コード例 #1
0
  /**
   * Unpack the file to local folder and return a list of derived files
   *
   * @param pipelineContext current ingest context
   * @param archiveFile file to unpack
   * @return list of unpacked derived files
   */
  void unpack(AbstractFile archiveFile) {
    String archiveFilePath;
    try {
      archiveFilePath = archiveFile.getUniquePath();
    } catch (TskCoreException ex) {
      archiveFilePath = archiveFile.getParentPath() + archiveFile.getName();
    }

    // check if already has derived files, skip
    try {
      if (archiveFile.hasChildren()) {
        // check if local unpacked dir exists
        if (new File(EmbeddedFileExtractorIngestModule.getUniqueName(archiveFile)).exists()) {
          logger.log(
              Level.INFO,
              "File already has been processed as it has children and local unpacked file, skipping: {0}",
              archiveFilePath); // NON-NLS
          return;
        }
      }
    } catch (TskCoreException e) {
      logger.log(
          Level.INFO,
          "Error checking if file already has been processed, skipping: {0}",
          archiveFilePath); // NON-NLS
      return;
    }

    List<AbstractFile> unpackedFiles = Collections.<AbstractFile>emptyList();

    // recursion depth check for zip bomb
    final long archiveId = archiveFile.getId();
    SevenZipExtractor.ArchiveDepthCountTree.Archive parentAr =
        archiveDepthCountTree.findArchive(archiveId);
    if (parentAr == null) {
      parentAr = archiveDepthCountTree.addArchive(null, archiveId);
    } else if (parentAr.getDepth() == MAX_DEPTH) {
      String msg =
          NbBundle.getMessage(
              this.getClass(),
              "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.warnMsg.zipBomb",
              archiveFile.getName());
      String details =
          NbBundle.getMessage(
              this.getClass(),
              "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.warnDetails.zipBomb",
              parentAr.getDepth(),
              archiveFilePath);
      // MessageNotifyUtil.Notify.error(msg, details);
      services.postMessage(
          IngestMessage.createWarningMessage(
              EmbeddedFileExtractorModuleFactory.getModuleName(), msg, details));
      return;
    }

    boolean hasEncrypted = false;
    boolean fullEncryption = true;

    ISevenZipInArchive inArchive = null;
    SevenZipContentReadStream stream = null;

    final ProgressHandle progress =
        ProgressHandleFactory.createHandle(
            NbBundle.getMessage(
                this.getClass(), "EmbeddedFileExtractorIngestModule.ArchiveExtractor.moduleName"));
    int processedItems = 0;

    boolean progressStarted = false;
    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);
      inArchive = SevenZip.openInArchive(options, stream);

      int numItems = inArchive.getNumberOfItems();
      logger.log(
          Level.INFO,
          "Count of items in archive: {0}: {1}",
          new Object[] {archiveFilePath, numItems}); // NON-NLS
      progress.start(numItems);
      progressStarted = true;

      final ISimpleInArchive simpleInArchive = inArchive.getSimpleInterface();

      // setup the archive local root folder
      final String uniqueArchiveFileName =
          EmbeddedFileExtractorIngestModule.getUniqueName(archiveFile);
      final String localRootAbsPath = getLocalRootAbsPath(uniqueArchiveFileName);
      final File localRoot = new File(localRootAbsPath);
      if (!localRoot.exists()) {
        try {
          localRoot.mkdirs();
        } catch (SecurityException e) {
          logger.log(
              Level.SEVERE,
              "Error setting up output path for archive root: {0}",
              localRootAbsPath); // NON-NLS
          // bail
          return;
        }
      }

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

      long freeDiskSpace = services.getFreeDiskSpace();

      // unpack and process every item in archive
      int itemNumber = 0;
      for (ISimpleInArchiveItem item : simpleInArchive.getArchiveItems()) {
        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);
            switch (ext) {
              case ".gz": // NON-NLS
                useName = base;
                break;
              case ".tgz": // NON-NLS
                useName = base + ".tar"; // NON-NLS
                break;
            }
          }

          if (useName == null) {
            pathInArchive = "/" + archName + "/" + Integer.toString(itemNumber);
          } else {
            pathInArchive = "/" + useName;
          }

          String msg =
              NbBundle.getMessage(
                  this.getClass(),
                  "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.unknownPath.msg",
                  archiveFilePath,
                  pathInArchive);
          logger.log(Level.WARNING, msg);
        }
        ++itemNumber;
        logger.log(Level.INFO, "Extracted item path: {0}", pathInArchive); // NON-NLS

