Merge branch develop of github.com:/EllisLab/CodeIgniter into session

1 files changed, 225 insertions, 259 deletions

diff --git a/system/core/Security.php b/system/core/Security.php
index e99418bdd..b22d2cf19 100755..100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -1,27 +1,37 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.1.6 or newer
+ * An open source application development framework for PHP 5.2.4 or newer
+ *
+ * NOTICE OF LICENSE
+ *
+ * Licensed under the Open Software License version 3.0
+ *
+ * This source file is subject to the Open Software License (OSL 3.0) that is
+ * bundled with this package in the files license.txt / license.rst.  It is
+ * also available through the world wide web at this URL:
+ * http://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to obtain it
+ * through the world wide web, please send an email to
+ * licensing@ellislab.com so we can send you a copy immediately.
  *
  * @package		CodeIgniter
- * @author		ExpressionEngine Dev Team
- * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
- * @license		http://codeigniter.com/user_guide/license.html
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
  * @since		Version 1.0
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * Security Class
  *
  * @package		CodeIgniter
  * @subpackage	Libraries
  * @category	Security
- * @author		ExpressionEngine Dev Team
+ * @author		EllisLab Dev Team
  * @link		http://codeigniter.com/user_guide/libraries/security.html
  */
 class CI_Security {
@@ -30,99 +40,99 @@ class CI_Security {
 	 * Random Hash for protecting URLs
 	 *
 	 * @var string
-	 * @access protected
 	 */
-	protected $_xss_hash			= '';
-	
+	protected $_xss_hash =	'';
+
 	/**
 	 * Random Hash for Cross Site Request Forgery Protection Cookie
 	 *
 	 * @var string
-	 * @access protected
 	 */
-	protected $_csrf_hash			= '';
-	
+	protected $_csrf_hash =	'';
+
 	/**
 	 * Expiration time for Cross Site Request Forgery Protection Cookie
 	 * Defaults to two hours (in seconds)
 	 *
 	 * @var int
-	 * @access protected
 	 */
-	protected $_csrf_expire			= 7200;
-	
+	protected $_csrf_expire =	7200;
+
 	/**
 	 * Token name for Cross Site Request Forgery Protection Cookie
 	 *
 	 * @var string
-	 * @access protected
 	 */
-	protected $_csrf_token_name		= 'ci_csrf_token';
-	
+	protected $_csrf_token_name =	'ci_csrf_token';
+
 	/**
 	 * Cookie name for Cross Site Request Forgery Protection Cookie
 	 *
 	 * @var string
-	 * @access protected
 	 */
-	protected $_csrf_cookie_name	= 'ci_csrf_token';
-	
+	protected $_csrf_cookie_name =	'ci_csrf_token';
+
 	/**
 	 * List of never allowed strings
 	 *
 	 * @var array
-	 * @access protected
 	 */
-	
-	protected $_never_allowed_str = array(
-					'document.cookie'	=> '[removed]',
-					'document.write'	=> '[removed]',
-					'.parentNode'		=> '[removed]',
-					'.innerHTML'		=> '[removed]',
-					'window.location'	=> '[removed]',
-					'-moz-binding'		=> '[removed]',
-					'<!--'				=> '&lt;!--',
-					'-->'				=> '--&gt;',
-					'<![CDATA['			=> '&lt;![CDATA['
+	protected $_never_allowed_str =	array(
+		'document.cookie'	=> '[removed]',
+		'document.write'	=> '[removed]',
+		'.parentNode'		=> '[removed]',
+		'.innerHTML'		=> '[removed]',
+		'window.location'	=> '[removed]',
+		'-moz-binding'		=> '[removed]',
+		'<!--'				=> '&lt;!--',
+		'-->'				=> '--&gt;',
+		'<![CDATA['			=> '&lt;![CDATA[',
+		'<comment>'			=> '&lt;comment&gt;'
 	);
 
 	/**
 	 * List of never allowed regex replacement
 	 *
 	 * @var array
-	 * @access protected
 	 */
 	protected $_never_allowed_regex = array(
-					"javascript\s*:"			=> '[removed]',
-					"expression\s*(\(|&\#40;)"	=> '[removed]', // CSS and IE
-					"vbscript\s*:"				=> '[removed]', // IE, surprise!
-					"Redirect\s+302"			=> '[removed]'
+		'javascript\s*:',
+		'expression\s*(\(|&\#40;)', // CSS and IE
+		'vbscript\s*:', // IE, surprise!
+		'Redirect\s+302',
+		"([\"'])?data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?"
 	);
 
