de.schlichtherle.crypto.generators
Class DigestRandom

java.lang.Object
  java.util.Random
      de.schlichtherle.crypto.generators.DigestRandom

All Implemented Interfaces:

Serializable

public class DigestRandom
extends Random

A Pseudo Random Number Generator (PRNG) using an arbitrary digest function. Similar to SecureRandom, this class is self-seeding. However, unlike SecureRandom, it's not seedable: Calling one of the Random.setSeed(long) methods does not have any effect!

Unlike its super class, this class does not support serialization.

Author:

Christian Schlichtherle

See Also:

Serialized Form

seeder

private static final SecureRandom seeder

in

private final byte[] in

counter

private long counter

digest

private final Digest digest

out

private final byte[] out

outOff

private int outOff

DigestRandom

public DigestRandom(Digest digest)

nextBytes

public void nextBytes(byte[] bytes)

Generates a user-specified number of pseudo random bytes. This method is used as the basis of all random entities returned by this class (except seed bytes).

Overrides:

nextBytes in class Random

Parameters:

bytes - The array to be filled in with random bytes.

next

protected final int next(int numBits)

Generates an integer containing the user-specified number of pseudo-random bits (right justified, with leading zeros). This method overrides a java.util.Random method, and serves to provide a source of random bits to all of the methods inherited from that class (for example, nextInt, nextLong, and nextFloat).

Overrides:

next in class Random

Parameters:

numBits - Number of pseudo-random bits to be generated, where 0 <= numBits <= 32.

Returns:

An int containing the user-specified number of pseudo-random bits (right justified, with leading zeros).

update

private void update()