PHP on nginx or Apache with PHP-FPM

This guide installs Zen Firewall for a PHP app served by nginx or Apache through PHP-FPM. Zen runs as a PHP extension inside the PHP-FPM workers, so you configure it in the PHP-FPM pool. nginx and Apache need no changes.

https://github.com/AikidoSec/firewall-php

Prerequisites

• PHP 7.2 or later (tested up to PHP 8.5).
• nginx or Apache that passes PHP requests to PHP-FPM (fastcgi_pass in nginx, proxy_fcgi in Apache).
• sudo access on the server.
• An Aikido account and a Zen Firewall token.

Set up Zen Firewall

1. 1

   Install the Zen package

   Zen for PHP is installed as a system package.

   Prerequisites:

   • Ensure you have sudo privileges.
   • Use a supported PHP version (7.2+).

   For Red Hat-based systems (RHEL, CentOS, Fedora):

   rpm -Uvh --oldpackage https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.x86_64.rpm

   For Red Hat-based arm64 / aarch64:

   rpm -Uvh --oldpackage https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.aarch64.rpm

   For Debian-based systems (Debian, Ubuntu):

   curl -L -O https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.x86_64.deb
   dpkg -i -E ./aikido-php-firewall.x86_64.deb

   For Debian-based arm64 / aarch64:

   curl -L -O https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.aarch64.deb
   dpkg -i -E ./aikido-php-firewall.aarch64.deb

   The package enables the extension for every PHP version and runtime it finds on the server, including PHP-FPM.

2. 2

   Add the token to your PHP-FPM pool

   PHP-FPM clears the environment of its workers by default (clear_env = yes), so variables you export in your shell or service manager don't reach Zen. Set them with env[...] in the pool that serves your app instead.

   Open the pool file. The default pool is called www:

   Debian and UbuntuRHEL, CentOS, and Fedora

   sudo nano /etc/php/<php-version>/fpm/pool.d/www.conf

   Add these lines at the end of the pool:

   env[AIKIDO_TOKEN] = AIK_RUNTIME_...
   env[AIKIDO_BLOCK] = false

   AIKIDO_BLOCK=false starts Zen in detection-only mode: it reports attacks but doesn't block them. Run it like this in staging for about 2 weeks to rule out false positives. See Configuration via environment variables for the other options.

   If your app uses more than 1 pool, add the lines to every pool that serves it. A pool without AIKIDO_TOKEN doesn't report to Aikido.

3. 3

   Restart PHP-FPM

   Restart PHP-FPM to load the extension and the new pool settings. Reloading nginx or Apache is not enough.

   Debian and UbuntuRHEL, CentOS, and Fedora

   sudo systemctl restart php<php-version>-fpm

4. 4

   Enable request blocking and user identification

   Use this middleware to enable rate limiting, user identification, and blocking features.

   Zen Firewall does not require this middleware to block attacks. Core attack protection works without it. The middleware provides additional request context that Zen uses for protections such as rate limiting, user blocking, bot blocking, country blocking, and threat actor blocking.

   Adapt the example to fit how your application identifies users and handles requests.

   Call set_user and should_block_request early in every request, for example in your front controller (index.php) or a shared bootstrap file:

   if (extension_loaded('aikido')) {
       \aikido\set_user('123', 'John Doe');
   
       $decision = \aikido\should_block_request();
   
       if ($decision->block) {
           if ($decision->type === 'ratelimited') {
               http_response_code(429);
               header('Retry-After: ' . $decision->retry_after);
               exit('You are rate limited by Zen.');
           }
           http_response_code(403);
           exit('You are blocked by Zen.');
       }
   }

5. 5

   Test your app

   Browse to your application and perform a couple of actions or open a couple of pages. Zen will automatically discover the routes in your application.

   Zen sends data back to Aikido every 10 minutes

   You can verify a working agent by looking at the following pages of your Zen application:

   • Events: Should show an "Application started" event.
   • Routes: After some time your application routes will start showing here with the method, route and requests.
   • Instances: Should show the number of active instances for your application where Zen is installed.

   

6. 6

   Set up rate limiting

   When you've added the Zen Firewall middleware you can test protecting a route from brute force attacks, you do this by setting up rate limit in the Aikido Dashboard:

   1. Click on the created app.
   2. Go to the Routes tab.
   3. Find the route you would like to limit and click Setup rate limiting.
   4. Follow the instructions to configure the rate limit (e.g., 5 requests per minute).

   

   

   Verify Rate Limiting

   Start your app and try to access the route you've rate limited 5 times within a minute. After the fifth attempt, you should receive a rate limit error:

   You are rate limited by Aikido firewall. (Your IP: 1.2.3.4)

7. 7

   Explore next steps

   Congrats you've successfully installed Zen Firewall. If you encountered any problems, have concerns or feature requests, don't hesitate to reach out to support.

   You can now go and explore the many features that Zen Firewall provides:

   • blocking-bot-traffic-with-zen-firewall.md
   • blocking-tor-traffic-with-zen-firewall.md
   • blocking-users-with-zen-firewall.md
   • blocking-known-threat-actors-with-zen-firewall.md
   • blocking-traffic-by-country-with-zen-firewall.md
   • setting-up-rate-limiting-for-routes.md
   • monitor-outbound-domains.md

   Additional information:

   • how-zen-works-performance-reliability.md
   • blocking-vs-detection-mode-in-zen-firewall.md
   • understanding-your-zen-statistics.md