gnu.crypto.cipher
public interface IBlockCipher extends Cloneable
The basic visible methods of any symmetric key block cipher.
A symmetric key block cipher is a function that maps n-bit plaintext blocks to n-bit ciphertext blocks; n being the cipher's block size. This encryption function is parameterised by a k-bit key, and is invertible. Its inverse is the decryption function.
Possible initialisation values for an instance of this type are:
reset()
is invoked on the instance. Furthermore, the size of
this key material shall be taken as an indication on the key size in which
to operate this instance.IMPLEMENTATION NOTE: Although all the concrete classes in this package implement the Cloneable interface, it is important to note here that such an operation DOES NOT clone any session key material that may have been used in initialising the source cipher (the instance to be cloned). Instead a clone of an already initialised cipher is another instance that operates with the same block size but without any knowledge of neither key material nor key size.
Version: $Revision: 1.8 $
Field Summary | |
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String | CIPHER_BLOCK_SIZE Property name of the block size in which to operate a block cipher. |
String | KEY_MATERIAL Property name of the user-supplied key material. |
Method Summary | |
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Iterator | blockSizes() Returns an Iterator over the supported block sizes. |
Object | clone() Returns a clone of this instance. |
int | currentBlockSize() Returns the currently set block size for this instance. |
void | decryptBlock(byte[] in, int inOffset, byte[] out, int outOffset) Decrypts exactly one block of ciphertext. |
int | defaultBlockSize() Returns the default value, in bytes, of the algorithm's block size. |
int | defaultKeySize() Returns the default value, in bytes, of the algorithm's key size. |
void | encryptBlock(byte[] in, int inOffset, byte[] out, int outOffset) Encrypts exactly one block of plaintext. |
void | init(Map attributes) Initialises the algorithm with designated attributes. |
Iterator | keySizes() Returns an Iterator over the supported key sizes. |
String | name() Returns the canonical name of this instance. |
void | reset() Resets the algorithm instance for re-initialisation and use with other characteristics. |
boolean | selfTest() A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT). |
Property name of the block size in which to operate a block cipher. The value associated with this property name is taken to be an Integer.
Property name of the user-supplied key material. The value associated to this property name is taken to be a byte array.
Returns an Iterator over the supported block sizes. Each element returned by this object is an Integer.
Returns: an Iterator over the supported block sizes.
Returns a clone of this instance.
Returns: a clone copy of this instance.
Returns the currently set block size for this instance.
Returns: the current block size for this instance.
Throws: IllegalStateException if the instance is not initialised.
Decrypts exactly one block of ciphertext.
Parameters: in the plaintext. inOffset index of in
from which to start considering
data. out the ciphertext. outOffset index of out
from which to store result.
Throws: IllegalStateException if the instance is not initialised.
Returns the default value, in bytes, of the algorithm's block size.
Returns: the default value, in bytes, of the algorithm's block size.
Returns the default value, in bytes, of the algorithm's key size.
Returns: the default value, in bytes, of the algorithm's key size.
Encrypts exactly one block of plaintext.
Parameters: in the plaintext. inOffset index of in
from which to start considering
data. out the ciphertext. outOffset index of out
from which to store result.
Throws: IllegalStateException if the instance is not initialised.
Initialises the algorithm with designated attributes. Permissible names and values are described in the class documentation above.
Parameters: attributes a set of name-value pairs that describes the desired future behaviour of this instance.
Throws: InvalidKeyException if the key data is invalid. IllegalStateException if the instance is already initialised.
See Also: KEY_MATERIAL CIPHER_BLOCK_SIZE
Returns an Iterator over the supported key sizes. Each element returned by this object is an Integer.
Returns: an Iterator over the supported key sizes.
Returns the canonical name of this instance.
Returns: the canonical name of this instance.
Resets the algorithm instance for re-initialisation and use with other characteristics. This method always succeeds.
A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT).
Returns: true
if the implementation passes simple
correctness tests. Returns false
otherwise.