 	/**
-	 * Constructor
+	 * Initialize security class
+	 *
+	 * @return	void
 	 */
 	public function __construct()
 	{
-		// CSRF config
-		foreach(array('csrf_expire', 'csrf_token_name', 'csrf_cookie_name') as $key)
+		// Is CSRF protection enabled?
+		if (config_item('csrf_protection') === TRUE)
 		{
-			if (FALSE !== ($val = config_item($key)))
+			// CSRF config
+			foreach (array('csrf_expire', 'csrf_token_name', 'csrf_cookie_name') as $key)
 			{
-				$this->{'_'.$key} = $val;
+				if (FALSE !== ($val = config_item($key)))
+				{
+					$this->{'_'.$key} = $val;
+				}
 			}
-		}
 
-		// Append application specific cookie prefix
-		if (config_item('cookie_prefix'))
-		{
-			$this->_csrf_cookie_name = config_item('cookie_prefix').$this->_csrf_cookie_name;
-		}
+			// Append application specific cookie prefix
+			if (config_item('cookie_prefix'))
+			{
+				$this->_csrf_cookie_name = config_item('cookie_prefix').$this->_csrf_cookie_name;
+			}
 
-		// Set the CSRF hash
-		$this->_csrf_set_hash();
+			// Set the CSRF hash
+			$this->_csrf_set_hash();
+		}
 
-		log_message('debug', "Security Class Initialized");
+		log_message('debug', 'Security Class Initialized');
 	}
 
 	// --------------------------------------------------------------------
@@ -134,12 +144,12 @@ class CI_Security {
 	 */
 	public function csrf_verify()
 	{
-		// If no POST data exists we will set the CSRF cookie
-		if (count($_POST) == 0)
+		// If it's not a POST request we will set the CSRF cookie
+		if (strtoupper($_SERVER['REQUEST_METHOD']) !== 'POST')
 		{
 			return $this->csrf_set_cookie();
 		}
-		
+
 		// Check if URI has been whitelisted from CSRF checks
 		if ($exclude_uris = config_item('csrf_exclude_uris'))
 		{
@@ -151,29 +161,27 @@ class CI_Security {
 		}
 
 		// Do the tokens exist in both the _POST and _COOKIE arrays?
-		if ( ! isset($_POST[$this->_csrf_token_name]) OR
-			 ! isset($_COOKIE[$this->_csrf_cookie_name]))
+		if ( ! isset($_POST[$this->_csrf_token_name]) OR ! isset($_COOKIE[$this->_csrf_cookie_name])
+			OR $_POST[$this->_csrf_token_name] !== $_COOKIE[$this->_csrf_cookie_name]) // Do the tokens match?
 		{
 			$this->csrf_show_error();
 		}
 
-		// Do the tokens match?
-		if ($_POST[$this->_csrf_token_name] != $_COOKIE[$this->_csrf_cookie_name])
+		// We kill this since we're done and we don't want to polute the _POST array
+		unset($_POST[$this->_csrf_token_name]);
+
+		// Regenerate on every submission?
+		if (config_item('csrf_regenerate'))
 		{
-			$this->csrf_show_error();
+			// Nothing should last forever
+			unset($_COOKIE[$this->_csrf_cookie_name]);
+			$this->_csrf_hash = '';
 		}
 
-		// We kill this since we're done and we don't want to
-		// polute the _POST array
-		unset($_POST[$this->_csrf_token_name]);
-
-		// Nothing should last forever
-		unset($_COOKIE[$this->_csrf_cookie_name]);
 		$this->_csrf_set_hash();
 		$this->csrf_set_cookie();
-		
-		log_message('debug', "CSRF token verified");
-		
+
+		log_message('debug', 'CSRF token verified');
 		return $this;
 	}
 
@@ -183,25 +191,28 @@ class CI_Security {
 	 * Set Cross Site Request Forgery Protection Cookie
 	 *
 	 * @return	object
+	 * @codeCoverageIgnore
 	 */
 	public function csrf_set_cookie()
 	{
 		$expire = time() + $this->_csrf_expire;
-		$secure_cookie = (config_item('cookie_secure') === TRUE) ? 1 : 0;
+		$secure_cookie = (bool) config_item('cookie_secure');
 