        // check if possible zip bomb
        if (isZipBombArchiveItemCheck(archiveFile, item)) {
          continue; // skip the item
        }

        // find this node in the hierarchy, create if needed
        SevenZipExtractor.UnpackedTree.UnpackedNode unpackedNode =
            unpackedTree.addNode(pathInArchive);

        String fileName = unpackedNode.getFileName();

        // update progress bar
        progress.progress(archiveFile.getName() + ": " + fileName, processedItems);

        final boolean isEncrypted = item.isEncrypted();
        final boolean isDir = item.isFolder();

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

        final Long size = item.getSize();
        if (size == null) {
          // If the size property cannot be determined, out-of-disk-space
          // situations cannot be ascertained.
          // Hence skip this file.
          logger.log(
              Level.WARNING,
              "Size cannot be determined. Skipping file in archive: {0}",
              pathInArchive); // NON-NLS
          continue;
        }

        // 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
            && size > 0) { // if known free space and file not empty
          long newDiskSpace = freeDiskSpace - size;
          if (newDiskSpace < MIN_FREE_DISK_SPACE) {
            String msg =
                NbBundle.getMessage(
                    this.getClass(),
                    "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.notEnoughDiskSpace.msg",
                    archiveFilePath,
                    fileName);
            String details =
                NbBundle.getMessage(
                    this.getClass(),
                    "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 Object[] {archiveFilePath, fileName}); // NON-NLS
            logger.log(
                Level.INFO, "Available disk space: {0}", new Object[] {freeDiskSpace}); // NON-NLS
            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 =
            uniqueArchiveFileName
                + File.separator
                + (item.getItemIndex() / 1000)
                + File.separator
                + item.getItemIndex()
                + new File(pathInArchive).getName();

        // final String localRelPath = unpackDir + File.separator + localFileRelPath;
        final String localRelPath = moduleDirRelative + File.separator + uniqueExtractedName;
        final String localAbsPath = moduleDirAbsolute + 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 (isDir) {
              localFile.mkdirs();
            } else {
              localFile.getParentFile().mkdirs();
              try {
                localFile.createNewFile();
              } catch (IOException ex) {
                logger.log(
                    Level.SEVERE,
                    "Error creating extracted file: " + localFile.getAbsolutePath(),
                    ex); // 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;
        }

        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;

        // record derived data in unode, to be traversed later after unpacking the archive
        unpackedNode.addDerivedInfo(
            size, !isDir, 0L, createtime, accesstime, modtime, localRelPath);

        // unpack locally if a file
        if (!isDir) {
          SevenZipExtractor.UnpackStream unpackStream = null;
          try {
            unpackStream = new SevenZipExtractor.UnpackStream(localAbsPath);
            item.extractSlow(unpackStream);
          } catch (Exception 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) {
              unpackStream.close();
            }
          }
        }

        // 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.addDerivedFilesToCase();
        unpackedFiles = unpackedTree.getAllFileObjects();

        // check if children are archives, update archive depth tracking
        for (AbstractFile unpackedFile : unpackedFiles) {
          if (isSevenZipExtractionSupported(unpackedFile)) {
            archiveDepthCountTree.addArchive(parentAr, unpackedFile.getId());
          }
        }

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

    } catch (SevenZipException ex) {
      logger.log(Level.SEVERE, "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(
                this.getClass(),
                "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.errUnpacking.msg",
                archiveFile.getName());
        String details =
            NbBundle.getMessage(
                this.getClass(),
                "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.errUnpacking.details",
                archiveFilePath,
                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_NAME.getTypeID(),
                EmbeddedFileExtractorModuleFactory.getModuleName(),
                encryptionType));
        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: "
                + archiveFilePath,
            ex); // NON-NLS
      }

      String msg =
          NbBundle.getMessage(
              this.getClass(),
              "EmbeddedFileExtractorIngestModule.ArchiveExtractor.unpack.encrFileDetected.msg");
      String details =
          NbBundle.getMessage(
              this.getClass(),
              "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));
      context.addFilesToJob(unpackedFiles);
    }
  }
コード例 #2
0
  /**
   * Check if the item inside archive is a potential zipbomb
   *
   * <p>Currently checks compression ratio.
   *
   * <p>More heuristics to be added here
   *
   * @param archiveName the parent archive
   * @param archiveFileItem the archive item
   * @return true if potential zip bomb, false otherwise
   */
  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(
                this.getClass(),
                "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(
                this.getClass(),
                "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.SEVERE,
          "Error getting archive item size and cannot detect if zipbomb. ",
          ex); // NON-NLS
      return false;
    }
  }