BrainCMS 1.8.1 (Only CMS)

/* 
Functions list Class User.
---------------
checkUser();
hashed();
loginTrue();
validName();
userData();
data();
*/
class User 
{
public static function checkUser($password, $passwordDb)
{
return (password_verify($password, $passwordDb));
}
public static function hashed($password)
{
return password_hash($password, PASSWORD_BCRYPT);
}
public static function loginTrue()
{
if (!loggedIn())
{
header("Location: ./index");
exit();
}
}
public static function validName($username)
{
if(strlen($username) <= 12 && strlen($username) >= 3 && ctype_alnum($username))
{
return true;
}
return false;
}
public static function userData($key)
{
if (loggedIn())
{
$fetch = DB::Fetch(DB::Query("SELECT * FROM users WHERE id = '" . $_SESSION['id'] . "'"));
return $fetch[$key];
}
return false;
}
public static function data($var, $where = 'id', $key = 'username')
 {
 $Query = DB::Query("SELECT * FROM users WHERE $where = '" . $var . "'");
 $fetch = DB::Fetch($Query);
 return $fetch[$key];
}