Redirect page when user is verified - php

Question

i have this code to verify if users have Administrator account to backoffice of my website, but if user don't have it don't redirect user to ..index.php. He stay in this page but no content is shown.
Code of verification
<?php
$Usuario = isset($_SESSION["Usuario"]) ? $_SESSION["Usuario"]: '';
$Rank = isset($_SESSION['Rank']) ? $_SESSION['Rank'] : '';
if ($Usuario != '' && $Rank == 'Administrador'){
}
else
{
echo "<script>alert(\"Area Restrita\");</scrpit>";
header("Location: ../index.php");
}
?>
In this page, (header) i call this file to verify session.
<?php
session_start();
require_once "../config.php";
require "verificar.php";
?>
<div id="header">
<img src="img/logo.png">
</div>

Answer 1

header("Location: ../index.php"); is not going to stop the rest of the code from running - if you just want to redirect him you should die(); or exit; right after you send the Location header
The alert part before the Location header is also unnecessary because the browser will redirect the user before he'll be able to see the alert. and also it is forbidden to call header function after you sent something to the output (for example, like you did with echo)
Another thing that you should consider - is the security issues that raised from validating user solely by looking at values in the $_SESSION - this means - that if someone is logged - you are not able to log him out until the session expires
The better way is to keep some token in the $_SESSION and save the status of the user in the database - that way, you can change his status directly from the DB without relying on the session/changing code

Answer 2

Your index file:
<?php
session_start();
require_once "../config.php";
require "verificar.php";
?>
<div id="header">
<img src="img/logo.png">
</div>
Your verification file:
<?php
$Usuario = isset($_SESSION["Usuario"]) ? $_SESSION["Usuario"]: '';
$Rank = isset($_SESSION['Rank']) ? $_SESSION['Rank'] : '';
if ($Usuario != '' && $Rank == 'Administrador'){
// do some action for administrator
}
else
{
header("Location: ../index.php");
exit();
//echo "<script>alert(\"Area Restrita\");</scrpit>"; <-- you don't need this here
}
?>
Note, that I commented echo. You mustn't output anything before header. If you will output something (and you do in your example) you will get headers already sent error.
Your main mistake is you output something first and after that tried to redirect.
Anyway, I think better to use a bit another approach.
Form and form handler:
<?
$username = $_POST['username'];
$password = $_POST['password'];
// here is some query which will check if this user with this password exists and get the role of the user
// if exists $userExists = true; else $userExists = false;
if($userExists) {
$_SESSION['userLoggedIn'] = true;
if($role == 'administrator') {
$_SESSION['isAdministrator'] = true;
}
else
{
$_SESSION['isAdministrator'] = false;
}
header('Location: index.php');
exit(); // <-- don't forget this
}
else
{
// handler for bad user/password
}
?>
<form action='' method='post'>
<input type='text' name='username' />
<input type='password' name='password' />
</form>
Now, pages which are restricted will start from this code:
<?
$isAdministrator = $_SESSION['isAdministrator'];
if(!$isAdministrator) {
ban_ban_ban();
die('bye bye');
}
// content for administrator
?>
NOTE: This is just example, don't forget to add some check everywhere!!!!!11
But, as you wish :) Hope, this will help you.