7Zip 
            //binding has a memory leak, so creating new unpack streams will not be
            //dereferenced. As a fix, we create one UnpackStream, and mutate its state,
            //so that there only exists one 8192 byte buffer in memory per archive.
            try {
                if (unpackStream != null) {
                    unpackStream.setNewOutputStream(localAbsPath);
                } else {
                    unpackStream = new UnpackStream(localAbsPath);
                }
            } catch (IOException ex) {
                logger.log(Level.WARNING, String.format("Error opening or setting new stream " //NON-NLS
                                                        + "for archive file at %s", localAbsPath), ex.getMessage()); //NON-NLS
                return null;
            }

            return unpackStream;
        }

        @Override
        public void prepareOperation(ExtractAskMode mode) throws SevenZipException {
            final Date createTime = (Date) inArchive.getProperty(
                    inArchiveItemIndex, PropID.CREATION_TIME);
            final Date accessTime = (Date) inArchive.getProperty(
                    inArchiveItemIndex, PropID.LAST_ACCESS_TIME);
            final Date writeTime = (Date) inArchive.getProperty(
                    inArchiveItemIndex, PropID.LAST_WRITE_TIME);

            createTimeInSeconds = createTime == null ? 0L
                    : createTime.getTime() / 1000;
            modTimeInSeconds = writeTime == null ? 0L
                    : writeTime.getTime() / 1000;
            accessTimeInSeconds = accessTime == null ? 0L
                    : accessTime.getTime() / 1000;

            progressHandle.progress(archiveFile.getName() + ": "
                                    + (String) inArchive.getProperty(inArchiveItemIndex, PropID.PATH),
                    inArchiveItemIndex);

        }

        @Override
        public void setOperationResult(ExtractOperationResult result) throws SevenZipException {

            final SevenZipExtractor.UnpackedTree.UnpackedNode unpackedNode
                    = archiveDetailsMap.get(inArchiveItemIndex).getUnpackedNode();
            final String localRelPath = archiveDetailsMap.get(
                    inArchiveItemIndex).getLocalRelPath();
            if (isFolder) {
                unpackedNode.addDerivedInfo(0,
                        !(Boolean) inArchive.getProperty(inArchiveItemIndex, PropID.IS_FOLDER),
                        0L, createTimeInSeconds, accessTimeInSeconds, modTimeInSeconds,
                        localRelPath);
                return;
            }

            final String localAbsPath = archiveDetailsMap.get(
                    inArchiveItemIndex).getLocalAbsPath();
            if (result != ExtractOperationResult.OK) {
                logger.log(Level.WARNING, "Extraction of : {0} encountered error {1}", //NON-NLS
                        new Object[]{localAbsPath, result});
                unpackSuccessful = false;
            }

            //record derived data in unode, to be traversed later after unpacking the archive
            unpackedNode.addDerivedInfo(unpackStream.getSize(),
                    !(Boolean) inArchive.getProperty(inArchiveItemIndex, PropID.IS_FOLDER),
                    0L, createTimeInSeconds, accessTimeInSeconds, modTimeInSeconds, localRelPath);

            try {
                unpackStream.close();
            } catch (IOException e) {
                logger.log(Level.WARNING, "Error closing unpack stream for file: {0}", localAbsPath); //NON-NLS
            }
        }

        @Override
        public void setTotal(long value) throws SevenZipException {
            //Not necessary for extract, left intenionally blank
        }

        @Override
        public void setCompleted(long value) throws SevenZipException {
            //Not necessary for extract, left intenionally blank
        }

        @Override
        public String cryptoGetTextPassword() throws SevenZipException {
            return password;
        }

        public boolean wasSuccessful() {
            return unpackSuccessful;
        }
    }

    private class UnpackedTree {

        final UnpackedNode rootNode;
        private int nodesProcessed = 0;

        UnpackedTree(String localPathRoot, AbstractFile archiveFile) {
            this.rootNode = new UnpackedNode();
            this.rootNode.setFile(archiveFile);
            this.rootNode.setFileName(archiveFile.getName());
            this.rootNode.setLocalRelPath(localPathRoot);
        }

