SevenZipExtractor.java

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/*
 * Autopsy Forensic Browser
 *
 * Copyright 2013-2018 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.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
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.ISequentialOutStream;
import net.sf.sevenzipjbinding.ISevenZipInArchive;
import net.sf.sevenzipjbinding.SevenZip;
import net.sf.sevenzipjbinding.SevenZipException;
import net.sf.sevenzipjbinding.SevenZipNativeInitializationException;
import net.sf.sevenzipjbinding.simple.ISimpleInArchive;
import net.sf.sevenzipjbinding.simple.ISimpleInArchiveItem;
import net.sf.sevenzipjbinding.ExtractOperationResult;
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.Blackboard;
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.ingest.ModuleDataEvent;
import org.sleuthkit.autopsy.modules.filetypeid.FileTypeDetector;
import org.sleuthkit.datamodel.AbstractFile;
import org.sleuthkit.datamodel.BlackboardArtifact;
import org.sleuthkit.datamodel.BlackboardAttribute;
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 IngestServices services = IngestServices.getInstance();
    private final IngestJobContext context;
    private final FileTypeDetector fileTypeDetector;
    //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 String moduleDirRelative;
    private String moduleDirAbsolute;

    private Blackboard blackboard;

    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, ISimpleInArchiveItem archiveFileItem) {
        try {
            final Long archiveItemSize = archiveFileItem.getSize();

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

            final Long archiveItemPackedSize = archiveFileItem.getPackedSize();

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

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

            if (cRatio >= MAX_COMPRESSION_RATIO) {
                String itemName = archiveFileItem.getPath();
                logger.log(Level.INFO, "Possible zip bomb detected, compression ration: {0} for in archive item: {1}", new Object[]{cRatio, itemName}); //NON-NLS
                String msg = NbBundle.getMessage(SevenZipExtractor.class,
                        "EmbeddedFileExtractorIngestModule.ArchiveExtractor.isZipBombCheck.warnMsg", archiveFile.getName(), itemName);
                String path;
                try {
                    path = archiveFile.getUniquePath();
                } catch (TskCoreException ex) {
                    path = archiveFile.getParentPath() + archiveFile.getName();
                }
                String details = NbBundle.getMessage(SevenZipExtractor.class,
                        "EmbeddedFileExtractorIngestModule.ArchiveExtractor.isZipBombCheck.warnDetails", cRatio, path);
                //MessageNotifyUtil.Notify.error(msg, details);
                services.postMessage(IngestMessage.createWarningMessage(EmbeddedFileExtractorModuleFactory.getModuleName(), msg, details));
                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 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) {
        try {
            return archiveFile.getUniquePath();
        } catch (TskCoreException ex) {
            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(ISimpleInArchiveItem item, int itemNumber, AbstractFile archiveFile) throws SevenZipException {
        String pathInArchive = item.getPath();

        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(itemNumber);
            } 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();
    }

    private SevenZipExtractor.UnpackedTree.UnpackedNode unpackNode(ISimpleInArchiveItem item, SevenZipExtractor.UnpackedTree.UnpackedNode unpackedNode, String password, long freeDiskSpace, String uniqueExtractedName) throws SevenZipException {
        //unpack locally if a file
        final String localAbsPath = moduleDirAbsolute + File.separator + uniqueExtractedName;
        final String localRelPath = moduleDirRelative + File.separator + uniqueExtractedName;
        final Date createTime = item.getCreationTime();
        final Date accessTime = item.getLastAccessTime();
        final Date writeTime = item.getLastWriteTime();
        final long createtime = createTime == null ? 0L : createTime.getTime() / 1000;
        final long modtime = writeTime == null ? 0L : writeTime.getTime() / 1000;
        final long accesstime = accessTime == null ? 0L : accessTime.getTime() / 1000;
        SevenZipExtractor.UnpackStream unpackStream = null;
        boolean isDir = item.isFolder();
        if (!isDir) {
            try {
                // NOTE: item.getSize() may return null in case of certain
                // archiving formats. Eg: BZ2
                if (item.getSize() != null) {
                    unpackStream = new SevenZipExtractor.KnownSizeUnpackStream(localAbsPath, item.getSize());
                } else {
                    unpackStream = new SevenZipExtractor.UnknownSizeUnpackStream(localAbsPath, freeDiskSpace);
                }
                ExtractOperationResult result;
                if (password == null) {
                    result = item.extractSlow(unpackStream);
                } else {
                    result = item.extractSlow(unpackStream, password);
                }
                if (result != ExtractOperationResult.OK) {
                    logger.log(Level.WARNING, "Extraction of : {0} encountered error {1}", new Object[]{localAbsPath, result}); //NON-NLS
                    return null;
                }

