hcaptcha.php

<?php
/**
 * @package     Joomla.Plugin
 * @subpackage  Captcha
 *
 * @author      Peter Martin
 * @copyright   Copyright 2016-2017 Peter Martin. All rights reserved.
 * @license     GNU General Public License version 2 or later
 * @link        https://db8.eu
 */

defined('_JEXEC') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\HTML\HTMLHelper;
use Joomla\CMS\Language\Text;
use Joomla\CMS\Plugin\CMSPlugin;
use Joomla\Utilities\IpHelper;

/**
 * hCaptcha Plugin
 * Using the https://www.hcaptcha.com/ CAPTCHA service
 *
 * @since  1.0.0
 */
class PlgCaptchaHcaptcha extends CMSPlugin
{
	/**
	 * Load the language file on instantiation.
	 *
	 * @var    boolean
	 * @since  1.0.0
	 */
	protected $autoloadLanguage = true;

	/**
	 * Initialise the captcha
	 *
	 * @return  boolean    True on success, false otherwise
	 *
	 * @since   1.0.0
	 * @throws  Exception
	 */
	public function onInit()
	{
		// If there is no Public Key set, then this plugin is no use, so exit
		if ($this->params->get('publicKey', '') === '')
		{
			throw new \RuntimeException(Text::_('PLG_HCAPTCHA_ERROR_NO_PUBLIC_KEY'));
		}

		// Load the JavaScript from hCaptcha
		HTMLHelper::_('script', 'https://hcaptcha.com/1/api.js', ['version' => 'auto', 'relative' => true], ['defer' => 'defer']);

		return true;
	}

	/**
	 * Gets the challenge HTML
	 *
	 * @param   string  $name   The name of the field. Not Used.
	 * @param   string  $id     The id of the field.
	 * @param   string  $class  The class of the field.
	 *
	 * @return  string  The HTML to be embedded in the form.
	 *
	 * @since  1.0.0
	 */
	public function onDisplay($name = null, $id = 'hcaptcha', $class = '')
	{
		$dom = new \DOMDocument('1.0', 'UTF-8');
		$ele = $dom->createElement('div');
		$ele->setAttribute('id', $id);
		$ele->setAttribute('class', 'h-captcha');
		$ele->setAttribute('data-sitekey', $this->params->get('publicKey', ''));
		$ele->setAttribute('data-theme', $this->params->get('theme', 'light'));
		$ele->setAttribute('data-size', $this->params->get('size', 'normal'));

		$dom->appendChild($ele);

		return $dom->saveHTML($ele);
	}

	/**
	 * Calls an HTTP POST function to verify if the user's guess was correct
	 *
	 * @param   string  $code  Answer provided by user. Not needed for the Hcaptcha implementation
	 *
	 * @return  boolean
	 * @since   1.0.0
	 * @throws  Exception
	 */
	public function onCheckAnswer($code = null)
	{
		$input            = Factory::getApplication()->input;
		$privateKey       = $this->params->get('privateKey');
		$remoteIp         = IpHelper::getIp();
		$hCaptchaResponse = $input->get('h-captcha-response', '', 'cmd');

		if (empty($privateKey))
		{
			throw new \RuntimeException(Text::_('PLG_HCAPTCHA_ERROR_NO_PRIVATE_KEY'));
		}

		if (empty($remoteIp))
		{
			throw new \RuntimeException(Text::_('PLG_HCAPTCHA_ERROR_NO_IP'));
		}

		if (empty($hCaptchaResponse))
		{
			throw new \RuntimeException(Text::_('PLG_HCAPTCHA_ERROR_EMPTY_SOLUTION'));
		}

		$verifyResponse = file_get_contents(
			'https://hcaptcha.com/siteverify?secret=' . $privateKey .
			'&response=' . $hCaptchaResponse .
			'&remoteip=' . $remoteIp
		);
		$responseData   = json_decode($verifyResponse);

		if ($responseData->success)
		{
			return true;
		}

		throw new \RuntimeException(Text::_('PLG_HCAPTCHA_ERROR_INCORRECT_CAPTCHA'));
	}
}