org.exoplatform.web.security.security

Class AutoReseedRandom

java.lang.Object

java.util.Random

java.security.SecureRandom

org.exoplatform.web.security.security.AutoReseedRandom

All Implemented Interfaces:

Serializable, Runnable

public class AutoReseedRandom
extends SecureRandom
implements Runnable

Subclass of SecureRandom which is able to reseed itself every reseedingPeriod milliseconds. All methods inherited from SecureRandom are passed to delegate. When reseeding the delegate is recreated. The reseeding happens in a new Thread not to block the Thread in which any of the next* methods is called.

Author:

Peter Palaga

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_RANDOM_ALGORITHM Default random algorithm "SHA1PRNG".
static String	DEFAULT_RANDOM_ALGORITHM_PROVIDER Default random algorithm provider.
static long	DEFAULT_RESEEDING_PERIOD Default expiration time in milliseconds, an equivalent of 24 hours.
static int	DEFAULT_SEED_LENGTH Default seed length 32.

Constructor Summary

Constructors

Constructor and Description
AutoReseedRandom()
AutoReseedRandom(String algorithm, String algorithmProvider, int seedLength, long reseedingPeriod)

Method Summary

Modifier and Type	Method and Description
byte[]	generateSeed(int numBytes)
String	getAlgorithm()
boolean	nextBoolean()
void	nextBytes(byte[] bytes)
double	nextDouble()
float	nextFloat()
double	nextGaussian()
int	nextInt()
int	nextInt(int n)
long	nextLong()
void	run() Called from the reseeding Thread.
void	setSeed(byte[] seed)
void	setSeed(long seed)

Methods inherited from class java.security.SecureRandom

getInstance, getInstance, getInstance, getInstanceStrong, getProvider, getSeed, next

Methods inherited from class java.util.Random

doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_RESEEDING_PERIOD

public static final long DEFAULT_RESEEDING_PERIOD

Default expiration time in milliseconds, an equivalent of 24 hours.

See Also:

Constant Field Values

DEFAULT_RANDOM_ALGORITHM

public static final String DEFAULT_RANDOM_ALGORITHM

Default random algorithm "SHA1PRNG".

See Also:

Constant Field Values

DEFAULT_RANDOM_ALGORITHM_PROVIDER

public static final String DEFAULT_RANDOM_ALGORITHM_PROVIDER

Default random algorithm provider.

DEFAULT_SEED_LENGTH

public static final int DEFAULT_SEED_LENGTH

Default seed length 32.

See Also:

Constant Field Values

Constructor Detail

AutoReseedRandom

public AutoReseedRandom()

AutoReseedRandom

public AutoReseedRandom(String algorithm,
                        String algorithmProvider,
                        int seedLength,
                        long reseedingPeriod)

Parameters:

algorithm - See SecureRandom.getInstance(String, String).

algorithmProvider - See SecureRandom.getInstance(String, String). In most cases you will want to use DEFAULT_RANDOM_ALGORITHM_PROVIDER which will lead to using SecureRandom.getInstance(String) instead of SecureRandom.getInstance(String, String). You may want to consider using "NativePRNG", "SUN" or other providers if you have special requirements.

seedLength - number of Bytes, see SecureRandom.generateSeed(int).

reseedingPeriod - Time in milliseconds after which the delegate gets reseeded by resetRandom()

Method Detail

run

public void run()

Called from the reseeding Thread.

Specified by:

run in interface Runnable

See Also:

checkReseed(), Runnable.run()

getAlgorithm

public String getAlgorithm()

Overrides:

getAlgorithm in class SecureRandom

setSeed

public void setSeed(byte[] seed)

Overrides:

setSeed in class SecureRandom

setSeed

public void setSeed(long seed)

Overrides:

setSeed in class SecureRandom

nextBytes

public void nextBytes(byte[] bytes)

Overrides:

nextBytes in class SecureRandom

generateSeed

public byte[] generateSeed(int numBytes)

Overrides:

generateSeed in class SecureRandom

nextInt

public int nextInt()

Overrides:

nextInt in class Random

nextInt

public int nextInt(int n)

Overrides:

nextInt in class Random

nextLong

public long nextLong()

Overrides:

nextLong in class Random

nextBoolean

public boolean nextBoolean()

Overrides:

nextBoolean in class Random

nextFloat

public float nextFloat()

Overrides:

nextFloat in class Random

nextDouble

public double nextDouble()

Overrides:

nextDouble in class Random

nextGaussian

public double nextGaussian()

Overrides:

nextGaussian in class Random