        UnpackedNode addNode(String filePath) {
            String[] toks = filePath.split("[\\/\\\\]");
            List<String> tokens = new ArrayList<>();
            for (int i = 0; i < toks.length; ++i) {
                if (!toks[i].isEmpty()) {
                    tokens.add(toks[i]);
                }
            }
            return addNode(rootNode, tokens);
        }

        private UnpackedNode addNode(UnpackedNode parent, List<String> tokenPath) {
            // we found all of the tokens
            if (tokenPath.isEmpty()) {
                return parent;
            }

            // get the next name in the path and look it up
            String childName = tokenPath.remove(0);
            UnpackedNode child = parent.getChild(childName);
            // create new node
            if (child == null) {
                child = new UnpackedNode(childName, parent);
                parent.addChild(child);
            }

            // go down one more level
            return addNode(child, tokenPath);
        }

        List<AbstractFile> getRootFileObjects() {
            List<AbstractFile> ret = new ArrayList<>();
            rootNode.getChildren().forEach((child) -> {
                ret.add(child.getFile());
            });
            return ret;
        }

        List<AbstractFile> getAllFileObjects() {
            List<AbstractFile> ret = new ArrayList<>();
            rootNode.getChildren().forEach((child) -> {
                getAllFileObjectsRec(ret, child);
            });
            return ret;
        }

        private void getAllFileObjectsRec(List<AbstractFile> list, UnpackedNode parent) {
            list.add(parent.getFile());
            parent.getChildren().forEach((child) -> {
                getAllFileObjectsRec(list, child);
            });
        }

        void updateOrAddFileToCaseRec(HashMap<String, ZipFileStatusWrapper> statusMap, String archiveFilePath) throws TskCoreException, NoCurrentCaseException {
            final FileManager fileManager = Case.getCurrentCaseThrows().getServices().getFileManager();
            for (UnpackedNode child : rootNode.getChildren()) {
                updateOrAddFileToCaseRec(child, fileManager, statusMap, archiveFilePath);
            }
        }

        private void updateOrAddFileToCaseRec(UnpackedNode node, FileManager fileManager, HashMap<String, ZipFileStatusWrapper> statusMap, String archiveFilePath) throws TskCoreException {
            DerivedFile df;
            progress.progress(String.format("%s: Adding/updating files in case database (%d of %d)", currentArchiveName, ++nodesProcessed, numItems));
            try {
                String nameInDatabase = getKeyFromUnpackedNode(node, archiveFilePath);
                ZipFileStatusWrapper existingFile = nameInDatabase == null ? null : statusMap.get(nameInDatabase);
                if (existingFile == null) {
                    df = fileManager.addDerivedFile(node.getFileName(), node.getLocalRelPath(), node.getSize(),
                            node.getCtime(), node.getCrtime(), node.getAtime(), node.getMtime(),
                            node.isIsFile(), node.getParent().getFile(), "", MODULE_NAME,
                            "", "", TskData.EncodingType.XOR1);
                    statusMap.put(getKeyAbstractFile(df), new ZipFileStatusWrapper(df, ZipFileStatus.EXISTS));
                } else {
                    String key = getKeyAbstractFile(existingFile.getFile());
                    if (existingFile.getStatus() == ZipFileStatus.EXISTS && existingFile.getFile().getSize() < node.getSize()) {
                        existingFile.setStatus(ZipFileStatus.UPDATE);
                        statusMap.put(key, existingFile);
                    }
                    if (existingFile.getStatus() == ZipFileStatus.UPDATE) {
                        //if the we are updating a file and its mime type was octet-stream we want to re-type it
                        String mimeType = existingFile.getFile().getMIMEType().equalsIgnoreCase("application/octet-stream") ? null : existingFile.getFile().getMIMEType();
                        df = fileManager.updateDerivedFile((DerivedFile) existingFile.getFile(), node.getLocalRelPath(), node.getSize(),
                                node.getCtime(), node.getCrtime(), node.getAtime(), node.getMtime(),
                                node.isIsFile(), mimeType, "", MODULE_NAME,
                                "", "", TskData.EncodingType.XOR1);
                    } else {
                        //ALREADY CURRENT - SKIP
                        statusMap.put(key, new ZipFileStatusWrapper(existingFile.getFile(), ZipFileStatus.SKIP));
                        df = (DerivedFile) existingFile.getFile();
                    }
                }
                node.setFile(df);
            } catch (TskCoreException ex) {
                logger.log(Level.SEVERE, "Error adding a derived file to db:" + node.getFileName(), ex); //NON-NLS
                throw new TskCoreException(
                        NbBundle.getMessage(SevenZipExtractor.class, "EmbeddedFileExtractorIngestModule.ArchiveExtractor.UnpackedTree.exception.msg",
                                node.getFileName()), ex);
            }
            //recurse adding the children if this file was incomplete the children presumably need to be added
            for (UnpackedNode child : node.getChildren()) {
                updateOrAddFileToCaseRec(child, fileManager, statusMap, getKeyFromUnpackedNode(node, archiveFilePath));
            }
        }

