From dd0f421015059247464efd5f6d2735c5ee08a400 Mon Sep 17 00:00:00 2001
From: Michael Save <savetheinternet@tinyboard.org>
Date: Thu, 12 Apr 2012 17:20:49 +1000
Subject: [PATCH] better anti-bot check

---
 inc/anti-bot.php                              | 236 ++++++++++++++++++
 inc/functions.php                             | 161 +-----------
 inc/image.php                                 |   1 -
 .../Twig/Extensions/Extension/Tinyboard.php   |   3 +-
 templates/post_form.html                      |  51 ++--
 5 files changed, 274 insertions(+), 178 deletions(-)
 create mode 100644 inc/anti-bot.php

diff --git a/inc/anti-bot.php b/inc/anti-bot.php
new file mode 100644
index 00000000..e8c26113
--- /dev/null
+++ b/inc/anti-bot.php
@@ -0,0 +1,236 @@
+<?php
+
+/*
+ *  Copyright (c) 2010-2012 Tinyboard Development Group
+ */
+
+if(realpath($_SERVER['SCRIPT_FILENAME']) == str_replace('\\', '/', __FILE__)) {
+	// You cannot request this file directly.
+	exit;
+}
+
+$hidden_inputs_twig = array();
+
+class AntiBot {
+	public $inputs = array(), $index = 0;
+	private $salt;
+	
+	public static function randomString($length, $uppercase = false, $special_chars = false) {
+		$chars = 'abcdefghijklmnopqrstuvwxyz0123456789';
+		if($uppercase)
+			$chars .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
+		if($special_chars)
+			$chars .= ' ~!@#$%^&*()_+,./;\'[]\\{}|:"<>?=-` ';
+		
+		$chars = str_split($chars);
+		
+		$ch = array();
+		
+		// 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) {
+		$chars = str_split($string);
+		
+		foreach($chars as &$c) {
+			if(rand(0, 2) != 0)
+				continue;
+			$c = mb_encode_numericentity($c, array(0, 0xffff, 0, 0xffff), 'UTF-8');
+		}
+		
+		return implode('', $chars);
+	}
+	
+	public function __construct(array $salt = array()) {
+		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']);
+		
+		$input_count = rand($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 || rand(0, 2) == 0) {
+				// Use an obscure name
+				$name = $this->randomString(rand(10, 40));
+			} 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(rand(0, 2) == 0) {
+				// Value must be null
+				$this->inputs[$name] = '';
+			} elseif(rand(0, 4) == 0) {
+				// Numeric value
+				$this->inputs[$name] = (string)rand(0, 100);
+			} else {
+				// Obscure value
+				$this->inputs[$name] = $this->randomString(rand(5, 100));
+			}
+		}
+	}
+	
+	public function html($count = false) {
+		$elements = array(
+			'<input type="hidden" name="%name%" value="%value%">',
+			'<input type="hidden" value="%value%" name="%name%">',
+			'<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 == 0) {
+			// 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)];
+				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(rand(0, 2) == 0)
+				$value = $this->make_confusing($value);
+			else
+				$value = utf8tohtml($value);
+				
+			$element = str_replace('%value%', $value, $element);
+			
+			$html .= $element;
+		}
+		
+		return $html;
+	}
+	
+	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);
+	}
+};;
+
+
+function hiddenInputs(array $salt, $print_the_rest = false) {
+	global $hidden_inputs_twig;
+	
+	$salt_str = implode(':', $salt);
+	
+	if(!isset($hidden_inputs_twig[$salt_str]))
+		$hidden_inputs_twig[$salt_str] = new AntiBot($salt);
+	
+	if($print_the_rest)
+		return $hidden_inputs_twig[$salt_str]->html(0);
+	else
+		return $hidden_inputs_twig[$salt_str]->html(rand(1, 5));
+}
+
+function hiddenInputsHash(array $salt) {
+	global $hidden_inputs_twig;
+	
+	$salt_str = implode(':', $salt);
+	
+	if(!isset($hidden_inputs_twig[$salt_str]))
+		$hidden_inputs_twig[$salt_str] = new AntiBot($salt);
+	
+	return $hidden_inputs_twig[$salt_str]->hash();
+}
+
+function checkSpam(array $extra_salt = array()) {
+	global $config;
+	
+	if(!isset($_POST['hash']))
+		return true;
+	
+	$hash = $_POST['hash'];
+	
+	if(!empty($extra_salt)) {
+		// create a salted hash of the "extra salt"
+		$extra_salt = implode(':', $extra_salt);
+	} else { 
+		$extra_salt = '';
+	}
+	
+	// Reconsturct the $inputs array
+	$inputs = array();
+	
+	foreach($_POST as $name => $value) {
+		if(in_array($name, $config['spam']['valid_inputs']))
+			continue;
+		
+		$inputs[$name] = $value;
+	}
+	
+	// Sort the inputs in alphabetical order (A-Z)
+	ksort($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
+	$_hash = sha1($_hash . $extra_salt);
+	
+	return $hash != $_hash;
+}
+
diff --git a/inc/functions.php b/inc/functions.php
index d7fcc3dd..3761b608 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -13,6 +13,7 @@ require_once 'inc/display.php';
 require_once 'inc/template.php';
 require_once 'inc/database.php';
 require_once 'inc/events.php';
+require_once 'inc/anti-bot.php';
 require_once 'inc/lib/gettext/gettext.inc';
 
