eve.security

Class SecureRandom

java.lang.Object

java.util.Random

eve.security.SecureRandom

All Implemented Interfaces:

Serializable

public class SecureRandom
extends Random

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SecureRandom()
SecureRandom(byte[] seed)

Method Summary

Modifier and Type	Method and Description
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 java.util.Random

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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

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