C++ LCG

main.cpp

#include <iostream>
#include <memory>

using namespace std;

typedef unsigned char BYTE;
int M = 0xA5;
int A = 0xc9;
int N = 256;
int init = 0x55;

BYTE *LCG(BYTE *data, int dataLength, BYTE seed) {
    int prev;
    BYTE *val = new BYTE[dataLength];
    for (int i = 0; i < dataLength; i++) {
        if (i == 0) {
            prev = ((M * (int)seed) + A) % N;
        }
        else {
            prev = ((M * (int)prev) + A) % N;
        }
        val[i] = (BYTE)prev^data[i];
    }
    return val;
}

int main(int argc, char* argv[]) {

    BYTE word[] = "apple";
    BYTE *x = LCG(word, 5, (BYTE)init);
    BYTE keyedWord[] = {0xF3, 0x93, 0x68, 0x2D, 0xCB};
    for (int i = 0; i < 5; i++) {
        cout << hex << (int)x[i] << endl;
    }
    BYTE *y = LCG(x, 5, (BYTE)init);
    for (int i = 0; i < 5; i++) {
        cout << y[i] << endl;
    }
    delete x;
    delete y;
    return 0;
}