pro.fessional.mirana.code

Class Crc8Long

java.lang.Object

pro.fessional.mirana.code.Crc8Long

@ThreadSafe
public class Crc8Long
extends Object

Perform pseudo-random obfuscation on 55(63-8) bit long numbers with non-negative inputs and outputs. Inserts crc8 checksums according to pseudoSeed, provides encode, decode, etc.

Since:

2019-05-20

Author:

trydofor

See Also:

CRC8Digest.java

Field Summary

Fields

Modifier and Type	Field and Description
static long	MAX_NUMBER
static long	MIN_NUMBER

Constructor Summary

Constructors

Constructor and Description
Crc8Long() Use the default pseudo-random seed
Crc8Long(int[] seed) Specifies pseudo-random seed to generate insert positions of obfuscated values (crc8).

Method Summary

Modifier and Type	Method and Description
long	decode(long value) decode a pseudo-random to the number fail if return Long.MIN_VALUE
long	encode(long number) encode a number to the pseudo-random fail if return Long.MIN_VALUE

Methods inherited from class java.lang.Object

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

Field Detail

MAX_NUMBER

public static final long MAX_NUMBER

See Also:

Constant Field Values

MIN_NUMBER

public static final long MIN_NUMBER

See Also:

Constant Field Values

Constructor Detail

Crc8Long

public Crc8Long()

Use the default pseudo-random seed

Crc8Long

public Crc8Long(int[] seed)

 Specifies pseudo-random seed to generate insert positions of obfuscated values (crc8).
 It is equivalent to dividing the 55bit number into 9 parts with 8 bits at the position (1-base) specified by seed.

 SEED requires that each element take a value in the range of [1,60], with decrementing no less than 1 between elements.
 If the number of elements exceeds 8, only the first 8 are taken, and if there are less than 8, an exception is thrown.
 

Parameters:

seed - pseudo-random seed

Throws:

IllegalArgumentException - After the distinct there are less than 8 elements.

Method Detail

encode

public long encode(long number)

encode a number to the pseudo-random fail if return Long.MIN_VALUE

decode

public long decode(long value)

decode a pseudo-random to the number fail if return Long.MIN_VALUE