ewe.security
Class SecureRandom

java.lang.Object
  ewe.util.Random
      ewe.security.SecureRandom

public class SecureRandom

extends Random

Constructor Summary

SecureRandom()

SecureRandom(byte[] seed)

Method Summary

byte[]	generateSeed(int numBytes)
protected int	next(int numBits) Generates an integer containing the user specified number of random bits.
void	nextBytes(byte[] bytes) Fills an array of bytes with random numbers.
void	setSeed(byte[] seed)
void	setSeed(long seed) Seeds the SecureRandom.

Methods inherited from class ewe.util.Random

nextBoolean, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, toString

Constructor Detail

SecureRandom

public SecureRandom()

SecureRandom

public SecureRandom(byte[] seed)

Method Detail

setSeed

public void setSeed(byte[] seed)

setSeed

public void setSeed(long seed)

Seeds the SecureRandom. The class is re-seeded for each call and each seed builds on the previous seed so as not to weaken security.

Overrides:

setSeed in class Random

Parameters:

seed - 8 seed bytes to seed with

nextBytes

public void nextBytes(byte[] bytes)

Description copied from class: Random

Fills an array of bytes with random numbers. All possible values are (approximately) equally likely. The JDK documentation gives no implementation, but it seems to be:

public void nextBytes(byte[] bytes)
{
  for (int i = 0; i < bytes.length; i += 4)
  {
    int random = next(32);
    for (int j = 0; i + j < bytes.length && j < 4; j++)
    {
      bytes[i+j] = (byte) (random & 0xff)
      random >>= 8;
    }
  }
}

Overrides:

nextBytes in class Random

Parameters:

bytes - the byte array that should be filled

generateSeed

public byte[] generateSeed(int numBytes)

next

protected final int next(int numBits)

Generates an integer containing the user specified number of random bits. It is right justified and padded with zeros.

Overrides:

next in class Random

Parameters:

numBits - number of random bits to get, 0 <= numBits <= 32;

Returns:

the random bits