cryptix.provider.cipher

Class RC2

java.lang.Object

xjava.security.IJCE_Traceable

xjava.security.Cipher

cryptix.provider.cipher.RC2

All Implemented Interfaces:

Parameterized, SymmetricCipher

public final class RC2
extends Cipher
implements SymmetricCipher

A subclass of Cipher to implement the RC2 (TM) block cipher algorithm in Java.

The source code (C version) from which this port was done, and (most of) the programming notes, are by P. Gutmann (pgut01@cs.auckland.ac.nz) -- as obtained from Usenet.

Eric Young (eay@mincom.oz.au) implementation, also based on Gutmann's work, and included in Eric's colossal SSL library ver 0.6.6 14 Jan 1997, was also used for the initial key data and the computation of the session key schedule. Code to tailor the session key for a specified length in bits is included in this Java implementation but is crippled (commented out). The current code behaves as if the session key is fixed at 1024-bit.

The RC2 algorithm is word (16-bit entity) oriented, operating on a block of 64 bits (or 8 Java bytes) divided into four words, with a key table of 64 words.

RC2 (TM) was designed by Ron Rivest, and was previously a trade secret of RSA Data Security, Inc. The algorithm has since been published as an RFC [reference?]. The name "RC2" is a trademark of RSA Data Security, Inc.

Copyright © 1997 Systemics Ltd on behalf of the Cryptix Development Team.
All rights reserved.

$Revision: 1.4 $

Author:

Raif S. Naffah

Field Summary

Fields

Modifier and Type	Field and Description
static int	BLOCK_SIZE The block size, in bytes, of this cipher.

Fields inherited from class xjava.security.Cipher

DECRYPT, ENCRYPT, UNINITIALIZED

Constructor Summary

Constructors

Constructor and Description
RC2() Constructs an RC2 cipher object, in the UNINITIALIZED state.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	clone() Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).
int	engineBlockSize() SPI: Returns the length of an input block, in bytes.
void	engineInitDecrypt(java.security.Key key) SPI: Initializes this cipher for decryption, using the specified key.
void	engineInitEncrypt(java.security.Key key) SPI: Initializes this cipher for encryption, using the specified key.
protected int	engineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset) SPI: This is the main engine method for updating data.
protected void	finalize() Cleans up resources used by this instance, if necessary.
static LinkStatus	getLinkStatus() Gets an object representing the native linking status of this class.

Methods inherited from class xjava.security.Cipher

blockSize, crypt, crypt, crypt, doFinal, doFinal, doFinal, doFinal, engineCiphertextBlockSize, engineCrypt, engineGetParameter, engineInBufferSize, engineOutBufferSize, enginePlaintextBlockSize, engineSetPaddingScheme, engineSetParameter, getAlgorithm, getAlgorithms, getAlgorithms, getCiphertextBlockSize, getInputBlockSize, getInstance, getInstance, getInstance, getMode, getOutputBlockSize, getPadding, getPaddingScheme, getParameter, getPlaintextBlockSize, getProvider, getState, inBufferSize, inBufferSizeFinal, initDecrypt, initEncrypt, isPaddingBlockCipher, outBufferSize, outBufferSizeFinal, setParameter, toString, update, update, update, update

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

BLOCK_SIZE

public static final int BLOCK_SIZE

The block size, in bytes, of this cipher.

See Also:

Constant Field Values

Constructor Detail

RC2

public RC2()

Constructs an RC2 cipher object, in the UNINITIALIZED state. This calls the Cipher constructor with implBuffering false, implPadding false and the provider set to "Cryptix".

See Also:

java.security.Cipher#UNINITIALIZED

Method Detail

getLinkStatus

public static LinkStatus getLinkStatus()

Gets an object representing the native linking status of this class.

finalize

protected final void finalize()

Cleans up resources used by this instance, if necessary.

Overrides:

finalize in class java.lang.Object

clone

public final java.lang.Object clone()
                             throws java.lang.CloneNotSupportedException

Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).

Overrides:

clone in class Cipher

Throws:

java.lang.CloneNotSupportedException - if the cipher is not cloneable.

engineBlockSize

public int engineBlockSize()

SPI: Returns the length of an input block, in bytes.

Overrides:

engineBlockSize in class Cipher

Returns:

the length in bytes of an input block for this cipher.

engineInitEncrypt

public void engineInitEncrypt(java.security.Key key)
                       throws java.security.KeyException

SPI: Initializes this cipher for encryption, using the specified key.

Specified by:

engineInitEncrypt in class Cipher

Parameters:

key - the key to use for encryption.

Throws:

java.security.KeyException - if the key is invalid.

engineInitDecrypt

public void engineInitDecrypt(java.security.Key key)
                       throws java.security.KeyException

SPI: Initializes this cipher for decryption, using the specified key.

Specified by:

engineInitDecrypt in class Cipher

Parameters:

key - the key to use for decryption.

Throws:

java.security.KeyException - if the key is invalid.

engineUpdate

protected int engineUpdate(byte[] in,
                           int inOffset,
                           int inLen,
                           byte[] out,
                           int outOffset)

SPI: This is the main engine method for updating data.

in and out may be the same array, and the input and output regions may overlap.

Specified by:

engineUpdate in class Cipher

Parameters:

in - the input data.

inOffset - the offset into in specifying where the data starts.

inLen - the length of the subarray.

out - the output array.

outOffset - the offset indicating where to start writing into the out array.

Returns:

the number of bytes written.

Throws:

CryptixException - if the native library is being used, and it reports an error.