            } catch (SevenZipException e) {
                //could be something unexpected with this file, move on
                logger.log(Level.WARNING, "Could not extract file from archive: " + localAbsPath, e); //NON-NLS
            } finally {
                if (unpackStream != null) {
                    //record derived data in unode, to be traversed later after unpacking the archive
                    unpackedNode.addDerivedInfo(unpackStream.getSize(), !isDir,
                            0L, createtime, accesstime, modtime, localRelPath);
                    unpackStream.close();
                }
            }
        } else { // this is a directory, size is always 0
            unpackedNode.addDerivedInfo(0, !isDir, 0L, createtime, accesstime, modtime, localRelPath);
        }
        return unpackedNode;
    }

    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."})
    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;
        int processedItems = 0;
        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;

        SevenZipContentReadStream stream = null;
        final ProgressHandle progress = ProgressHandle.createHandle(Bundle.EmbeddedFileExtractorIngestModule_ArchiveExtractor_moduleName());
        //recursion depth check for zip bomb
        final long archiveId = archiveFile.getId();
        Archive parentAr;
        try {
            blackboard = Case.getCurrentCaseThrows().getServices().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(archiveId);
        if (parentAr == null) {
            parentAr = new Archive(archiveId, 0);
            depthMap.put(archiveId, parentAr);
        } else if (parentAr.getDepth() == MAX_DEPTH) {
            String msg = NbBundle.getMessage(SevenZipExtractor.class,
                    "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.warnMsg.zipBomb", archiveFile.getName());
            String details = NbBundle.getMessage(SevenZipExtractor.class,
                    "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.warnDetails.zipBomb",
                    parentAr.getDepth(), escapedArchiveFilePath);
            //MessageNotifyUtil.Notify.error(msg, details);
            services.postMessage(IngestMessage.createWarningMessage(EmbeddedFileExtractorModuleFactory.getModuleName(), msg, details));
            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);
            }
            int numItems = inArchive.getNumberOfItems();
            logger.log(Level.INFO, "Count of items in archive: {0}: {1}", new Object[]{escapedArchiveFilePath, numItems}); //NON-NLS
            progress.start(numItems);
            progressStarted = true;
            final ISimpleInArchive simpleInArchive = inArchive.getSimpleInterface();

            //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;
            }
            //unpack and process every item in archive
            int itemNumber = 0;

            for (ISimpleInArchiveItem item : simpleInArchive.getArchiveItems()) {
                String pathInArchive = getPathInArchive(item, itemNumber, archiveFile);

                //query for path in db
                ++itemNumber;

                //check if possible zip bomb
                if (isZipBombArchiveItemCheck(archiveFile, item)) {
                    unpackSuccessful = false;
                    return unpackSuccessful;
                }
                SevenZipExtractor.UnpackedTree.UnpackedNode unpackedNode = unpackedTree.addNode(pathInArchive);
                //update progress bar
                progress.progress(archiveFile.getName() + ": " + item.getPath(), processedItems);

                final boolean isEncrypted = item.isEncrypted();