 // the user is not currently logged in as a moderator
@@ -1160,166 +1161,6 @@ function checkMute() {
 	}
 }
 
-function createHiddenInputs($extra_salt = array()) {
-	global $config;
-	
-	if(!empty($extra_salt)) {
-		// create a salted hash of the "extra salt"
-		$extra_salt = implode(':', $extra_salt);
-	} else { 
-		$extra_salt = '';
-	}
-	
-	$inputs = array();
-	
-	shuffle($config['spam']['hidden_input_names']);
-	$hidden_input_names_x = 0;
-	
-	$input_count = rand($config['spam']['hidden_inputs_min'], $config['spam']['hidden_inputs_max']);
-	for($x=0;$x<$input_count;$x++) {
-		if(rand(0, 2) == 0 || $hidden_input_names_x < 0) {
-			// Use an obscure name
-			$name = strtolower(substr(base64_encode(sha1(rand(), true)), 0, rand(2, 20)));
-			
-		} 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 = -1;
-		}
-		
-		if(rand(0, 2) == 0) {
-			// Value must be null
-			$inputs[$name] = '';
-		} elseif(rand(0, 4) == 0) {
-			// Numeric value
-			$inputs[$name] = rand(0, 100);
-		} else {
-			// Obscure value
-			$inputs[$name] = substr(base64_encode(sha1(rand(), true) . sha1(rand(), true)), 0, rand(2, 54));
-		}
-	}
-	
-	$content = '';
-	foreach($inputs as $name => $value) {
-		$display_type = rand(0, 8);
-		
-		switch($display_type) {
-			case 0:
-				$content .= '<input type="hidden" name="' . htmlspecialchars($name) . '" value="' .
-					htmlspecialchars($value) . '" />';
-				break;
-			case 1:
-				$content .= '<input style="display:none" name="' . htmlspecialchars($name) . '" value="' .
-					htmlspecialchars($value) . '" />';
-				break;
-			case 2:
-				$content .= '<input type="hidden" value="' . htmlspecialchars($value) . '" name="' .
-					htmlspecialchars($name) . '" />';
-				break;
-			case 3:
-				$content .= '<input type="hidden" name="' . htmlspecialchars($name) . '" value="' .
-					htmlspecialchars($value) . '" />';
-				break;
-			case 4:
-				$content .= '<span style="display:none"><input type="text" name="' . htmlspecialchars($name) . '" value="' .
-					htmlspecialchars($value) .'" /></span>';
-				break;
-			case 5:
-				$content .= '<div style="display:none"><input type="text" name="' . htmlspecialchars($name) . '" value="' .
-					htmlspecialchars($value) . '" /></div>';
-				break;
-			case 6:
-				if(!empty($value))
-					$content .= '<textarea style="display:none" name="' . htmlspecialchars($name) . '">' .
-						htmlspecialchars($value) . '</textarea>';
-				else
-					$content .= '<input type="hidden" name="' . htmlspecialchars($name) . '" value="' .
-						htmlspecialchars($value) . '" />';
-				break;
-			case 7:
-				if(!empty($value))
-					$content .= '<textarea name="' . htmlspecialchars($name) . '" style="display:none">' .
-						htmlspecialchars($value) . '</textarea>';
-				else
-					$content .= '<input type="hidden" name="' . htmlspecialchars($name) . '" value="' .
-						htmlspecialchars($value) . '" />';
-				break;
-			case 8:
-				$content .= '<div style="display:none"><textarea name="' . htmlspecialchars($name) . '" style="display:none">' .
-					htmlspecialchars($value) . '</textarea></div>';
-				break;
-		}
-	}
-	
-	// Create a hash to validate it after
-	// This is the tricky part.
-	
-	// First, sort the keys in alphabetical order (A-Z)
-	ksort($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
-	$hash = sha1($hash . $extra_salt);
-	
-	// Append it to the HTML
-	$content .= '<input type="hidden" name="hash" value="' . $hash . '" />';
-	
-	return $content;
-}
-
-function checkSpam($extra_salt = array()) {
-	global $config;
-	
-	if(!isset($_POST['hash']))
-		return true;
-	
-	$hash = $_POST['hash'];
-	
-	if(!empty($extra_salt)) {
-		// create a salted hash of the "extra salt"
-		$extra_salt = implode(':', $extra_salt);
-	} else { 
-		$extra_salt = '';
-	}
-	
-	// Reconsturct the $inputs array
-	$inputs = array();
-	
-	foreach($_POST as $name => $value) {
-		if(in_array($name, $config['spam']['valid_inputs']))
-			continue;
-		
-		$inputs[$name] = $value;
-	}
-	
-	// Sort the inputs in alphabetical order (A-Z)
-	ksort($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
-	$_hash = sha1($_hash . $extra_salt);
-	
-	return $hash != $_hash;
-}
 
