gnu.javax.crypto.mode
Class BaseMode
- Cloneable, IBlockCipher, IMode
A basic abstract class to facilitate implementing block cipher modes of
operations.
protected IBlockCipher | cipher- The underlying block cipher implementation.
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protected int | cipherBlockSize- The block size, in bytes, to operate the underlying block cipher in.
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protected byte[] | iv- The initialisation vector value.
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protected Object | lock- The instance lock.
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protected int | modeBlockSize- The block size, in bytes, in which to operate the mode instance.
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protected String | name- The canonical name prefix of this mode.
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protected int | state- The state indicator of this instance.
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Iterator<E> | blockSizes()- Returns an
Iterator over the supported block sizes.
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abstract Object | clone()- Returns a clone of this instance.
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int | currentBlockSize()- Returns the currently set block size for this instance.
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abstract void | decryptBlock(byte[] in, int i, byte[] out, int o)- Decrypts exactly one block of ciphertext.
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int | defaultBlockSize()- Returns the default value, in bytes, of the mode's block size.
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int | defaultKeySize()- Returns the default value, in bytes, of the underlying block cipher key
size.
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abstract void | encryptBlock(byte[] in, int i, byte[] out, int o)- Encrypts exactly one block of plaintext.
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void | init(Map<K,V> attributes)- Initialises the algorithm with designated attributes.
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Iterator<E> | keySizes()- Returns an
Iterator over the supported underlying block cipher key
sizes.
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String | name()- Returns the canonical name of this instance.
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void | reset()- Resets the algorithm instance for re-initialisation and use with other
characteristics.
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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).
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abstract void | setup()- The initialisation phase of the concrete mode implementation.
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abstract void | teardown()- The termination phase of the concrete mode implementation.
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void | update(byte[] in, int inOffset, byte[] out, int outOffset)
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clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait |
cipherBlockSize
protected int cipherBlockSize
The block size, in bytes, to operate the underlying block cipher in.
iv
protected byte[] iv
The initialisation vector value.
modeBlockSize
protected int modeBlockSize
The block size, in bytes, in which to operate the mode instance.
name
protected String name
The canonical name prefix of this mode.
state
protected int state
The state indicator of this instance.
BaseMode
protected BaseMode(String name,
IBlockCipher underlyingCipher,
int cipherBlockSize) Trivial constructor for use by concrete subclasses.
name - the canonical name prefix of this mode.underlyingCipher - the implementation of the underlying cipher.cipherBlockSize - the block size, in bytes, in which to operate the
underlying cipher.
blockSizes
public Iterator<E> blockSizes()
Returns an
Iterator over the supported block sizes. Each element
returned by this object is an
Integer.
The default behaviour is to return an iterator with just one value, which
is that currently configured for the underlying block cipher. Concrete
implementations may override this behaviour to signal their ability to
support other values.
- blockSizes in interface IBlockCipher
- an
Iterator over the supported block sizes.
decryptBlock
public abstract void decryptBlock(byte[] in,
int i,
byte[] out,
int o) Decrypts exactly one block of ciphertext.
- decryptBlock in interface IBlockCipher
in - the plaintext.out - the ciphertext.
defaultBlockSize
public int defaultBlockSize()
Returns the default value, in bytes, of the mode's block size. This value
is part of the construction arguments passed to the Factory methods in
ModeFactory. Unless changed by an invocation of any of the
init() methods, a
Mode instance would operate with
the same block size as its underlying block cipher. As mentioned earlier,
the block size of the underlying block cipher itself is specified in one of
the method(s) available in the factory class.
- defaultBlockSize in interface IBlockCipher
- the default value, in bytes, of the mode's block size.
defaultKeySize
public int defaultKeySize()
Returns the default value, in bytes, of the underlying block cipher key
size.
- defaultKeySize in interface IBlockCipher
- the default value, in bytes, of the underlying cipher's key size.
encryptBlock
public abstract void encryptBlock(byte[] in,
int i,
byte[] out,
int o) Encrypts exactly one block of plaintext.
- encryptBlock in interface IBlockCipher
in - the plaintext.out - the ciphertext.
init
public void init(Map<K,V> attributes)
throws InvalidKeyException,
IllegalStateException Initialises the algorithm with designated attributes. Permissible names and
values are described in the class documentation above.
- init in interface IBlockCipher
attributes - a set of name-value pairs that describes the desired
future behaviour of this instance.
name
public String name()
Returns the canonical name of this instance.
- name in interface IBlockCipher
- the canonical name of this instance.
reset
public void reset()
Resets the algorithm instance for re-initialisation and use with other
characteristics. This method always succeeds.
- reset in interface IBlockCipher
selfTest
public 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).
- selfTest in interface IBlockCipher
true if the implementation passes simple
correctness tests. Returns false otherwise.
setup
public abstract void setup()
The initialisation phase of the concrete mode implementation.
teardown
public abstract void teardown()
The termination phase of the concrete mode implementation.
BaseMode.java --
Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc.
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