[5.1] A simple Captcha, which not every AI can solve

administrator/components/com_admin/sql/updates/mysql/5.1.0-2024-02-08.sql

@@ -0,0 +1,2 @@
+INSERT INTO `#__extensions` (`package_id`, `name`, `type`, `element`, `folder`, `client_id`, `enabled`, `access`, `protected`, `locked`, `manifest_cache`, `params`, `custom_data`, `ordering`, `state`) VALUES
+(0, 'plg_captcha_math', 'plugin', 'math', 'captcha', 0, 0, 1, 0, 1, '', '{}', '', 1, 0);

administrator/components/com_admin/sql/updates/postgresql/5.1.0-2024-02-08.sql

@@ -0,0 +1,2 @@
+INSERT INTO "#__extensions" ("package_id", "name", "type", "element", "folder", "client_id", "enabled", "access", "protected", "locked", "manifest_cache", "params", "custom_data", "ordering", "state") VALUES
+(0, 'plg_captcha_math', 'plugin', 'math', 'captcha', 0, 0, 1, 0, 1, '', '{}', '', 1, 0);

administrator/language/en-GB/plg_captcha_math.ini

@@ -0,0 +1,11 @@
+; Joomla! Project
+; (C) 2024 Open Source Matters, Inc. <https://www.joomla.org>
+; License GNU General Public License version 2 or later; see LICENSE.txt
+; Note : All ini files need to be saved as UTF-8
+
+PLG_CAPTCHA_MATH="Captcha - Math"
+PLG_CAPTCHA_MATH_XML_DESCRIPTION="A simple Captcha plugin that uses Math."
+
+PLG_CAPTCHA_MATH_EMPTY_STORE="Captcha Math solution not found, please make sure you did not submit the same form twice."
+PLG_CAPTCHA_MATH_ENTER_SOLUTION="Enter solution (all or remaining digits) for"
+PLG_CAPTCHA_MATH_WRONG_SOLUTION="Incorrect math solution for the Captcha."

administrator/language/en-GB/plg_captcha_math.sys.ini

@@ -0,0 +1,7 @@
+; Joomla! Project
+; (C) 2024 Open Source Matters, Inc. <https://www.joomla.org>
+; License GNU General Public License version 2 or later; see LICENSE.txt
+; Note : All ini files need to be saved as UTF-8
+
+PLG_CAPTCHA_MATH="Captcha - Math"
+PLG_CAPTCHA_MATH_XML_DESCRIPTION="A simple Captcha plugin that uses Math."

installation/sql/mysql/base.sql

@@ -264,6 +264,7 @@ INSERT INTO `#__extensions` (`package_id`, `name`, `type`, `element`, `folder`,
 (0, 'plg_behaviour_compat', 'plugin', 'compat', 'behaviour', 0, 1, 1, 0, 1, '', '{"classes_aliases":"1","es5_assets":"1"}', '', 1, 0),
 (0, 'plg_behaviour_taggable', 'plugin', 'taggable', 'behaviour', 0, 1, 1, 0, 1, '', '{}', '', 2, 0),
 (0, 'plg_behaviour_versionable', 'plugin', 'versionable', 'behaviour', 0, 1, 1, 0, 1, '', '{}', '', 3, 0),
+(0, 'plg_captcha_math', 'plugin', 'math', 'captcha', 0, 0, 1, 0, 1, '', '{}', '', 1, 0),
 (0, 'plg_content_confirmconsent', 'plugin', 'confirmconsent', 'content', 0, 0, 1, 0, 1, '', '{}', '', 1, 0),
 (0, 'plg_content_contact', 'plugin', 'contact', 'content', 0, 1, 1, 0, 1, '', '', '', 2, 0),
 (0, 'plg_content_emailcloak', 'plugin', 'emailcloak', 'content', 0, 1, 1, 0, 1, '', '{"mode":"1"}', '', 3, 0),