-		if ($secure_cookie)
+		if ($secure_cookie && (empty($_SERVER['HTTPS']) OR strtolower($_SERVER['HTTPS']) === 'off'))
 		{
-			$req = isset($_SERVER['HTTPS']) ? $_SERVER['HTTPS'] : FALSE;
-
-			if ( ! $req OR $req == 'off')
-			{
-				return FALSE;
-			}
+			return FALSE;
 		}
 
-		setcookie($this->_csrf_cookie_name, $this->_csrf_hash, $expire, config_item('cookie_path'), config_item('cookie_domain'), $secure_cookie);
-
-		log_message('debug', "CRSF cookie Set");
+		setcookie(
+			$this->_csrf_cookie_name,
+			$this->_csrf_hash,
+			$expire,
+			config_item('cookie_path'),
+			config_item('cookie_domain'),
+			$secure_cookie,
+			config_item('cookie_httponly')
+		);
+		log_message('debug', 'CRSF cookie Set');
 
 		return $this;
 	}
@@ -239,7 +250,7 @@ class CI_Security {
 	 *
 	 * Getter Method
 	 *
-	 * @return 	string 	self::csrf_token_name
+	 * @return 	string 	self::_csrf_token_name
 	 */
 	public function get_csrf_token_name()
 	{
@@ -259,7 +270,7 @@ class CI_Security {
 	 * the filter.
 	 *
 	 * Note: This function should only be used to deal with data
-	 * upon submission.  It's not something that should
+	 * upon submission. It's not something that should
 	 * be used for general runtime processing.
 	 *
 	 * This function was based in part on some code and ideas I
@@ -276,10 +287,7 @@ class CI_Security {
 	 */
 	public function xss_clean($str, $is_image = FALSE)
 	{
-		/*
-		 * Is the string an array?
-		 *
-		 */
+		// Is the string an array?
 		if (is_array($str))
 		{
 			while (list($key) = each($str))
@@ -290,13 +298,8 @@ class CI_Security {
 			return $str;
 		}
 
-		/*
-		 * Remove Invisible Characters
-		 */
-		$str = remove_invisible_characters($str);
-
-		// Validate Entities in URLs
-		$str = $this->_validate_entities($str);
+		// Remove Invisible Characters and validate entities in URLs
+		$str = $this->_validate_entities(remove_invisible_characters($str));
 
 		/*
 		 * URL Decode
@@ -306,7 +309,6 @@ class CI_Security {
 		 * <a href="http://%77%77%77%2E%67%6F%6F%67%6C%65%2E%63%6F%6D">Google</a>
 		 *
 		 * Note: Use rawurldecode() so it does not remove plus signs
-		 *
 		 */
 		$str = rawurldecode($str);
 
@@ -316,16 +318,11 @@ class CI_Security {
 		 * This permits our tests below to work reliably.
 		 * We only convert entities that are within tags since
 		 * these are the ones that will pose security problems.
-		 *
 		 */
-
 		$str = preg_replace_callback("/[a-z]+=([\'\"]).*?\\1/si", array($this, '_convert_attribute'), $str);
+		$str = preg_replace_callback('/<\w+.*?(?=>|<|$)/si', array($this, '_decode_entity'), $str);
 
-		$str = preg_replace_callback("/<\w+.*?(?=>|<|$)/si", array($this, '_decode_entity'), $str);
-
-		/*
-		 * Remove Invisible Characters Again!
-		 */
+		// Remove Invisible Characters Again!
 		$str = remove_invisible_characters($str);
 
 		/*
@@ -336,15 +333,9 @@ class CI_Security {
 		 * NOTE: preg_replace was found to be amazingly slow here on
 		 * large blocks of data, so we use str_replace.
 		 */
+		$str = str_replace("\t", ' ', $str);
 
-		if (strpos($str, "\t") !== FALSE)
-		{
-			$str = str_replace("\t", ' ', $str);
-		}
-
-		/*
-		 * Capture converted string for later comparison
-		 */
+		// Capture converted string for later comparison
 		$converted_string = $str;
 
