reCAPTCHA V2 for Joomla 2.5 with chronoforms 4

Because of the server environment and other immutable factors, we can only modify the program source code to support the new reCAPTCHA v2.

1. Download the check_recaptcha and load_recaptcha components from the administrator/components directory

   administrator
   └──components
      ├── check_recaptcha
      └── load_recaptcha

2. Open the check_recaptcha/check_recaptcha.php

2.1. Download the ReCaptcha = 1.1.2 library and unzip it into check_recaptcha/vendor

# Download link
https://github.com/google/recaptcha/archive/1.1.2.tar.gz

# Tree
.
├── check_recaptcha.ctp
├── check_recaptcha.php
├── index.html
└── vendor
    └── ReCaptcha
        ├── ReCaptcha
        │   ├── ReCaptcha.php
        │   ├── RequestMethod
        │   │   ├── Curl.php
        │   │   ├── CurlPost.php
        │   │   ├── Post.php
        │   │   ├── Socket.php
        │   │   └── SocketPost.php
        │   ├── RequestMethod.php
        │   ├── RequestParameters.php
        │   └── Response.php
        └── autoload.php

2.2. Add the following line

require_once dirname(__FILE__).'/vendor/ReCaptcha/autoload.php';

use ReCaptcha\ReCaptcha;

2.3. change run, recaptcha_check_answer and load methods, and then remove the _recaptcha_http_post methods

function run($form, $actiondata)
{
    $params = new JParameter($actiondata->params);

    if(!defined('RECAPTCHA_VERIFY_SERVER')){
        define('RECAPTCHA_VERIFY_SERVER', $params->get('verify_server'));
    }

    $resp = $this->recaptcha_check_answer(
        $params->get('private_key'),
        JRequest::getVar("g-recaptcha-response"),
        $_SERVER["REMOTE_ADDR"]
    );

    if ( !$resp->is_valid ) {
        $form->validation_errors['recaptcha'] = $params->get('error', "The reCAPTCHA wasn't entered correctly. Please try it again.");
        $form->debug[] = "( reCAPTCHA said: ".$resp->error." )";
        $this->events['fail'] = 1;
    }else{
        $this->events['success'] = 1;
    }
}

function recaptcha_check_answer ($privkey, $recaptcha_response_param, $remoteip, $extra_params = array())
{
    if ( $privkey == null || $privkey == '' ) {
        die ("To use reCAPTCHA you must get an API key from
            <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
    }

    if ( $remoteip == null || $remoteip == '' ) {
        die ("For security reasons, you must pass the remote ip to reCAPTCHA");
    }

    //discard spam submissions
    if ($recaptcha_response_param == null || strlen($recaptcha_response_param) == 0) {
        $recaptcha_response = new CFReCaptchaResponse();
        $recaptcha_response->is_valid = false;
        $recaptcha_response->error = 'incorrect-captcha-sol';

        return $recaptcha_response;
    }

    $recaptcha = new ReCaptcha($privkey);
    $response  = $recaptcha->verify($recaptcha_response_param, $remoteip);

    $recaptcha_response = new CFReCaptchaResponse();

    if ($response->isSuccess()) {
        $recaptcha_response->is_valid = true;
    } else {
        $recaptcha_response->is_valid = false;
        $recaptcha_response->error = array_shift($response->getErrorCodes());
    }

    return $recaptcha_response;
}

function load($clear){
    if($clear){
        $action_params = array(
            'private_key' => 'DEMO-PUBLIC-KEY',
            'verify_server' => 'www.google.com',
            'error' => "The reCAPTCHA wasn't entered correctly. Please try it again."
        );
    }
    return array('action_params' => $action_params);
}

3. Open the load_recaptcha/load_recaptcha.php

3.1. Change run, recaptcha_get_html and load methods

function run($form, $actiondata)
{
    $mainframe = JFactory::getApplication();
    $params = new JParameter($actiondata->params);

    if(!defined('RECAPTCHA_API_SERVER')){
        define('RECAPTCHA_API_SERVER', $params->get('api_server'));
    }
    if(!defined('RECAPTCHA_API_SECURE_SERVER')){
        define('RECAPTCHA_API_SECURE_SERVER', $params->get('api_secure_server'));
    }

    if (!defined('RECAPTCHA_API_LANG')) {
        define('RECAPTCHA_API_LANG', $params->get('lang', 'en'));
    }

    if (!defined('RECAPTCHA_API_THEME')) {
        define('RECAPTCHA_API_THEME', $params->get('theme', 'light'));
    }

    $recaptcha_load = "<div id='recaptcha'>".$this->recaptcha_get_html($params->get('public_key'))."</div>";

    //replace the string
    $form->form_details->content = str_replace('{ReCaptcha}', $recaptcha_load, $form->form_details->content);
}

function recaptcha_get_html($pubkey, $error = null, $use_ssl = false)
{
    if ( $pubkey == null || $pubkey == '' ) {
        die ("To use reCAPTCHA you must get an API key from
        <a href='https://www.google.com/recaptcha/admin/create'>https://www.google.com/recaptcha/admin/create</a>");
    }

    if ( $use_ssl ) {
        $server = RECAPTCHA_API_SECURE_SERVER;
    } else {
        $server = RECAPTCHA_API_SERVER;
    }

    $html  = '<div class="g-recaptcha" data-sitekey="'.$pubkey.'" data-theme="'.RECAPTCHA_API_THEME.'"></div>';
    $html .= '<script type="text/javascript" src="'.$server.'/api.js?hl='.RECAPTCHA_API_LANG.'"></script>';

    return $html;
}

function load($clear)
{
    if ( $clear ) {
        $action_params = array(
            'public_key' => 'DEMO-PUBLIC-KEY',
            'ssl_server' => '0',
            'theme' => 'white',
            'lang' => 'en',
            'api_server' => 'http://www.google.com/recaptcha',
            'api_secure_server' => 'https://www.google.com/recaptcha'
        );
    }
    return array('action_params' => $action_params);
}

3.2. Open the load_recaptcha/load_recaptcha.ctp, and change the recaptcha theme options

<?php echo $HtmlHelper->input('action_load_recaptcha_{n}_theme_config', array(
        'type' => 'select',
        'label' => 'Theme',
        'options' => array(
            'light' => 'Light',
            'dark' => 'Dark'
        )
    )
);
?>

4. Save and upload the changed file to server, and login to the control panel update the reCAPTCHA public and private key
5. Finished