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 Fortuna.Generator

Enclosing Class:
Fortuna
Implemented Interfaces:
Cloneable, IRandom
public static class Fortuna.Generator
extends BasePRNG
implements Cloneable
The Fortuna generator function. The generator is a PRNG in its own right; Fortuna itself is basically a wrapper around this generator that manages reseeding in a secure way.

Field Summary

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

buffer, initialised, name, ndx

Constructor Summary

Generator(IBlockCipher cipher, IMessageDigest hash)

Method Summary

void
addRandomByte(byte b)
Supplement, or possibly replace, the random state of this PRNG with a random byte.
void
addRandomBytes(byte[] seed, int offset, int length)
Supplement, or possibly replace, the random state of this PRNG with a sequence of new random bytes.
void
fillBlock()
byte
nextByte()
Returns the next 8 bits of random data generated from this instance.
void
nextBytes(byte[] out, int offset, int length)
Fills the designated byte array, starting from byte at index offset, for a maximum of length bytes with the output of this generator instance.
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

Constructor Details

Generator

public Generator(IBlockCipher cipher,
                 IMessageDigest hash)

Method Details

addRandomByte

public void addRandomByte(byte b)
Supplement, or possibly replace, the random state of this PRNG with a random byte.

Implementations are not required to implement this method in any meaningful way; this may be a no-operation, and implementations may throw an UnsupportedOperationException.

Specified by:
addRandomByte in interface IRandom
Overrides:
addRandomByte in interface BasePRNG
Parameters:
b - The byte to add.

addRandomBytes

public void addRandomBytes(byte[] seed,
                           int offset,
                           int length)
Supplement, or possibly replace, the random state of this PRNG with a sequence of new random bytes.

Implementations are not required to implement this method in any meaningful way; this may be a no-operation, and implementations may throw an UnsupportedOperationException.

Specified by:
addRandomBytes in interface IRandom
Overrides:
addRandomBytes in interface BasePRNG
Parameters:
offset - The offset from whence to begin reading random bytes.
length - The number of random bytes to add.
Throws:
IndexOutOfBoundsException - If offset, length, or offset+length is out of bounds.

fillBlock

public void fillBlock()
Overrides:
fillBlock in interface BasePRNG

nextByte

public byte nextByte()
Returns the next 8 bits of random data generated from this instance.
Specified by:
nextByte in interface IRandom
Overrides:
nextByte in interface BasePRNG
Returns:
the next 8 bits of random data generated from this instance.
Throws:
IllegalStateException - if the instance is not yet initialised.

nextBytes

public void nextBytes(byte[] out,
                      int offset,
                      int length)
Fills the designated byte array, starting from byte at index offset, for a maximum of length bytes with the output of this generator instance.
Specified by:
nextBytes in interface IRandom
Overrides:
nextBytes in interface BasePRNG
Parameters:
out - the placeholder to contain the generated random bytes.
offset - the starting index in out to consider. This method does nothing if this parameter is not within 0 and out.length.
length - the maximum number of required random bytes. This method does nothing if this parameter is less than 1.
Throws:
IllegalStateException - if the instance is not yet initialised.

setup

public void setup(Map<K,V> attributes)
Overrides:
setup in interface BasePRNG
Fortuna.java -- The Fortuna PRNG. Copyright (C) 2004, 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