 		// Remove Strings that are never allowed
@@ -364,7 +355,7 @@ class CI_Security {
 			// Images have a tendency to have the PHP short opening and
 			// closing tags every so often so we skip those and only
 			// do the long opening tags.
-			$str = preg_replace('/<\?(php)/i', "&lt;?\\1", $str);
+			$str = preg_replace('/<\?(php)/i', '&lt;?\\1', $str);
 		}
 		else
 		{
@@ -378,22 +369,18 @@ class CI_Security {
 		 * These words are compacted back to their correct state.
 		 */
 		$words = array(
-				'javascript', 'expression', 'vbscript', 'script',
-				'applet', 'alert', 'document', 'write', 'cookie', 'window'
-			);
+			'javascript', 'expression', 'vbscript', 'script', 'base64',
+			'applet', 'alert', 'document', 'write', 'cookie', 'window'
+		);
+
 
 		foreach ($words as $word)
 		{
-			$temp = '';
-
-			for ($i = 0, $wordlen = strlen($word); $i < $wordlen; $i++)
-			{
-				$temp .= substr($word, $i, 1)."\s*";
-			}
+			$word = implode('\s*', str_split($word)).'\s*';
 
 			// We only want to do this when it is followed by a non-word character
 			// That way valid stuff like "dealer to" does not become "dealerto"
-			$str = preg_replace_callback('#('.substr($temp, 0, -3).')(\W)#is', array($this, '_compact_exploded_words'), $str);
+			$str = preg_replace_callback('#('.substr($word, 0, -3).')(\W)#is', array($this, '_compact_exploded_words'), $str);
 		}
 
 		/*
@@ -406,22 +393,22 @@ class CI_Security {
 		{
 			$original = $str;
 
-			if (preg_match("/<a/i", $str))
+			if (preg_match('/<a/i', $str))
 			{
-				$str = preg_replace_callback("#<a\s+([^>]*?)(>|$)#si", array($this, '_js_link_removal'), $str);
+				$str = preg_replace_callback('#<a\s+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
 			}
 
-			if (preg_match("/<img/i", $str))
+			if (preg_match('/<img/i', $str))
 			{
-				$str = preg_replace_callback("#<img\s+([^>]*?)(\s?/?>|$)#si", array($this, '_js_img_removal'), $str);
+				$str = preg_replace_callback('#<img\s+([^>]*?)(?:\s?/?>|$)#si', array($this, '_js_img_removal'), $str);
 			}
 
-			if (preg_match("/script/i", $str) OR preg_match("/xss/i", $str))
+			if (preg_match('/script|xss/i', $str))
 			{
-				$str = preg_replace("#<(/*)(script|xss)(.*?)\>#si", '[removed]', $str);
+				$str = preg_replace('#</*(?:script|xss).*?>#si', '[removed]', $str);
 			}
 		}
-		while($original != $str);
+		while ($original !== $str);
 
 		unset($original);
 
@@ -445,15 +432,16 @@ class CI_Security {
 		 *
 		 * Similar to above, only instead of looking for
 		 * tags it looks for PHP and JavaScript commands
-		 * that are disallowed.  Rather than removing the
+		 * that are disallowed. Rather than removing the
 		 * code, it simply converts the parenthesis to entities
 		 * rendering the code un-executable.
 		 *
 		 * For example:	eval('some code')
-		 * Becomes:		eval&#40;'some code'&#41;
+		 * Becomes:	eval&#40;'some code'&#41;
 		 */
-		$str = preg_replace('#(alert|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si', "\\1\\2&#40;\\3&#41;", $str);
-
+		$str = preg_replace('#(alert|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si',
+					'\\1\\2&#40;\\3&#41;',
+					$str);
 
 		// Final clean up
 		// This adds a bit of extra precaution in case
@@ -469,13 +457,12 @@ class CI_Security {
 		 * string post-removal of XSS, then it fails, as there was unwanted XSS
 		 * code found and removed/changed during processing.
 		 */
-
 		if ($is_image === TRUE)
 		{
-			return ($str == $converted_string) ? TRUE: FALSE;
+			return ($str === $converted_string);
 		}
 
-		log_message('debug', "XSS Filtering completed");
+		log_message('debug', 'XSS Filtering completed');
 		return $str;
 	}
 
