#include "stdafx.h" // IWYU pragma: keep
#include "encryption.h"
#include "tree.h"
#include "functions.h"
#ifdef _WIN32
#include <windows.h>
#endif

// 1re étape: chaque bit de la clé d'entrée est un gauche ou droite dans l'arbre
// l'arbre est de profondeur inégale et random

Node* gen_tree(){
    Node* r = new Node(); // root
    r->value ^= '1';
    Node* a = new Node(); // left
    a->value ^= '8';
    Node* aa = new Node(); // left left
    aa->value ^= ('3'^0xbe);
    Node* ab = new Node();
    ab->value ^= ('7'^0xef);
    Node* b = new Node();
    b->value ^= '5';
    Node* ba = new Node();
    ba->value ^= '4';
    Node* bb = new Node();
    bb->value ^= '2';
    // defining tree links
    r->left = a;
    r->right = b;
    a->left = aa;
    a->right = ab;
    b->left = ba;
    b->right = bb;
    aa->value^=0xbe;
    ab->value^=0xef;
    return r;
}

char* derive_key_from_tree(char* key){
    auto stdfunclist = new Obfuscated_stdFunclist();
    char* res = (char*) stdfunclist->obfusc_malloc(sizeof(char)*9*8);
    Node* root = gen_tree();
    Node* current = root;
    int i_key = 0;
    int i_res = 0;
    while(key[i_key] != '\0'){
        char character = key[i_key];
        for (int j = 0; j < 8; j++){
            int bit = ((character >> j)  & 0x01); // gets byte number j
            if(bit){ // right
                current = current->r();
            } else { // left
                current = current->l();
            }
            if(current->is_leaf()){
                res[i_res] = current->v();
                current = root;
                i_res ++;
            }
        }
        i_key++;
    }
    res[i_res] = current->v();
    res[i_res+1] = '\0';
    return res;
}

void encrypt_decrypt(char* key, char* msg){
    #ifdef _WIN32
    DWORD old;
    VirtualProtect(msg, 0x100, PAGE_EXECUTE_READWRITE, &old);
    #endif
    char* newkey = derive_key_from_tree(key);
    // printf("%s\n",newkey);
    int i = 0;
    int j = 0;
    while (msg[i] != '\0'){
        msg[i] ^= newkey[j];
        // printf("\\x%x",msg[i]);
        j++;
        if (newkey[j] == '\0'){
            j = 0;
        }
        i++;
    }
    // printf("%s\n",msg);
}