de.schlichtherle.crypto.modes
Class SICSeekableBlockCipher

java.lang.Object
  de.schlichtherle.crypto.modes.SICSeekableBlockCipher

All Implemented Interfaces:

SeekableBlockCipher, BlockCipher

public class SICSeekableBlockCipher
extends Object
implements SeekableBlockCipher

Implements the Segmented Integer Counter (SIC) alias Counter (CTR) mode on top of a simple block cipher. This code is based on the SICBlockCipher class (as of version 1.30 of Bouncy Castle's Lightweight API for JDK 1.4), but also allows random access to a block.

Since:

TrueZIP 3.1

Version:

TrueZIP 6.7

Author:

The Legion of the Bouncy Castle (majority of the code), Christian Schlichtherle (optimizations and extension to support seeking)

Constructor Summary

SICSeekableBlockCipher(BlockCipher c)
Basic constructor.

Method Summary

String	getAlgorithmName()
long	getBlockCounter() Returns the index of the block, starting at 0, which will be processed next when BlockCipher.processBlock(byte[], int, byte[], int) is called.
int	getBlockSize()
BlockCipher	getUnderlyingCipher() return the underlying blockCounter cipher that we are wrapping.
void	init(boolean forEncryption, CipherParameters params)
int	processBlock(byte[] in, int inOff, byte[] out, int outOff)
void	reset()
void	setBlockCounter(long block) Sets the counter so that the block with the given index, starting at 0, can be processed next.

Methods inherited from class java.lang.Object

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

Constructor Detail

SICSeekableBlockCipher

public SICSeekableBlockCipher(BlockCipher c)

Basic constructor.

Parameters:

c - the blockCounter cipher to be used.

Method Detail

getUnderlyingCipher

public BlockCipher getUnderlyingCipher()

return the underlying blockCounter cipher that we are wrapping.

Returns:

the underlying blockCounter cipher that we are wrapping.

init

public void init(boolean forEncryption,
                 CipherParameters params)
          throws IllegalArgumentException

Specified by:

init in interface BlockCipher

Throws:

IllegalArgumentException

getAlgorithmName

public String getAlgorithmName()

Specified by:

getAlgorithmName in interface BlockCipher

getBlockSize

public int getBlockSize()

Specified by:

getBlockSize in interface BlockCipher

processBlock

public int processBlock(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)
                 throws DataLengthException,
                        IllegalStateException

Specified by:

processBlock in interface BlockCipher

Throws:

DataLengthException

IllegalStateException

setBlockCounter

public void setBlockCounter(long block)

Description copied from interface: SeekableBlockCipher

Sets the counter so that the block with the given index, starting at 0, can be processed next.

Specified by:

setBlockCounter in interface SeekableBlockCipher

Parameters:

block - The index of the block, starting at 0, which will be processed next when BlockCipher.processBlock(byte[], int, byte[], int) is called.

getBlockCounter

public long getBlockCounter()

Description copied from interface: SeekableBlockCipher

Returns the index of the block, starting at 0, which will be processed next when BlockCipher.processBlock(byte[], int, byte[], int) is called.

Specified by:

getBlockCounter in interface SeekableBlockCipher

reset

public void reset()

Specified by:

reset in interface BlockCipher