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Diffstat (limited to 'system/libraries/Input.php')
| -rw-r--r-- | system/libraries/Input.php | 1067 |
1 files changed, 1067 insertions, 0 deletions
diff --git a/system/libraries/Input.php b/system/libraries/Input.php new file mode 100644 index 000000000..e7bf72779 --- /dev/null +++ b/system/libraries/Input.php @@ -0,0 +1,1067 @@ +<?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) 2008 - 2009, 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 $xss_hash = ''; + var $ip_address = FALSE; + var $user_agent = FALSE; + var $allow_get_array = FALSE; + + /* never allowed, string replacement */ + var $never_allowed_str = array( + 'document.cookie' => '[removed]', + 'document.write' => '[removed]', + '.parentNode' => '[removed]', + '.innerHTML' => '[removed]', + 'window.location' => '[removed]', + '-moz-binding' => '[removed]', + '<!--' => '<!--', + '-->' => '-->', + '<![CDATA[' => '<![CDATA[' + ); + /* never allowed, regex replacement */ + var $never_allowed_regex = array( + "javascript\s*:" => '[removed]', + "expression\s*(\(|&\#40;)" => '[removed]', // CSS and IE + "vbscript\s*:" => '[removed]', // IE, surprise! + "Redirect\s+302" => '[removed]' + ); + + /** + * 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 + { + $_GET = $this->_clean_input_data($_GET); + } + + // Clean $_POST Data + $_POST = $this->_clean_input_data($_POST); + + // Clean $_COOKIE Data + // Also get rid of specially treated cookies that might be set by a server + // or silly application, that are of no use to a CI application anyway + // but that when present will trip our 'Disallowed Key Characters' alarm + // http://www.ietf.org/rfc/rfc2109.txt + // note that the key names below are single quoted strings, and are not PHP variables + unset($_COOKIE['$Version']); + unset($_COOKIE['$Path']); + unset($_COOKIE['$Domain']); + $_COOKIE = $this->_clean_input_data($_COOKIE); + + 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 + if (strpos($str, "\r") !== FALSE) + { + $str = str_replace(array("\r\n", "\r"), "\n", $str); + } + + return $str; + } + + // -------------------------------------------------------------------- + + /** + * Clean Keys + * + * This is a helper function. To prevent malicious users + * from trying to exploit keys we make sure that keys are + * only named with alpha-numeric text and a few other items. + * + * @access private + * @param string + * @return string + */ + function _clean_input_keys($str) + { + if ( ! preg_match("/^[a-z0-9:_\/-]+$/i", $str)) + { + exit('Disallowed Key Characters.'); + } + + return $str; + } + + // -------------------------------------------------------------------- + + /** + * Fetch from array + * + * This is a helper function to retrieve values from global arrays + * + * @access private + * @param array + * @param string + * @param bool + * @return string + */ + function _fetch_from_array(&$array, $index = '', $xss_clean = FALSE) + { + if ( ! isset($array[$index])) + { + return FALSE; + } + + if ($xss_clean === TRUE) + { + return $this->xss_clean($array[$index]); + } + + return $array[$index]; + } + + // -------------------------------------------------------------------- + + /** + * Fetch an item from the GET array + * + * @access public + * @param string + * @param bool + * @return string + */ + function get($index = '', $xss_clean = FALSE) + { + return $this->_fetch_from_array($_GET, $index, $xss_clean); + } + + // -------------------------------------------------------------------- + + /** + * Fetch an item from the POST array + * + * @access public + * @param string + * @param bool + * @return string + */ + function post($index = '', $xss_clean = FALSE) + { + return $this->_fetch_from_array($_POST, $index, $xss_clean); + } + + // -------------------------------------------------------------------- + + /** + * Fetch an item from either the GET array or the POST + * + * @access public + * @param string The index key + * @param bool XSS cleaning + * @return string + */ + function get_post($index = '', $xss_clean = FALSE) + { + if ( ! isset($_POST[$index]) ) + { + return $this->get($index, $xss_clean); + } + else + { + return $this->post($index, $xss_clean); + } + } + + // -------------------------------------------------------------------- + + /** + * Fetch