Merge pull request #858 from vichan-devel/removecurrentantibot

Remove current antibot system

inc/anti-bot.php

@@ -1,199 +1,5 @@
 <?php
 
 /*
- *  Copyright (c) 2010-2013 Tinyboard Development Group
+ *  Anti-bot.php has been deprecated and removed due to its functions not being necessary and being easily bypassable, by both customized and uncustomized spambots.
  */
-
-defined('TINYBOARD') or exit;
-
-class AntiBot {
-	public $salt;
-	public $inputs = [];
-	public $index = 0;
-
-	public static function randomString($length, $uppercase = false, $special_chars = false, $unicode_chars = false) {
-		$chars = 'abcdefghijklmnopqrstuvwxyz0123456789';
-		if ($uppercase) {
-			$chars .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
-		}
-		if ($special_chars) {
-			$chars .= ' ~!@#$%^&*()_+,./;\'[]\\{}|:<>?=-` ';
-		}
-		if ($unicode_chars) {
-			$len = strlen($chars) / 10;
-			for ($n = 0; $n < $len; $n++) {
-				$chars .= mb_convert_encoding('&#' . mt_rand(0x2600, 0x26FF) . ';', 'UTF-8', 'HTML-ENTITIES');
-			}
-		}
-
-		$chars = preg_split('//u', $chars, -1, PREG_SPLIT_NO_EMPTY);
-
-		$ch = [];
-
-		// fill up $ch until we reach $length
-		while (count($ch) < $length) {
-			$n = $length - count($ch);
-			$keys = array_rand($chars, $n > count($chars) ? count($chars) : $n);
-			if ($n == 1) {
-				$ch[] = $chars[$keys];
-				break;
-			}
-			shuffle($keys);
-			foreach ($keys as $key) {
-				$ch[] = $chars[$key];
-			}
-		}
-
-		$chars = $ch;
-
-		return implode('', $chars);
-	}
-
-	public static function make_confusing($string) {
-		$chars = preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY);
-
-		foreach ($chars as &$c) {
-			if (mt_rand(0, 3) != 0) {
-				$c = utf8tohtml($c);
-			} else {
-				$c = mb_encode_numericentity($c, [ 0, 0xffff, 0, 0xffff ], 'UTF-8');
-			}
-		}
-
-		return implode('', $chars);
-	}
-
-	public function __construct(array $salt = []) {
-		global $config;
-
-		if (!empty($salt)) {
-			// Create a salted hash of the "extra salt"
-			$this->salt = implode(':', $salt);
-		} else {
-			$this->salt = '';
-		}
-
-		shuffle($config['spam']['hidden_input_names']);
-
-		$input_count = mt_rand($config['spam']['hidden_inputs_min'], $config['spam']['hidden_inputs_max']);
-		$hidden_input_names_x = 0;
-
-		for ($x = 0; $x < $input_count ; $x++) {
-			if ($hidden_input_names_x === false || mt_rand(0, 2) == 0) {
-				// Use an obscure name
-				$name = $this->randomString(mt_rand(10, 40), false, false, $config['spam']['unicode']);
-			} else {
-				// Use a pre-defined confusing name
-				$name = $config['spam']['hidden_input_names'][$hidden_input_names_x++];
-				if ($hidden_input_names_x >= count($config['spam']['hidden_input_names'])) {
-					$hidden_input_names_x = false;
-				}
-			}
-
-			if (mt_rand(0, 2) == 0) {
-				// Value must be null
-				$this->inputs[$name] = '';
-			} elseif (mt_rand(0, 4) == 0) {
-				// Numeric value
-				$this->inputs[$name] = (string)mt_rand(0, 100000);
-			} else {
-				// Obscure value
-				$this->inputs[$name] = $this->randomString(mt_rand(5, 100), true, true, $config['spam']['unicode']);
-			}
-		}
-	}
-
-	public static function space() {
-		if (mt_rand(0, 3) != 0) {
-			return ' ';
-		}
-		return str_repeat(' ', mt_rand(1, 3));
-	}
-
-	public function html($count = false) {
-		$elements = [
-			'<input type="hidden" name="%name%" value="%value%">',
-			'<input type="hidden" value="%value%" name="%name%">',
-			'<input name="%name%" value="%value%" type="hidden">',
-			'<input value="%value%" name="%name%" type="hidden">',
-			'<input style="display:none" type="text" name="%name%" value="%value%">',
-			'<input style="display:none" type="text" value="%value%" name="%name%">',
-			'<span style="display:none"><input type="text" name="%name%" value="%value%"></span>',
-			'<div style="display:none"><input type="text" name="%name%" value="%value%"></div>',
-			'<div style="display:none"><input type="text" name="%name%" value="%value%"></div>',
-			'<textarea style="display:none" name="%name%">%value%</textarea>',
-			'<textarea name="%name%" style="display:none">%value%</textarea>'
-		];
-
-		$html = '';
-
-		if ($count === false) {
-			$count = mt_rand(1, (int)abs(count($this->inputs) / 15) + 1);
-		}
-
-		if ($count === true) {
-			// All elements
-			$inputs = array_slice($this->inputs, $this->index);
-		} else {
-			$inputs = array_slice($this->inputs, $this->index, $count);
-		}
-		$this->index += count($inputs);
-
-		foreach ($inputs as $name => $value) {
-			$element = false;
-			while (!$element) {
-				$element = $elements[array_rand($elements)];
-				$element = str_replace(' ', self::space(), $element);
-				if (mt_rand(0, 5) == 0) {
-					$element = str_replace('>', self::space() . '>', $element);
-				}
-				if (strpos($element, 'textarea') !== false && $value == '') {
-					// There have been some issues with mobile web browsers and empty <textarea>'s.
-					$element = false;
-				}
-			}
-
-			$element = str_replace('%name%', utf8tohtml($name), $element);
-
-			if (mt_rand(0, 2) == 0) {
-				$value = $this->make_confusing($value);
-			} else {
-				$value = utf8tohtml($value);
-			}
-
-			if (strpos($element, 'textarea') === false) {
-				$value = str_replace('"', '&quot;', $value);
-			}
-
-			$element = str_replace('%value%', $value, $element);
-
-			$html .= $element;
-		}
-
-		return $html;
-	}
-
-	public function reset() {
-		$this->index = 0;
-	}
-
-	public function hash() {
-		global $config;
-
-		// This is the tricky part: create a hash to validate it after
-		// First, sort the keys in alphabetical order (A-Z)
-		$inputs = $this->inputs;
-		ksort($inputs);
-
-		$hash = '';
-		// Iterate through each input
-		foreach ($inputs as $name => $value) {
-			$hash .= $name . '=' . $value;
-		}
-		// Add a salt to the hash
-		$hash .= $config['cookies']['salt'];
-
-		// Use SHA1 for the hash
-		return sha1($hash . $this->salt);
-	}
-}

