de.flexiprovider.core.rijndael
Class Rijndael

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

Direct Known Subclasses:

Rijndael.AES

public class Rijndael

extends BlockCipher

This class implements the Rijndael block cipher. Rijndael uses a block size of 16, 24 or 32 bytes. The key size can be 16, 24 or 32 bytes. Encryption/decryption takes 32 rounds. For more information, see http://csrc.nist.gov/archive/aes/index.html.

Author:

Katja Rauch

Inner Class Summary

static class

Rijndael.AES

Field Summary

static java.lang.String	ALG_NAME The algorithm name.
protected java.lang.String	algName The algorithm name returned by getName().
protected int	blockSize the block length in words (word width is 32 bits)
protected boolean	blockSizeIsMutable flag indicating whether block length may be changed
protected int	keySize the key size in words (word width is 32 bits)
protected boolean	keySizeIsMutable flag indicating whether key size may be changed

Fields inherited from class de.flexiprovider.api.BlockCipher

random

Fields inherited from class de.flexiprovider.api.Cipher

DECRYPT_MODE, ENCRYPT_MODE, opMode

Constructor Summary

Rijndael()
Constructor.

Method Summary

protected int	getCipherBlockSize() Return the blocksize the algorithm uses.
int	getKeySize(Key key) Return the key size of the given key object.
java.lang.String	getName()
protected void	initCipherDecrypt(SecretKey key, AlgorithmParameterSpec params) Initialize the block cipher with a given key and parameters for data decryption.
protected void	initCipherEncrypt(SecretKey key, AlgorithmParameterSpec params) Initialize the block cipher with a given key and parameters for data encryption.
protected void	singleBlockDecrypt(byte[] input, int inOff, byte[] output, int outOff) Decrypt a single block of data.
protected void	singleBlockEncrypt(byte[] input, int inOff, byte[] output, int outOff) Encrypt 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.

algName

protected java.lang.String algName

The algorithm name returned by getName().

keySize

protected int keySize

the key size in words (word width is 32 bits)

keySizeIsMutable

protected boolean keySizeIsMutable

flag indicating whether key size may be changed

blockSize

protected int blockSize

the block length in words (word width is 32 bits)

blockSizeIsMutable

protected boolean blockSizeIsMutable

flag indicating whether block length may be changed

Constructor Detail

Rijndael

public Rijndael()

Constructor.

Method Detail

getName

public final java.lang.String getName()

Overrides:

getName in class Cipher

Returns:

the name of this cipher

getKeySize

public int getKeySize(Key key)
               throws InvalidKeyException

Return the key size of the given key object. Check whether the key object is an instance of RijndaelKey and whether the key size is valid for Rijndael. 128, 192 and 256 bit keys are allowed.

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

protected int getCipherBlockSize()

Description copied from class: BlockCipher

Return the blocksize the algorithm uses. This method will usually be called by the mode.

Overrides:

getCipherBlockSize in class BlockCipher

Returns:

the block size (in bytes)

initCipherEncrypt

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

Initialize the block cipher with a given key and parameters for data encryption.

Overrides:

initCipherEncrypt in class BlockCipher

Parameters:

key - SecretKey to be used to encrypt data

params - AlgorithmParameterSpec to be used with this algorithm. Only instances of RijndaelParameterSpec are allowed.

Throws:

InvalidKeyException - if the given key is illegal for this cipher.

InvalidAlgorithmParameterException - if the parameters are illegal for this cipher.

initCipherDecrypt

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

Initialize the block cipher with a given key and parameters for data decryption.

Overrides:

initCipherDecrypt in class BlockCipher

Parameters:

key - SecretKey to be used to decrypt data

params - AlgorithmParameterSpec to be used with this algorithm. Only instances of RijndaelParameterSpec are allowed.

Throws:

InvalidKeyException - if the given key is illegal for this cipher.

InvalidAlgorithmParameterException - if the parameters are illegal for this cipher.

singleBlockEncrypt

protected void singleBlockEncrypt(byte[] input,
                                  int inOff,
                                  byte[] output,
                                  int outOff)

Encrypt a single block of data.

Overrides:

singleBlockEncrypt in class BlockCipher

Parameters:

input - byte array containing the plaintext block to be encrypted

inOff - index where the plaintext block starts

output - byte array to hold the ciphertext block

outOff - index where the ciphertext block will start

singleBlockDecrypt

protected void singleBlockDecrypt(byte[] input,
                                  int inOff,
                                  byte[] output,
                                  int outOff)

Decrypt a single block of data.

Overrides:

singleBlockDecrypt in class BlockCipher

Parameters:

input - byte array containing the ciphertext block to be decrypted

inOff - index where the ciphertext block starts

output - byte array to hold the plaintext block

outOff - index where the plaintext block will start