                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.getSize() 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
                if (freeDiskSpace != IngestMonitor.DISK_FREE_SPACE_UNKNOWN && item.getSize() != null && item.getSize() > 0) { //if free space is known and file is not empty.
                    long newDiskSpace = freeDiskSpace - item.getSize();
                    if (newDiskSpace < MIN_FREE_DISK_SPACE) {
                        String msg = NbBundle.getMessage(SevenZipExtractor.class,
                                "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.notEnoughDiskSpace.msg",
                                escapedArchiveFilePath, item.getPath());
                        String details = NbBundle.getMessage(SevenZipExtractor.class,
                                "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.notEnoughDiskSpace.details");
                        //MessageNotifyUtil.Notify.error(msg, details);
                        services.postMessage(IngestMessage.createErrorMessage(EmbeddedFileExtractorModuleFactory.getModuleName(), msg, details));
                        logger.log(Level.INFO, "Skipping archive item due to insufficient disk space: {0}, {1}", new String[]{escapedArchiveFilePath, item.getPath()}); //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 + (item.getItemIndex() / 1000) + File.separator + item.getItemIndex() + "_" + new File(pathInArchive).getName());

                //create local dirs and empty files before extracted
                File localFile = new java.io.File(moduleDirAbsolute + File.separator + uniqueExtractedName);
                //cannot rely on files in top-bottom order
                if (!localFile.exists()) {
                    try {
                        if (item.isFolder()) {
                            localFile.mkdirs();
                        } else {
                            localFile.getParentFile().mkdirs();
                            try {
                                localFile.createNewFile();
                            } catch (IOException e) {
                                logger.log(Level.SEVERE, "Error creating extracted file: " + localFile.getAbsolutePath(), e); //NON-NLS
                            }
                        }
                    } catch (SecurityException e) {
                        logger.log(Level.SEVERE, "Error setting up output path for unpacked file: {0}", pathInArchive); //NON-NLS
                        //TODO consider bail out / msg to the user
                    }
                }
                // skip the rest of this loop if we couldn't create the file
                if (localFile.exists() == false) {
                    continue;
                }
                //find this node in the hierarchy, create if neede;
                unpackedNode = unpackNode(item, unpackedNode, password,
                        freeDiskSpace, uniqueExtractedName);
                if (unpackedNode == null) {
                    unpackSuccessful = false;
                }

                //update units for progress bar
                ++processedItems;
            }
            // 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 (AbstractFile unpackedFile : unpackedFiles) {
                    if (unpackedFile == null) {
                        continue;
                    }
                    if (isSevenZipExtractionSupported(unpackedFile)) {
                        Archive child = new Archive(unpackedFile.getId(), parentAr.getDepth() + 1);
                        parentAr.addChild(child);
                        depthMap.put(unpackedFile.getId(), child);
                    }
                }

            } 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",
                        archiveFile.getName());
                String details = NbBundle.getMessage(SevenZipExtractor.class,
                        "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.errUnpacking.details",
                        escapedArchiveFilePath, ex.getMessage());
                services.postMessage(IngestMessage.createErrorMessage(EmbeddedFileExtractorModuleFactory.getModuleName(), 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, EmbeddedFileExtractorModuleFactory.getModuleName(), encryptionType));

                try {
                    // index the artifact for keyword search
                    blackboard.indexArtifact(artifact);
                } 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());
                }

                services.fireModuleDataEvent(new ModuleDataEvent(EmbeddedFileExtractorModuleFactory.getModuleName(), BlackboardArtifact.ARTIFACT_TYPE.TSK_ENCRYPTION_DETECTED));
            } 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",
                    archiveFile.getName(), EmbeddedFileExtractorModuleFactory.getModuleName());
            services.postMessage(IngestMessage.createWarningMessage(EmbeddedFileExtractorModuleFactory.getModuleName(), 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 abstract static class UnpackStream implements ISequentialOutStream {

        private OutputStream output;
        private String localAbsPath;