@@ -488,17 +475,9 @@ class CI_Security {
 	 */
 	public function xss_hash()
 	{
-		if ($this->_xss_hash == '')
+		if ($this->_xss_hash === '')
 		{
-			if (phpversion() >= 4.2)
-			{
-				mt_srand();
-			}
-			else
-			{
-				mt_srand(hexdec(substr(md5(microtime()), -8)) & 0x7fffffff);
-			}
-
+			mt_srand();
 			$this->_xss_hash = md5(time() + mt_rand(0, 1999999999));
 		}
 
@@ -512,14 +491,11 @@ class CI_Security {
 	 *
 	 * This function is a replacement for html_entity_decode()
 	 *
-	 * In some versions of PHP the native function does not work
-	 * when UTF-8 is the specified character set, so this gives us
-	 * a work-around.  More info here:
-	 * http://bugs.php.net/bug.php?id=25670
-	 *
-	 * NOTE: html_entity_decode() has a bug in some PHP versions when UTF-8 is the
-	 * character set, and the PHP developers said they were not back porting the
-	 * fix to versions other than PHP 5.x.
+	 * The reason we are not using html_entity_decode() by itself is because
+	 * while it is not technically correct to leave out the semicolon
+	 * at the end of an entity most browsers will still interpret the entity
+	 * correctly. html_entity_decode() does not convert entities without
+	 * semicolons, so we are left with our own little solution here. Bummer.
 	 *
 	 * @param	string
 	 * @param	string
@@ -527,41 +503,19 @@ class CI_Security {
 	 */
 	public function entity_decode($str, $charset = NULL)
 	{
-		if (stristr($str, '&') === FALSE)
+		if (strpos($str, '&') === FALSE)
 		{
 			return $str;
 		}
-		
+
 		if (empty($charset))
 		{
 			$charset = config_item('charset');
 		}
 
-		// The reason we are not using html_entity_decode() by itself is because
-		// while it is not technically correct to leave out the semicolon
-		// at the end of an entity most browsers will still interpret the entity
-		// correctly.  html_entity_decode() does not convert entities without
-		// semicolons, so we are left with our own little solution here. Bummer.
-
-		if (function_exists('html_entity_decode') &&
-			(strtolower($charset) != 'utf-8'))
-		{
-			$str = html_entity_decode($str, ENT_COMPAT, $charset);
-			$str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str);
-			return preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str);
-		}
-
-		// Numeric Entities
-		$str = preg_replace('~&#x(0*[0-9a-f]{2,5});{0,1}~ei', 'chr(hexdec("\\1"))', $str);
-		$str = preg_replace('~&#([0-9]{2,4});{0,1}~e', 'chr(\\1)', $str);
-
-		// Literal Entities - Slightly slow so we do another check
-		if (stristr($str, '&') === FALSE)
-		{
-			$str = strtr($str, array_flip(get_html_translation_table(HTML_ENTITIES)));
-		}
-
-		return $str;
+		$str = html_entity_decode($str, ENT_COMPAT, $charset);
+		$str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str);
+		return preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str);
 	}
 
 	// --------------------------------------------------------------------
@@ -576,38 +530,23 @@ class CI_Security {
 	public function sanitize_filename($str, $relative_path = FALSE)
 	{
 		$bad = array(
-						"../",
-						"<!--",
-						"-->",
-						"<",
-						">",
-						"'",
-						'"',
-						'&',
-						'$',
-						'#',
-						'{',
-						'}',
-						'[',
-						']',
-						'=',
-						';',
-						'?',
-						"%20",
-						"%22",
-						"%3c",		// <
-						"%253c",	// <
-						"%3e",		// >
-						"%0e",		// >
-						"%28",		// (
-						"%29",		// )
-						"%2528",	// (
-						"%26",		// &
-						"%24",		// $
-						"%3f",		// ?
-						"%3b",		// ;
-						"%3d"		// =
-					);
+			'../', '<!--', '-->', '<', '>',
+			"'", '"', '&', '$', '#',
+			'{', '}', '[', ']', '=',
+			';', '?', '%20', '%22',
+			'%3c',		// <
+			'%253c',	// <
+			'%3e',		// >
+			'%0e',		// >
+			'%28',		// (
+			'%29',		// )
+			'%2528',	// (
+			'%26',		// &
+			'%24',		// $
+			'%3f',		// ?
+			'%3b',		// ;
+			'%3d'		// =
+		);
 
 		if ( ! $relative_path)
 		{
@@ -622,13 +561,26 @@ class CI_Security {
 	// ----------------------------------------------------------------
 
