<?php
session_start();
if (!isset($_SESSION['initiated']))
{
	session_regenerate_id();
	$_SESSION['initiated'] = true;
}
if (isset($_SESSION['HTTP_USER_AGENT']))
{
	if ($_SESSION['HTTP_USER_AGENT'] != md5($_SERVER['HTTP_USER_AGENT']))
	{
		Header('Location: login_form.php');
		exit();
	}
}
else
{
	$_SESSION['HTTP_USER_AGENT'] = md5($_SERVER['HTTP_USER_AGENT']);
}
$username = $_POST['username'];
$pass1 = $_POST['pass1'];
$pass2 = $_POST['pass2'];
if($pass1 != $pass2)
	echo 'passwords didnt match <br /><a href='register_form.php'>Back</a>';
	exit();
if(strlen($username) > 30)
	echo 'username is to long<br /> <a ahref='register_form.php'>Back</a>';
$hash = hash('sha256', $pass);
function createSalt()
{
	$string = md5(uniqid(rand(), true));
	return substr($string 0, 3);
}
$salt = createSalt();
$hash = hash('sha256, $salt . $hash);

require 'connect.php';
//sanitize username
$username = mysql_real_escape_string($username);
$query = "INSERT INTO users ( username, password, salt )
	VALUES ( '$username' , '$hash', $salt' ); ";
mysql_query($query);
mysql_close();
echo 'User registered!<br /><a href='login_form.php'>Login</a>';

?>