| <?php if (!defined('BASEPATH')) exit('No direct script access allowed');
|
| /**
|
| * CodeIgniter
|
| *
|
| * An open source application development framework for PHP 4.3.2 or newer
|
| *
|
| * @package CodeIgniter
|
| * @author ExpressionEngine Dev Team
|
| * @copyright Copyright (c) 2006, EllisLab, Inc.
|
| * @license http://codeigniter.com/user_guide/license.html
|
| * @link http://codeigniter.com
|
| * @since Version 1.0
|
| * @filesource
|
| */
|
|
|
| // ------------------------------------------------------------------------
|
|
|
| /**
|
| * Input Class
|
| *
|
| * Pre-processes global input data for security
|
| *
|
| * @package CodeIgniter
|
| * @subpackage Libraries
|
| * @category Input
|
| * @author ExpressionEngine Dev Team
|
| * @link http://codeigniter.com/user_guide/libraries/input.html
|
| */
|
| class CI_Input {
|
| var $use_xss_clean = FALSE;
|
| var $ip_address = FALSE;
|
| var $user_agent = FALSE;
|
| var $allow_get_array = FALSE;
|
|
|
| /**
|
| * Constructor
|
| *
|
| * Sets whether to globally enable the XSS processing
|
| * and whether to allow the $_GET array
|
| *
|
| * @access public
|
| */
|
| function CI_Input()
|
| {
|
| log_message('debug', "Input Class Initialized");
|
|
|
| $CFG =& load_class('Config');
|
| $this->use_xss_clean = ($CFG->item('global_xss_filtering') === TRUE) ? TRUE : FALSE;
|
| $this->allow_get_array = ($CFG->item('enable_query_strings') === TRUE) ? TRUE : FALSE;
|
| $this->_sanitize_globals();
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Sanitize Globals
|
| *
|
| * This function does the following:
|
| *
|
| * Unsets $_GET data (if query strings are not enabled)
|
| *
|
| * Unsets all globals if register_globals is enabled
|
| *
|
| * Standardizes newline characters to \n
|
| *
|
| * @access private
|
| * @return void
|
| */
|
| function _sanitize_globals()
|
| {
|
| // Would kind of be "wrong" to unset any of these GLOBALS
|
| $protected = array('_SERVER', '_GET', '_POST', '_FILES', '_REQUEST', '_SESSION', '_ENV', 'GLOBALS', 'HTTP_RAW_POST_DATA',
|
| 'system_folder', 'application_folder', 'BM', 'EXT', 'CFG', 'URI', 'RTR', 'OUT', 'IN');
|
|
|
| // Unset globals for security.
|
| // This is effectively the same as register_globals = off
|
| foreach (array($_GET, $_POST, $_COOKIE, $_SERVER, $_FILES, $_ENV, (isset($_SESSION) && is_array($_SESSION)) ? $_SESSION : array()) as $global)
|
| {
|
| if (! is_array($global))
|
| {
|
| if (! in_array($global, $protected))
|
| {
|
| unset($GLOBALS[$global]);
|
| }
|
| }
|
| else
|
| {
|
| foreach ($global as $key => $val)
|
| {
|
| if (! in_array($key, $protected))
|
| {
|
| unset($GLOBALS[$key]);
|
| }
|
|
|
| if (is_array($val))
|
| {
|
| foreach($val as $k => $v)
|
| {
|
| if (! in_array($k, $protected))
|
| {
|
| unset($GLOBALS[$k]);
|
| }
|
| }
|
| }
|
| }
|
| }
|
| }
|
|
|
| // Is $_GET data allowed? If not we'll set the $_GET to an empty array
|
| if ($this->allow_get_array == FALSE)
|
| {
|
| $_GET = array();
|
| }
|
| else
|
| {
|
| if (is_array($_GET) AND count($_GET) > 0)
|
| {
|
| foreach($_GET as $key => $val)
|
| {
|
| $_GET[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
|
| }
|
| }
|
| }
|
|
|
| // Clean $_POST Data
|
| if (is_array($_POST) AND count($_POST) > 0)
|
| {
|
| foreach($_POST as $key => $val)
|
| {
|
| $_POST[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
|
| }
|
| }
|
|
|
| // Clean $_COOKIE Data
|
| if (is_array($_COOKIE) AND count($_COOKIE) > 0)
|
| {
|
| foreach($_COOKIE as $key => $val)
|
| {
|
| $_COOKIE[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
|
| }
|
| }
|
|
|
| log_message('debug', "Global POST and COOKIE data sanitized");
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Clean Input Data
|
| *
|
| * This is a helper function. It escapes data and
|
| * standardizes newline characters to \n
|
| *
|
| * @access private
|
| * @param string
|
| * @return string
|
| */
|
| function _clean_input_data($str)
|
| {
|
| if (is_array($str))
|
| {
|
| $new_array = array();
|
| foreach ($str as $key => $val)
|
| {
|
| $new_array[$this->_clean_input_keys($key)] = $this->_clean_input_data($val);
|
| }
|
| return $new_array;
|
| }
|
|
|
| // We strip slashes if magic quotes is on to keep things consistent
|
| if (get_magic_quotes_gpc())
|
| {
|
| $str = stripslashes($str);
|
| }
|
|
|
| // Should we filter the input data?
