de.flexiprovider.core.idea
Class IDEA

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

Direct Known Subclasses:

IDEA.IDEA_CBC, IDEA.IDEA_CFB, IDEA.IDEA_ECB, IDEA.IDEA_OFB

public class IDEA

extends BlockCipher

BlockCipherIDEA implements the IDEA Cipher. It uses a block size of 64 (8 Bytes), a 128 bit key and uses 8 rounds for encryption/decryption.

Author:

Ralph Kuhnert, Anders Adamson, Oliver Seiler

Inner Class Summary

static class	IDEA.IDEA_CBC IDEA_CBC
static class	IDEA.IDEA_CFB IDEA_CFB
static class	IDEA.IDEA_ECB IDEA_ECB
static class	IDEA.IDEA_OFB IDEA_OFB

Field Summary

static java.lang.String	ALG_NAME The algorithm name.
static java.lang.String	OID The OID of IDEA.

Fields inherited from class de.flexiprovider.api.BlockCipher

random

Fields inherited from class de.flexiprovider.api.Cipher

DECRYPT_MODE, ENCRYPT_MODE, opMode

Constructor Summary

	IDEA() Constructor.
protected	IDEA(java.lang.String modeName)

Method Summary

protected int	getCipherBlockSize() Return the blocksize the algorithm uses.
int	getKeySize(Key key) Return the key size in bits 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[] input, int inOff, byte[] output, int outOff) This method decrypts a single block of data, and may only be called, if the block cipher is in decrytion mode.
protected void	singleBlockEncrypt(byte[] input, int inOff, byte[] output, int outOff) This method encrypts a single block of data, and may only be called, if 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.

OID

public static final java.lang.String OID

The OID of IDEA.

Constructor Detail

IDEA

protected IDEA(java.lang.String modeName)

IDEA

public IDEA()

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 in bits of the given key object. Checks whether the key object is an instance of IDEAKey or SecretKeySpec. The key size for IDEA is always fixed to 128 bits as per the specification.

Overrides:

getKeySize in class Cipher

Parameters:

key - the key object

Returns:

the key size in bits 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 of the cipher

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[] input,
                                  int inOff,
                                  byte[] output,
                                  int outOff)

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

Overrides:

singleBlockEncrypt in class BlockCipher

Parameters:

input - array of bytes which contains the plaintext to be encrypted

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

output - array of bytes which will contain the ciphertext startig at outOffset

outOff - index in array out, where the ciphertext block will start

singleBlockDecrypt

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

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

Overrides:

singleBlockDecrypt in class BlockCipher

Parameters:

input - array of bytes which contains the ciphertext to be decrypted

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

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

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