Cryptography does not read spaces

Question

Well, I’m trying to encrypt a text file with the following "program":

#include <iostream>
#include <fstream>
using namespace std;

void writeFile(char* filename, string str){
    ofstream f(filename);
    f << str;
}

string readFile(char* filename){
    string str;
    ifstream f(filename);
    f >> str;
    return str;
}
string encryptDecrypt(string toEncrypt) {
    char key[3] = {'K', 'C', 'Q'}; //Any chars will work
    string output = toEncrypt;

    for (int i = 0; i < toEncrypt.size(); i++)
        output[i] = toEncrypt[i] ^ key[i % (sizeof(key) / sizeof(char))];

    return output;
}

int main(int argc, const char * argv[])
{
    string encrypted = encryptDecrypt(readFile("file.lua"));
    cout << "Encrypted:" << encrypted << "\n";

    string decrypted = encryptDecrypt(encrypted);
    cout << "Decrypted:" << decrypted << "\n";

    return 0;
}

The content of the "file.lua" file is:

local a = ola

But the output of the program is:

Encrypted:',2*/ Decrypted:local

But if instead of :

string encrypted = encryptDecrypt(readFile("file.lua"));

me use:

string encrypted = encryptDecrypt("local a = ola");

It works normal, and the output gets:

Encrypted:',2*/qclk,= Decrypted:local a = ola

Answer 1

The problem is that the operator >> eliminates all blank spaces (line breaks, spaces, tabs). That is, in the case you are only taking the first word, up to the space. The ideal would be to replace in the method readFile the line:

f >> str;

by this sequence of commands:

stringstream buffer;
buffer << f.rdbuf();
str = buffer.str();

This will read the entire file, including all whitespace.