|
| if ($this->use_xss_clean === TRUE)
|
| {
|
| $str = $this->xss_clean($str);
|
| }
|
|
|
| // Standardize newlines
|
| return preg_replace("/\015\012|\015|\012/", "\n", $str);
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Clean Keys
|
| *
|
| * This is a helper function. To prevent malicious users
|
| * from trying to exploit keys we make sure that keys are
|
| * only named with alpha-numeric text and a few other items.
|
| *
|
| * @access private
|
| * @param string
|
| * @return string
|
| */
|
| function _clean_input_keys($str)
|
| {
|
| if (! preg_match("/^[a-z0-9:_\/-]+$/i", $str))
|
| {
|
| exit('Disallowed Key Characters.');
|
| }
|
|
|
| return $str;
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Fetch an item from the GET array
|
| *
|
| * @access public
|
| * @param string
|
| * @param bool
|
| * @return string
|
| */
|
| function get($index = '', $xss_clean = FALSE)
|
| {
|
| if (! isset($_GET[$index]))
|
| {
|
| return FALSE;
|
| }
|
|
|
| if ($xss_clean === TRUE)
|
| {
|
| if (is_array($_GET[$index]))
|
| {
|
| foreach($_GET[$index] as $key => $val)
|
| {
|
| $_GET[$index][$key] = $this->xss_clean($val);
|
| }
|
| }
|
| else
|
| {
|
| return $this->xss_clean($_GET[$index]);
|
| }
|
| }
|
|
|
| return $_GET[$index];
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Fetch an item from the POST array
|
| *
|
| * @access public
|
| * @param string
|
| * @param bool
|
| * @return string
|
| */
|
| function post($index = '', $xss_clean = FALSE)
|
| {
|
| if (! isset($_POST[$index]))
|
| {
|
| return FALSE;
|
| }
|
|
|
| if ($xss_clean === TRUE)
|
| {
|
| if (is_array($_POST[$index]))
|
| {
|
| foreach($_POST[$index] as $key => $val)
|
| {
|
| $_POST[$index][$key] = $this->xss_clean($val);
|
| }
|
| }
|
| else
|
| {
|
| return $this->xss_clean($_POST[$index]);
|
| }
|
| }
|
|
|
| return $_POST[$index];
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Fetch an item from the COOKIE array
|
| *
|
| * @access public
|
| * @param string
|
| * @param bool
|
| * @return string
|
| */
|
| function cookie($index = '', $xss_clean = FALSE)
|
| {
|
| if (! isset($_COOKIE[$index]))
|
| {
|
| return FALSE;
|
| }
|
|
|
| if ($xss_clean === TRUE)
|
| {
|
| if (is_array($_COOKIE[$index]))
|
| {
|
| $cookie = array();
|
| foreach($_COOKIE[$index] as $key => $val)
|
| {
|
| $cookie[$key] = $this->xss_clean($val);
|
| }
|
|
|
| return $cookie;
|
| }
|
| else
|
| {
|
| return $this->xss_clean($_COOKIE[$index]);
|
| }
|
| }
|
| else
|
| {
|
| return $_COOKIE[$index];
|
| }
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Fetch an item from the SERVER array
|
| *
|
| * @access public
|
| * @param string
|
| * @param bool
|
| * @return string
|
| */
|
| function server($index = '', $xss_clean = FALSE)
|
| {
|
| if (! isset($_SERVER[$index]))
|
| {
|
| return FALSE;
|
| }
|
|
|
| if ($xss_clean === TRUE)
|
| {
|