inc/config.php

@@ -275,83 +275,6 @@
 	// To prevent bump attacks; returns the thread to last position after the last post is deleted.
 	$config['anti_bump_flood'] = false;
 
-	/*
-	 * Introduction to vichan's spam filter:
-	 *
-	 * In simple terms, whenever a posting form on a page is generated (which happens whenever a
-	 * post is made), vichan will add a random amount of hidden, obscure fields to it to
-	 * confuse bots and upset hackers. These fields and their respective obscure values are
-	 * validated upon posting with a 160-bit "hash". That hash can only be used as many times
-	 * as you specify; otherwise, flooding bots could just keep reusing the same hash.
-	 * Once a new set of inputs (and the hash) are generated, old hashes for the same thread
-	 * and board are set to expire. Because you have to reload the page to get the new set
-	 * of inputs and hash, if they expire too quickly and more than one person is viewing the
-	 * page at a given time, vichan would return false positives (depending on how long the
-	 * user sits on the page before posting). If your imageboard is quite fast/popular, set
-	 * $config['spam']['hidden_inputs_max_pass'] and $config['spam']['hidden_inputs_expire'] to
-	 * something higher to avoid false positives.
-	 *
-	 * See also: https://github.com/vichan-devel/vichan/wiki/your_request_looks_automated
-	 *
-	 */
-
-	// Number of hidden fields to generate.
-	$config['spam']['hidden_inputs_min'] = 4;
-	$config['spam']['hidden_inputs_max'] = 12;
-
-	// How many times can a "hash" be used to post?
-	$config['spam']['hidden_inputs_max_pass'] = 12;
-
-	// How soon after regeneration do hashes expire (in seconds)?
-	$config['spam']['hidden_inputs_expire'] = 60 * 60 * 3; // three hours
-
-	// Whether to use Unicode characters in hidden input names and values.
-	$config['spam']['unicode'] = true;
-
-	// These are fields used to confuse the bots. Make sure they aren't actually used by vichan, or it won't work.
-	$config['spam']['hidden_input_names'] = array(
-		'user',
-		'username',
-		'login',
-		'search',
-		'q',
-		'url',
-		'firstname',
-		'lastname',
-		'text',
-		'message'
-	);
-
-	// Always update this when adding new valid fields to the post form, or EVERYTHING WILL BE DETECTED AS SPAM!
-	$config['spam']['valid_inputs'] = array(
-		'hash',
-		'board',
-		'thread',
-		'mod',
-		'name',
-		'email',
-		'subject',
-		'post',
-		'body',
-		'password',
-		'sticky',
-		'lock',
-		'raw',
-		'embed',
-		'g-recaptcha-response',
-		'h-captcha-response',
-		'captcha_cookie',
-		'captcha_text',
-		'spoiler',
-		'page',
-		'file_url',
-		'json_response',
-		'user_flag',
-		'no_country',
-		'tag',
-		'simple_spam'
-	);
-
 	// Enable simple anti-spam measure. Requires the end-user to answer a question before making a post.
 	// Works very well against uncustomized spam. Answers are case-insensitive.
 	// $config['simple_spam'] = array (

