Package net.i2p.util

Class RandomSource

java.lang.Object

java.util.Random

java.security.SecureRandom

net.i2p.util.RandomSource

All Implemented Interfaces:

Serializable, java.util.random.RandomGenerator, EntropyHarvester

Direct Known Subclasses:

FortunaRandomSource

public class RandomSource
extends SecureRandom
implements EntropyHarvester

Singleton for whatever PRNG i2p uses.

Author:

jrandom

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.random.RandomGenerator

java.util.random.RandomGenerator.ArbitrarilyJumpableGenerator, java.util.random.RandomGenerator.JumpableGenerator, java.util.random.RandomGenerator.LeapableGenerator, java.util.random.RandomGenerator.SplittableGenerator, java.util.random.RandomGenerator.StreamableGenerator

Field Summary

Fields

Modifier and Type	Field	Description
protected final I2PAppContext	_context

Constructor Summary

Constructors

Constructor	Description
RandomSource(I2PAppContext context)	Deprecated - do not instantiate this directly, as you won't get the good one (Fortuna).

Method Summary

Modifier and Type	Method	Description
void	feedEntropy(String source, byte[] data, int offset, int len)	Feed the entropy pools with data[offset:offset+len]
void	feedEntropy(String source, long data, int bitoffset, int bits)	Feed the entropy pools with the bits in the data
static RandomSource	getInstance()	Singleton for whatever PRNG i2p uses.
EntropyHarvester	harvester()
final boolean	initSeed(byte[] buf)	May block up to 10 seconds
void	loadSeed()	May block up to 10 seconds
void	nextBytes(byte[] buf, int offset, int length)	Not part of java.util.SecureRandom, but added since Fortuna supports it.
int	nextInt(int n)	According to the java docs (http://java.sun.com/j2se/1.4.1/docs/api/java/util/Random.html#nextInt(int)) nextInt(n) should return a number between 0 and n (including 0 and excluding n).
long	nextLong(long n)	Like the modified nextInt, nextLong(n) returns a random number from 0 through n, including 0, excluding n.
void	saveSeed()
int	signedNextInt()	This code unused, see FortunaRandomSource override
static final void	writeSeed(byte[] buf)

Methods inherited from class java.security.SecureRandom

generateSeed, getAlgorithm, getInstance, getInstance, getInstance, getInstance, getInstance, getInstance, getInstanceStrong, getParameters, getProvider, getSeed, next, nextBytes, nextBytes, reseed, reseed, setSeed, setSeed, toString

Methods inherited from class java.util.Random

doubles, doubles, doubles, doubles, from, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextDouble, nextFloat, nextGaussian, nextInt, nextLong

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.random.RandomGenerator

isDeprecated, nextDouble, nextDouble, nextExponential, nextFloat, nextFloat, nextGaussian, nextInt, nextLong

Field Details

_context

protected final transient I2PAppContext _context

Constructor Details

RandomSource

public RandomSource(I2PAppContext context)

Deprecated - do not instantiate this directly, as you won't get the good one (Fortuna). Use getInstance() or I2PAppContext.getGlobalContext().random() to get the FortunaRandomSource instance.

Method Details

getInstance

public static RandomSource getInstance()

Singleton for whatever PRNG i2p uses. Same as I2PAppContext.getGlobalContext().random(); use context.random() if you have a context already.

Returns:

I2PAppContext.getGlobalContext().random()

nextInt

public int nextInt(int n)

According to the java docs (http://java.sun.com/j2se/1.4.1/docs/api/java/util/Random.html#nextInt(int)) nextInt(n) should return a number between 0 and n (including 0 and excluding n). However, their pseudocode, as well as sun's, kaffe's, and classpath's implementation INCLUDES NEGATIVE VALUES. Ok, so we're going to have it return between 0 and n (including 0, excluding n), since thats what it has been used for. This code unused, see FortunaRandomSource override

Specified by:

nextInt in interface java.util.random.RandomGenerator

Overrides:

nextInt in class Random

signedNextInt

public int signedNextInt()

This code unused, see FortunaRandomSource override

Returns:

all possible int values, positive and negative

Since:

0.9.54

nextLong

public long nextLong(long n)

Like the modified nextInt, nextLong(n) returns a random number from 0 through n, including 0, excluding n. This code unused, see FortunaRandomSource override

Specified by:

nextLong in interface java.util.random.RandomGenerator

nextBytes

public void nextBytes(byte[] buf,
 int offset,
 int length)

Not part of java.util.SecureRandom, but added since Fortuna supports it. This code unused, see FortunaRandomSource override

Since:

0.8.12

harvester

public EntropyHarvester harvester()

feedEntropy

public void feedEntropy(String source,
 long data,
 int bitoffset,
 int bits)

Description copied from interface: EntropyHarvester

Feed the entropy pools with the bits in the data

Specified by:

feedEntropy in interface EntropyHarvester

Parameters:

source - origin of the entropy, allowing the harvester to determine how much to value the data

bitoffset - bit index into the data array to start (using java standard big-endian)

bits - how many bits to use

feedEntropy

public void feedEntropy(String source,
 byte[] data,
 int offset,
 int len)

Description copied from interface: EntropyHarvester

Feed the entropy pools with data[offset:offset+len]

Specified by:

feedEntropy in interface EntropyHarvester

Parameters:

source - origin of the entropy, allowing the harvester to determine how much to value the data

offset - index into the data array to start

len - how many bytes to use

loadSeed

public void loadSeed()

May block up to 10 seconds

saveSeed

public void saveSeed()

writeSeed

public static final void writeSeed(byte[] buf)

initSeed

public final boolean initSeed(byte[] buf)

May block up to 10 seconds