iaik.security.random

Class JDKSeedGenerator

java.lang.Object

iaik.security.random.SeedGenerator

iaik.security.random.VarLengthSeedGenerator

iaik.security.random.JDKSeedGenerator

public class JDKSeedGenerator
extends VarLengthSeedGenerator

This class is a simple wrapper for the seed generator used in JDK SecureRandom. If required, the SecureRandom that is used to obtain the seed can also be set manually, via JDKSeedGenerator.setSecureRandom(SecureRandom). This is recommended, if the SecureRandom selected by default does not generate a secure seed. It can generate as many bytes as you need, but it is fairly slow. That process is started when you call getSeed(). Per default this class generates a 256 bit seed (32 bytes).

Version:

File Revision 18

Field Summary

Fields inherited from class iaik.security.random.SeedGenerator

seedGenListener

Constructor Summary

Constructors

Constructor and Description
JDKSeedGenerator() Initialize generation of a seed with the default amount of randomness (256 bit).
JDKSeedGenerator(int numBits) Initialize generation of a seed with the specified number of bits of randomness.

Method Summary

Methods

Modifier and Type	Method and Description
static java.security.SecureRandom	getSecureRandom() Returns the SecureRandom instance that is in use by all JDKSeedGenerator instances.
byte[]	getSeed() Return the seed.
int[]	getStatus() Return the status of seed generation.
static void	setSecureRandom(java.security.SecureRandom random) Sets the SecureRandom instance to be used by all JDKSeedGenerator instances.

Methods inherited from class iaik.security.random.VarLengthSeedGenerator

getDefault, getSeedLength, hasSeedLengthChanged, reinit, setDefault, setSeedLength

Methods inherited from class iaik.security.random.SeedGenerator

callSeedGenListener, getDefault, getDefaultSeedGenerator, seedAvailable, setDefaultSeedGenerator, setSeedGenListener

Methods inherited from class java.lang.Object

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

Constructor Detail

JDKSeedGenerator

public JDKSeedGenerator()

Initialize generation of a seed with the default amount of randomness (256 bit).

JDKSeedGenerator

public JDKSeedGenerator(int numBits)

Initialize generation of a seed with the specified number of bits of randomness.

Method Detail

getStatus

public int[] getStatus()

Return the status of seed generation. This is always {numBits, numBits}, i.e. it is always ok to call getSeed().

Specified by:

getStatus in class SeedGenerator

getSeed

public byte[] getSeed()

Return the seed. It takes about 1/3 of a second per byte until this method returns (when called for the first time, later it will return the same seed again instantly).

Specified by:

getSeed in class SeedGenerator

setSecureRandom

public static void setSecureRandom(java.security.SecureRandom random)

Sets the SecureRandom instance to be used by all JDKSeedGenerator instances.

Parameters:

random - the SecureRandom instance

getSecureRandom

public static java.security.SecureRandom getSecureRandom()

Returns the SecureRandom instance that is in use by all JDKSeedGenerator instances.

Returns:

a SecureRandom instance