Hello to all programmers:
I have been working on the following program but I am encountering some difficulties any help whatsoever would be greatly appreciated. My difficulty is that when I run the program, it does not perform the encryption nor decryption on the file I type in. Is something wrong with my functions? I can't figure the problem!

My instructions are:
Write a c++ program,
1. Prompts the user for a choice of encrypt or decrypt, prompts for the input and output filenames
2. has a function for encryption
a. generates a random key
b. stores the key in the encrypted file
c. encrypts the data from the input file by performing xor of the key with every byte from the input file
3. has a function for decryption
a. reads the key from the encrypted file
b. decrypts the data from the input file by performing xor of the key wit every byte from the file
4. performs the encryption or decryption based on the user's choice.

#include <iostream>
#include <string>
#include <ctime>
#include <cstdlib>
#include <fstream>
using namespace std;
void encrypt(char inname[80], char outname[80]);
void decrypt(char inname[80], char outname[80]);
int decryptencrypt;
char inname[80], outname[80];
void main()
{
srand((unsigned)time(NULL));

cout << "Enter 1 to decrypt" << endl;
cout << "Enter 2 to encrypt" << endl;
cin >> decryptencrypt;
cout << "Enter the input filename" << endl;
cin >> inname;
cout << "Enter the output filename" << endl;
cin >> outname;
if(decryptencrypt == 1)
{
decrypt( inname, outname);
}
else if(decryptencrypt == 2)
encrypt( inname, outname);

}

void encrypt(char inname[80], char outname[80]){
ifstream in;
ofstream out;
in.open(inname);
out.open(outname);
char key = rand() % 255;
out << key;
char c;
in.get(c);
while(in != 0)
{
out << (c ^ key);
in.get(c);

}
return;
}

void decrypt(char inname[80], char outname[80]){
ifstream in;
ofstream out;
in.open(inname);
out.open(outname);
char key;
in.get(key); // Read the key out of the encrypted file

char c;
in.get(c);
while(in != 0)
{
out << (c ^ key); // Do XOR to restore it to its original values
in.get(c);
}
return;
}

You need to start filling your program with a load of couts, so you can find out where it's going wrong.


Just as a side note, you may need to read and write in binary mode, we'll get to that later though.

In the mean time find out if each part is doing what it should be.

> usingnamespace std;
Whatever crappy code colouring tool you're using, stop using it and use the board code tags.
Few people are going to be bothered to trawl through unindented code which isn't even compilable, and has been corrupted in transmission.
http://www.daniweb.com/techtalkforums/announcement8-3.html

> help with encryption! asap
Your urgency isn't our problem
http://www.catb.org/~esr/faqs/smart-questions.html#urgent

As for the rest of the problem, start with a program that simply copies one file to another without any changes. If you can't manage that, then you're wasting time trying to do encryption.

Oh, and main() really does return an int. Use it or be doomed.

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