cryptix.provider.cipher

Class RC4

Implemented Interfaces:
Parameterized, SymmetricCipher

public final class RC4
extends Cipher
implements SymmetricCipher

This class implements the RC4 (TM) stream cipher.

The source code (C version) from which this port was done, is the one posted to the sci.crypt, alt.security, comp.security.misc, and alt.privacy newsgroups on Wed, 14 Sep 1994 06:35:31 GMT by "David Sterndark" <sterndark@netcom.com> (Message-ID: <sternCvKL4B.Hyy@netcom.com>)

RC4 (TM) was designed by Ron Rivest, and was previously a trade secret of RSA Data Security, Inc. The algorithm is now in the public domain. The name "RC4" is a trademark of RSA Data Security, Inc.

References:

  1. Bruce Schneier, "Section 17.1 RC4," Applied Cryptography, 2nd edition, John Wiley & Sons, 1996.

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

$Revision: 1.5 $

Authors:
Raif S. Naffah
David Hopwood

Since:
Cryptix 2.2.2

Field Summary

Fields inherited from class xjava.security.Cipher

DECRYPT, ENCRYPT, UNINITIALIZED

Fields inherited from class xjava.security.IJCE_Traceable

tracing

Constructor Summary

RC4()
Constructs an RC4 cipher object, in the UNINITIALIZED state.

Method Summary

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

Methods inherited from class xjava.security.Cipher

blockSize, clone, crypt, crypt, crypt, doFinal, doFinal, doFinal, doFinal, engineBlockSize, engineCiphertextBlockSize, engineCrypt, engineGetParameter, engineInBufferSize, engineInitDecrypt, engineInitEncrypt, engineOutBufferSize, enginePlaintextBlockSize, engineSetPaddingScheme, engineSetParameter, engineUpdate, 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 xjava.security.IJCE_Traceable

disableTracing, enableTracing, traceMethod, traceResult, traceResult, traceVoidMethod

Constructor Details

RC4

public RC4()
Constructs an RC4 cipher object, in the UNINITIALIZED state. This calls the Cipher constructor with implBuffering false, implPadding false and the provider set to "Cryptix".

Method Details

clone

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


engineBlockSize

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

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


engineInitDecrypt

public void engineInitDecrypt(Key key)
            throws InvalidKeyException
SPI: Initializes this cipher for decryption, using the specified key.
Overrides:
engineInitDecrypt in interface Cipher

Parameters:
key - the key to use for decryption.


engineInitEncrypt

public void engineInitEncrypt(Key key)
            throws InvalidKeyException
SPI: Initializes this cipher for encryption, using the specified key.
Overrides:
engineInitEncrypt in interface Cipher

Parameters:
key - the key to use for encryption.


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.

Overrides:
engineUpdate in interface 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.


finalize

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


getLinkStatus

public static LinkStatus getLinkStatus()