 	/**
+	 * Strip Image Tags
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	public function strip_image_tags($str)
+	{
+		return preg_replace(array('#<img\s+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img\s+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
+	}
+
+	// ----------------------------------------------------------------
+
+	/**
 	 * Compact Exploded Words
 	 *
 	 * Callback function for xss_clean() to remove whitespace from
 	 * things like j a v a s c r i p t
 	 *
-	 * @param	type
-	 * @return	type
+	 * @param	array
+	 * @return	string
 	 */
 	protected function _compact_exploded_words($matches)
 	{
@@ -637,8 +589,8 @@ class CI_Security {
 
 	// --------------------------------------------------------------------
 
-	/*
-	 * Remove Evil HTML Attributes (like evenhandlers and style)
+	/**
+	 * Remove Evil HTML Attributes (like event handlers and style)
 	 *
 	 * It removes the evil attribute and either:
 	 * 	- Everything up until a space
@@ -655,7 +607,7 @@ class CI_Security {
 	protected function _remove_evil_attributes($str, $is_image)
 	{
 		// All javascript event handlers (e.g. onload, onclick, onmouseover), style, and xmlns
-		$evil_attributes = array('on\w*', 'style', 'xmlns');
+		$evil_attributes = array('on\w*', 'style', 'xmlns', 'formaction');
 
 		if ($is_image === TRUE)
 		{
@@ -667,11 +619,32 @@ class CI_Security {
 		}
 
 		do {
-			$str = preg_replace(
-				"#<(/?[^><]+?)([^A-Za-z\-])(".implode('|', $evil_attributes).")(\s*=\s*)([\"][^>]*?[\"]|[\'][^>]*?[\']|[^>]*?)([\s><])([><]*)#i",
-				"<$1$6",
-				$str, -1, $count
-			);
+			$count = 0;
+			$attribs = array();
+
+			// find occurrences of illegal attribute strings without quotes
+			preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', $str, $matches, PREG_SET_ORDER);
+
+			foreach ($matches as $attr)
+			{
+
+				$attribs[] = preg_quote($attr[0], '/');
+			}
+
+			// find occurrences of illegal attribute strings with quotes (042 and 047 are octal quotes)
+			preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is', $str, $matches, PREG_SET_ORDER);
+
+			foreach ($matches as $attr)
+			{
+				$attribs[] = preg_quote($attr[0], '/');
+			}
+
+			// replace illegal attribute strings that are inside an html tag
+			if (count($attribs) > 0)
+			{
+				$str = preg_replace('/<(\/?[^><]+?)([^A-Za-z<>\-])(.*?)('.implode('|', $attribs).')(.*?)([\s><])([><]*)/i', '<$1 $3$5$6$7', $str, -1, $count);
+			}
+
 		} while ($count);
 
 		return $str;
@@ -689,14 +662,9 @@ class CI_Security {
 	 */
 	protected function _sanitize_naughty_html($matches)
 	{
-		// encode opening brace
-		$str = '&lt;'.$matches[1].$matches[2].$matches[3];
-
-		// encode captured opening or closing brace to prevent recursive vectors
-		$str .= str_replace(array('>', '<'), array('&gt;', '&lt;'),
-							$matches[4]);
-
-		return $str;
+		return '&lt;'.$matches[1].$matches[2].$matches[3] // encode opening brace
+			// encode captured opening or closing brace to prevent recursive vectors:
+			.str_replace(array('>', '<'), array('&gt;', '&lt;'), $matches[4]);
 	}
 
 	// --------------------------------------------------------------------
@@ -714,9 +682,12 @@ class CI_Security {
 	 */
 	protected function _js_link_removal($match)
 	{
-		$attributes = $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]));
-
-		return str_replace($match[1], preg_replace("#href=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si", "", $attributes), $match[0]);
+		return str_replace($match[1],
+					preg_replace('#href=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|data\s*:)#si',
+							'',
+							$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
+					),
+					$match[0]);
 	}
 
 	// --------------------------------------------------------------------
@@ -734,9 +705,12 @@ class CI_Security {
 	 */
 	protected function _js_img_removal($match)
 	{
-		$attributes = $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]));
-
-		return str_replace($match[1], preg_replace("#src=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si", "", $attributes), $match[0]);
+		return str_replace($match[1],
+					preg_replace('#src=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
+							'',
+							$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
+					),
+					$match[0]);
 	}
 
