lava.security.des
Class DesCfbDecoder

java.lang.Object
  |
  +--lava.security.des.DesFbCoder
        |
        +--lava.security.des.DesCfbDecoder

public class DesCfbDecoder

extends DesFbCoder

DES decryption in Cipher FeedBack (CFB) mode.

Details: DesCfbDecoder performs data decryption using DES in cipher feedback (CFB) mode. This special mode of DES is described in FIPS PUB 81. Refer to the superclass documentation and for details.

Since:

1999.08.23

Author:

Sharky

See Also:

DesCfbEncoder

Constructor Summary

DesCfbDecoder(DesKey key, int k, long iv)
Initializes with DES funcction, value for k, and initialization vector.

DesCfbDecoder(IBlockCipher64 engine, int k, long iv)
Initializes with arbitrary block cipher, value for k, and initialization vector.

Method Summary

int	continueTransform(java.lang.Object input, java.lang.Object output, int len) ITextTransform interface method.

Methods inherited from class lava.security.des.DesFbCoder

beginTransform, completeTransform, getTransformInputWidth, getTransformOutputWidth

Methods inherited from class java.lang.Object

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

Constructor Detail

DesCfbDecoder

public DesCfbDecoder(IBlockCipher64 engine,
                     int k,
                     long iv)

Initializes with arbitrary block cipher, value for k, and initialization vector.

Details: This constructor initializes a new instance to decrypt k-bit symbols using the given 64-bit block cipher and initialization vector (IV).

Parameters:

engine - the block cipher

k - the symbol width

iv - the initialization vector

DesCfbDecoder

public DesCfbDecoder(DesKey key,
                     int k,
                     long iv)

Initializes with DES funcction, value for k, and initialization vector.

Details: This constructor initializes a new instance to decrypt k-bit symbols using the DES encryption function corresponding to the given key and initialization vector (IV).

Parameters:

engine - the block cipher

k - the symbol width

iv - the initialization vector

Method Detail

continueTransform

public int continueTransform(java.lang.Object input,
                             java.lang.Object output,
                             int len)

ITextTransform interface method.

Details: Refer to ITextTransform for a description of this interface method's contract.

This implementation immediately produces one output symbol for each input symbol.

Parameters:

input - the input symbols

output - buffer for output symbols

len - number of input symbols to process

Returns:

number of output symbols written to output