gnu.crypto.assembly
Class Stage
public abstract class Stage
A
Stage in a Cascade Cipher.
Each stage may be either an implementation of a Block Cipher Mode of
Operation (
IMode
) or another Cascade Cipher (
Cascade
). Each
stage has also a
natural operational direction when constructed for
inclusion within a
Cascade
. This
natural direction dictates
how data flows from one stage into another when stages are chained together
in a cascade. One can think of a stage and its natural direction as the
specification of how to wire the stage into the chain. The following diagrams
may help understand the paradigme. The first shows two stages chained each
with a
Direction.FORWARD
direction.
FORWARD FORWARD
+------+ +-------+
| | | |
| +--in --+ | +--in --+
---+ | Stage | | | Stage | +---
+--out--+ | +--out--+ |
| | | |
+-------+ +------+
The second diagram shows two stages, one in a
Direction.FORWARD
direction, while the other is wired in a
Direction.REVERSED
direction.
FORWARD REVERSED
+------+ +------+
| | | |
| +--in --+ +--in --+ |
---+ | Stage | | Stage | +---
+--out--+ +--out--+
| |
+---------------+
abstract Set | blockSizes() - Returns the
Set of supported block sizes for this
Stage .
|
abstract int | currentBlockSize() - Returns the currently set block size for the stage.
|
static Stage | getInstance(Cascade cascade, Direction forwardDirection)
|
static Stage | getInstance(IMode mode, Direction forwardDirection)
|
void | init(Map attributes) - Initialises the stage for operation with specific characteristics.
|
(package private) abstract void | initDelegate(Map attributes)
|
void | reset() - Resets the stage for re-initialisation and use with other characteristics.
|
(package private) abstract void | resetDelegate()
|
abstract boolean | selfTest() - Conducts a simple correctness test that consists of basic symmetric
encryption / decryption test(s) for all supported block and key sizes of
underlying block cipher(s) wrapped by Mode leafs.
|
void | update(byte[] in, int inOffset, byte[] out, int outOffset) - Processes exactly one block of plaintext (if initialised in the
Direction.FORWARD state) or ciphertext (if initialised in
the Direction.REVERSED state).
|
(package private) abstract void | updateDelegate(byte[] in, int inOffset, byte[] out, int outOffset)
|
DIRECTION
public static final String DIRECTION
Stage
protected Stage(Direction forwardDirection)
blockSizes
public abstract Set blockSizes()
Returns the Set
of supported block sizes for this
Stage
. Each element in the returned Set
is an
instance of Integer
.
- a
Set
of supported block sizes.
currentBlockSize
public abstract int currentBlockSize()
throws IllegalStateException
Returns the currently set block size for the stage.
- the current block size for this stage.
init
public void init(Map attributes)
throws InvalidKeyException
Initialises the stage for operation with specific characteristics.
attributes
- a set of name-value pairs that describes the desired
future behaviour of this instance.
initDelegate
(package private) abstract void initDelegate(Map attributes)
throws InvalidKeyException
reset
public void reset()
Resets the stage for re-initialisation and use with other characteristics.
This method always succeeds.
resetDelegate
(package private) abstract void resetDelegate()
selfTest
public abstract boolean selfTest()
Conducts a simple correctness test that consists of basic symmetric
encryption / decryption test(s) for all supported block and key sizes of
underlying block cipher(s) wrapped by Mode leafs. The test also includes
one (1) variable key Known Answer Test (KAT) for each block cipher.
true
if the implementation passes simple
correctness tests. Returns false
otherwise.
update
public void update(byte[] in,
int inOffset,
byte[] out,
int outOffset)
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.
updateDelegate
(package private) abstract void updateDelegate(byte[] in,
int inOffset,
byte[] out,
int outOffset)
Copyright © 2001, 2002, 2003
Free Software Foundation,
Inc. All Rights Reserved.