installation/sql/postgresql/base.sql

@@ -270,6 +270,7 @@ INSERT INTO "#__extensions" ("package_id", "name", "type", "element", "folder",
 (0, 'plg_behaviour_compat', 'plugin', 'compat', 'behaviour', 0, 1, 1, 0, 1, '', '{"classes_aliases":"1","es5_assets":"1"}', '', 1, 0),
 (0, 'plg_behaviour_taggable', 'plugin', 'taggable', 'behaviour', 0, 1, 1, 0, 1, '', '{}', '', 2, 0),
 (0, 'plg_behaviour_versionable', 'plugin', 'versionable', 'behaviour', 0, 1, 1, 0, 1, '', '{}', '', 3, 0),
+(0, 'plg_captcha_math', 'plugin', 'math', 'captcha', 0, 0, 1, 0, 1, '', '{}', '', 1, 0),
 (0, 'plg_content_confirmconsent', 'plugin', 'confirmconsent', 'content', 0, 0, 1, 0, 1, '', '{}', '', 1, 0),
 (0, 'plg_content_contact', 'plugin', 'contact', 'content', 0, 1, 1, 0, 1, '', '', '', 2, 0),
 (0, 'plg_content_emailcloak', 'plugin', 'emailcloak', 'content', 0, 1, 1, 0, 1, '', '{"mode":"1"}', '', 3, 0),

layouts/plugins/captcha/math/mathcaptcha.php

@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * @package     Joomla.Plugin
+ * @subpackage  Captcha.math
+ *
+ * @copyright   (C) 2024 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\Document\Document;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Layout\FileLayout;
+
+extract($displayData);
+
+/**
+ * Layout variables
+ * -----------------
+ * @var   string       $name           Name of the input field.
+ * @var   array        $attributes     List of input attributes
+ * @var   string       $formula        Formula
+ * @var   integer      $inputIdx       Active Input index
+ * @var   Document     $document       Document instance
+ * @var   FileLayout   $this           Context
+ */
+
+$id    = $attributes['id'] ?? '';
+$class = str_replace(' required', '', ($attributes['class'] ?? ''));
+
+$letters = 'abcdefghijklmnopqrstuvwxyz';
+$classes = [
+    substr(str_shuffle($letters), 0, 2) . bin2hex(random_bytes(rand(2, 7))),
+    substr(str_shuffle($letters), 0, 2) . bin2hex(random_bytes(rand(2, 7))),
+    substr(str_shuffle($letters), 0, 2) . bin2hex(random_bytes(rand(2, 7))),
+];
+
+$styles = '';
+foreach ($classes as $i => $c) {
+    $styles .= '.' . $c . '{display:' . ($i !== $inputIdx ? 'none' : 'block') . '}';
+}
+
+$document->getWebAssetManager()->addInlineStyle($styles, ['name' => 'inline.plg_captcha_math'])
+?>
+<div class="input-group mb-3">
+    <span class="input-group-text"><?php echo Text::_('PLG_CAPTCHA_MATH_ENTER_SOLUTION') ?> <?php echo $this->escape($formula); ?></span>
+    <input type="text" value="" size="4" name="<?php echo $name; ?>[]" id="<?php echo $id; ?>" class="form-control <?php echo $classes[0] . ' ' . $class; ?>"/>
+    <input type="text" value="" size="4" name="<?php echo $name; ?>[]" id="<?php echo $id; ?>1" class="form-control <?php echo $classes[1] . ' ' . $class; ?>"/>
+    <input type="text" value="" size="4" name="<?php echo $name; ?>[]" id="<?php echo $id; ?>2" class="form-control <?php echo $classes[2] . ' ' . $class; ?>"/>
+</div>

libraries/src/Captcha/Captcha.php

@@ -193,7 +193,7 @@ public function display($name, $id, $class = '')
     /**
      * Checks if the answer is correct.
      *
-     * @param   string  $code  The answer.
+     * @param   mixed  $code  The answer.
      *
      * @return  bool    Whether the provided answer was correct
      *
@@ -203,6 +203,9 @@ public function display($name, $id, $class = '')
     public function checkAnswer($code)
     {
         if ($this->provider) {
+            if (!is_scalar($code)) {
+                $code = json_encode($code);
+            }
             return $this->provider->checkAnswer($code);
         }
 

