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## gnu.crypto.prng
Class FortunaStandalone

    java.lang.Object
      gnu.crypto.prng.BasePRNGStandalone
          gnu.crypto.prng.FortunaStandalone

All Implemented Interfaces:
  IRandomStandalone, RandomEventListenerStandalone, Serializable, Cloneable, EventListener

Direct Known Subclasses:
  AsyncFortunaStandalone

    public class FortunaStandalone

extends BasePRNGStandalone
implements Serializable, RandomEventListenerStandalone

The Fortuna continuously-seeded pseudo-random number generator. This generator is composed of two major pieces: the entropy accumulator and the generator function. The former takes in random bits and incorporates them into the generator's state. The latter takes this base entropy and generates pseudo-random bits from it.

There are some things users of this class must be aware of:

Adding Random Data
  This class does not do any polling of random sources, but rather provides an interface for adding random events. Applications that use this code must provide this mechanism. We use this design because an application writer who knows the system he is targeting is in a better position to judge what random data is available.
Storing the Seed
  This class implements `Serializable` in such a way that it writes a 64 byte seed to the stream, and reads it back again when being deserialized. This is the extent of seed file management, however, and those using this class are encouraged to think deeply about when, how often, and where to store the seed.

References:

- Niels Ferguson and Bruce Schneier, Practical Cryptography, pp. 155--184. Wiley Publishing, Indianapolis. (2003 Niels Ferguson and Bruce Schneier). ISBN 0-471-22357-3.

Modified by jrandom for I2P to use a standalone gnu-crypto SHA256, Cryptix's AES, to strip out some unnecessary dependencies and increase the buffer size. Renamed from Fortuna to FortunaStandalone so it doesn't conflict with the gnu-crypto implementation, which has been imported into GNU/classpath

See Also:
  Serialized Form

Nested Class Summary
`static class` | `FortunaStandalone.Generator` The Fortuna generator function.

Field Summary
`(package private) FortunaStandalone.Generator` | `generator`
`(package private) static long` | `lastRefill`
`(package private) long` | `lastReseed`
`(package private) static int` | `MIN_POOL_SIZE`
`(package private) static int` | `NUM_POOLS`
`(package private) int` | `pool`
`(package private) int` | `pool0Count`
`(package private) Sha256Standalone[]` | `pools`
`(package private) static long` | `refillCount`
`(package private) int` | `reseedCount`
`static String` | `SEED`

Fields inherited from class gnu.crypto.prng.BasePRNGStandalone
`buffer, initialised, name, ndx`

Constructor Summary
`FortunaStandalone()`

Method Summary
`void` | `addRandomByte(byte b)` Supplement, or possibly replace, the random state of this PRNG with a random byte.
`void` | `addRandomBytes(byte[] buf, int offset, int length)` Supplement, or possibly replace, the random state of this PRNG with a sequence of new random bytes.
`void` | `addRandomEvent(RandomEventStandalone event)`
`protected void` | `allocBuffer()`
`void` | `fillBlock()`
`void` | `seed(byte[] val)`
`void` | `setup(Map attributes)`

Methods inherited from class gnu.crypto.prng.BasePRNGStandalone
`addRandomBytes, clone, init, isInitialised, name, nextByte, nextBytes, nextBytes`

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

Field Detail

### NUM_POOLS

    static final int NUM_POOLS

See Also:
  Constant Field Values

### MIN_POOL_SIZE

    static final int MIN_POOL_SIZE

See Also:
  Constant Field Values

### generator

    final FortunaStandalone.Generator generator

### pools

    final Sha256Standalone[] pools

### lastReseed

    long lastReseed

### pool

    int pool

### pool0Count

    int pool0Count

### reseedCount

    int reseedCount

### refillCount

    static long refillCount

### lastRefill

    static long lastRefill

### SEED

    public static final String SEED

See Also:
  Constant Field Values

Constructor Detail

### FortunaStandalone

    public FortunaStandalone()

Method Detail

### allocBuffer

    protected void allocBuffer()

### seed

    public void seed(byte[] val)

### setup

    public void setup(Map attributes)

  Specified by:
    `setup` in class `BasePRNGStandalone`

### fillBlock

    public void fillBlock()

  Specified by:
    `fillBlock` in class `BasePRNGStandalone`

### addRandomByte

    public void addRandomByte(byte b)

  Description copied from interface: `IRandomStandalone`

  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 `IRandomStandalone`
  Overrides:
    `addRandomByte` in class `BasePRNGStandalone`
  Parameters:
    `b` - The byte to add.

### addRandomBytes

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

  Description copied from interface: `IRandomStandalone`

  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 `IRandomStandalone`
  Overrides:
    `addRandomBytes` in class `BasePRNGStandalone`
  Parameters:
    `buf` - The buffer of new random bytes to add.
    `offset` - The offset from whence to begin reading random bytes.
    `length` - The number of random bytes to add.

### addRandomEvent

    public void addRandomEvent(RandomEventStandalone event)

  Specified by:
    `addRandomEvent` in interface `RandomEventListenerStandalone`

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