net.i2p.util

Class RandomSource

java.lang.Object

java.util.Random

java.security.SecureRandom

net.i2p.util.RandomSource

All Implemented Interfaces:

Serializable, EntropyHarvester

Direct Known Subclasses:

FortunaRandomSource

public class RandomSource
extends SecureRandom
implements EntropyHarvester

Singleton for whatever PRNG i2p uses.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected I2PAppContext	_context

Constructor Summary

Constructors

Constructor and 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 and 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()
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 void	writeSeed(byte[] buf)

Methods inherited from class java.security.SecureRandom

generateSeed, getAlgorithm, getInstance, getInstance, getInstance, getInstanceStrong, getProvider, getSeed, next, nextBytes, setSeed, setSeed

Methods inherited from class java.util.Random

doubles, doubles, doubles, doubles, 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, toString, wait, wait, wait

Field Detail

_context

protected final transient I2PAppContext _context

Constructor Detail

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 Detail

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

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

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()

harvester

public EntropyHarvester harvester()

initSeed

public final boolean initSeed(byte[] buf)

May block up to 10 seconds

loadSeed

public void loadSeed()

May block up to 10 seconds

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

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

Overrides:

nextInt in class Random

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

saveSeed

public void saveSeed()

signedNextInt

public int signedNextInt()

This code unused, see FortunaRandomSource override

Returns:

all possible int values, positive and negative

writeSeed

public static final void writeSeed(byte[] buf)