oracle.security.crypto.core
Class EntropySource

java.lang.Object
oracle.security.crypto.core.EntropySource

Direct Known Subclasses:

SpinnerEntropySource, SREntropySource

public abstract class EntropySource

extends java.lang.Object

An abstract class representing sources of seed material for PRNGs. It is important to note that the entropy gathered by such a source should be used as seeding material to a secure PRNG only, and never as cryptographic material -- such as keys or initialization vectors -- in raw form.

Currently, only one subclass is provided, SpinnerEntropySource. Developers may wish to create their own subclasses based on other sources, such as AWT events or dedicated hardware devices.

See Also:

SpinnerEntropySource, RandomBitsSource

Constructor Summary

protected

EntropySource()

Method Summary

abstract void	clear() Destroys (writes zero to) sensitive internal data structures used by the entropy source.
abstract byte	generateByte() Generate a byte of seeding material.
byte[]	generateBytes(byte[] bytes) Supplies the requisite number of bytes, by successive calls to generateByte().
static EntropySource	getDefault() Returns the system-wide default entropy source.
static void	setDefault(EntropySource es) Sets the system-wide default entropy source.

Methods inherited from class java.lang.Object

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

Constructor Detail

EntropySource

protected EntropySource()

Method Detail

generateByte

public abstract byte generateByte()

Generate a byte of seeding material. Depending on the algorithm used, may be resource intensive, slow, and/or subject to failures in external devices (which should result in an IllegalStateException being thrown.)

generateBytes

public byte[] generateBytes(byte[] bytes)

Supplies the requisite number of bytes, by successive calls to generateByte().

clear

public abstract void clear()

Destroys (writes zero to) sensitive internal data structures used by the entropy source.

getDefault

public static EntropySource getDefault()

Returns the system-wide default entropy source.

setDefault

public static void setDefault(EntropySource es)

Sets the system-wide default entropy source.