qa-recaptcha-captcha.php

<?php
/*
	Question2Answer by Gideon Greenspan and contributors
	http://www.question2answer.org/

	File: qa-plugin/recaptcha-captcha/qa-recaptcha-captcha.php
	Description: Captcha module for reCAPTCHA


	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	More about this license: http://www.question2answer.org/license.php
*/

class qa_recaptcha_captcha
{
	private $directory;

	public function load_module($directory, $urltoroot)
	{
		$this->directory=$directory;
	}


	public function admin_form()
	{
		$saved=false;

		if (qa_clicked('recaptcha_save_button')) {
			qa_opt('recaptcha_public_key', qa_post_text('recaptcha_public_key_field'));
			qa_opt('recaptcha_private_key', qa_post_text('recaptcha_private_key_field'));

			$saved=true;
		}

		$form=array(
			'ok' => $saved ? 'reCAPTCHA settings saved' : null,

			'fields' => array(
				'public' => array(
					'label' => 'reCAPTCHA public key:',
					'value' => qa_opt('recaptcha_public_key'),
					'tags' => 'name="recaptcha_public_key_field"',
				),

				'private' => array(
					'label' => 'reCAPTCHA private key:',
					'value' => qa_opt('recaptcha_private_key'),
					'tags' => 'name="recaptcha_private_key_field"',
					'error' => $this->recaptcha_error_html(),
				),
			),

			'buttons' => array(
				array(
					'label' => 'Save Changes',
					'tags' => 'name="recaptcha_save_button"',
				),
			),
		);

		return $form;
	}


	public function recaptcha_error_html()
	{
		if (!function_exists('fsockopen'))
			return 'To use reCAPTCHA, the fsockopen() PHP function must be enabled on your server. Please check with your system administrator.';

		elseif ( (!strlen(trim(qa_opt('recaptcha_public_key')))) || (!strlen(trim(qa_opt('recaptcha_private_key')))) ) {
			require_once $this->directory.'recaptchalib.php';

			$url=recaptcha_get_signup_url(@$_SERVER['HTTP_HOST'], qa_opt('site_title'));

			return 'To use reCAPTCHA, you must <a href="'.qa_html($url).'">sign up</a> to get these keys.';
		}

		return null;
	}


	public function allow_captcha()
	{
		return function_exists('fsockopen') && strlen(trim(qa_opt('recaptcha_public_key'))) && strlen(trim(qa_opt('recaptcha_private_key')));
	}


	public function form_html(&$qa_content, $error)
	{
		require_once $this->directory.'recaptchalib.php';

		$language=qa_opt('site_language');
		if (strpos('|en|nl|fr|de|pt|ru|es|tr|', '|'.$language.'|')===false) // supported as of 3/2010
			$language='en';

		$qa_content['script_lines'][]=array(
			"var RecaptchaOptions={",
			"\ttheme:'white',",
			"\tlang:".qa_js($language),
			"};",
		);

		return recaptcha_get_html(qa_opt('recaptcha_public_key'), $error, qa_is_https_probably());
	}


	public function validate_post(&$error)
	{
		if ( (!empty($_POST['recaptcha_challenge_field'])) && (!empty($_POST['recaptcha_response_field'])) ) {
			require_once $this->directory.'recaptchalib.php';

			$answer=recaptcha_check_answer(
				qa_opt('recaptcha_private_key'),
				qa_remote_ip_address(),
				$_POST['recaptcha_challenge_field'],
				$_POST['recaptcha_response_field']
			);

			if ($answer->is_valid)
				return true;

			$error=@$answer->error;
		}

		return false;
	}
}