 function buildIndex() {
 	global $board, $config;
diff --git a/inc/image.php b/inc/image.php
index f6bc3e7c..d1c292dc 100644
--- a/inc/image.php
+++ b/inc/image.php
@@ -194,7 +194,6 @@ class ImageImagick extends ImageBase {
 			foreach($this->original as $frame) {
 				$delay += $frame->getImageDelay();
 				
-				//if($i < $config['thumb_keep_animation_frames']) {
 				if(in_array($i, $keep_frames)) {
 					// $frame->scaleImage($this->width, $this->height, false);
 					$frame->sampleImage($this->width, $this->height);
diff --git a/inc/lib/Twig/Extensions/Extension/Tinyboard.php b/inc/lib/Twig/Extensions/Extension/Tinyboard.php
index 0cf7705a..7e2149e5 100644
--- a/inc/lib/Twig/Extensions/Extension/Tinyboard.php
+++ b/inc/lib/Twig/Extensions/Extension/Tinyboard.php
@@ -35,7 +35,8 @@ class Twig_Extensions_Extension_Tinyboard extends Twig_Extension
 		return Array(
 			'time' => new Twig_Filter_Function('time', array('needs_environment' => false)),
 			'timezone' => new Twig_Filter_Function('twig_timezone_function', array('needs_environment' => false)),
-			'createHiddenInputs' => new Twig_Filter_Function('createHiddenInputs', array('needs_environment' => false))
+			'hiddenInputs' => new Twig_Filter_Function('hiddenInputs', array('needs_environment' => false)),
+			'hiddenInputsHash' => new Twig_Filter_Function('hiddenInputsHash', array('needs_environment' => false))
 		);
 	}
 	