| return $this->xss_clean($_SERVER[$index]);
|
| }
|
|
|
| return $_SERVER[$index];
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Fetch the IP Address
|
| *
|
| * @access public
|
| * @return string
|
| */
|
| function ip_address()
|
| {
|
| if ($this->ip_address !== FALSE)
|
| {
|
| return $this->ip_address;
|
| }
|
|
|
| if ($this->server('REMOTE_ADDR') AND $this->server('HTTP_CLIENT_IP'))
|
| {
|
| $this->ip_address = $_SERVER['HTTP_CLIENT_IP'];
|
| }
|
| elseif ($this->server('REMOTE_ADDR'))
|
| {
|
| $this->ip_address = $_SERVER['REMOTE_ADDR'];
|
| }
|
| elseif ($this->server('HTTP_CLIENT_IP'))
|
| {
|
| $this->ip_address = $_SERVER['HTTP_CLIENT_IP'];
|
| }
|
| elseif ($this->server('HTTP_X_FORWARDED_FOR'))
|
| {
|
| $this->ip_address = $_SERVER['HTTP_X_FORWARDED_FOR'];
|
| }
|
|
|
| if ($this->ip_address === FALSE)
|
| {
|
| $this->ip_address = '0.0.0.0';
|
| return $this->ip_address;
|
| }
|
|
|
| if (strstr($this->ip_address, ','))
|
| {
|
| $x = explode(',', $this->ip_address);
|
| $this->ip_address = end($x);
|
| }
|
|
|
| if (! $this->valid_ip($this->ip_address))
|
| {
|
| $this->ip_address = '0.0.0.0';
|
| }
|
|
|
| return $this->ip_address;
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Validate IP Address
|
| *
|
| * Updated version suggested by Geert De Deckere
|
| *
|
| * @access public
|
| * @param string
|
| * @return string
|
| */
|
| function valid_ip($ip)
|
| {
|
| $ip_segments = explode('.', $ip);
|
|
|
| // Always 4 segments needed
|
| if (count($ip_segments) != 4)
|
| {
|
| return FALSE;
|
| }
|
| // IP can not start with 0
|
| if (substr($ip_segments[0], 0, 1) == '0')
|
| {
|
| return FALSE;
|
| }
|
| // Check each segment
|
| foreach ($ip_segments as $segment)
|
| {
|
| // IP segments must be digits and can not be
|
| // longer than 3 digits or greater then 255
|
| if (preg_match("/[^0-9]/", $segment) OR $segment > 255 OR strlen($segment) > 3)
|
| {
|
| return FALSE;
|
| }
|
| }
|
|
|
| return TRUE;
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * User Agent
|
| *
|
| * @access public
|
| * @return string
|
| */
|
| function user_agent()
|
| {
|
| if ($this->user_agent !== FALSE)
|
| {
|
| return $this->user_agent;
|
| }
|
|
|
| $this->user_agent = (! isset($_SERVER['HTTP_USER_AGENT'])) ? FALSE : $_SERVER['HTTP_USER_AGENT'];
|
|
|
| return $this->user_agent;
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Filename Security
|
| *
|
| * @access public
|
| * @param string
|
| * @return string
|
| */
|
| function filename_security($str)
|
| {
|
| $bad = array(
|
| "../",
|
| "./",
|
| "<!--",
|
| "-->",
|
| "<",
|
| ">",
|
| "'",
|
| '"',
|
| '&',
|
| '$',
|
| '#',
|
| '{',
|
| '}',
|
| '[',
|
| ']',
|
| '=',
|
| ';',
|
| '?',
|
| "%20",
|
| "%22",
|
| "%3c", // <
|
| "%253c", // <
|
| "%3e", // >
|
| "%0e", // >
|
| "%28", // (
|
| "%29", // )
|
| "%2528", // (
|
| "%26", // &
|
| "%24", // $
|
| "%3f", // ?