an item from the COOKIE array + * + * @access public + * @param string + * @param bool + * @return string + */ + function cookie($index = '', $xss_clean = FALSE) + { + return $this->_fetch_from_array($_COOKIE, $index, $xss_clean); + } + + // -------------------------------------------------------------------- + + /** + * Fetch an item from the SERVER array + * + * @access public + * @param string + * @param bool + * @return string + */ + function server($index = '', $xss_clean = FALSE) + { + return $this->_fetch_from_array($_SERVER, $index, $xss_clean); + } + + // -------------------------------------------------------------------- + + /** + * Fetch the IP Address + * + * @access public + * @return string + */ + function ip_address() + { + if ($this->ip_address !== FALSE) + { + return $this->ip_address; + } + + if (config_item('proxy_ips') != '' && $this->server('HTTP_X_FORWARDED_FOR') && $this->server('REMOTE_ADDR')) + { + $proxies = preg_split('/[\s,]/', config_item('proxy_ips'), -1, PREG_SPLIT_NO_EMPTY); + $proxies = is_array($proxies) ? $proxies : array($proxies); + + $this->ip_address = in_array($_SERVER['REMOTE_ADDR'], $proxies) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR']; + } + elseif ($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); + $this->ip_address = trim(end($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 ($ip_segments[0][0] == '0') + { + return FALSE; + } + // Check each segment + foreach ($ip_segments as $segment) + { + // IP segments must be digits and can not be + // longer than 3 digits or greater then 255 + if ($segment == '' OR 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, $is_image = FALSE) + { + /* + * Is the string an array? + * + */ + if (is_array($str)) + { + while (list($key) = each($str)) + { + $str[$key] = $this->xss_clean($str[$key]); + } + + return $str; + } + + /* + * Remove Invisible Characters + */ + $str = $this->_remove_invisible_characters($str); + + /* + * Protect GET variables in URLs + */ + + // 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); + + /* + * 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); + + /* + * Un-Protect GET variables in URLs + */ + $str = str_replace($this->xss_hash(), '&', $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, '_convert_attribute'), $str); + + $str = preg_replace_callback("/<\w+.*?(?=>|<|$)/si", array($this, '_html_entity_decode_callback'), $str); + + /* + * Remove Invisible Characters Again! + */ + $str = $this->_remove_invisible_characters($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. + * + */ + + if (strpos($str, "\t") !== FALSE) + { + $str = str_replace("\t", ' ', $str); + } + + /* + * Capture converted string for later comparison + */ + $converted_string = $str; + + /* + * Not Allowed Under Any Conditions + */ + + foreach ($this->never_allowed_str as $key => $val) + { + $str = str_replace($key, $val, $str); + } + + foreach ($this->never_allowed_regex as $key => $val) + { + $str = preg_replace("#".$key."#i", $val, $str); + } + + /* + * Makes PHP tags safe + * + * Note: XML tags are inadvertently replaced too: + * + * <?xml + * + * But it doesn't seem to pose a problem. + * + */ + if ($is_image === TRUE) + { + // 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', "<?\\1", $str); + } + else + { + $str = str_replace(array('<?', '?'.'>'), array('<?', '?>'), $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, $wordlen = strlen($word); $i < $wordlen; $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" + $str = preg_replace_callback('#('.substr($temp, 0, -3).')(\W)#is', array($this, '_compact_exploded_words'), $str); + } + + /* + * Remove disallowed Javascript in links or img tags + * We used to do some version comparisons and use of stripos for PHP5, but it is dog slow compared + * to these simplified non-capturing preg_match(), especially if the pattern exists in the string + */ + do + { + $original = $str; + + if (preg_match("/<a/i", $str)) + { + $str = preg_replace_callback("#<a\s+([^>]*?)(>|$)#si", array($this, '_js_link_removal'), $str); + } + + if (preg_match("/<img/i", $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)) + { + $str = preg_replace("#<(/*)(script|xss)(.*?)