I've been attempting to do a basic XOR encoder but I got this problem:
Everytime the result of the XOR operation is 10, the app writes 0xA 0xD, and I can't avoid this.
Code:
#include <iostream>
#include <fstream>
#include <stdio.h>
using namespace std;
char* readfile(char * filename,int* size){
int i = 0;
ifstream file (filename, ios::in|ios::binary|ios::ate);
if (file.is_open())
{
*size = (int)file.tellg();
static char * memblock = new char [*size];
file.seekg (0, ios::beg);
file.read (memblock, *size);
file.close();
return memblock;
}
else
{
cout << "Error while opening the file";
return 0;
}
}
void echo_file(char* memblock,int file_length)
{
for(int i = 0;i < file_length; i++) putchar(*(memblock+i));
}
void writefile(char * memblock, int size, char * filename){
ofstream file (filename);
int i = 0;
for(i=0; i < size; i++){
if(file.is_open()){file << memblock[i];}
else{cout << "An error happened";}
}
file.close();
}
int xor(int a, int b)// I know about the ^ operator, is only for learning purposes
{
_asm{
mov eax,a
xor eax,b
}
}
char* encode_file(char * memblock, char * key, int size){
int temp = 0;
static char * encoded_char = new char[size];
int i = 0;
for(i=0; i < size; i++){
*(encoded_char+i) = xor(*(memblock+i),*((key+i%strlen(key))));
}
return encoded_char;
}
int main (int argc, char* argv[]) {
int tmpchar = 0;
int k = 2;
int i = 0;
if(argc < 4){
cout << "Use: [input file][key][output file]";
return 0;
}
else{
int size = 0;
char * thefile = readfile(argv[1], &size);
if(thefile == 0) exit(EXIT_SUCCESS);
char* enc_file = encode_file(thefile,argv[2],size);
writefile(enc_file,size,argv[3]);
printf("File size: %d \n",size);
}
return 0;
}P.D.Sorry for my poor english
