FileCrypt.cpp

//A small simple file crypting tool in C++
//By Ben Jones Hope you like it.

#include <iostream>
using namespace std;

int main(int argc, char *argv[])
{
	FILE *fin = NULL;
	char *pws;
	int idx = 0, i = 0;
	FILE *fout = NULL;
	char c = '\0';

	if (argc < 3){
		std::cout << "Incorrect number of parameters." << endl;
		std::cout << "Syntax InputFile OutputFile Password" << endl;
		return 1;
	}
	//Open source file.

	fin = fopen(argv[1], "rb");
	if (fin == NULL){
		std::cout << "Error opening input filename." << endl;
		return 2;
	}

	//Open output file for writing.
	fout = fopen(argv[2], "wb");
	//Check if can write to output.
	if (fout == NULL){
		std::cout << "Error writing output file." << endl;
		fclose(fin);
		return 2;
	}

	pws = new char[strlen(argv[3])];
	//Copy password from argv[3] to pws
	strcpy(pws, argv[3]);

	while (!feof(fin)){
		//Encrypt char.
		c = getc(fin) ^ pws[idx];
		//Get password char
		idx = (i % strlen(pws));
		//INC counter
		i++;
		//Check if not end of file.
		if (!feof(fin)){
			//Write char to output file.
			putc(c, fout);
		}
	}
	//Close output file.
	fclose(fout);
	//Close input file.
	fclose(fin);
	return 0;
}