Package io.vertx.ext.auth.prng

Class PRNG

java.lang.Object

io.vertx.ext.auth.prng.PRNG

All Implemented Interfaces:

VertxContextPRNG

public class PRNG
extends Object
implements VertxContextPRNG

Wrapper around secure random that periodically seeds the PRNG with new entropy. To avoid entropy exhaustion the entropy is only refreshed if the PRNG is used. This introduces a new variable which reduces the probability of cracking the random number generator.

Author:

Paulo Lopes

Constructor Summary

Constructors

Constructor	Description
PRNG(Vertx vertx)

Method Summary

Modifier and Type	Method	Description
void	close()	stop seeding the PRNG
boolean	nextBoolean()	Returns a secure random boolean
void	nextBytes(byte[] bytes)	Fills the given byte array with random bytes.
double	nextDouble()	Returns a secure random double value.
float	nextFloat()	Returns a secure random float value.
double	nextGaussian()	Returns a secure random double value.
int	nextInt()	Returns a secure random int
int	nextInt(int bound)	Returns a secure random int, between 0 (inclusive) and the specified bound (exclusive).
long	nextLong()	Returns a secure random long
String	nextString(int length)	Returns a Base64 url encoded String of random data with the given length.

Methods inherited from class java.lang.Object

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

Constructor Detail

PRNG

public PRNG(Vertx vertx)

Method Detail

close

public void close()

Description copied from interface: VertxContextPRNG

stop seeding the PRNG

Specified by:

close in interface VertxContextPRNG

nextBytes

public void nextBytes(byte[] bytes)

Description copied from interface: VertxContextPRNG

Fills the given byte array with random bytes.

Specified by:

nextBytes in interface VertxContextPRNG

Parameters:

bytes - a byte array.

nextInt

public int nextInt()

Description copied from interface: VertxContextPRNG

Returns a secure random int

Specified by:

nextInt in interface VertxContextPRNG

Returns:

random int.

nextInt

public int nextInt(int bound)

Description copied from interface: VertxContextPRNG

Returns a secure random int, between 0 (inclusive) and the specified bound (exclusive).

Specified by:

nextInt in interface VertxContextPRNG

Parameters:

bound - the upper bound (exclusive), which must be positive.

Returns:

random int.

nextBoolean

public boolean nextBoolean()

Description copied from interface: VertxContextPRNG

Returns a secure random boolean

Specified by:

nextBoolean in interface VertxContextPRNG

Returns:

random boolean.

nextLong

public long nextLong()

Description copied from interface: VertxContextPRNG

Returns a secure random long

Specified by:

nextLong in interface VertxContextPRNG

Returns:

random long.

nextFloat

public float nextFloat()

Description copied from interface: VertxContextPRNG

Returns a secure random float value. The value is uniformly distributed between 0.0 and 1.0

Specified by:

nextFloat in interface VertxContextPRNG

Returns:

random float.

nextDouble

public double nextDouble()

Description copied from interface: VertxContextPRNG

Returns a secure random double value. The value is uniformly distributed between 0.0 and 1.0

Specified by:

nextDouble in interface VertxContextPRNG

Returns:

random double.

nextGaussian

public double nextGaussian()

Description copied from interface: VertxContextPRNG

Returns a secure random double value. The value is Gaussian ("normally") distributed with mean 0.0 and standard deviation 1.0

Specified by:

nextGaussian in interface VertxContextPRNG

Returns:

random double.

nextString

public String nextString(int length)

Description copied from interface: VertxContextPRNG

Returns a Base64 url encoded String of random data with the given length. The length parameter refers to the length of the String before the encoding step.

Specified by:

nextString in interface VertxContextPRNG

Parameters:

length - the desired string length before Base64 encoding.

Returns:

A base 64 encoded string.