com.motorola.iden.provider
Class RC5

java.lang.Object
  |
  +--com.motorola.iden.crypto.CipherSpi
        |
        +--com.motorola.iden.provider.RC5

public final class RC5

extends CipherSpi

This class specifies the parameters used with the RC5 algorithm.

The parameters consist of a version number, a rounds count, a word size, and optionally an initialization vector (IV) (only in feedback mode).

This class can be used to initialize a Cipher object that implements the RC5 algorithm as supplied by RSA Data Security, Inc. (RSA DSI), or any parties authorized by RSA DSI.

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© Copyright 2002 - 2004 Motorola, Inc. All Rights Reserved.

See Also:

[CipherSpi]

Constructor Summary

RC5()

Method Summary

protected byte[]	engineDoFinal(byte[] input, int inputOffset, int inputLen) Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
protected int	engineGetBlockSize() Gets the bloksize of the cipher.
protected byte[]	engineGetIV() Gets the bloksize of the cipher.
protected void	engineInit(int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random) Initializes this cipher with a key, a set of algorithm parameters, and a source of random.
protected void	engineSetMode(java.lang.String mode) Sets the mode of the cipher(ECB,CBC,CFB or OFB).
protected void	engineSetPadding(java.lang.String padding) Sets the Padding of the cipher.
protected byte[]	engineUpdate(byte[] input, int inputOffset, int inputLen) Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part.
protected void	finalize()

Methods inherited from class java.lang.Object

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

Constructor Detail

RC5

public RC5()

Method Detail

engineSetMode

protected void engineSetMode(java.lang.String mode)
                      throws NoSuchAlgorithmException

Sets the mode of the cipher(ECB,CBC,CFB or OFB).

Overrides:

engineSetMode in class CipherSpi

Parameters:

String - mode. Mode ECB is set defaultly when parameter mode is null.

Returns:

void.

Throws:

NoSuchAlgorithmException - if the requested mode mechanism does not exist

engineSetPadding

protected void engineSetPadding(java.lang.String padding)
                         throws NoSuchPaddingException

Sets the Padding of the cipher.

Overrides:

engineSetPadding in class CipherSpi

Parameters:

String - padding. PKCS5Padding is set defaultly when parameter padding is null.

Throws:

NoSuchPaddingException - if the requested padding mechanism does not exist

engineGetBlockSize

protected int engineGetBlockSize()

Gets the bloksize of the cipher.

Overrides:

engineGetBlockSize in class CipherSpi

Parameters:

viod. -

Returns:

int blocksize (bytes)..

engineGetIV

protected byte[] engineGetIV()

Gets the bloksize of the cipher.

Overrides:

engineGetIV in class CipherSpi

Parameters:

viod. -

Returns:

int blocksize (bytes)..

engineInit

protected void engineInit(int opmode,
                          Key key,
                          AlgorithmParameterSpec params,
                          SecureRandom random)
                   throws InvalidKeyException,
                          InvalidAlgorithmParameterException

Initializes this cipher with a key, a set of algorithm parameters, and a source of random.

The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode.

If this cipher requires any algorithm parameters and params is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidAlgorithmParameterException if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using engineGetIV (if the parameter is an IV).

If this cipher (including its underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random.

Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.

Overrides:

engineInit in class CipherSpi

Parameters:

opmode - the operation mode of this cipher (this is one of the following: ENCRYPT_MODE, DECRYPT_MODE,

key - the encryption key

params - the algorithm parameters

random - the source of randomness

Throws:

InvalidKeyException - if the given key is inappropriate for initializing this cipher

InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this cipher, or if this cipher is being initialized for decryption and requires algorithm parameters and params is null.

engineUpdate

protected byte[] engineUpdate(byte[] input,
                              int inputOffset,
                              int inputLen)

Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part.

The first inputLen bytes in the input buffer, starting at inputOffset inclusive, are processed, and the result is stored in a new buffer.

Overrides:

engineUpdate in class CipherSpi

Parameters:

input - the input buffer

inputOffset - the offset in input where the input starts

inputLen - the input length

Returns:

the new buffer with the result, or null if the underlying cipher is a block cipher and the input data is too short to result in a new block.

engineDoFinal

protected byte[] engineDoFinal(byte[] input,
                               int inputOffset,
                               int inputLen)
                        throws IllegalBlockSizeException,
                               BadPaddingException

Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how this cipher was initialized.

The first inputLen bytes in the input buffer, starting at inputOffset inclusive, and any input bytes that may have been buffered during a previous update operation, are processed, with padding (if requested) being applied. The result is stored in a new buffer.

A call to this method resets this cipher object to the state it was in when previously initialized via a call to engineInit. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call to engineInit) more data.

Overrides:

engineDoFinal in class CipherSpi

Parameters:

input - the input buffer

inputOffset - the offset in input where the input starts

inputLen - the input length

Returns:

the new buffer with the result

Throws:

IllegalBlockSizeException - if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size

BadPaddingException - if this cipher is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytes

finalize

protected void finalize()

Overrides:

finalize in class java.lang.Object