WB 2.08.x

<?php

// $Id: filter-routines.php 1208 2009-12-03 18:06:39Z Luisehahne $

/*

 Website Baker Project <http://www.websitebaker.org/>

 Copyright (C) 2004-2009, Ryan Djurovich

 Website Baker 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.

 Website Baker 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.

 You should have received a copy of the GNU General Public License

 along with Website Baker; if not, write to the Free Software

 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 * @category   frontend

 * @package    outputfilter

 * @author(s)  Dietmar W?llbrink <Luisehahne>, Dietrich Roland Pehlke <Aldus>

 * @platform   WB 2.8.0

 * @require    PHP 5.2.x

 * @license    http://www.gnu.org/licenses/gpl.html

 * @link       http://project.websitebaker2.org/browser/branches/2.8.x/wb/modules/output_filter/filter-routines.php

 * @changeset   2009/12/03 change searchstring mdcr.js, workout crypt emails

*/

// prevent this file from being accessed directly

if(!defined('WB_PATH')) die(header('Location: ../index.php'));

// function to read the current filter settings

if (!function_exists('get_output_filter_settings')) {

	function get_output_filter_settings() {

		global $database, $admin;

		// connect to database and read out filter settings

		$result = $database->query("SELECT * FROM " .TABLE_PREFIX ."mod_output_filter");

		if($result && $result->numRows() > 0) {

			// get all data

			$data = $result->fetchRow();

			$filter_settings['email_filter'] = $admin->strip_slashes($data['email_filter']);

			$filter_settings['mailto_filter'] = $admin->strip_slashes($data['mailto_filter']);

			$filter_settings['at_replacement'] = $admin->strip_slashes($data['at_replacement']);

			$filter_settings['dot_replacement'] = $admin->strip_slashes($data['dot_replacement']);

		} else {

			// something went wrong, use default values

			$filter_settings['email_filter'] = '0';

			$filter_settings['mailto_filter'] = '0';

			$filter_settings['at_replacement'] = '(at)';

			$filter_settings['dot_replacement'] = '(dot)';

		}

		// return array with filter settings

		return $filter_settings;

	}

}

// function to filter the output before displaying it on the frontend

if (!function_exists('filter_frontend_output')) {

	function filter_frontend_output($content) {

		// get output filter settings from database

		$filter_settings = get_output_filter_settings();

		// work out the defined output filter mode: possible output filter modes: [0], 1, 2, 3, 6, 7

		// 2^0 * (0.. disable, 1.. enable) filtering of mail addresses in text

		// 2^1 * (0.. disable, 1.. enable) filtering of mail addresses in mailto links

		// 2^2 * (0.. disable, 1.. enable) Javascript mailto encryption (only if mailto filtering enabled)

		// only filter output if we are supposed to

		if($filter_settings['email_filter'] != '1' && $filter_settings['mailto_filter'] != '1'){

			// nothing to do ...

			return $content;

		}

		// check if non mailto mail addresses needs to be filtered

		$output_filter_mode = ($filter_settings['email_filter'] == '1') ? 1 : 0;		// 0|1

		// check if mailto mail addresses needs to be filtered

		if($filter_settings['mailto_filter'] == '1') {

			$output_filter_mode = $output_filter_mode + 2;								// 0|2

			// check if Javascript mailto encryption is enabled (call register_frontend_functions in the template)

			$search = '<script src="' .WB_URL .'/modules/output_filter/js/mdcr.js" type="text/javascript"></script>';

			$search_droplet = '<script src="' .WB_URL .'/modules/droplets/js/mdcr.js" type="text/javascript"></script>';

			if(strpos($content, $search) !== false || strpos($content, $search_droplet) !== false) { 

				$output_filter_mode = $output_filter_mode + 4;							// 0|4

			}

		}

		// define some constants so we do not call the database in the callback function again

		define('OUTPUT_FILTER_MODE', (int) $output_filter_mode);

		define('OUTPUT_FILTER_AT_REPLACEMENT', $filter_settings['at_replacement']);

		define('OUTPUT_FILTER_DOT_REPLACEMENT', $filter_settings['dot_replacement']);

		// first search part to find all mailto email addresses

		$pattern = '#(<a[^<]*href\s*?=\s*?"\s*?mailto\s*?:\s*?)([A-Z0-9._%+-]+@(?:[A-Z0-9-]+\.)+[A-Z]{2,4})([^"]*?)"([^>]*>)(.*?)</a>';

		// second part to find all non mailto email addresses

		$pattern .= '|(value\s*=\s*"|\')??\b([A-Z0-9._%+-]+@(?:[A-Z0-9-]+\.)+[A-Z]{2,4})\b#i';

		/*

		Sub 1:\b(<a.[^<]*href\s*?=\s*?"\s*?mailto\s*?:\s*?)			-->	"<a id="yyy" class="xxx" href = " mailto :" ignoring white spaces

		Sub 2:([A-Z0-9._%+-]+@(?:[A-Z0-9-]+\.)+[A-Z]{2,4})			-->	the email address in the mailto: part of the mail link

		Sub 3:([^"]*?)"												--> possible ?Subject&cc... stuff attached to the mail address

		Sub 4:([^>]*>)												--> all class or id statements after the mailto but before closing ..>

		Sub 5:(.*?)</a>\b											--> the mailto text; all characters between >xxxxx</a>