|
| "%3b", // ;
|
| "%3d" // =
|
| );
|
|
|
| return stripslashes(str_replace($bad, '', $str));
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * XSS Clean
|
| *
|
| * Sanitizes data so that Cross Site Scripting Hacks can be
|
| * prevented. This function does a fair amount of work but
|
| * it is extremely thorough, designed to prevent even the
|
| * most obscure XSS attempts. Nothing is ever 100% foolproof,
|
| * of course, but I haven't been able to get anything passed
|
| * the filter.
|
| *
|
| * Note: This function should only be used to deal with data
|
| * upon submission. It's not something that should
|
| * be used for general runtime processing.
|
| *
|
| * This function was based in part on some code and ideas I
|
| * got from Bitflux: http://blog.bitflux.ch/wiki/XSS_Prevention
|
| *
|
| * To help develop this script I used this great list of
|
| * vulnerabilities along with a few other hacks I've
|
| * harvested from examining vulnerabilities in other programs:
|
| * http://ha.ckers.org/xss.html
|
| *
|
| * @access public
|
| * @param string
|
| * @return string
|
| */
|
| function xss_clean($str)
|
| {
|
| /*
|
| * Remove Null Characters
|
| *
|
| * This prevents sandwiching null characters
|
| * between ascii characters, like Java\0script.
|
| *
|
| */
|
| $str = preg_replace('/\0+/', '', $str);
|
| $str = preg_replace('/(\\\\0)+/', '', $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]+)[\x00-\x20]*;?#i', "\\1;", $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);
|
|
|
| /*
|
| * URL Decode
|
| *
|
| * Just in case stuff like this is submitted:
|
| *
|
| * <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);
|
|
|
| /*
|
| * Convert character entities to ASCII
|
| *
|
| * 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, '_attribute_conversion'), $str);
|
|
|
| $str = preg_replace_callback("/<([\w]+)[^>]*>/si", array($this, '_html_entity_decode_callback'), $str);
|
|
|
| /*
|
|
|
| Old Code that when modified to use preg_replace()'s above became more efficient memory-wise
|
|
|
| if (preg_match_all("/[a-z]+=([\'\"]).*?\\1/si", $str, $matches))
|
| {
|
| for ($i = 0; $i < count($matches[0]); $i++)
|
| {
|
| if (stristr($matches[0][$i], '>'))
|
| {
|
| $str = str_replace( $matches['0'][$i],
|
| str_replace('>', '<', $matches[0][$i]),
|
| $str);
|
| }
|
| }
|
| }
|
|
|
| if (preg_match_all("/<([\w]+)[^>]*>/si", $str, $matches))
|
| {
|
| for ($i = 0; $i < count($matches[0]); $i++)
|
| {
|
| $str = str_replace($matches[0][$i],
|
| $this->_html_entity_decode($matches[0][$i], $charset),
|
| $str);
|
| }
|
| }
|
| */
|
|
|
| /*
|
| * Convert all tabs to spaces
|
| *
|
| * This prevents strings like this: ja vascript
|
| * NOTE: we deal with spaces between characters later.
|
| * 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);
|
|
|
| /*
|
| * Not Allowed Under Any Conditions
|
| */
|
| $bad = array(
|
| 'document.cookie' => '[removed]',
|
| 'document.write' => '[removed]',
|
| '.parentNode' => '[removed]',
|
| '.innerHTML' => '[removed]',
|
| 'window.location' => '[removed]',
|
| '-moz-binding' => '[removed]',
|
| '<!--' => '<!--',
|
| '-->' => '-->',
|
| '<!CDATA[' => '<![CDATA['
|
| );
|
|
|
| foreach ($bad as $key => $val)
|
| {
|
| $str = str_replace($key, $val, $str);
|
| }
|
|
|
| $bad = array(
|
| "javascript\s*:" => '[removed]',
|
| "expression\s*\(" => '[removed]', // CSS and IE
|
| "Redirect\s+302" => '[removed]'
|
| );
|
|
|
| foreach ($bad as $key => $val)
|
| {
|
| $str = preg_replace("#".$key."#i", $val, $str);
|
| }
|
|
|
| /*
|
| * Makes PHP tags safe
|
| *
|
| * Note: XML tags are inadvertently replaced too:
|
| *
|
| * <?xml
|
| *
|
| * But it doesn't seem to pose a problem.