        private class UnpackedNode {

            private String fileName;
            private AbstractFile file;
            private final List<UnpackedNode> children = new ArrayList<>();
            private String localRelPath = "";
            private long size;
            private long ctime, crtime, atime, mtime;
            private boolean isFile;
            private UnpackedNode parent;

            //root constructor
            UnpackedNode() {
            }

            //child node constructor
            UnpackedNode(String fileName, UnpackedNode parent) {
                this.fileName = fileName;
                this.parent = parent;
                this.localRelPath = parent.getLocalRelPath() + File.separator + fileName;
            }

            long getCtime() {
                return ctime;
            }

            long getCrtime() {
                return crtime;
            }

            long getAtime() {
                return atime;
            }

            long getMtime() {
                return mtime;
            }

            void setFileName(String fileName) {
                this.fileName = fileName;
            }

            void addChild(UnpackedNode child) {
                children.add(child);
            }

            List<UnpackedNode> getChildren() {
                return children;
            }

            UnpackedNode getParent() {
                return parent;
            }

            void addDerivedInfo(long size,
                                boolean isFile,
                                long ctime, long crtime, long atime, long mtime, String relLocalPath) {
                this.size = size;
                this.isFile = isFile;
                this.ctime = ctime;
                this.crtime = crtime;
                this.atime = atime;
                this.mtime = mtime;
                this.localRelPath = relLocalPath;
            }

            void setFile(AbstractFile file) {
                this.file = file;
            }

            UnpackedNode getChild(String childFileName) {
                UnpackedNode ret = null;
                for (UnpackedNode child : children) {
                    if (child.getFileName().equals(childFileName)) {
                        ret = child;
                        break;
                    }
                }
                return ret;
            }

            String getFileName() {
                return fileName;
            }

            AbstractFile getFile() {
                return file;
            }

            String getLocalRelPath() {
                return localRelPath;
            }

            void setLocalRelPath(String localRelativePath) {
                localRelPath = localRelativePath;
            }

            long getSize() {
                return size;
            }

            boolean isIsFile() {
                return isFile;
            }
        }
    }

    static class Archive {

        //depth will be 0 for the root archive unpack was called on, and increase as unpack recurses down through archives contained within
        private final int depth;
        private final List<Archive> children;
        private final long rootArchiveId;
        private boolean flaggedAsZipBomb = false;
        private final AbstractFile archiveFile;

        Archive(int depth, long rootArchiveId, AbstractFile archiveFile) {
            this.children = new ArrayList<>();
            this.depth = depth;
            this.rootArchiveId = rootArchiveId;
            this.archiveFile = archiveFile;
        }

        void addChild(Archive child) {
            children.add(child);
        }

        synchronized void flagAsZipBomb() {
            flaggedAsZipBomb = true;
        }

        synchronized boolean isFlaggedAsZipBomb() {
            return flaggedAsZipBomb;
        }

        AbstractFile getArchiveFile() {
            return archiveFile;
        }

        long getRootArchiveId() {
            return rootArchiveId;
        }

        long getObjectId() {
            return archiveFile.getId();
        }

        int getDepth() {
            return depth;
        }
    }

    private final class ZipFileStatusWrapper {

        private final AbstractFile abstractFile;
        private ZipFileStatus zipStatus;

        private ZipFileStatusWrapper(AbstractFile file, ZipFileStatus status) {
            abstractFile = file;
            zipStatus = status;
        }

        private AbstractFile getFile() {
            return abstractFile;
        }

        private ZipFileStatus getStatus() {
            return zipStatus;
        }

        private void setStatus(ZipFileStatus status) {
            zipStatus = status;
        }

    }

    private enum ZipFileStatus {
        UPDATE, //Should be updated //NON-NLS
        SKIP, //File is current can be skipped //NON-NLS
        EXISTS //File exists but it is unknown if it is current //NON-NLS
    }
}