cryptix.provider.cipher

Class Rijndael

Implemented Interfaces:
Parameterized, SymmetricCipher

public final class Rijndael
extends Cipher
implements SymmetricCipher

Rijndael --pronounced Reindaal-- is a symmetric cipher with a 128-bit block size and variable key-size (128-, 192- and 256-bit).

Rijndael was designed by Vincent Rijmen and Joan Daemen.

Version:
$Revision: 1.1 $
Authors:
Raif S. Naffah
Paulo S. L. M. Barreto (pbarreto@cryptix.org)
Jeroen C. van Gelderen (gelderen@cryptix.org)
Edwin Woudt (edwin@cryptix.org)
Since:
Cryptix 3.1.3/3.2.0

Field Summary

Fields inherited from class xjava.security.Cipher

DECRYPT, ENCRYPT, UNINITIALIZED

Fields inherited from class xjava.security.IJCE_Traceable

tracing

Constructor Summary

Rijndael()
Deprecated.

Method Summary

protected void
coreInit(Key key, boolean decrypt)
protected int
engineBlockSize()
SPI: Returns the length of a block, in bytes.
protected void
engineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the specified key.
protected void
engineInitEncrypt(Key key)
SPI: Initializes this cipher for encryption, using the specified key.
protected int
engineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset)
SPI: This is the main engine method for updating data.

Methods inherited from class xjava.security.Cipher

blockSize, clone, crypt, crypt, crypt, doFinal, doFinal, doFinal, doFinal, engineBlockSize, engineCiphertextBlockSize, engineCrypt, engineGetParameter, engineInBufferSize, engineInitDecrypt, engineInitEncrypt, engineOutBufferSize, enginePlaintextBlockSize, engineSetPaddingScheme, engineSetParameter, engineUpdate, getAlgorithm, getAlgorithms, getAlgorithms, getCiphertextBlockSize, getInputBlockSize, getInstance, getInstance, getInstance, getMode, getOutputBlockSize, getPadding, getPaddingScheme, getParameter, getPlaintextBlockSize, getProvider, getState, inBufferSize, inBufferSizeFinal, initDecrypt, initEncrypt, isPaddingBlockCipher, outBufferSize, outBufferSizeFinal, setParameter, toString, update, update, update, update

Methods inherited from class xjava.security.IJCE_Traceable

disableTracing, enableTracing, traceMethod, traceResult, traceResult, traceVoidMethod

Constructor Details

Rijndael

public Rijndael()

Deprecated.

The JCE docs say: "Constructor used for dynamic instantiation." I don't understand why this is needed. --DJH

Method Details

coreInit

protected void coreInit(Key key,
                        boolean decrypt)
            throws InvalidKeyException

engineBlockSize

protected int engineBlockSize()
SPI: Returns the length of a block, in bytes. Ciphers for which plaintext and ciphertext blocks are the same size may override this method. Otherwise, both enginePlaintextBlockSize and engineCiphertextBlockSize should be overridden.

The value may change when initEncrypt or initDecrypt is called, but it should not change at other times.

Overrides:
engineBlockSize in interface Cipher
Returns:
the length in bytes of a block for this cipher.

engineInitDecrypt

protected void engineInitDecrypt(Key key)
            throws KeyException
SPI: Initializes this cipher for decryption, using the specified key.

After a call to this method, the cipher's state is set to DECRYPT.

Overrides:
engineInitDecrypt in interface Cipher
Parameters:
key - the key to use for decryption.

engineInitEncrypt

protected void engineInitEncrypt(Key key)
            throws KeyException
SPI: Initializes this cipher for encryption, using the specified key.

After a call to this method, the cipher's state is set to ENCRYPT.

Overrides:
engineInitEncrypt in interface Cipher
Parameters:
key - the key to use for encryption.

engineUpdate

protected int engineUpdate(byte[] in,
                           int inOffset,
                           int inLen,
                           byte[] out,
                           int outOffset)
SPI: This is the main engine method for updating data.

When implBuffering is true, this method will be called with the same data that is passed to update or crypt (i.e. there will be exactly one call to engineUpdate for each call to update or crypt).

When implBuffering is false, the Cipher superclass will ensure that when it calls this method, inLen is a non-negative multiple of getInputBlockSize().

in and out may be the same array, and the input and output regions may overlap. A cipher implementation should not use any part of in or out as working storage for intermediate steps of the algorithm. It should copy only the final result into the out array.

SECURITY: if array arguments are passed to native code, the implementation must ensure that a buffer overflow or illegal memory access cannot occur, regardless of the arguments passed to this method. I.e. the native library should not be called if:

   in == null || out == null || inLen <320 || inLen % (block size) != 0 ||
   inOffset <320 || (long)inOffset + inLen > in.length ||
   outOffset <320 || (long)outOffset + (number of bytes to be written) > out.length
 

Note that the (long) casts are essential, because inOffset or outOffset could be close to Integer.MAX_VALUE. The native method being called should be private. This is important because untrusted code could subclass the cipher implementation, and call this method directly with any arguments.

Overrides:
engineUpdate in interface Cipher
Parameters:
in - the input data.
inOffset - the offset into in specifying where the data starts.
inLen - the length of the subarray.
out - the output array.
outOffset - the offset indicating where to start writing into the out array.
Returns:
the number of bytes written.