public class

PGPCFBBlockCipher

extends Object
implements BlockCipher
java.lang.Object
   ↳ org.bouncycastle.crypto.modes.PGPCFBBlockCipher

Class Overview

Implements OpenPGP's rather strange version of Cipher-FeedBack (CFB) mode on top of a simple cipher. For further info see RFC 2440.

Summary

Public Constructors
PGPCFBBlockCipher(BlockCipher cipher, boolean inlineIv)
Basic constructor.
Public Methods
String getAlgorithmName()
return the algorithm name and mode.
int getBlockSize()
return the block size we are operating at.
BlockCipher getUnderlyingCipher()
return the underlying block cipher that we are wrapping.
void init(boolean forEncryption, CipherParameters params)
Initialise the cipher and, possibly, the initialisation vector (IV).
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 chaining vector back to the IV and reset the underlying cipher.
[Expand]
Inherited Methods
From class java.lang.Object
From interface org.bouncycastle.crypto.BlockCipher

Public Constructors

public PGPCFBBlockCipher (BlockCipher cipher, boolean inlineIv)

Basic constructor.

Parameters
cipher the block cipher to be used as the basis of the feedback mode.
inlineIv if true this is for PGP CFB with a prepended iv.

Public Methods

public String getAlgorithmName ()

return the algorithm name and mode.

Returns
  • the name of the underlying algorithm followed by "/PGPCFB" and the block size in bits.

public int getBlockSize ()

return the block size we are operating at.

Returns
  • the block size we are operating at (in bytes).

public BlockCipher getUnderlyingCipher ()

return the underlying block cipher that we are wrapping.

Returns
  • the underlying block cipher that we are wrapping.

public void init (boolean forEncryption, CipherParameters params)

Initialise the cipher and, possibly, the initialisation vector (IV). If an IV isn't passed as part of the parameter, the IV will be all zeros. An IV which is too short is handled in FIPS compliant fashion.

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
IllegalArgumentException if the params argument is inappropriate.

public 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.

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.
IllegalStateException if the cipher isn't initialised.

public void reset ()

reset the chaining vector back to the IV and reset the underlying cipher.