de.flexiprovider.core.rc2
Class RC2

java.lang.Object
  |
  +--javax.crypto.CipherSpi
        |
        +--de.flexiprovider.api.Cipher
              |
              +--de.flexiprovider.api.BlockCipher
                    |
                    +--de.flexiprovider.core.rc2.RC2

Direct Known Subclasses:

RC2.RC2_CBC

public class RC2

extends BlockCipher

This class implements the RC2 block-cipher algorithm according to RFC 2268. RC2 was invented by Ronald Rivest for RSA Security in 1987. Further information can be found at RSA Security and in RFC 2268.

The efficiency of this implementation has been tested on a AMD K6-III, 450 MHz, running Windows 2000 Prof., using jdk 1.2.2. The encryption/decryption rate is about xxx.x MBits.

Author:

Oliver Seiler

Inner Class Summary

static class

RC2.RC2_CBC RC2_CBC

Field Summary

static java.lang.String

ALG_NAME The algorithm name.

Fields inherited from class de.flexiprovider.api.BlockCipher

random

Fields inherited from class de.flexiprovider.api.Cipher

DECRYPT_MODE, ENCRYPT_MODE, opMode

Constructor Summary

RC2()

Method Summary

int	getCipherBlockSize() This method returns the blocksize the algorithm uses.
int	getKeySize(Key key) Returns the key size of the given key object.
java.lang.String	getName()
protected void	initCipherDecrypt(SecretKey key, AlgorithmParameterSpec params) This method guarantees the AlgorithmParameterSpec compatibility.
protected void	initCipherEncrypt(SecretKey key, AlgorithmParameterSpec params) This method guarantees the AlgorithmParameterSpec compatibility.
protected void	singleBlockDecrypt(byte[] in, int inOffset, byte[] out, int outOffset) This method decrypts a single block of data, and may only be called, when the block cipher is in decrytion mode.
protected void	singleBlockEncrypt(byte[] in, int inOffset, byte[] out, int outOffset) This method encrypts a single block of data, and may only be called, when the block cipher is in encrytion mode.

Methods inherited from class de.flexiprovider.api.BlockCipher

doFinal, doFinal, engineInit, getBlockSize, getIV, getOutputSize, getParameters, initDecrypt, initDecrypt, initDecrypt, initEncrypt, initEncrypt, initEncrypt, initEncrypt, setMode, setPadding, update, update

Methods inherited from class de.flexiprovider.api.Cipher

doFinal, doFinal, engineDoFinal, engineDoFinal, engineGetBlockSize, engineGetIV, engineGetKeySize, engineGetOutputSize, engineGetParameters, engineInit, engineInit, engineSetMode, engineSetPadding, engineUpdate, engineUpdate, update

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ALG_NAME

public static final java.lang.String ALG_NAME

The algorithm name.

Constructor Detail

RC2

public RC2()

Method Detail

getName

public java.lang.String getName()

Overrides:

getName in class Cipher

Returns:

the name of this cipher

getKeySize

public int getKeySize(Key key)
               throws InvalidKeyException

Returns the key size of the given key object. Checks whether the key object is an instance of RC2Key or SecretKeySpec.

Overrides:

getKeySize in class Cipher

Parameters:

key - the key object

Returns:

the key size of the given key object.

Throws:

InvalidKeyException - if key is invalid.

getCipherBlockSize

public int getCipherBlockSize()

This method returns the blocksize the algorithm uses. This method will normally be called by the padding scheme.

Overrides:

getCipherBlockSize in class BlockCipher

Returns:

used blocksize in bytes

initCipherEncrypt

protected void initCipherEncrypt(SecretKey key,
                                 AlgorithmParameterSpec params)
                          throws InvalidKeyException

This method guarantees the AlgorithmParameterSpec compatibility. As these are not used here it just calls the origin InitDecrypt method.

Overrides:

initCipherEncrypt in class BlockCipher

Parameters:

key - the SecretKey which has to be used to decrypt data.

params - algorithmParameterSpec, not used for here

Throws:

InvalidKeyException - if the given key is inappropriate for initialising this cipher.

initCipherDecrypt

protected void initCipherDecrypt(SecretKey key,
                                 AlgorithmParameterSpec params)
                          throws InvalidKeyException

This method guarantees the AlgorithmParameterSpec compatibility. As these are not used here it just calls the origin InitDecrypt method.

Overrides:

initCipherDecrypt in class BlockCipher

Parameters:

key - the SecretKey which has to be used to decrypt data.

params - algorithmParameterSpec, not used for here

Throws:

InvalidKeyException - if the given key is inappropriate for initialising this cipher.

singleBlockEncrypt

protected void singleBlockEncrypt(byte[] in,
                                  int inOffset,
                                  byte[] out,
                                  int outOffset)

This method encrypts a single block of data, and may only be called, when the block cipher is in encrytion mode. It has to be asured, too, that the array in contains a whole block starting at inOffset and that out is large enogh to hold an encrypted block starting at outOffset

Overrides:

singleBlockEncrypt in class BlockCipher

Parameters:

in - byte[] containing the plaintext to be encrypted starting at inOffset

inOffset - int index in the array in where the plaintext block starts

out - byte[] which will contain the ciphertext startig at outOffset

outOffset - int index in the array out where the ciphertext block will start

singleBlockDecrypt

protected void singleBlockDecrypt(byte[] in,
                                  int inOffset,
                                  byte[] out,
                                  int outOffset)

This method decrypts a single block of data, and may only be called, when the block cipher is in decrytion mode. It has to be asured, too, that the array in contains a whole block starting at inOffset and that out is large enogh to hold an decrypted block starting at outOffset

Overrides:

singleBlockDecrypt in class BlockCipher

Parameters:

in - byte[] containing the ciphertext to be decrypted starting at inOffset

inOffset - int index in the array in where the ciphertext block starts

out - byte[] which will contain the plaintext startig at outOffset

outOffset - int index in the array out where the plaintext block will start