Simulator - XOR Encryption / Decryption

xor_encryption.c

/***********************************************************************************
 * Developed by: SLAYER OWNER | sl4y3r 0wn3r
 * 
 * This is a simple script for simulator XOR Encryption/Decryption
 * and for being an "simple script", remember that I not responsible
 * any lack of security ;)
 *
 * For more information, read this:
 * https://slayerowner.blogspot.com.br/2015/08/xor-cipher-playin-in-morning.html
 * 
 * mailto: slayerowner!:!gmail!!com:!:
 *********************************************************************************/
#include "stdio.h"
#include <stdlib.h>
#include <string.h>
#define MAX 512
void r_newline(char *r_);
void xor(FILE *infile, FILE *outfile, char *key);
int main(int argc, char *argv[]){
    if(argc != 3){
        fprintf(stdout,"\t\t\t\t************************************\n");
        fprintf(stdout,"\t\t\t\t********** X0R ENCRYPTI0N **********\n");
        fprintf(stdout,"\t\t\t\t************sl4y3r 0wn3r************\n");
        fprintf(stdout,"\t\t\t\t************************************\n");
        fprintf(stdout,"\t\t\t\t Usage: %s <SOURCE> <DESTINE>\n",argv[0]);
        exit(0);}

     FILE *input; FILE *output;
     input=fopen(argv[1],"r"); output=fopen(argv[2],"w");

     if(input == NULL){fprintf(stdout,"[!] An error occurred in an attempt to read the %s.\n",argv[1]);
     exit(0);}
     if(output == NULL){fprintf(stdout,"[!] An error occurred in an attempt to write into %s.\n",argv[2]);
     exit(0);}

     char *key = malloc(MAX);
     fprintf(stdout,"Chave: ");
     fgets(key, MAX, stdin);

     fprintf(stdout,"[+] %s is encrypting...\n",argv[1]);

     r_newline(key);
     xor(input, output, key);

     fprintf(stdout,"[+] Well done. Your %s data has been encrypted with successfully.\n",argv[2]);

     free(key);
     fclose(input);
     fclose(output);

     return 0;
}

void xor(FILE *infile, FILE *outfile, char *key){
    int encrypt, k=0;
    while((encrypt=fgetc(infile)) != EOF){fputc(encrypt ^ key[k], outfile);}
    ++k;}

void r_newline(char *r_){
   if(r_[strlen(r_)-1]=='\n'){r_[strlen(r_)-1]='\0';}
}