Overview Package Class Use Source Tree Index Deprecated About
Prev Class | Next ClassFrames | No Frames
Summary: Nested | Field | Method | ConstrDetail: Nested | Field | Method | Constr

gnu.javax.crypto.prng

Class ICMGenerator

Implemented Interfaces:
Cloneable, IRandom
public class ICMGenerator
extends BasePRNG
implements Cloneable
Counter Mode is a way to define a pseudorandom keystream generator using a block cipher. The keystream can be used for additive encryption, key derivation, or any other application requiring pseudorandom data.

In ICM, the keystream is logically broken into segments. Each segment is identified with a segment index, and the segments have equal lengths. This segmentation makes ICM especially appropriate for securing packet-based protocols.

This implementation adheres to the definition of the ICM keystream generation function that allows for any symetric key block cipher algorithm (initialisation parameter gnu.crypto.prng.icm.cipher.name taken to be an instance of String) to be used. If such a parameter is not defined/included in the initialisation Map, then the "Rijndael" algorithm is used. Furthermore, if the initialisation parameter gnu.crypto.cipher.block.size (taken to be a instance of Integer) is missing or undefined in the initialisation Map, then the cipher's default block size is used.

The practical limits and constraints of such generator are:

NOTE: Rijndael is used as the default symmetric key block cipher algorithm because, with its default block and key sizes, it is the AES. Yet being Rijndael, the algorithm offers more versatile block and key sizes which may prove to be useful for generating longer key streams.

References:

  1. Integer Counter Mode, David A. McGrew.

Field Summary

static String
BLOCK_INDEX_LENGTH
Property name of ICM's block index length.
static String
CIPHER
Property name of underlying block cipher for this ICM generator.
static String
OFFSET
Property name of ICM's offset.
static String
SEGMENT_INDEX
Property name of ICM's segment index.
static String
SEGMENT_INDEX_LENGTH
Property name of ICM's segment index length.

Fields inherited from class gnu.java.security.prng.BasePRNG

buffer, initialised, name, ndx

Constructor Summary

ICMGenerator()
Trivial 0-arguments constructor.

Method Summary

void
fillBlock()
void
setup(Map<K,V> attributes)

Methods inherited from class gnu.java.security.prng.BasePRNG

addRandomByte, addRandomBytes, addRandomBytes, clone, fillBlock, init, isInitialised, name, nextByte, nextBytes, nextBytes, setup

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

BLOCK_INDEX_LENGTH

public static final String BLOCK_INDEX_LENGTH
Property name of ICM's block index length.
Field Value:
"gnu.crypto.prng.icm.block.index.length"

CIPHER

public static final String CIPHER
Property name of underlying block cipher for this ICM generator.
Field Value:
"gnu.crypto.prng.icm.cipher.name"

OFFSET

public static final String OFFSET
Property name of ICM's offset.
Field Value:
"gnu.crypto.prng.icm.offset"

SEGMENT_INDEX

public static final String SEGMENT_INDEX
Property name of ICM's segment index.
Field Value:
"gnu.crypto.prng.icm.segment.index"

SEGMENT_INDEX_LENGTH

public static final String SEGMENT_INDEX_LENGTH
Property name of ICM's segment index length.
Field Value:
"gnu.crypto.prng.icm.segment.index.length"

Constructor Details

ICMGenerator

public ICMGenerator()
Trivial 0-arguments constructor.

Method Details

fillBlock

public void fillBlock()
            throws LimitReachedException
Overrides:
fillBlock in interface BasePRNG

setup

public void setup(Map<K,V> attributes)
Overrides:
setup in interface BasePRNG
ICMGenerator.java -- Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc. This file is a part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.

Overview Package Class Use Source Tree Index Deprecated About