gnu.crypto.prng

Class DevRandom

java.lang.Object

gnu.crypto.prng.DevRandom

All Implemented Interfaces:

IRandomStandalone, Cloneable

class DevRandom
extends Object
implements IRandomStandalone

Simple /dev/random reader

Constructor Summary

Constructors

Constructor and Description
DevRandom()

Method Summary

Modifier and Type	Method and Description
void	addRandomByte(byte b) Supplement, or possibly replace, the random state of this PRNG with a random byte.
void	addRandomBytes(byte[] in) Supplement, or possibly replace, the random state of this PRNG with a sequence of new random bytes.
void	addRandomBytes(byte[] in, int offset, int length) Supplement, or possibly replace, the random state of this PRNG with a sequence of new random bytes.
Object	clone() Returns a clone copy of this instance.
void	init(Map<String,byte[]> attributes) Initialises the pseudo-random number generator scheme with the appropriate attributes.
static boolean	isSupported()
String	name() Returns the canonical name of this instance.
byte	nextByte() Returns the next 8 bits of random data generated from this instance.
void	nextBytes(byte[] out)
void	nextBytes(byte[] out, int offset, int length) Fills the designated byte array, starting from byte at index offset, for a maximum of length bytes with the output of this generator instance.

Methods inherited from class java.lang.Object

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

Constructor Detail

DevRandom

DevRandom()

Method Detail

addRandomByte

public void addRandomByte(byte b)

Description copied from interface: IRandomStandalone

Supplement, or possibly replace, the random state of this PRNG with a random byte.

Implementations are not required to implement this method in any meaningful way; this may be a no-operation, and implementations may throw an UnsupportedOperationException.

Specified by:

addRandomByte in interface IRandomStandalone

Parameters:

b - The byte to add.

addRandomBytes

public void addRandomBytes(byte[] in)

Description copied from interface: IRandomStandalone

Supplement, or possibly replace, the random state of this PRNG with a sequence of new random bytes.

Implementations are not required to implement this method in any meaningful way; this may be a no-operation, and implementations may throw an UnsupportedOperationException.

Specified by:

addRandomBytes in interface IRandomStandalone

Parameters:

in - The buffer of new random bytes to add.

addRandomBytes

public void addRandomBytes(byte[] in,
                           int offset,
                           int length)

Description copied from interface: IRandomStandalone

Supplement, or possibly replace, the random state of this PRNG with a sequence of new random bytes.

Implementations are not required to implement this method in any meaningful way; this may be a no-operation, and implementations may throw an UnsupportedOperationException.

Specified by:

addRandomBytes in interface IRandomStandalone

Parameters:

in - The buffer of new random bytes to add.

offset - The offset from whence to begin reading random bytes.

length - The number of random bytes to add.

clone

public Object clone()
             throws CloneNotSupportedException

Description copied from interface: IRandomStandalone

Returns a clone copy of this instance.

Specified by:

clone in interface IRandomStandalone

Overrides:

clone in class Object

Returns:

a clone copy of this instance.

Throws:

CloneNotSupportedException

init

public void init(Map<String,byte[]> attributes)

Description copied from interface: IRandomStandalone

Initialises the pseudo-random number generator scheme with the appropriate attributes.

Specified by:

init in interface IRandomStandalone

Parameters:

attributes - a set of name-value pairs that describe the desired future instance behaviour.

isSupported

public static boolean isSupported()

name

public String name()

Description copied from interface: IRandomStandalone

Returns the canonical name of this instance.

Specified by:

name in interface IRandomStandalone

Returns:

the canonical name of this instance.

nextByte

public byte nextByte()

Description copied from interface: IRandomStandalone

Returns the next 8 bits of random data generated from this instance.

Specified by:

nextByte in interface IRandomStandalone

Returns:

the next 8 bits of random data generated from this instance.

nextBytes

public void nextBytes(byte[] out)
               throws IllegalStateException

Specified by:

nextBytes in interface IRandomStandalone

Throws:

IllegalStateException

nextBytes

public void nextBytes(byte[] out,
                      int offset,
                      int length)
               throws IllegalStateException

Description copied from interface: IRandomStandalone

Fills the designated byte array, starting from byte at index offset, for a maximum of length bytes with the output of this generator instance.

Specified by:

nextBytes in interface IRandomStandalone

Parameters:

out - the placeholder to contain the generated random bytes.

offset - the starting index in out to consider. This method does nothing if this parameter is not within 0 and out.length.

length - the maximum number of required random bytes. This method does nothing if this parameter is less than 1.

Throws:

IllegalStateException - if the instance is not yet initialised. theoretical limit for generating non-repetitive pseudo-random data.