 	// --------------------------------------------------------------------
@@ -767,12 +741,11 @@ class CI_Security {
 	protected function _filter_attributes($str)
 	{
 		$out = '';
-
 		if (preg_match_all('#\s*[a-z\-]+\s*=\s*(\042|\047)([^\\1]*?)\\1#is', $str, $matches))
 		{
 			foreach ($matches[0] as $match)
 			{
-				$out .= preg_replace("#/\*.*?\*/#s", '', $match);
+				$out .= preg_replace('#/\*.*?\*/#s', '', $match);
 			}
 		}
 
@@ -810,33 +783,28 @@ class CI_Security {
 		 * Protect GET variables in URLs
 		 */
 
-		 // 901119URL5918AMP18930PROTECT8198
-
-		$str = preg_replace('|\&([a-z\_0-9\-]+)\=([a-z\_0-9\-]+)|i', $this->xss_hash()."\\1=\\2", $str);
+		// 901119URL5918AMP18930PROTECT8198
+		$str = preg_replace('|\&([a-z\_0-9\-]+)\=([a-z\_0-9\-]+)|i', $this->xss_hash().'\\1=\\2', $str);
 
 		/*
 		 * Validate standard character entities
 		 *
 		 * Add a semicolon if missing.  We do this to enable
 		 * the conversion of entities to ASCII later.
-		 *
 		 */
-		$str = preg_replace('#(&\#?[0-9a-z]{2,})([\x00-\x20])*;?#i', "\\1;\\2", $str);
+		$str = preg_replace('#(&\#?[0-9a-z]{2,})([\x00-\x20])*;?#i', '\\1;\\2', $str);
 
 		/*
 		 * Validate UTF16 two byte encoding (x00)
 		 *
 		 * Just as above, adds a semicolon if missing.
-		 *
 		 */
-		$str = preg_replace('#(&\#x?)([0-9A-F]+);?#i',"\\1\\2;",$str);
+		$str = preg_replace('#(&\#x?)([0-9A-F]+);?#i', '\\1\\2;', $str);
 
 		/*
 		 * Un-Protect GET variables in URLs
 		 */
-		$str = str_replace($this->xss_hash(), '&', $str);
-
-		return $str;
+		return str_replace($this->xss_hash(), '&', $str);
 	}
 
 	// ----------------------------------------------------------------------
@@ -851,14 +819,11 @@ class CI_Security {
 	 */
 	protected function _do_never_allowed($str)
 	{
-		foreach ($this->_never_allowed_str as $key => $val)
-		{
-			$str = str_replace($key, $val, $str);
-		}
+		$str = str_replace(array_keys($this->_never_allowed_str), $this->_never_allowed_str, $str);
 
-		foreach ($this->_never_allowed_regex as $key => $val)
+		foreach ($this->_never_allowed_regex as $regex)
 		{
-			$str = preg_replace("#".$key."#i", $val, $str);
+			$str = preg_replace('#'.$regex.'#is', '[removed]', $str);
 		}
 
 		return $str;
@@ -873,19 +838,20 @@ class CI_Security {
 	 */
 	protected function _csrf_set_hash()
 	{
-		if ($this->_csrf_hash == '')
+		if ($this->_csrf_hash === '')
 		{
 			// If the cookie exists we will use it's value.
 			// We don't necessarily want to regenerate it with
 			// each page load since a page could contain embedded
 			// sub-pages causing this feature to fail
 			if (isset($_COOKIE[$this->_csrf_cookie_name]) &&
-				$_COOKIE[$this->_csrf_cookie_name] != '')
+				preg_match('#^[0-9a-f]{32}$#iS', $_COOKIE[$this->_csrf_cookie_name]) === 1)
 			{
 				return $this->_csrf_hash = $_COOKIE[$this->_csrf_cookie_name];
 			}
 
-			return $this->_csrf_hash = md5(uniqid(rand(), TRUE));
+			$this->_csrf_hash = md5(uniqid(rand(), TRUE));
+			$this->csrf_set_cookie();
 		}
 
 		return $this->_csrf_hash;
@@ -894,4 +860,4 @@ class CI_Security {
 }
 
 /* End of file Security.php */
-/* Location: ./system/libraries/Security.php */
\ No newline at end of file
+/* Location: ./system/core/Security.php */
\ No newline at end of file