inc/functions.php

@@ -391,12 +391,6 @@ function define_groups() {
 	ksort($config['mod']['groups']);
 }
 
-function create_antibot($board, $thread = null) {
-	require_once dirname(__FILE__) . '/anti-bot.php';
-
-	return _create_antibot($board, $thread);
-}
-
 function sprintf3($str, $vars, $delim = '%') {
 	$replaces = array();
 	foreach ($vars as $k => $v) {
@@ -1528,43 +1522,6 @@ function purge_old_antispam() {
 	return $query->rowCount();
 }
 
-function _create_antibot($board, $thread) {
-	global $config, $purged_old_antispam;
-
-	$antibot = new AntiBot([$board, $thread]);
-
-	// Delete old expired antispam, skipping those with NULL expiration timestamps (infinite lifetime).
-	if (!isset($purged_old_antispam) && $config['auto_maintenance']) {
-		$purged_old_antispam = true;
-		query('DELETE FROM ``antispam`` WHERE `expires` < UNIX_TIMESTAMP()') or error(db_error());
-	}
-
-	// Keep the now invalid timestamps around for a bit to enable users to post if they're still on an old version of
-	// the HTML page.
-	// By virtue of existing, we know that we're making a new version of the page, and the user from now on may just reload.
-	if ($thread) {
-		$query = prepare('UPDATE ``antispam`` SET `expires` = UNIX_TIMESTAMP() + :expires WHERE `board` = :board AND `thread` = :thread AND `expires` IS NULL');
-	} else {
-		$query = prepare('UPDATE ``antispam`` SET `expires` = UNIX_TIMESTAMP() + :expires WHERE `board` = :board AND `thread` IS NULL AND `expires` IS NULL');
-	}
-
-	$query->bindValue(':board', $board);
-	if ($thread) {
-		$query->bindValue(':thread', $thread);
-	}
-	$query->bindValue(':expires', $config['spam']['hidden_inputs_expire']);
-	$query->execute() or error(db_error($query));
-
-	// Insert an antispam with infinite life as the HTML page of a thread might last well beyond the expiry date.
-	$query = prepare('INSERT INTO ``antispam`` VALUES (:board, :thread, :hash, UNIX_TIMESTAMP(), NULL, 0)');
-	$query->bindValue(':board', $board);
-	$query->bindValue(':thread', $thread);
-	$query->bindValue(':hash', $antibot->hash());
-	$query->execute() or error(db_error($query));
-
-	return $antibot;
-}
-
 function checkSpam(array $extra_salt = array()) {
 	global $config, $pdo;
 
@@ -1632,7 +1589,6 @@ function buildIndex($global_api = "yes") {
 	$catalog_api_action = generation_strategy('sb_api', array($board['uri']));
 
 	$pages = null;
-	$antibot = null;
 
 	if ($config['api']['enabled']) {
 		$api = new Api(
@@ -1684,21 +1640,12 @@ function buildIndex($global_api = "yes") {
 				if ($wont_build_this_page) continue;
 			}
 
