de.flexiprovider.core.serpent
Class Serpent

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

Direct Known Subclasses:

Serpent.Serpent128_CBC, Serpent.Serpent128_CFB, Serpent.Serpent128_ECB, Serpent.Serpent128_OFB, Serpent.Serpent192_CBC, Serpent.Serpent192_CFB, Serpent.Serpent192_ECB, Serpent.Serpent192_OFB, Serpent.Serpent256_CBC, Serpent.Serpent256_CFB, Serpent.Serpent256_ECB, Serpent.Serpent256_OFB

public class Serpent

extends BlockCipher

This class implementes the Serpent block cipher. For more information, see http://www.cl.cam.ac.uk/~ rja14/serpent.html. Serpent uses a block size of 128 bits. The key size can be 128, 192, or 256 bits. Encryption/decryption takes 32 rounds.

Author:

Katja Rauch, Martin Döring

Inner Class Summary

static class	Serpent.Serpent128_CBC Serpent128_CBC
static class	Serpent.Serpent128_CFB Serpent128_CFB
static class	Serpent.Serpent128_ECB Serpent128_ECB
static class	Serpent.Serpent128_OFB Serpent128_OFB
static class	Serpent.Serpent192_CBC Serpent192_CBC
static class	Serpent.Serpent192_CFB Serpent192_CFB
static class	Serpent.Serpent192_ECB Serpent192_ECB
static class	Serpent.Serpent192_OFB Serpent192_OFB
static class	Serpent.Serpent256_CBC Serpent256_CBC
static class	Serpent.Serpent256_CFB Serpent256_CFB
static class	Serpent.Serpent256_ECB Serpent256_ECB
static class	Serpent.Serpent256_OFB Serpent256_OFB

Field Summary

static java.lang.String	ALG_NAME The algorithm name.
static java.lang.String	OID The OID of Serpent (defined by the GNU project, see http://www.gnupg.org/oids.html).

Fields inherited from class de.flexiprovider.api.BlockCipher

random

Fields inherited from class de.flexiprovider.api.Cipher

DECRYPT_MODE, ENCRYPT_MODE, opMode

Constructor Summary

	Serpent() Constructor.
protected	Serpent(java.lang.String modeName, int keySize) Constructor.

Method Summary

int	getCipherBlockSize() This method returns 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 secret key for data decryption.
protected void	initCipherEncrypt(SecretKey key, AlgorithmParameterSpec params) Initialize the block cipher with a secret key for data encryption.
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.

OID

public static final java.lang.String OID

The OID of Serpent (defined by the GNU project, see http://www.gnupg.org/oids.html).

Constructor Detail

Serpent

protected Serpent(java.lang.String modeName,
                  int keySize)

Constructor.

Parameters:

modeName - the mode to use

keySize - the key size in words

Serpent

public Serpent()

Constructor.

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

Return the key size of the given key object. Checks whether the key object is an instance of SerpentKey or SecretKeySpec and whether the key size is within the specified range for Serpent. For the AES submission, the key size was fixed to be either 128, 192, or 256 bits, however shorter keys are allowed and appropriately padded as long as the key size is a multiple of 32 bits.

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

Initialize the block cipher with a secret key for data encryption. The algorithm parameters are not used.

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

Initialize the block cipher with a secret key for data decryption. The algorithm parameters are not used.

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