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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

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