Bouncy Castle Cryptography Library 1.65

org.bouncycastle.crypto.modes
Class SICBlockCipher

java.lang.Object
  extended byorg.bouncycastle.crypto.StreamBlockCipher
      extended byorg.bouncycastle.crypto.modes.SICBlockCipher
All Implemented Interfaces:
BlockCipher, SkippingCipher, SkippingStreamCipher, StreamCipher

public class SICBlockCipher
extends StreamBlockCipher
implements SkippingStreamCipher

Implements the Segmented Integer Counter (SIC) mode on top of a simple block cipher. This mode is also known as CTR mode.


Constructor Summary
SICBlockCipher(BlockCipher c)
          Basic constructor.
 
Method Summary
protected  byte calculateByte(byte in)
           
 java.lang.String getAlgorithmName()
          Return the name of the algorithm the cipher implements.
 int getBlockSize()
          Return the block size for this cipher (in bytes).
 long getPosition()
          Return the current "position" of the cipher
 void init(boolean forEncryption, CipherParameters params)
          Initialise the cipher.
 int processBlock(byte[] in, int inOff, byte[] out, int outOff)
          Process one block of input from the array in and write it to the out array.
 void reset()
          reset the cipher.
 long seekTo(long position)
          Reset the cipher and then skip forward to a given position.
 long skip(long numberOfBytes)
          Skip numberOfBytes forwards, or backwards.
 
Methods inherited from class org.bouncycastle.crypto.StreamBlockCipher
getUnderlyingCipher, processBytes, returnByte
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.bouncycastle.crypto.StreamCipher
processBytes, returnByte
 

Constructor Detail

SICBlockCipher

public SICBlockCipher(BlockCipher c)
Basic constructor.

Parameters:
c - the block cipher to be used.
Method Detail

init

public void init(boolean forEncryption,
                 CipherParameters params)
          throws java.lang.IllegalArgumentException
Description copied from interface: StreamCipher
Initialise the cipher.

Specified by:
init in interface StreamCipher
Parameters:
forEncryption - if true the cipher is initialised for encryption, if false for decryption.
params - the key and other data required by the cipher.
Throws:
java.lang.IllegalArgumentException - if the params argument is inappropriate.

getAlgorithmName

public java.lang.String getAlgorithmName()
Description copied from interface: StreamCipher
Return the name of the algorithm the cipher implements.

Specified by:
getAlgorithmName in interface StreamCipher
Returns:
the name of the algorithm the cipher implements.

getBlockSize

public int getBlockSize()
Description copied from interface: BlockCipher
Return the block size for this cipher (in bytes).

Specified by:
getBlockSize in interface BlockCipher
Returns:
the block size for this cipher in bytes.

processBlock

public int processBlock(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)
                 throws DataLengthException,
                        java.lang.IllegalStateException
Description copied from interface: BlockCipher
Process one block of input from the array in and write it to the out array.

Specified by:
processBlock in interface BlockCipher
Parameters:
in - the array containing the input data.
inOff - offset into the in array the data starts at.
out - the array the output data will be copied into.
outOff - the offset into the out array the output will start at.
Returns:
the number of bytes processed and produced.
Throws:
DataLengthException - if there isn't enough data in in, or space in out.
java.lang.IllegalStateException - if the cipher isn't initialised.

calculateByte

protected byte calculateByte(byte in)
                      throws DataLengthException,
                             java.lang.IllegalStateException
Specified by:
calculateByte in class StreamBlockCipher
Throws:
DataLengthException
java.lang.IllegalStateException

reset

public void reset()
Description copied from interface: StreamCipher
reset the cipher. This leaves it in the same state it was at after the last init (if there was one).

Specified by:
reset in interface StreamCipher

skip

public long skip(long numberOfBytes)
Description copied from interface: SkippingCipher
Skip numberOfBytes forwards, or backwards.

Specified by:
skip in interface SkippingCipher
Parameters:
numberOfBytes - the number of bytes to skip (positive forward, negative backwards).
Returns:
the number of bytes actually skipped.

seekTo

public long seekTo(long position)
Description copied from interface: SkippingCipher
Reset the cipher and then skip forward to a given position.

Specified by:
seekTo in interface SkippingCipher
Parameters:
position - the number of bytes in to set the cipher state to.
Returns:
the byte position moved to.

getPosition

public long getPosition()
Description copied from interface: SkippingCipher
Return the current "position" of the cipher

Specified by:
getPosition in interface SkippingCipher
Returns:
the current byte position.

Bouncy Castle Cryptography Library 1.65