[MySQL][PHP]System Sesji Opcje

[webmaestro]

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<?php
	define('COOKIE_NAME', 'tuibgidf'); // losowe
	define('COOKIE_EXPIRE', 3600); // 1 godzina
	$time = time();
	//laczenie baza danych
	$mysql_host = 'localhost';
	$mysql_login = 'login';
	$mysql_haslo = 'password';
	$mysql_baza = 'baza';
	$polaczenie = mysql_connect($mysql_host, $mysql_login, $mysql_haslo) or die(mysql_error());
 
	mysql_select_db($mysql_baza) or die('Błąd: nie udało się wybrać schematu bazy danych.');
	//end laczenie baza danych
 
	//IP, browser, sesje
	$ip = $_SERVER['REMOTE_ADDR'];
	$browser = $_SERVER['HTTP_USER_AGENT'];
	$newId = sha1(uniqid(time().$ip));
	$wynik = mysql_query("SELECT * FROM sessions WHERE session_ip = '$ip' AND session_browser = '$browser' AND session_time > ".($time - COOKIE_EXPIRE)) or die(mysql_error());
	$count = mysql_num_rows($wynik);
	if($count > 0)
	{
		$row = mysql_fetch_row( $wynik );
		if($_COOKIE[COOKIE_NAME] == $row[0] && strlen($_COOKIE[COOKIE_NAME]) == 40 && isset($_COOKIE[COOKIE_NAME]))
		{
			if($_SESSION['session_user'] == $row[1] && $_SESSION['session_user'] != 0)
			{
				$session_user = $row[1];
				$old = $row[0];
				$result = mysql_query("UPDATE sessions SET session_id='$old', session_browser ='$browser', session_time = '$time', session_user = '$session_user' WHERE session_ip = '$ip' AND session_browser = '$browser'") or die(mysql_error());
				setcookie(COOKIE_NAME, $old, time() + COOKIE_EXPIRE);
				$result = mysql_query("SELECT * FROM users WHERE user_id = '$session_user'") or die(mysql_error()); 
				$user = mysql_fetch_array( $result );
			}
			else
			{
				$old = $row[0];
				$result = mysql_query("UPDATE sessions SET session_id='$old', session_browser ='$browser', session_time = '$time', session_user = '0' WHERE session_ip = '$ip' AND session_browser = '$browser'") or die(mysql_error());
				setcookie(COOKIE_NAME, $old, time() + COOKIE_EXPIRE);
			}
		}
		else
		{
			$_SESSION['session_user'] = '0';
			setcookie(COOKIE_NAME, $newId, time() + COOKIE_EXPIRE);
			$result = mysql_query("UPDATE sessions SET session_id='$newId', session_browser ='$browser', session_time = '$time', session_user = '0' WHERE session_ip = '$ip' AND session_browser = '$browser'") or die(mysql_error());
		}
	}
	else
	{
		$_SESSION['session_user'] = '0';
		setcookie(COOKIE_NAME, $newId, time() + COOKIE_EXPIRE);
		mysql_query("INSERT INTO sessions (session_id, session_user, session_ip, session_browser, session_time) VALUES('$newId', '0', '$ip', '$browser', '$time' ) ") or die(mysql_error()); 
	}
	?>
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[SQL] pobierz, plaintext 
CREATE TABLE IF NOT EXISTS `sessions` (
  `session_id` varchar(40) NOT NULL,
  `session_user` int(8) NOT NULL DEFAULT '0',
  `session_ip` varchar(15) NOT NULL DEFAULT '',
  `session_browser` varchar(255) NOT NULL DEFAULT '',
  `session_time` int(11) NOT NULL DEFAULT '0',
  PRIMARY KEY (`session_id`)
) ENGINE=MEMORY DEFAULT CHARSET=latin2;
 
CREATE TABLE IF NOT EXISTS `users` (
  `user_id` int(10) NOT NULL AUTO_INCREMENT,
  `user_login` varchar(30) NOT NULL,
  `user_password` varchar(40) NOT NULL,
  `user_email` varchar(100) NOT NULL,
  `user_group` int(1) NOT NULL,
  `user_lastvisit` int(8) NOT NULL,
  `user_register` int(20) NOT NULL,
  `user_banned` int(1) NOT NULL,
  `user_reason_ban` varchar(255) NOT NULL,
  `user_time_limit` int(20) NOT NULL,
  `user_active` int(1) NOT NULL,
  `user_key` varchar(13) NOT NULL,
  PRIMARY KEY (`user_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin2 AUTO_INCREMENT=1 ;
[SQL] pobierz, plaintext 

Witam! Panowie pomozecie w zabezpieczeniu skryptu ? I czy poprawnie go napisalem ? Moze jakies poprawki wedlug Was ?
Pozdrawiam!