FortunaRandomSource (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- java.util.Random
- - java.security.SecureRandom
  - - net.i2p.util.RandomSource
    - - net.i2p.util.FortunaRandomSource

All Implemented Interfaces:
Serializable, EntropyHarvester
```
public class FortunaRandomSource
extends RandomSource
implements EntropyHarvester
```
Wrapper around GNU-Crypto's Fortuna PRNG. This seeds from /dev/urandom and ./prngseed.rnd on startup (if they exist), writing a new seed to ./prngseed.rnd on an explicit call to saveSeed().
See Also:
Serialized Form

Field Summary
- Fields inherited from class net.i2p.util.RandomSource
  _context

Constructor Summary
Constructors
Constructor and Description
FortunaRandomSource(I2PAppContext context)
May block up to 10 seconds or forever

Constructors
Constructor and Description
`FortunaRandomSource(I2PAppContext context)` May block up to 10 seconds or forever

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`feedEntropy(String source, byte[] data, int offset, int len)` reseed the fortuna
`void`	`feedEntropy(String source, long data, int bitoffset, int bits)` reseed the fortuna
`protected int`	`nextBits(int numBits)` Pull the next numBits of random data off the fortuna instance (returning 0 through 2^numBits-1 Caller must synchronize!
`boolean`	`nextBoolean()` Random boolean.
`byte`	`nextByte()` Not part of java.util.SecureRandom, but added for efficiency, since Fortuna supports it.
`void`	`nextBytes(byte[] buf)` Fill buffer with random bytes.
`void`	`nextBytes(byte[] buf, int offset, int length)` Not part of java.util.SecureRandom, but added for efficiency, since Fortuna supports it.
`double`	`nextDouble()` Implementation from sun's java.util.Random javadocs
`float`	`nextFloat()` Implementation from sun's java.util.Random javadocs
`double`	`nextGaussian()` Implementation from sun's java.util.Random javadocs
`int`	`nextInt()` Non-negative random int.
`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()` All possible long values, positive and negative.
`long`	`nextLong(long n)` Like the modified nextInt, nextLong(n) returns a random number from 0 through n, including 0, excluding n.
`void`	`setSeed(byte[] buf)` Seed the Fortuna PRNG.
`void`	`shutdown()` Note - methods may hang or NPE or throw IllegalStateExceptions after this
`int`	`signedNextInt()` This code unused, see FortunaRandomSource override

Methods inherited from class net.i2p.util.RandomSource
getInstance, harvester, initSeed, loadSeed, saveSeed, writeSeed

Methods inherited from class java.security.SecureRandom
generateSeed, getAlgorithm, getInstance, getInstance, getInstance, getInstanceStrong, getProvider, getSeed, next, setSeed

Methods inherited from class java.util.Random
doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - FortunaRandomSource
```
public FortunaRandomSource(I2PAppContext context)
```
    May block up to 10 seconds or forever
    Parameters:
    context - the context
- Method Detail
  - feedEntropy
```
public void feedEntropy(String source,
                        byte[] data,
                        int offset,
                        int len)
```
    reseed the fortuna
    Specified by:
    feedEntropy in interface EntropyHarvester
    Overrides:
    feedEntropy in class RandomSource
    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)
```
    reseed the fortuna
    Specified by:
    feedEntropy in interface EntropyHarvester
    Overrides:
    feedEntropy in class RandomSource
    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
  - nextBits
```
protected int nextBits(int numBits)
```
    Pull the next numBits of random data off the fortuna instance (returning 0 through 2^numBits-1 Caller must synchronize!
  - nextBoolean
```
public boolean nextBoolean()
```
    Random boolean.
    Overrides:
    nextBoolean in class Random
  - nextByte
```
public byte nextByte()
```
    Not part of java.util.SecureRandom, but added for efficiency, since Fortuna supports it.
    Returns:
    the result
  - nextBytes
```
public void nextBytes(byte[] buf)
```
    Fill buffer with random bytes.
    Overrides:
    nextBytes in class SecureRandom
  - nextBytes
```
public void nextBytes(byte[] buf,
                      int offset,
                      int length)
```
    Not part of java.util.SecureRandom, but added for efficiency, since Fortuna supports it.
    Overrides:
    nextBytes in class RandomSource
  - nextDouble
```
public double nextDouble()
```
    Implementation from sun's java.util.Random javadocs
    Overrides:
    nextDouble in class Random
  - nextFloat
```
public float nextFloat()
```
    Implementation from sun's java.util.Random javadocs
    Overrides:
    nextFloat in class Random
  - nextGaussian
```
public double nextGaussian()
```
    Implementation from sun's java.util.Random javadocs
    Overrides:
    nextGaussian in class Random
  - nextInt
```
public int nextInt()
```
    Non-negative random int.
    Overrides:
    nextInt in class 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. Unlike Java's Random, which throws IAE, this returns 0 if n is 0.
    Overrides:
    nextInt in class RandomSource
    Parameters:
    n - non-negative
    Throws:
    IllegalArgumentException - if n is negative
  - nextLong
```
public long nextLong()
```
    All possible long values, positive and negative.
    Overrides:
    nextLong 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. Unlike Java's Random, which throws IAE, this returns 0 if n is 0.
    Overrides:
    nextLong in class RandomSource
    Parameters:
    n - non-negative
    Throws:
    IllegalArgumentException - if n is negative
  - setSeed
```
public void setSeed(byte[] buf)
```
    Seed the Fortuna PRNG.
    Overrides:
    setSeed in class SecureRandom
  - shutdown
```
public void shutdown()
```
    Note - methods may hang or NPE or throw IllegalStateExceptions after this
  - signedNextInt
```
public int signedNextInt()
```
    Description copied from class: RandomSource
    This code unused, see FortunaRandomSource override
    Overrides:
    signedNextInt in class RandomSource
    Returns:
    all possible int values, positive and negative

Class FortunaRandomSource

Field Summary

Fields inherited from class net.i2p.util.RandomSource

Constructor Summary

Method Summary

Methods inherited from class net.i2p.util.RandomSource

Methods inherited from class java.security.SecureRandom

Methods inherited from class java.util.Random

Methods inherited from class java.lang.Object

Constructor Detail

FortunaRandomSource

Method Detail

feedEntropy

feedEntropy

nextBits

nextBoolean

nextByte

nextBytes

nextBytes

nextDouble

nextFloat

nextGaussian

nextInt

nextInt

nextLong

nextLong

setSeed

shutdown

signedNextInt