-			if ($config['try_smarter']) {
-				$antibot = create_antibot($board['uri'], 0 - $page);
-				$content['current_page'] = $page;
-			}
-			elseif (!$antibot) {
-				$antibot = create_antibot($board['uri']);
-			}
-			$antibot->reset();
 			if (!$pages) {
 				$pages = getPages();
 			}
 			$content['pages'] = $pages;
 			$content['pages'][$page-1]['selected'] = true;
 			$content['btn'] = getPageButtons($content['pages']);
-			$content['antibot'] = $antibot;
 			if ($mod) {
 				$content['pm'] = create_pm_header();
 			}
@@ -2282,7 +2229,6 @@ function buildThread($id, $return = false, $mod = false) {
 			error($config['error']['nonexistant']);
 
 		$hasnoko50 = $thread->postCount() >= $config['noko50_min'];
-		$antibot = $mod || $return ? false : create_antibot($board['uri'], $id);
 
 		$options = [
 			'board' => $board,
@@ -2293,7 +2239,6 @@ function buildThread($id, $return = false, $mod = false) {
 			'mod' => $mod,
 			'hasnoko50' => $hasnoko50,
 			'isnoko50' => false,
-			'antibot' => $antibot,
 			'boardlist' => createBoardlist($mod),
 			'return' => ($mod ? '?' . $board['url'] . $config['file_index'] : $config['root'] . $board['dir'] . $config['file_index'])
 		];
@@ -2330,20 +2275,17 @@ function buildThread($id, $return = false, $mod = false) {
 	} elseif ($action == 'rebuild') {
 		$noko50fn = $board['dir'] . $config['dir']['res'] . link_for($thread, true);
 		if ($hasnoko50 || file_exists($noko50fn)) {
-			buildThread50($id, $return, $mod, $thread, $antibot);
+			buildThread50($id, $return, $mod, $thread);
 		}
 
 		file_write($board['dir'] . $config['dir']['res'] . link_for($thread), $body);
 	}
 }
 
-function buildThread50($id, $return = false, $mod = false, $thread = null, $antibot = false) {
+function buildThread50($id, $return = false, $mod = false, $thread = null) {
 	global $board, $config;
 	$id = round($id);
 
-	if ($antibot)
-		$antibot->reset();
-
 	if (!$thread) {
 		$query = prepare(sprintf("SELECT * FROM ``posts_%s`` WHERE (`thread` IS NULL AND `id` = :id) OR `thread` = :id ORDER BY `thread`,`id` DESC LIMIT :limit", $board['uri']));
 		$query->bindValue(':id', $id, PDO::PARAM_INT);
@@ -2405,7 +2347,6 @@ function buildThread50($id, $return = false, $mod = false, $thread = null, $anti
 		'mod' => $mod,
 		'hasnoko50' => $hasnoko50,
 		'isnoko50' => true,
-		'antibot' => $mod ? false : ($antibot ? $antibot : create_antibot($board['uri'], $id)),
 		'boardlist' => createBoardlist($mod),
 		'return' => ($mod ? '?' . $board['url'] . $config['file_index'] : $config['root'] . $board['dir'] . $config['file_index'])
 	];

