私が開発したサイトは最近、ブルートフォース攻撃またはレインボーテーブル攻撃によって侵害されました。元のログインスクリプトにはSALTがなく、パスワードはMD5に保存されていました。
以下は、SALTとIPアドレスの禁止を含む更新されたスクリプトです。さらに、同じIPアドレスまたはアカウントで4回のログインに失敗した場合、Maydayの電子メールとSMSを送信し、アカウントを無効にします。よく見て、何が改善できるのか、何が欠けているのか、そして何がまったく奇妙なのかを教えてください。
<?php
//Start session
session_start();
//Include DB config
include $_SERVER['DOCUMENT_ROOT'] . '/includes/pdo_conn.inc.php';
//Error message array
$errmsg_arr = array();
$errflag = false;
//Function to sanitize values received from the form. Prevents SQL injection
function clean($str) {
$str = @trim($str);
if(get_magic_quotes_gpc()) {
$str = stripslashes($str);
}
return $str;
}
//Define a SALT, the one here is for demo
define('SALT', '63Yf5QNA');
//Sanitize the POST values
$login = clean($_POST['login']);
$password = clean($_POST['password']);
//Encrypt password
$encryptedPassword = md5(SALT . $password);
//Input Validations
//Obtain IP address and check for past failed attempts
$ip_address = $_SERVER['REMOTE_ADDR'];
$checkIPBan = $db->prepare("SELECT COUNT(*) FROM ip_ban WHERE ipAddr = ? OR login = ?");
$checkIPBan->execute(array($ip_address, $login));
$numAttempts = $checkIPBan->fetchColumn();
//If there are 4 failed attempts, send back to login and temporarily ban IP address
if ($numAttempts == 1) {
$getTotalAttempts = $db->prepare("SELECT attempts FROM ip_ban WHERE ipAddr = ? OR login = ?");
$getTotalAttempts->execute(array($ip_address, $login));
$totalAttempts = $getTotalAttempts->fetch();
$totalAttempts = $totalAttempts['attempts'];
if ($totalAttempts >= 4) {
//Send Mayday SMS
$to = "admin@somewhere.com";
$subject = "Banned Account - $login";
$mailheaders = 'From: noreply@somewhere.com' . "\r\n";
$mailheaders .= 'Reply-To: noreply@somewhere.com' . "\r\n";
$mailheaders .= 'MIME-Version: 1.0' . "\r\n";
$mailheaders .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";
$msg = "<p>IP Address - " . $ip_address . ", Username - " . $login . "</p>";
mail($to, $subject, $msg, $mailheaders);
$setAccountBan = $db->query("UPDATE ip_ban SET isBanned = 1 WHERE ipAddr = '$ip_address'");
$setAccountBan->execute();
$errmsg_arr[] = 'Too Many Login Attempts';
$errflag = true;
}
}
if($login == '') {
$errmsg_arr[] = 'Login ID missing';
$errflag = true;
}
if($password == '') {
$errmsg_arr[] = 'Password missing';
$errflag = true;
}
//If there are input validations, redirect back to the login form
if($errflag) {
$_SESSION['ERRMSG_ARR'] = $errmsg_arr;
session_write_close();
header('Location: http://somewhere.com/login.php');
exit();
}
//Query database
$loginSQL = $db->prepare("SELECT password FROM user_control WHERE username = ?");
$loginSQL->execute(array($login));
$loginResult = $loginSQL->fetch();
//Compare passwords
if($loginResult['password'] == $encryptedPassword) {
//Login Successful
session_regenerate_id();
//Collect details about user and assign session details
$getMemDetails = $db->prepare("SELECT * FROM user_control WHERE username = ?");
$getMemDetails->execute(array($login));
$member = $getMemDetails->fetch();
$_SESSION['SESS_MEMBER_ID'] = $member['user_id'];
$_SESSION['SESS_USERNAME'] = $member['username'];
$_SESSION['SESS_FIRST_NAME'] = $member['name_f'];
$_SESSION['SESS_LAST_NAME'] = $member['name_l'];
$_SESSION['SESS_STATUS'] = $member['status'];
$_SESSION['SESS_LEVEL'] = $member['level'];
//Get Last Login
$_SESSION['SESS_LAST_LOGIN'] = $member['lastLogin'];
//Set Last Login info
$updateLog = $db->prepare("UPDATE user_control SET lastLogin = DATE_ADD(NOW(), INTERVAL 1 HOUR), ip_addr = ? WHERE user_id = ?");
$updateLog->execute(array($ip_address, $member['user_id']));
session_write_close();
//If there are past failed log-in attempts, delete old entries
if ($numAttempts > 0) {
//Past failed log-ins from this IP address. Delete old entries
$deleteIPBan = $db->prepare("DELETE FROM ip_ban WHERE ipAddr = ?");
$deleteIPBan->execute(array($ip_address));
}
if ($member['level'] != "3" || $member['status'] == "Suspended") {
header("location: http://somewhere.com");
} else {
header('Location: http://somewhere.com');
}
exit();
} else {
//Login failed. Add IP address and other details to ban table
if ($numAttempts < 1) {
//Add a new entry to IP Ban table
$addBanEntry = $db->prepare("INSERT INTO ip_ban (ipAddr, login, attempts) VALUES (?,?,?)");
$addBanEntry->execute(array($ip_address, $login, 1));
} else {
//increment Attempts count
$updateBanEntry = $db->prepare("UPDATE ip_ban SET ipAddr = ?, login = ?, attempts = attempts+1 WHERE ipAddr = ? OR login = ?");
$updateBanEntry->execute(array($ip_address, $login, $ip_address, $login));
}
header('Location: http://somewhere.com/login.php');
exit();
}
?>
編集
さて、これがランダムソルトでの私の試みです。まず、テーブルに挿入するソルトを作成します。
define('SALT_LENGTH', 15);
function createSalt()
{
$key = '!@#$%^&*()_+=-{}][;";/?<>.,';
$salt = substr(hash('sha512',uniqid(rand(), true).$key.microtime()), 0, SALT_LENGTH);
return $salt;
}
$salt = createSalt()
//More prep for entering into table...
次に、ランダムソルトを使用してハッシュを生成します。
$hash = hash('sha256', $salt . $pw); //$pw is the cleaned user submitted password
ユーザーがログインしたら、保存されたランダムに生成されたソルトを使用して、保存されたハッシュを比較します。
$loginHash = hash('sha256', $dbSalt . $pw);
if ($loginHash == $dbHash) {
//Logged in
} else {
//Failed
}
それはどのように見えますか？