C-plus-plus-Scrambler

Beispielcode für Verschleierung

#ifndef SCRAMBLER_H
#define SCRAMBLER_H

#include <QDateTime>
#include <iostream>
#include <math.h>
#include <QDebug>

class Scrambler
{
private:
    int _saltLength;
    qlonglong _seed;
    char _minChar;
    int _range;
public:
    Scrambler(int saltLength = 4, char minChar = ' ', char maxChar = (char) 127): _saltLength(saltLength), _seed(0x1234567890abcdefLL), _minChar(minChar), _range(maxChar - minChar + 1)
    {
    }
public:
    qlonglong trueRandom(){
        qlonglong dummy = 0x1234567887654321LL;
        return _seed ^ qlonglong(QDateTime::currentMSecsSinceEpoch()) ^ qlonglong(&dummy) ^ + dummy;
    }
    int random(int minValue, int maxValue)
    {
        _seed = 0x7f293278193 * _seed + 0x8585205a;
        int rc = abs(int(_seed) ^ int(_seed >> 32));
        return minValue + (rc % (maxValue - minValue));
    }
    QString getRandomString(int length)
    {
        _seed = trueRandom();
        QString rc;
        for (int ix = 0; ix < length; ix++){
            rc += QChar(ushort(_minChar + random(0, _range)));
        }
        return rc;
    }
    qlonglong getSalt(QString string)
    {
        qlonglong rc = 0;
        for (int ix = 0; ix < _saltLength; ix++){
            rc = (rc << 8) + (rc >> (64 - 8)) + string[ix].unicode();
        }
        return rc;
    }
    QString encode(QString clearText)
    {
        QString rc = getRandomString(_saltLength);
        _seed = getSalt(rc);
        for (int ix = 0; ix < clearText.length(); ix++){
            ushort value = clearText[ix].unicode() - ushort(_minChar);
            QChar cc(_minChar + (value + random(0, _range)) % _range);
            rc += cc;
        }
        return rc;
    }
    QString decode(QString encoded)
    {
        QString rc;
        _seed = getSalt(encoded);

        for (int ix = _saltLength; ix < encoded.length(); ix++){
            ushort value = encoded[ix].unicode() - ushort(_minChar);
            QChar cc(_minChar + (_range + value - random(0, _range)) % _range);
            rc += cc;
        }
        return rc;
    }
    void testOne(QString string)
    {
        QString encoded = encode(string);
        QString decoded = decode(encoded);
        if (decoded != string){
            qDebug() << "+++ failed: " << string << " / " << decoded;
        } else {
            qDebug() << string << " -> " << encoded;
        }
    }
    void test()
    {
        testOne("abc");
        testOne(" !\"\'?\\$%&/()=");
        for (int len = 3; len < 127; len++){
            QString string = getRandomString(len);
            testOne(string);
        }
        testOne("This is the end.");
    }
};

#endif // SCRAMBLER_H