diff --git a/templates/post_form.html b/templates/post_form.html
index 1ac1dfcf..69b179fd 100644
--- a/templates/post_form.html
+++ b/templates/post_form.html
@@ -1,49 +1,60 @@
 <form name="post" onsubmit="return dopost(this);" enctype="multipart/form-data" action="{{ config.post_url }}" method="post">
-{{ createHiddenInputs([board.uri, id]) }}
-{% if id %}<input type="hidden" name="thread" value="{{ id }}" />{% endif %}
-<input type="hidden" name="board" value="{{ board.uri }}" />
-{% if mod %}<input type="hidden" name="mod" value="1" />{% endif %}
+{{ hiddenInputs([board.uri, id]) }}
+{% if id %}<input type="hidden" name="thread" value="{{ id }}">{% endif %}
+{{ hiddenInputs([board.uri, id]) }}
+<input type="hidden" name="board" value="{{ board.uri }}">
+{{ hiddenInputs([board.uri, id]) }}
+{% if mod %}<input type="hidden" name="mod" value="1">{% endif %}
 	<table>
 		{% if not config.field_disable_name or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri)) %}<tr>
 			<th>
 				{% trans %}Name{% endtrans %}
+				{{ hiddenInputs([board.uri, id]) }}
 			</th>
 			<td>
-				<input type="text" name="name" size="25" maxlength="50" autocomplete="off" />
+				<input type="text" name="name" size="25" maxlength="50" autocomplete="off">
+				{{ hiddenInputs([board.uri, id]) }}
 			</td>
 		</tr>{% endif %}
 		{% if not config.field_disable_email or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri)) %}<tr>
 			<th>
 				{% trans %}Email{% endtrans %}
+				{{ hiddenInputs([board.uri, id]) }}
 			</th>
 			<td>
-				<input type="text" name="email" size="25" maxlength="40" autocomplete="off" />
+				<input type="text" name="email" size="25" maxlength="40" autocomplete="off">
+				{{ hiddenInputs([board.uri, id]) }}
 			</td>
 		</tr>{% endif %}
 		<tr>
 			<th>
 				{% trans %}Subject{% endtrans %}
+				{{ hiddenInputs([board.uri, id]) }}
 			</th>
 			<td>
-				<input style="float:left;" type="text" name="subject" size="25" maxlength="100" autocomplete="off" />
-				<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 %}
+				<input style="float:left;" type="text" name="subject" size="25" maxlength="100" autocomplete="off">
+				<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 %}
 			</td>
 		</tr>
 		<tr>
 			<th>
 				{% trans %}Comment{% endtrans %}
+				{{ hiddenInputs([board.uri, id]) }}
 			</th>
 			<td>
 				<textarea name="body" id="body" rows="5" cols="35"></textarea>
+				{{ hiddenInputs([board.uri, id]) }}
 			</td>
 		</tr>
 		{% if config.recaptcha %}
 		<tr>
 			<th>
 				{% trans %}Verification{% endtrans %}
+				{{ hiddenInputs([board.uri, id]) }}
 			</th>
 			<td>
 				<script type="text/javascript" src="http://www.google.com/recaptcha/api/challenge?k={{ config.recaptcha_public }}"></script>
+				{{ hiddenInputs([board.uri, id]) }}
 			</td>
 		</tr>
 		{% endif %}
@@ -52,16 +63,19 @@
 				{% trans %}File{% endtrans %}
 			</th>
 			<td>
-				<input type="file" name="file" />
+				<input type="file" name="file">
+				{{ hiddenInputs([board.uri, id]) }}
 			</td>
 		</tr>
 		{% if config.enable_embedding %}
 		<tr>
 			<th>
 				{% trans %}Embed{% endtrans %}
+				{{ hiddenInputs([board.uri, id]) }}
 			</th>
 			<td>
-				<input type="text" name="embed" size="30" maxlength="120" autocomplete="off" />
+				<input type="text" name="embed" size="30" maxlength="120" autocomplete="off">
+				{{ hiddenInputs([board.uri, id]) }}
 			</td>
 		</tr>
 		{% endif %}
@@ -73,15 +87,15 @@
 			<td>
 				{% if not id and post.mod|hasPermission(config.mod.sticky, board.uri) %}<div>
 					<label for="sticky">{% trans %}Sticky{% endtrans %}</label>
-					<input title="{% trans %}Sticky{% endtrans %}" type="checkbox" name="sticky" id="sticky" /><br />
+					<input title="{% trans %}Sticky{% endtrans %}" type="checkbox" name="sticky" id="sticky"><br>
 				</div>{% endif %}
 				{% if not id and post.mod|hasPermission(config.mod.lock, board.uri) %}<div>
-					<label for="lock">{% trans %}Lock{% endtrans %}</label><br />
-					<input title="{% trans %}Lock{% endtrans %}" type="checkbox" name="lock" id="lock" />
+					<label for="lock">{% trans %}Lock{% endtrans %}</label><br>
+					<input title="{% trans %}Lock{% endtrans %}" type="checkbox" name="lock" id="lock">
 				</div>{% endif %}
 				{% if post.mod|hasPermission(config.mod.rawhtml, board.uri) %}<div>
-					<label for="raw">{% trans %}Raw HTML{% endtrans %}</label><br />
-					<input title="{% trans %}Raw HTML{% endtrans %}" type="checkbox" name="raw" id="raw" />
+					<label for="raw">{% trans %}Raw HTML{% endtrans %}</label><br>
+					<input title="{% trans %}Raw HTML{% endtrans %}" type="checkbox" name="raw" id="raw">
 				</div>{% endif %}
 			</td>
 		</tr>
@@ -89,13 +103,18 @@
 		{% if not config.field_disable_password or (mod and post.mod|hasPermission(config.mod.bypass_field_disable, board.uri)) %}<tr>
 			<th>
 				{% trans %}Password{% endtrans %}
+				{{ hiddenInputs([board.uri, id]) }}
 			</th>
 			<td>
-				<input type="password" name="password" size="12" maxlength="18" autocomplete="off" /> 
+				<input type="password" name="password" size="12" maxlength="18" autocomplete="off"> 
 				<span class="unimportant">{% trans %}(For file deletion.){% endtrans %}</span>
+				{{ hiddenInputs([board.uri, id]) }}
 			</td>
 		</tr>{% endif %}
 	</table>
+{{ hiddenInputs([board.uri, id]) }}
+<input type="hidden" name="hash" value="{{ hiddenInputsHash([board.uri, id]) }}">
+{{ hiddenInputs([board.uri, id], true) }}
 </form>
 
 <script type="text/javascript">{% raw %}