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gnu.javax.crypto.prng
Class Fortuna.Generator  

java.lang.Object
  gnu.java.security.prng.BasePRNG
      gnu.javax.crypto.prng.Fortuna.Generator

All Implemented Interfaces:

java.lang.Cloneable, gnu.java.security.prng.IRandom

Enclosing class:

Fortuna

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public static class Fortuna.Generator

extends gnu.java.security.prng.BasePRNG

implements java.lang.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.

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Field Summary
private  gnu.javax.crypto.cipher.IBlockCipher	cipher
private  byte[]	counter
private  gnu.java.security.hash.IMessageDigest	hash
private  byte[]	key
private static int	LIMIT
private  boolean	seeded

 

Fields inherited from class gnu.java.security.prng.BasePRNG

buffer, initialised, name, ndx

 

Constructor Summary

Fortuna.Generator(gnu.javax.crypto.cipher.IBlockCipher cipher, gnu.java.security.hash.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()
private  void	incrementCounter()           Increment `counter' as a sixteen-byte little-endian unsigned integer by one.
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.
private  void	resetKey()           Resets the cipher's key.
void	setup(java.util.Map attributes)

 

Methods inherited from class gnu.java.security.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

 

Field Detail

LIMIT

private static final int LIMIT

See Also:

Constant Field Values

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cipher

private final gnu.javax.crypto.cipher.IBlockCipher cipher

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hash

private final gnu.java.security.hash.IMessageDigest hash

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counter

private final byte[] counter

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key

private final byte[] key

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seeded

private boolean seeded

Constructor Detail

Fortuna.Generator

public Fortuna.Generator(gnu.javax.crypto.cipher.IBlockCipher cipher,
                         gnu.java.security.hash.IMessageDigest hash)

Method Detail

nextByte

public byte nextByte()

Description copied from interface: gnu.java.security.prng.IRandom

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

Specified by:

nextByte in interface gnu.java.security.prng.IRandom

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nextBytes

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

Description copied from interface: gnu.java.security.prng.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 gnu.java.security.prng.IRandom

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addRandomByte

public void addRandomByte(byte b)

Description copied from interface: gnu.java.security.prng.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 java.lang.UnsupportedOperationException.

Specified by:

addRandomByte in interface gnu.java.security.prng.IRandom

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addRandomBytes

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

Description copied from interface: gnu.java.security.prng.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 java.lang.UnsupportedOperationException.

Specified by:

addRandomBytes in interface gnu.java.security.prng.IRandom

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fillBlock

public void fillBlock()

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setup

public void setup(java.util.Map attributes)

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resetKey

private void resetKey()

Resets the cipher's key. This is done after every reseed, which combines the old key and the seed, and processes that throigh the hash function.

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incrementCounter

private void incrementCounter()

Increment `counter' as a sixteen-byte little-endian unsigned integer by one.

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> gnu >> javax >> crypto >> [ prng overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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