templates/post_form.html

@@ -1,9 +1,6 @@
 <form name="post" onsubmit="return doPost(this);" enctype="multipart/form-data" action="{{ config.post_url }}" method="post">
-{{ antibot.html() }}
 {% if id %}<input type="hidden" name="thread" value="{{ id }}">{% endif %}
-{{ antibot.html() }}
 <input type="hidden" name="board" value="{{ board.uri }}">
-{{ antibot.html() }}
 {% if current_page %}
 	<input type="hidden" name="page" value="{{ current_page }}">
 {% endif %}
@@ -12,11 +9,9 @@
 		{% if not config.field_disable_name or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri)) %}<tr>
 			<th>
 				{% trans %}Name{% endtrans %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<input type="text" name="name" size="25" maxlength="35" autocomplete="off"> {% if config.allow_no_country and config.country_flags %}<input id="no_country" name="no_country" type="checkbox"> <label for="no_country">{% trans %}Don't show my flag{% endtrans %}</label>{% endif %}
-				{{ antibot.html() }}
 			</td>
 		</tr>{% endif %}
 		{% if not config.field_disable_email or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri)) %}<tr>
@@ -26,7 +21,6 @@
 				{% else %}
 				{% trans %}Email{% endtrans %}
 				{% endif %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				{% if (mod and not post.mod|hasPermission(config.mod.bypass_field_disable, board.uri) and config.field_email_selectbox) or (not mod and config.field_email_selectbox) %}
@@ -39,17 +33,14 @@
 				{% else %}
 				<input type="text" name="email" size="25" maxlength="40" autocomplete="off">
 				{% endif %}
-				{{ antibot.html() }}
 				{% if not (not (config.field_disable_subject or (id and config.field_disable_reply_subject)) or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri))) %}
 				<input accesskey="s" style="margin-left:2px;" type="submit" name="post" value="{% if id %}{{ config.button_reply }}{% else %}{{ config.button_newtopic }}{% endif %}" />{% if config.spoiler_images %} <input id="spoiler" name="spoiler" type="checkbox"> <label for="spoiler">{% trans %}Spoiler Image{% endtrans %}</label>				{% endif %}
 				{% endif %}
-				{{ antibot.html() }}
 			</td>
 		</tr>{% endif %}
 		{% if not (config.field_disable_subject or (id and config.field_disable_reply_subject)) or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri)) %}<tr>
 			<th>
 				{% trans %}Subject{% endtrans %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<input style="float:left;" type="text" name="subject" size="25" maxlength="100" autocomplete="off">
@@ -60,11 +51,9 @@
 		<tr>
 			<th>
 				{% trans %}Comment{% endtrans %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<textarea name="body" id="body" rows="5" cols="35"></textarea>
-				{{ antibot.html() }}
 				{% if not (not (config.field_disable_subject or (id and config.field_disable_reply_subject)) or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri))) %}
 				{% if not (not config.field_disable_email or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri))) %}
 				<input accesskey="s" style="margin-left:2px;" type="submit" name="post" value="{% if id %}{{ config.button_reply }}{% else %}{{ config.button_newtopic }}{% endif %}" />{% if config.spoiler_images %} <input id="spoiler" name="spoiler" type="checkbox"> <label for="spoiler">{% trans %}Spoiler Image{% endtrans %}</label>{% endif %}
@@ -80,11 +69,9 @@
 		{% endif %}
 			<th>
 				{% trans %}Verification{% endtrans %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<div class="g-recaptcha" data-sitekey="{{ config.captcha.recaptcha.sitekey }}"></div>
-				{{ antibot.html() }}
 			</td>
 		</tr>
 		{% endif %}
@@ -92,11 +79,9 @@
 		<tr>
 			<th>
 				{% trans %}Verification{% endtrans %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<div class="h-captcha" data-sitekey="{{ config.captcha.hcaptcha.sitekey }}"></div>
-				{{ antibot.html() }}
 			</td>
 		</tr>
 		{% endif %}
@@ -173,14 +158,12 @@
 						<input style="display:inline" type="text" id="file_url" name="file_url" size="35">
 					</div>
 				{% endif %}
-				{{ antibot.html() }}
 			</td>
 		</tr>
 		{% if config.enable_embedding %}
 		<tr id="upload_embed">
 			<th>
 				{% trans %}Embed{% endtrans %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<input type="text" name="embed" value="" size="30" maxlength="120" autocomplete="off">
@@ -211,27 +194,21 @@
 		{% if not config.field_disable_password or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri)) %}<tr>
 			<th>
 				{% trans %}Password{% endtrans %}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<input type="text" name="password" value="" size="12" maxlength="18" autocomplete="off">
 				<span class="unimportant">{% trans %}(For file deletion.){% endtrans %}</span>
-				{{ antibot.html() }}
 			</td>
 		</tr>{% endif %}
 		{% if config.simple_spam and not id %}<tr>
 			<th>
 				{{ config.simple_spam.question }}
-				{{ antibot.html() }}
 			</th>
 			<td>
 				<input type="text" name="simple_spam" value="" size="12" maxlength="18" autocomplete="off">
-				{{ antibot.html() }}
 			</td>
 		</tr>{% endif %}
 	</table>
-{{ antibot.html(true) }}
-<input type="hidden" name="hash" value="{{ antibot.hash() }}">
 </form>
 
 <script type="text/javascript">{% verbatim %}