        UnpackStream(String localAbsPath) {
            this.localAbsPath = localAbsPath;
            try {
                output = new EncodedFileOutputStream(new FileOutputStream(localAbsPath), TskData.EncodingType.XOR1);
            } catch (IOException ex) {
                logger.log(Level.SEVERE, "Error writing extracted file: " + localAbsPath, ex); //NON-NLS
            }

        }

        public abstract long getSize();

        OutputStream getOutput() {
            return output;
        }

        String getLocalAbsPath() {
            return localAbsPath;
        }

        public void close() {
            if (output != null) {
                try {
                    output.flush();
                    output.close();
                } catch (IOException e) {
                    logger.log(Level.SEVERE, "Error closing unpack stream for file: {0}", localAbsPath); //NON-NLS
                }
            }
        }
    }

    private static class UnknownSizeUnpackStream extends UnpackStream {

        private long freeDiskSpace;
        private boolean outOfSpace = false;
        private long bytesWritten = 0;

        UnknownSizeUnpackStream(String localAbsPath, long freeDiskSpace) {
            super(localAbsPath);
            this.freeDiskSpace = freeDiskSpace;
        }

        @Override
        public long getSize() {
            return this.bytesWritten;
        }

        @Override
        public int write(byte[] bytes) throws SevenZipException {
            try {
                // If the content size is unknown, cautiously write to disk.
                // Write only if byte array is less than 80% of the current
                // free disk space.
                if (freeDiskSpace == IngestMonitor.DISK_FREE_SPACE_UNKNOWN || bytes.length < 0.8 * freeDiskSpace) {
                    getOutput().write(bytes);
                    // NOTE: this method is called multiple times for a
                    // single extractSlow() call. Update bytesWritten and
                    // freeDiskSpace after every write operation.
                    this.bytesWritten += bytes.length;
                    this.freeDiskSpace -= bytes.length;
                } else {
                    this.outOfSpace = true;
                    logger.log(Level.INFO, NbBundle.getMessage(
                            SevenZipExtractor.class,
                            "EmbeddedFileExtractorIngestModule.ArchiveExtractor.UnpackStream.write.noSpace.msg"));
                    throw new SevenZipException(
                            NbBundle.getMessage(SevenZipExtractor.class, "EmbeddedFileExtractorIngestModule.ArchiveExtractor.UnpackStream.write.noSpace.msg"));
                }
            } catch (IOException ex) {
                throw new SevenZipException(
                        NbBundle.getMessage(SevenZipExtractor.class, "EmbeddedFileExtractorIngestModule.ArchiveExtractor.UnpackStream.write.exception.msg",
                                getLocalAbsPath()), ex);
            }
            return bytes.length;
        }

        @Override
        public void close() {
            if (getOutput() != null) {
                try {
                    getOutput().flush();
                    getOutput().close();
                    if (this.outOfSpace) {
                        Files.delete(Paths.get(getLocalAbsPath()));
                    }
                } catch (IOException e) {
                    logger.log(Level.SEVERE, "Error closing unpack stream for file: {0}", getLocalAbsPath()); //NON-NLS
                }
            }
        }
    }

    private static class KnownSizeUnpackStream extends UnpackStream {

        private long size;

        KnownSizeUnpackStream(String localAbsPath, long size) {
            super(localAbsPath);
            this.size = size;
        }

        @Override
        public long getSize() {
            return this.size;
        }

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

    private class UnpackedTree {

        final UnpackedNode rootNode;

        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<>();
            for (UnpackedNode child : rootNode.getChildren()) {
                ret.add(child.getFile());
            }
            return ret;
        }

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

        private void getAllFileObjectsRec(List<AbstractFile> list, UnpackedNode parent) {
            list.add(parent.getFile());
            for (UnpackedNode child : parent.getChildren()) {
                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;
            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(), "", EmbeddedFileExtractorModuleFactory.getModuleName(),
                            "", "", 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, "", EmbeddedFileExtractorModuleFactory.getModuleName(),
                                "", "", 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 long objectId;
        private final List<Archive> children;

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

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

        long getObjectId() {
            return objectId;
        }

        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
    }
}