friendly-lite-server - Self Hosted Captcha Server, compatible with Friendly Captcha

Motivation

Friendly Captcha offers a privacy aware captcha service. This service offers you to host a lite server version of the service with some basic features for puzzle and verification on your machine.

Subscriptions

If you need more advanced security features or want to support our work, we highly recommend to subscribe to the Friendly Captcha service.

Requirements

• PHP 7.4 or higher
• sodium support
• apcu support

Installation

You need a web server running PHP 7.4 or later.

1. Install the public folder to the your document root.
2. Copy and adapt env.template.php to env.php
3. Change the friendly captcha widgets endpoint to user your server
4. In your backend configuration, use the your own server endpoint and

Endpoints

Instead of https://api.friendlycaptcha.com/api/v1/siteverify use https://yourserver/siteverify.php. Instead of https://(eu-)api.friendlycaptcha.eu/api/v1/puzzle" use https://yourserver/puzzle.php.

What works

• Check of signature
• Check of puzzles
• Check of timestamps
• Replay checks
• Basic difficulty scaling

License

This software is fair-code distributed under Apache 2.0 with Commons Clause license.

Troubleshooting

The widget shows an error when loading the puzzle

• Check your server log for errors
• Open /puzzle.php manually and see if there are any errors displayed
• Is LibSodium available?

Captcha is not validated, even generated by the widget itself

• This should not happen, maybe file an issue including the server logs

Invalid Captchas are accepted (for example form submitted before captcha was solved)

• Friendly Captcha recommends to accept Captcha solutions on server errors, so also here check for server errors
• Is APCU and LibSodium available?