plugins/captcha/math/math.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<extension type="plugin" group="captcha" method="upgrade">
+	<name>PLG_CAPTCHA_MATH</name>
+	<version>5.1.0</version>
+	<creationDate>2024-02</creationDate>
+	<author>Joomla! Project</author>
+	<authorEmail>[email protected]</authorEmail>
+	<authorUrl>www.joomla.org</authorUrl>
+	<copyright>(C) 2024 Open Source Matters, Inc.</copyright>
+	<license>GNU General Public License version 2 or later; see LICENSE.txt</license>
+	<description>PLG_CAPTCHA_MATH_XML_DESCRIPTION</description>
+	<namespace path="src">Joomla\Plugin\Captcha\Math</namespace>
+	<files>
+		<folder plugin="math">services</folder>
+		<folder>src</folder>
+	</files>
+	<languages>
+		<language tag="en-GB">language/en-GB/plg_captcha_math.ini</language>
+		<language tag="en-GB">language/en-GB/plg_captcha_math.sys.ini</language>
+	</languages>
+	<config/>
+</extension>

plugins/captcha/math/services/provider.php

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @package     Joomla.Plugin
+ * @subpackage  Captcha.math
+ *
+ * @copyright   (C) 2024 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+\defined('_JEXEC') or die;
+
+use Joomla\CMS\Extension\PluginInterface;
+use Joomla\CMS\Factory;
+use Joomla\CMS\Plugin\PluginHelper;
+use Joomla\DI\Container;
+use Joomla\DI\ServiceProviderInterface;
+use Joomla\Event\DispatcherInterface;
+use Joomla\Plugin\Captcha\Math\Extension\Math;
+
+return new class () implements ServiceProviderInterface {
+    /**
+     * Registers the service provider with a DI container.
+     *
+     * @param   Container  $container  The DI container.
+     *
+     * @return  void
+     *
+     * @since   __DEPLOY_VERSION__
+     */
+    public function register(Container $container)
+    {
+        $container->set(
+            PluginInterface::class,
+            function (Container $container) {
+                $plugin = new Math(
+                    $container->get(DispatcherInterface::class),
+                    (array) PluginHelper::getPlugin('captcha', 'math')
+                );
+                $plugin->setApplication(Factory::getApplication());
+
+                return $plugin;
+            }
+        );
+    }
+};

plugins/captcha/math/src/Extension/Math.php

@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * @package     Joomla.Plugin
+ * @subpackage  Captcha.math
+ *
+ * @copyright   (C) 2024 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Plugin\Captcha\Math\Extension;
+
+use Joomla\CMS\Event\Captcha\CaptchaSetupEvent;
+use Joomla\CMS\Plugin\CMSPlugin;
+use Joomla\Event\SubscriberInterface;
+use Joomla\Plugin\Captcha\Math\Provider\MathCaptchaProvider;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * Math captcha Plugin
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+final class Math extends CMSPlugin implements SubscriberInterface
+{
+    /**
+     * Returns an array of events this plugin will listen to.
+     *
+     * @return  array
+     *
+     * @since  __DEPLOY_VERSION__
+     */
+    public static function getSubscribedEvents(): array
+    {
+        return [
+            'onCaptchaSetup' => 'onCaptchaSetup',
+        ];
+    }
+
+    /**
+     * Register Captcha instance
+     *
+     * @param CaptchaSetupEvent $event
+     *
+     * @return void
+     *
+     * @since  __DEPLOY_VERSION__
+     */
+    public function onCaptchaSetup(CaptchaSetupEvent $event)
+    {
+        $this->loadLanguage();
+        $event->getCaptchaRegistry()->add(new MathCaptchaProvider($this->getApplication()));
+    }
+}