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gnu.crypto.prng
Class Fortuna.Generator

java.lang.Object
  extended by gnu.crypto.prng.BasePRNG
      extended by gnu.crypto.prng.Fortuna.Generator
All Implemented Interfaces:
IRandom, Cloneable
Enclosing class:
Fortuna

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
Fortuna.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.
 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.
 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
addRandomBytes, clone, init, isInitialised, name, nextBytes
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Fortuna.Generator

public Fortuna.Generator(IBlockCipher cipher,
                         IMessageDigest hash)
Method Detail

nextByte

public byte nextByte()
Description copied from interface: IRandom

Returns the next 8 bits of random data generated from this instance.

Specified by:
nextByte in interface IRandom
Overrides:
nextByte in class BasePRNG
Returns:
the next 8 bits of random data generated from this instance.

nextBytes

public void nextBytes(byte[] out,
                      int offset,
                      int length)
Description copied from interface: IRandom

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 class 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.

addRandomByte

public void addRandomByte(byte b)
Description copied from interface: IRandom

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 class BasePRNG
Parameters:
b - The byte to add.

addRandomBytes

public void addRandomBytes(byte[] seed,
                           int offset,
                           int length)
Description copied from interface: IRandom

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 class BasePRNG
Parameters:
seed - 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.

fillBlock

public void fillBlock()
Specified by:
fillBlock in class BasePRNG

setup

public void setup(Map attributes)
Specified by:
setup in class BasePRNG

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