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ReCaptcha

Description

This recipe implements Google reCAPTCHA. reCAPTCHA can be embedded into forms used by PmWiki. The ReCaptcha recipe works by displaying a "I'm not a robot" test as part of an input form. Requests to save a page that don't pass the ReCaptcha will be denied, with an opportunity to re-submit. For example:

(:input form action={*$PageUrl} method=post:)
(:input default request=1:)
(:recaptcha:)
(:input submit:)
(:input end:)

The ReCaptcha widget looks like this using default settings:

Download and Install

1. Register: Register a new site and obtain public and private keys from Google:
   • Goto reCAPTCHA Admin
   • Register a new site. You can enter mutiple domains.
   • Once registered, you'll be shown a "Site Key" and a "Secret Key". You'll need these in the config step.
   • Optional: Further down the registration page you'll see Advanced settings where you can make the reCAPTCHA easier, or more difficult.
2. Download: Download the latest version as a ZIP file.
   • Copy contents into the cookbook/ directory. You'll have a recaptcha directory in cookbook.
3. Configure: Add this to local/config.php, using your own site and secret keys between quotes. The condition will allow users with Edit permissions to by-pass the ReCaptcha:

   $rc_Settings = array (
      'sitekey' => '',  // paste your Site Key between quotes
      'secret' => ''    // paste your Secret Key between quotes
   );
   if (!CondAuth($pagename,'edit'))
      include_once("$FarmD/cookbook/recaptcha/recaptcha.php");
   
4. Display: Add the widget towards the end of the form you want to protect. For example, to require a captcha in order to edit a page, add the following markup to an appropriate place in the Site.EditForm page:

   (:recaptcha:)
   
5. Settings: Optionally change the behavior or look of the widget.

Settings

Global Settings

Some settings apply to all ReCaptchas.

These are defined in config.php:

$rc_Settings = array (
	'enabled' => 1,
   'sitekey' => '',  // paste your Site Key between quotes
	'secret' => '',   // paste your Secret Key between quotes
	'language' => 'en',
	'curl' => 0,
	'script' => 'https://www.google.com/recaptcha/api.js'
);

Widget Specific Settings

The following settings can be applied to each widget can be defined either globally or for each widget:

You can define these settings per widget, or globally:

• Per widget, in the (:recaptcha:) markup.

  (:recaptcha theme=dark type=audio size=compact tabindex=2:)
  
• Globally in config.php:

  $rc_Settings['options'] = array(
     'theme' => 'light',
     'type' => 'image',
     'size' => 'normal',
     'tabindex' => '0',
     'callback' => '',
     'expired-callback' => ''
  );
  

Internationalization

Add this to config.php to translate error codes:

XLSDV('en', array('missing-input-response'=>'Please verify you are not a robot.'));

FAQ

invalid-json

If your host doesn't support or enable PHP setting file_get_contents you may receive 'invalid-json' errors. In which case there are two options:

1. either change the setting in php.ini. Be aware of security implications of doing this.

     allow_url_fopen = on
   

2. turn on the ReCaptcha 'curl' setting, which uses an alternate communication mechanism:

   $rc_Settings = array ( 'curl' => 1 );
   

Selective Enabling

If you want all users to have to enter the ReCaptcha just include the configuration with no condition:

$rc_Settings = array (
   'sitekey' => '',  // paste your Site Key between quotes
   'secret' => ''    // paste your Secret Key between quotes
);
include_once("$FarmD/cookbook/recaptcha/recaptcha.php");

Captcha not Displayed

If you don't see a captcha box, ensure your skin specifies a <!--HTMLFooter--> directive.

Libraries

• Code and idea based on Captcha
• Implementation of the captcha is by Google reCAPTCHA
• Also uses Google reCAPTCHA PHP library

Known Issues

None known.

Change Log

0.0.3 (28-Mar-2016)

• bug: Added 'curl' parameter to prevent 'invalid-json' errors.

0.0.2 (28-Mar-2016)

• chg: First release.