		Sub 6:|\b([A-Z0-9._%+-]+@(?:[A-Z0-9-]+\.)+[A-Z]{2,4})\b		--> email addresses which may appear in the text (require word boundaries)

		*/

		// find all email addresses embedded in the content and filter them using a callback function

		$content = preg_replace_callback($pattern, 'filter_mail_addresses', $content);

		return $content;

	}

}		

// function to filter mail addresses embedded in text or mailto links before outputing them on the frontend

if (!function_exists('filter_mail_addresses')) {

	function filter_mail_addresses($match) { 

		// check if required output filter mode is defined

		if(!(defined('OUTPUT_FILTER_MODE') && defined('OUTPUT_FILTER_MODE') && defined('OUTPUT_FILTER_MODE'))) {

			return $match[0];

		}

		$search = array('@', '.');

		$replace = array(OUTPUT_FILTER_AT_REPLACEMENT ,OUTPUT_FILTER_DOT_REPLACEMENT);

		// check if the match contains the expected number of subpatterns (6|8)

		if(count($match) == 8) {

			/**

				OUTPUT FILTER FOR EMAIL ADDRESSES EMBEDDED IN TEXT

			**/

			// 1.. text mails only, 3.. text mails + mailto (no JS), 7 text mails + mailto (JS)

			if(!in_array(OUTPUT_FILTER_MODE, array(1,3,7))) return $match[0];

			// do not filter mail addresses included in input tags (<input ... value = "test@mail)

			if (strpos($match[6], 'value') !== false) return $match[0];

			// filtering of non mailto email addresses enabled

			return str_replace($search, $replace, $match[0]);

		} elseif(count($match) == 6) {

			/**

				OUTPUT FILTER FOR EMAIL ADDRESSES EMBEDDED IN MAILTO LINKS

			**/

			// 2.. mailto only (no JS), 3.. text mails + mailto (no JS), 6.. mailto only (JS), 7.. all filters active

			if(!in_array(OUTPUT_FILTER_MODE, array(2,3,6,7))) return $match[0];

			// check if last part of the a href link: >xxxx</a> contains a email address we need to filter

			$pattern = '#[A-Z0-9._%+-]+@(?:[A-Z0-9-]+\.)+[A-Z]{2,4}#i';

			if(preg_match_all($pattern, $match[5], $matches)) {

				foreach($matches as $submatch) {

					foreach($submatch as $value) {

						// replace all . and all @ in email address parts by (dot) and (at) strings

						$match[5] = str_replace($value, str_replace($search, $replace, $value), $match[5]);

					}

				}

			}

			// check if Javascript encryption routine is enabled

			if(in_array(OUTPUT_FILTER_MODE, array(6,7))) {

				/** USE JAVASCRIPT ENCRYPTION FOR MAILTO LINKS **/

				// extract possible class and id attribute from ahref link

				preg_match('/class\s*?=\s*?("|\')(.*?)\1/ix', $match[0], $class_attr);

				$class_attr = empty($class_attr) ? '' : 'class="' . $class_attr[2] . '" ';

				preg_match('/id\s*?=\s*?("|\')(.*?)\1/ix', $match[0], $id_attr);

				$id_attr = empty($id_attr) ? '' : 'id="' . $id_attr[2] . '" ';

				// preprocess mailto link parts for further usage

				$search = array('@', '.', '_', '-'); $replace = array('F', 'Z', 'X', 'K');

				$email_address = str_replace($search, $replace, strtolower($match[2]));

				$email_subject = rawurlencode(html_entity_decode($match[3]));

				// create a random encryption key for the Caesar cipher

				mt_srand((double)microtime()*1000000);	// (PHP < 4.2.0)

				$shift = mt_rand(1, 25);

				// encrypt the email using an adapted Caesar cipher

		  		$encrypted_email = "";

				for($i = strlen($email_address) -1; $i > -1; $i--) {

					if(preg_match('#[FZXK0-9]#', $email_address[$i], $characters)) {

						$encrypted_email .= $email_address[$i];

					} else {	

						$encrypted_email .= chr((ord($email_address[$i]) -97 + $shift) % 26 + 97);

					}

				}

				$encrypted_email .= chr($shift + 97);

				// build the encrypted Javascript mailto link

				$mailto_link  = "<a {$class_attr}{$id_attr}href=\"javascript:mdcr('$encrypted_email','$email_subject')\">" .$match[5] ."</a>";

				return $mailto_link;	

			} else {

				/** DO NOT USE JAVASCRIPT ENCRYPTION FOR MAILTO LINKS **/

				// as minimum protection, replace replace @ in the mailto part by (at)

				// dots are not transformed as this would transform my.name@domain.com into: my(dot)name(at)domain(dot)com

				// rebuild the mailto link from the subpatterns (at the missing characters " and </a>")

				return $match[1] .str_replace('@', OUTPUT_FILTER_AT_REPLACEMENT, $match[2]) .$match[3] .'"' .$match[4] .$match[5] .'</a>';

				// if you want to protect both, @ and dots, comment out the line above and remove the comment from the line below

				// return $match[1] .str_replace($search, $replace, $match[2]) .$match[3] .'"' .$match[4] .$match[5] .'</a>';

			}

		}

		// number of subpatterns do not match the requirements ... do nothing

		return $match[0];

	}		

}

?>