cryptix.provider.cipher

Class RC2

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
static intBLOCK_SIZE
The block size, in bytes, of this cipher.
Constructor Summary
RC2()
Constructs an RC2 cipher object, in the UNINITIALIZED state.
Method Summary
Objectclone()
Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).
intengineBlockSize()
SPI: Returns the length of an input block, in bytes.
voidengineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the specified key.
voidengineInitEncrypt(Key key)
SPI: Initializes this cipher for encryption, using the specified key.
protected intengineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset)
SPI: This is the main engine method for updating data.
protected voidfinalize()
Cleans up resources used by this instance, if necessary.
static LinkStatusgetLinkStatus()
Gets an object representing the native linking status of this class.

Field Detail

BLOCK_SIZE

public static final int BLOCK_SIZE
The block size, in bytes, of this cipher.

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

clone

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

engineBlockSize

public int engineBlockSize()
SPI: Returns the length of an input block, in bytes.

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

engineInitDecrypt

public void engineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the specified key.

Parameters: key the key to use for decryption.

Throws: KeyException if the key is invalid.

engineInitEncrypt

public void engineInitEncrypt(Key key)
SPI: Initializes this cipher for encryption, using the specified key.

Parameters: key the key to use for encryption.

Throws: 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.

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.

finalize

protected final void finalize()
Cleans up resources used by this instance, if necessary.

getLinkStatus

public static LinkStatus getLinkStatus()
Gets an object representing the native linking status of this class.