gnu.crypto.prng
Class BasePRNG
- Cloneable, IRandom
public abstract class BasePRNG
extends java.lang.Object
An abstract class to facilitate implementing PRNG algorithms.
Version:
protected byte[] | buffer - A temporary buffer to serve random bytes.
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protected boolean | initialised - Indicate if this instance has already been initialised or not.
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protected String | name - The canonical name prefix of the PRNG algorithm.
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protected int | ndx - The index into buffer of where the next byte will come from.
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BasePRNG(String name) - Trivial constructor for use by concrete subclasses.
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Object | clone() - Returns a clone copy of this instance.
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void | fillBlock()
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void | init(Map attributes) - Initialises the pseudo-random number generator scheme with the
appropriate attributes.
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boolean | isInitialised()
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String | name() - Returns the canonical name of this instance.
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byte | nextByte() - Returns the next 8 bits of random data generated from this instance.
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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.
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void | setup(Map attributes)
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buffer
protected byte[] buffer
A temporary buffer to serve random bytes.
initialised
protected boolean initialised
Indicate if this instance has already been initialised or not.
name
protected String name
The canonical name prefix of the PRNG algorithm.
ndx
protected int ndx
The index into buffer of where the next byte will come from.
BasePRNG
protected BasePRNG(String name)
Trivial constructor for use by concrete subclasses.
name
- the canonical name of this instance.
clone
public Object clone()
Returns a clone copy of this instance.
- clone in interface IRandom
- a clone copy of this instance.
init
public void init(Map attributes)
Initialises the pseudo-random number generator scheme with the
appropriate attributes.
- init in interface IRandom
attributes
- a set of name-value pairs that describe the desired
future instance behaviour.
isInitialised
public boolean isInitialised()
name
public String name()
Returns the canonical name of this instance.
- name in interface IRandom
- the canonical name of this instance.
nextByte
public byte nextByte()
throws IllegalStateException,
LimitReachedException
Returns the next 8 bits of random data generated from this instance.
- nextByte in interface IRandom
- the next 8 bits of random data generated from this instance.
LimitReachedException
- if this instance has reached its
theoretical limit for generating non-repetitive pseudo-random data.
nextBytes
public void nextBytes(byte[] out,
int offset,
int length)
throws IllegalStateException,
LimitReachedException
Fills the designated byte array, starting from byte at index
offset
, for a maximum of length
bytes with the
output of this generator instance.
- nextBytes in interface IRandom
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
.
LimitReachedException
- if this instance has reached its
theoretical limit for generating non-repetitive pseudo-random data.
setup
public void setup(Map attributes)
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Free Software Foundation,
Inc. All Rights Reserved.