gnu.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.crypto.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.

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

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.

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 attributes)

Methods inherited from class gnu.crypto.prng.BasePRNG

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

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.

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.

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.

setup

public void setup(Map attributes)
Overrides:
setup in interface BasePRNG

Copyright © 2001, 2002, 2003 Free Software Foundation, Inc. All Rights Reserved.