de.schlichtherle.truezip.fs.archive.zip.raes
Class ParanoidZipRaesDriver

java.lang.Object
  de.schlichtherle.truezip.fs.FsDriver
      de.schlichtherle.truezip.fs.archive.FsArchiveDriver<E>
          de.schlichtherle.truezip.fs.archive.FsCharsetArchiveDriver<ZipArchiveEntry>
              de.schlichtherle.truezip.fs.archive.zip.ZipDriver
                  de.schlichtherle.truezip.fs.archive.zip.JarDriver
                      de.schlichtherle.truezip.fs.archive.zip.raes.ZipRaesDriver
                          de.schlichtherle.truezip.fs.archive.zip.raes.ParanoidZipRaesDriver

All Implemented Interfaces:

ZipEntryFactory<ZipArchiveEntry>

@Immutable
public class ParanoidZipRaesDriver
extends ZipRaesDriver

A paranoid archive driver which builds RAES encrypted ZIP files. This driver always checks the cipher text of input archive files using the RAES Message Authentication Code (MAC), which makes it slower than the SafeZipRaesDriver for archive files larger than 512 KB and may pause the client application on the first access to the archive file for a while if the file is large. Note that the CRC-32 value of the plain text ZIP file is never checked because this is made redundant by the MAC verification.

In addition, this driver limits the number of concurrent entry output streams to one, so that writing unencrypted temporary files is inhibited.

Author:

Christian Schlichtherle

See Also:

SafeZipRaesDriver

ParanoidZipRaesDriver

public ParanoidZipRaesDriver(IOPoolProvider ioPoolProvider,
                             KeyManagerProvider keyManagerProvider)

getAuthenticationTrigger

public final long getAuthenticationTrigger()

Description copied from class: ZipRaesDriver

Constructs a new abstract ZIP.RAES driver which uses the given byte size to trigger verification of the Message Authentication Code (MAC). Note that the given parameter only affects the authentication of the cipher text in input archives - the cipher key and file length are always authenticated with RAES. Returns the value of the property authenticationTrigger. If the size of an input file is smaller than or equal to this value, the Message Authentication Code (MAC) for the entire cipher text is computed and verified in order to authenticate the file. Otherwise, only the cipher key and the file length get authenticated.

Consequently, if the value of this property is set to a negative value, the cipher text gets never verified, and if set to Long.MAX_VALUE, the cipher text gets always authenticated.

Specified by:

getAuthenticationTrigger in class ZipRaesDriver

Returns:

The value of the property authenticationTrigger.

newOutputShop

public final OutputShop<ZipArchiveEntry> newOutputShop(FsModel model,
                                                       OutputSocket<?> output,
                                                       InputShop<ZipArchiveEntry> source)
                                                throws IOException

This implementation calls ZipRaesDriver.getRaesParameters(de.schlichtherle.truezip.fs.FsModel), with which it initializes a new RaesOutputStream, and finally passes the resulting stream to ZipDriver.newZipOutputShop(de.schlichtherle.truezip.fs.FsModel, java.io.OutputStream, de.schlichtherle.truezip.fs.archive.zip.ZipInputShop).

Note that this limits the number of concurrent output entry streams to one in order to inhibit writing unencrypted temporary files for buffering the written entries.

Overrides:

newOutputShop in class ZipRaesDriver

Throws:

IOException