Protection Against Attacks

<?php
// Start session
session_start();

// Rate limiting function for IP address
function rateLimiter($maxRequests = 100, $timeFrame = 60) {
    $ip = $_SERVER['REMOTE_ADDR'];
    $currentTime = time();

    // Create or load the requests tracking file
    $file = "requests.json";
    $requests = file_exists($file) ? json_decode(file_get_contents($file), true) : [];

    // Remove outdated records
    if (isset($requests[$ip]) && $currentTime - $requests[$ip]['start'] > $timeFrame) {
        unset($requests[$ip]);
    }

    // Update request count
    if (!isset($requests[$ip])) {
        $requests[$ip] = ['count' => 1, 'start' => $currentTime];
    } else {
        $requests[$ip]['count']++;
    }

    file_put_contents($file, json_encode($requests));

    // Block access if the limit is exceeded
    if ($requests[$ip]['count'] > $maxRequests) {
        header("HTTP/1.1 429 Too Many Requests");
        die("Too many requests. Please try again later.");
    }
}

// Activate the rate limiter
rateLimiter(100, 60); // 100 requests within 60 seconds

// Function to sanitize input data
function sanitizeInput($data) {
    return htmlspecialchars(strip_tags($data), ENT_QUOTES, 'UTF-8');
}

// Protection against SQL injection
function secureDatabaseQuery($conn, $query, $params) {
    $stmt = $conn->prepare($query);
    $stmt->execute($params);
    return $stmt;
}

// Limit login attempts
if (!isset($_SESSION['login_attempts'])) {
    $_SESSION['login_attempts'] = 0;
}

if ($_SESSION['login_attempts'] >= 5) {
    die("Too many login attempts. Please try again later.");
}

// Example login
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $username = sanitizeInput($_POST['username']);
    $password = sanitizeInput($_POST['password']);

    // Login check
    if ($username === 'admin' && $password === 'password123') {
        echo "Welcome, $username!";
        $_SESSION['login_attempts'] = 0;
    } else {
        $_SESSION['login_attempts']++;
        echo "Invalid username or password.";
    }
}
?>