|
| *
|
| */
|
| $str = str_replace(array('<?php', '<?PHP', '<?', '?'.'>'), array('<?php', '<?PHP', '<?', '?>'), $str);
|
|
|
| /*
|
| * Compact any exploded words
|
| *
|
| * This corrects words like: j a v a s c r i p t
|
| * These words are compacted back to their correct state.
|
| *
|
| */
|
| $words = array('javascript', 'expression', 'vbscript', 'script', 'applet', 'alert', 'document', 'write', 'cookie', 'window');
|
| foreach ($words as $word)
|
| {
|
| $temp = '';
|
| for ($i = 0; $i < strlen($word); $i++)
|
| {
|
| $temp .= substr($word, $i, 1)."\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"
|
| $str = preg_replace('#('.substr($temp, 0, -3).')(\W)#ise', "preg_replace('/\s+/s', '', '\\1').'\\2'", $str);
|
| }
|
|
|
| /*
|
| * Remove disallowed Javascript in links or img tags
|
| */
|
| do
|
| {
|
| $original = $str;
|
|
|
| if ((version_compare(PHP_VERSION, '5.0', '>=') === TRUE && stripos($str, '</a>') !== FALSE) OR
|
| preg_match("/<\/a>/i", $str))
|
| {
|
| $str = preg_replace_callback("#<a.*?</a>#si", array($this, '_js_link_removal'), $str);
|
| }
|
|
|
| if ((version_compare(PHP_VERSION, '5.0', '>=') === TRUE && stripos($str, '<img') !== FALSE) OR
|
| preg_match("/img/i", $str))
|
| {
|
| $str = preg_replace_callback("#<img.*?".">#si", array($this, '_js_img_removal'), $str);
|
| }
|
|
|
| if ((version_compare(PHP_VERSION, '5.0', '>=') === TRUE && (stripos($str, 'script') !== FALSE OR stripos($str, 'xss') !== FALSE)) OR
|
| preg_match("/(script|xss)/i", $str))
|
| {
|
| $str = preg_replace("#</*(script|xss).*?\>#si", "", $str);
|
| }
|
| }
|
| while($original != $str);
|
|
|
| unset($original);
|
|
|
| /*
|
| * Remove JavaScript Event Handlers
|
| *
|
| * Note: This code is a little blunt. It removes
|
| * the event handler and anything up to the closing >,
|
| * but it's unlikely to be a problem.
|
| *
|
| */
|
| $event_handlers = array('onblur','onchange','onclick','onfocus','onload','onmouseover','onmouseup','onmousedown','onselect','onsubmit','onunload','onkeypress','onkeydown','onkeyup','onresize', 'xmlns');
|
| $str = preg_replace("#<([^>]+)(".implode('|', $event_handlers).")([^>]*)>#iU", "<\\1\\2\\3>", $str);
|
|
|
| /*
|
| * Sanitize naughty HTML elements
|
| *
|
| * If a tag containing any of the words in the list
|
| * below is found, the tag gets converted to entities.
|
| *
|
| * So this: <blink>
|
| * Becomes: <blink>
|
| *
|
| */
|
| $str = preg_replace('#<(/*\s*)(alert|applet|basefont|base|behavior|bgsound|blink|body|embed|expression|form|frameset|frame|head|html|ilayer|iframe|input|layer|link|meta|object|plaintext|style|script|textarea|title|xml|xss)([^>]*)>#is', "<\\1\\2\\3>", $str);
|
|
|
| /*
|
| * Sanitize naughty scripting elements
|
| *
|
| * Similar to above, only instead of looking for
|
| * tags it looks for PHP and JavaScript commands
|
| * 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('some code')
|
| *
|
| */
|
| $str = preg_replace('#(alert|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si', "\\1\\2(\\3)", $str);
|
|
|
| /*
|
| * Final clean up
|
| *
|
| * This adds a bit of extra precaution in case
|
| * something got through the above filters
|
| *
|
| */
|
| $bad = array(
|
| 'document.cookie' => '[removed]',
|
| 'document.write' => '[removed]',
|
| '.parentNode' => '[removed]',
|
| '.innerHTML' => '[removed]',
|
| 'window.location' => '[removed]',
|
| '-moz-binding' => '[removed]',
|
| '<!--' => '<!--',
|
| '-->' => '-->',
|
| '<!CDATA[' => '<![CDATA['
|
| );
|
|
|
| foreach ($bad as $key => $val)
|
| {
|
| $str = str_replace($key, $val, $str);
|
| }
|
|
|
| $bad = array(
|
| "javascript\s*:" => '[removed]',
|
| "expression\s*\(" => '[removed]', // CSS and IE
|
| "Redirect\s+302" => '[removed]'
|
| );
|
|
|
| foreach ($bad as $key => $val)
