Osynapsy CSRF Protection

A lightweight and simple CSRF protection package for Osynapsy forms and actions.
Provides a stateless, HMAC-based token system to secure sensitive POST operations.

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Features

• Generate CSRF tokens (nonce + token) for forms.
• Easy integration with Osynapsy Form components.
• Optional check in actions extending AbstractAction.
• Minimal and explicit: only enable CSRF where necessary.
• No session overhead, fully stateless.

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Installation

Install via Composer:

composer require osynapsy/csrf

Usage

Adding CSRF fields to a form

use Osynapsy\Csrf\FormCsrf;

$form = new \MyProject\Form\UserEditForm();
\FormCsrf::apply($form, $_ENV['CSRF_SECRET']);

This will add two hidden fields to your form:

• csrf_nonce
• csrf_token

Checking CSRF in an action

Extend your action from Osynapsy\Csrf\Action\AbstractAction:

public function execute()
{
    $this->checkCsrf(); // Validates the CSRF token and nonce

    // Your action logic here
}

The check will throw an exception if the CSRF token is missing or invalid.

Security Notes

Only enable CSRF on forms that perform sensitive POST operations. Use HTTPS and set secure cookies for sessions. Keep SECRET_KEY secret and unique per project. The package is stateless, so no server-side session storage is required.

Classes

Osynapsy\Csrf\Token – Generates and verifies CSRF tokens. Osynapsy\Csrf\FormCsrf – Helper to apply CSRF fields to a form. Osynapsy\Csrf\Action\AbstractAction – Base action with checkCsrf() method.

License

MIT licence