de.flexiprovider.core.mars
Class MARS

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

public class MARS

extends BlockCipher

MARSBlockCipher implements the MARS Cipher. For more information see: http://csrc.nist.gov/encryption/aes/round2/AESAlgs/MARS/mars.pdf For more information about this implementation see: Thesis 'Implementierung von symmetrischen Verschluesselungsverfahren' by Katja Rauch MARS uses a blocksize of 16 bytes. The key length can be 16, 24, 32, 40, 48 or 56 bytes. Encryption/decryption takes 32 rounds. Performance tests on an Intel Pentium Celeron processor with 400 MHz, 64 MB main storage and Windows 98 running on it, achieved an encryption/decryption time of approximately 28,5 Mbit/s.

Author:

Katja Rauch

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

MARS()

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.
protected void	singleBlockEncrypt(byte[] in, int inoffset, byte[] out, int outoffset) This method encrypts a single block of data.

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

MARS

public MARS()

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 MARSKey or SecretKeySpec and whether the key size is within the specified range for MARS. Any key size between 128 and 448 bits that is divisible by 8 is fine.

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. It will be called by the padding scheme.

Overrides:

getCipherBlockSize in class BlockCipher

Returns:

the 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. The array in must contain a whole block starting at inOffset and out must be large enough to hold an encrypted block starting at outOffset .

Overrides:

singleBlockEncrypt in class BlockCipher

Parameters:

in - array of bytes containing the plaintext to be encrypted

inoffset - index in array in, where the plaintext block starts

out - array of bytes which will contain the ciphertext starting at outOffset

outoffset - index in 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. The array in must contain a whole block starting at inOffset and out must be large enough to hold an encrypted block starting at outOffset .

Overrides:

singleBlockDecrypt in class BlockCipher

Parameters:

in - array of bytes containig the ciphertext to be decrypted

inoffset - index in array in, where the ciphertext block starts

out - array of bytes which will contain the plaintext starting at outOffset

outoffset - index in array out, where the plaintext block will start