cryptix.provider.cipher
public final class CAST5 extends Cipher implements SymmetricCipher
In this RFC, Carlisle Adams (the CA in CAST, ST standing for Stafford Tavares) describes CAST5 as:
"...a DES-like Substitution-Permutation Network (SPN) cryptosystem which appears to have good resistance to differential cryptanalysis, linear cryptanalysis, and related-key cryptanalysis. This cipher also possesses a number of other desirable cryptographic properties, including avalanche, Strict Avalanche Criterion (SAC), Bit Independence Criterion (BIC), no complementation property, and an absence of weak and semi-weak keys."
CAST5 is a symmetric block cipher with a block-size of 8 bytes and a variable key-size of up to 128 bits. Its authors and their employer (Entrust Technologies, a Nortel majority-owned company) made it available worldwide on a royalty-free basis for commercial and non-commercial uses.
The CAST5 encryption algorithm has been designed to allow a key size that can vary from 40 bits to 128 bits, in 8-bit increments (that is, the allowable key sizes are 40, 48, 56, 64, ..., 112, 120, and 128 bits. For variable keysize operation, the specification is as follows:
References:
Copyright © 1997
Systemics Ltd on behalf of the
Cryptix Development Team.
All rights reserved.
$Revision: 1.6 $
Since: Cryptix 2.2.2
Constructor Summary | |
---|---|
CAST5()
Constructs a CAST5 cipher object, in the UNINITIALIZED state.
|
Method Summary | |
---|---|
Object | clone()
Always throws a CloneNotSupportedException (cloning of ciphers is not
supported for security reasons). |
protected int | engineBlockSize()
SPI: Returns the length of an input 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.
|
protected void | finalize()
Cleans up resources used by this instance, if necessary. |
static LinkStatus | getLinkStatus()
Gets an object representing the native linking status of this class. |
See Also: java.security.Cipher#UNINITIALIZED
Returns: the length in bytes of an input block for this cipher.
Parameters: key the key to use for decryption.
Throws: KeyException
when one of the following occurs:
Parameters: key the key to use for encryption.
Throws: KeyException
when one of the following occurs:
in and out may be the same array, and the input and output regions may overlap.
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.
Throws: CryptixException if the native library is being used, and it reports an error.