Package org.apache.poi.openxml4j.util

Class ZipSecureFile

java.lang.Object
org.apache.commons.compress.archivers.zip.ZipFile
org.apache.poi.openxml4j.util.ZipSecureFile
All Implemented Interfaces:
Closeable, AutoCloseable
@Internal public class ZipSecureFile extends org.apache.commons.compress.archivers.zip.ZipFile
This class wraps a ZipFile in order to check the entries for zip bombs while reading the archive.

The alert limits can be globally defined via setMaxEntrySize(long) and setMinInflateRatio(double).

  • Nested Class Summary

    Nested classes/interfaces inherited from class org.apache.commons.compress.archivers.zip.ZipFile

    org.apache.commons.compress.archivers.zip.ZipFile.Builder

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    MAX_FILE_COUNT_MSG
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    ZipSecureFile(File file)
     
    ZipSecureFile(String name)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static long
    getGraceEntrySize()
    Returns the current threshold for decompressed data in zip entries that are regarded as too small to worry about from a Zip Bomb perspective (default is 100Kb).
    ZipArchiveThresholdInputStream
    getInputStream(org.apache.commons.compress.archivers.zip.ZipArchiveEntry entry)
    Returns an input stream for reading the contents of the specified zip file entry.
    static long
    getMaxEntrySize()
    Returns the current maximum allowed uncompressed file size.
    static long
    getMaxFileCount()
    Returns the current maximum file count that is used.
    static long
    getMaxTextSize()
    Returns the current maximum allowed text size.
    static double
    getMinInflateRatio()
    Returns the current minimum compression rate that is used.
    String
    getName()
    Deprecated, for removal: This API element is subject to removal in a future version.
    there is no need for this method - it will be removed in a future version of POI (deprecated since POI 5.3.0)
    static void
    setGraceEntrySize(long graceEntrySize)
    Sets the grace entry size of a single zip entry.
    static void
    setMaxEntrySize(long maxEntrySize)
    Sets the maximum file size of a single zip entry.
    static void
    setMaxFileCount(long maxFileCount)
    Sets the maximum file count that we allow inside zip files that we read - including OOXML files like xlsx, docx, pptx, etc.
    static void
    setMaxTextSize(long maxTextSize)
    Sets the maximum number of characters of text that are extracted before an exception is thrown during extracting text from documents.
    static void
    setMinInflateRatio(double ratio)
    Sets the ratio between de- and inflated bytes to detect zipbomb.

    Methods inherited from class org.apache.commons.compress.archivers.zip.ZipFile

    builder, canReadEntryData, close, closeQuietly, copyRawEntries, finalize, getContentBeforeFirstLocalFileHeader, getEncoding, getEntries, getEntries, getEntriesInPhysicalOrder, getEntriesInPhysicalOrder, getEntry, getFirstLocalFileHeaderOffset, getRawInputStream, getUnixSymlink, stream

    Methods inherited from class java.lang.Object

    clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Constructor Details

    • ZipSecureFile

      public ZipSecureFile(File file) throws IOException
      Parameters:
      file - the File, possibly including path traversal - it is up to users to validate that the input value is safe
      Throws:
      IOException - if an error occurs while reading the file.

    • ZipSecureFile

      public ZipSecureFile(String name) throws IOException
      Parameters:
      name - the file name, possibly including path traversal - it is up to users to validate that the input value is safe
      Throws:
      IOException - if an error occurs while reading the file.

  • Method Details

    • setMinInflateRatio

      public static void setMinInflateRatio(double ratio)
      Sets the ratio between de- and inflated bytes to detect zipbomb. It defaults to 1% (= 0.01d), i.e. when the compression is better than 1% for any given read package part, the parsing will fail indicating a Zip-Bomb.
      Parameters:
      ratio - the ratio between de- and inflated bytes to detect zipbomb

    • getMinInflateRatio

      public static double getMinInflateRatio()
      Returns the current minimum compression rate that is used. See setMinInflateRatio() for details.
      Returns:
      The min accepted compression-ratio.

    • getMaxFileCount

      public static long getMaxFileCount()
      Returns the current maximum file count that is used. See setMaxFileCount() for details.
      Returns:
      The max accepted file count (i.e. the max number of files we allow inside zip files that we read - including OOXML files like xlsx, docx, pptx, etc.).
      Since:
      5.2.4

    • setMaxFileCount

      public static void setMaxFileCount(long maxFileCount)
      Sets the maximum file count that we allow inside zip files that we read - including OOXML files like xlsx, docx, pptx, etc. The default is 1000.
      Parameters:
      maxFileCount - The max accepted file count
      Since:
      5.2.4

    • setMaxEntrySize

      public static void setMaxEntrySize(long maxEntrySize)
      Sets the maximum file size of a single zip entry. It defaults to 4GB, i.e. the 32-bit zip format maximum. This can be used to limit memory consumption and protect against security vulnerabilities when documents are provided by users.
      Parameters:
      maxEntrySize - the max. file size of a single zip entry
      Throws:
      IllegalArgumentException - for negative maxEntrySize

    • getMaxEntrySize

      public static long getMaxEntrySize()
      Returns the current maximum allowed uncompressed file size. See setMaxEntrySize() for details.
      Returns:
      The max accepted uncompressed file size.

    • setGraceEntrySize

      public static void setGraceEntrySize(long graceEntrySize)
      Sets the grace entry size of a single zip entry. It defaults to 100Kb. When decompressed data in a zip entry is smaller than this size, the Minimum Inflation Ratio check is ignored. Setting this to a very small value may lead to more files being flagged as potential Zip Bombs are rejected as a result.
      Parameters:
      graceEntrySize - the grace entry size of a single zip entry
      Throws:
      IllegalArgumentException - for negative graceEntrySize
      Since:
      5.2.4

    • getGraceEntrySize

      public static long getGraceEntrySize()
      Returns the current threshold for decompressed data in zip entries that are regarded as too small to worry about from a Zip Bomb perspective (default is 100Kb). See setGraceEntrySize() for details.
      Returns:
      The current grace entry size
      Since:
      5.2.4

    • setMaxTextSize

      public static void setMaxTextSize(long maxTextSize)
      Sets the maximum number of characters of text that are extracted before an exception is thrown during extracting text from documents. This can be used to limit memory consumption and protect against security vulnerabilities when documents are provided by users.
      Parameters:
      maxTextSize - the max. file size of a single zip entry
      Throws:
      IllegalArgumentException - for negative maxTextSize

    • getMaxTextSize

      public static long getMaxTextSize()
      Returns the current maximum allowed text size.
      Returns:
      The max accepted text size.
      See Also:

    • getInputStream

      public ZipArchiveThresholdInputStream getInputStream(org.apache.commons.compress.archivers.zip.ZipArchiveEntry entry) throws IOException
      Returns an input stream for reading the contents of the specified zip file entry.

      Closing this ZIP file will, in turn, close all input streams that have been returned by invocations of this method.

      Overrides:
      getInputStream in class org.apache.commons.compress.archivers.zip.ZipFile
      Parameters:
      entry - the zip file entry
      Returns:
      the input stream for reading the contents of the specified zip file entry.
      Throws:
      IOException - if an I/O error has occurred
      IllegalStateException - if the zip file has been closed

    • getName

      @Deprecated(since="5.3.0", forRemoval=true) @Removal(version="7.0.0") public String getName()
      Deprecated, for removal: This API element is subject to removal in a future version.
      there is no need for this method - it will be removed in a future version of POI (deprecated since POI 5.3.0)
      Returns the path name of the ZIP file.
      Returns:
      the path name of the ZIP file