|
| {
|
| $str = preg_replace("#".$key."#i", $val, $str);
|
| }
|
|
|
|
|
| log_message('debug', "XSS Filtering completed");
|
| return $str;
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * JS Link Removal
|
| *
|
| * Callback function for xss_clean() to sanitize links
|
| * This limits the PCRE backtracks, making it more performance friendly
|
| * and prevents PREG_BACKTRACK_LIMIT_ERROR from being triggered in
|
| * PHP 5.2+ on link-heavy strings
|
| *
|
| * @access private
|
| * @param array
|
| * @return string
|
| */
|
| function _js_link_removal($match)
|
| {
|
| return preg_replace("#<a.+?href=.*?(alert\(|alert&\#40;|javascript\:|window\.|document\.|\.cookie|<script|<xss).*?\>.*?</a>#si", "", $match[0]);
|
| }
|
|
|
| /**
|
| * JS Image Removal
|
| *
|
| * Callback function for xss_clean() to sanitize image tags
|
| * This limits the PCRE backtracks, making it more performance friendly
|
| * and prevents PREG_BACKTRACK_LIMIT_ERROR from being triggered in
|
| * PHP 5.2+ on image tag heavy strings
|
| *
|
| * @access private
|
| * @param array
|
| * @return string
|
| */
|
| function _js_img_removal($match)
|
| {
|
| return preg_replace("#<img.+?src=.*?(alert\(|alert&\#40;|javascript\:|window\.|document\.|\.cookie|<script|<xss).*?\>#si", "", $match[0]);
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Attribute Conversion
|
| *
|
| * Used as a callback for XSS Clean
|
| *
|
| * @access public
|
| * @param array
|
| * @return string
|
| */
|
| function _attribute_conversion($match)
|
| {
|
| return str_replace('>', '<', $match[0]);
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * HTML Entity Decode Callback
|
| *
|
| * Used as a callback for XSS Clean
|
| *
|
| * @access public
|
| * @param array
|
| * @return string
|
| */
|
| function _html_entity_decode_callback($match)
|
| {
|
| global $CFG;
|
| $charset = $CFG->item('charset');
|
|
|
| return $this->_html_entity_decode($match[0], strtoupper($charset));
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * HTML Entities Decode
|
| *
|
| * This function is a replacement for html_entity_decode()
|
| *
|
| * In some versions of PHP the native function does not work
|
| * when UTF-8 is the specified character set, so this gives us
|
| * a work-around. More info here:
|
| * http://bugs.php.net/bug.php?id=25670
|
| *
|
| * @access private
|
| * @param string
|
| * @param string
|
| * @return string
|
| */
|
| /* -------------------------------------------------
|
| /* Replacement for html_entity_decode()
|
| /* -------------------------------------------------*/
|
|
|
| /*
|
| NOTE: html_entity_decode() has a bug in some PHP versions when UTF-8 is the
|
| character set, and the PHP developers said they were not back porting the
|
| fix to versions other than PHP 5.x.
|
| */
|
| function _html_entity_decode($str, $charset='UTF-8')
|
| {
|
| if (stristr($str, '&') === FALSE) return $str;
|
|
|
| // The reason we are not using html_entity_decode() by itself is because
|
| // while it is not technically correct to leave out the semicolon
|
| // at the end of an entity most browsers will still interpret the entity
|
| // correctly. html_entity_decode() does not convert entities without
|
| // semicolons, so we are left with our own little solution here. Bummer.
|
|
|
| if (function_exists('html_entity_decode') && (strtolower($charset) != 'utf-8' OR version_compare(phpversion(), '5.0.0', '>=')))
|
| {
|
| $str = html_entity_decode($str, ENT_COMPAT, $charset);
|
| $str = preg_replace('~&#x([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([0-9a-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;
|
| }
|
|
|
| }
|
| // END Input class
|
| |
| /* End of file Input.php */ |
| /* Location: ./system/libraries/Input.php */ |