\>#si", '[removed]', $str); + } + } + while($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. + * + */ + $event_handlers = array('[^a-z_\-]on\w*','xmlns'); + + if ($is_image === TRUE) + { + /* + * Adobe Photoshop puts XML metadata into JFIF images, including namespacing, + * so we have to allow this for images. -Paul + */ + unset($event_handlers[array_search('xmlns', $event_handlers)]); + } + + $str = preg_replace("#<([^><]+?)(".implode('|', $event_handlers).")(\s*=\s*[^><]*)([><]*)#i", "<\\1\\4", $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> + * + */ + $naughty = 'alert|applet|audio|basefont|base|behavior|bgsound|blink|body|embed|expression|form|frameset|frame|head|html|ilayer|iframe|input|isindex|layer|link|meta|object|plaintext|style|script|textarea|title|video|xml|xss'; + $str = preg_replace_callback('#<(/*\s*)('.$naughty.')([^><]*)([><]*)#is', array($this, '_sanitize_naughty_html'), $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)", $str); + + /* + * Final clean up + * + * This adds a bit of extra precaution in case + * something got through the above filters + * + */ + foreach ($this->never_allowed_str as $key => $val) + { + $str = str_replace($key, $val, $str); + } + + foreach ($this->never_allowed_regex as $key => $val) + { + $str = preg_replace("#".$key."#i", $val, $str); + } + + /* + * Images are Handled in a Special Way + * - Essentially, we want to know that after all of the character conversion is done whether + * any unwanted, likely XSS, code was found. If not, we return TRUE, as the image is clean. + * However, if the string post-conversion does not matched the string post-removal of XSS, + * then it fails, as there was unwanted XSS code found and removed/changed during processing. + */ + + if ($is_image === TRUE) + { + if ($str == $converted_string) + { + return TRUE; + } + else + { + return FALSE; + } + } + + log_message('debug', "XSS Filtering completed"); + return $str; + } + + // -------------------------------------------------------------------- + + /** + * Random Hash for protecting URLs + * + * @access public + * @return string + */ + function xss_hash() + { + if ($this->xss_hash == '') + { + if (phpversion() >= 4.2) + mt_srand(); + else + mt_srand(hexdec(substr(md5(microtime()), -8)) & 0x7fffffff); + + $this->xss_hash = md5(time() + mt_rand(0, 1999999999)); + } + + return $this->xss_hash; + } + + // -------------------------------------------------------------------- + + /** + * Remove Invisible Characters + * + * This prevents sandwiching null characters + * between ascii characters, like Java\0script. + * + * @access public + * @param string + * @return string + */ + function _remove_invisible_characters($str) + { + static $non_displayables; + + if ( ! isset($non_displayables)) + { + // every control character except newline (dec 10), carriage return (dec 13), and horizontal tab (dec 09), + $non_displayables = array( + '/%0[0-8bcef]/', // url encoded 00-08, 11, 12, 14, 15 + '/%1[0-9a-f]/', // url encoded 16-31 + '/[\x00-\x08]/', // 00-08 + '/\x0b/', '/\x0c/', // 11, 12 + '/[\x0e-\x1f]/' // 14-31 + ); + } + + do + { + $cleaned = $str; + $str = preg_replace($non_displayables, '', $str); + } + while ($cleaned != $str); + + return $str; + } + + // -------------------------------------------------------------------- + + /** + * Compact Exploded Words + * + * Callback function for xss_clean() to remove whitespace from + * things like j a v a s c r i p t + * + * @access public + * @param type + * @return type + */ + function _compact_exploded_words($matches) + { + return preg_replace('/\s+/s', '', $matches[1]).$matches[2]; + } + + // -------------------------------------------------------------------- + + /** + * Sanitize Naughty HTML + * + * Callback function for xss_clean() to remove naughty HTML elements + * + * @access private + * @param array + * @return string + */ + function _sanitize_naughty_html($matches) + { + // encode opening brace + $str = '<'.$matches[1].$matches[2].$matches[3]; + + // encode captured opening or closing brace to prevent recursive vectors + $str .= str_replace(array('>', '<'), array('>', '<'), $matches[4]); + + 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) + { + $attributes = $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1])); + return str_replace($match[1], preg_replace("#href=.*?(alert\(|alert&\#40;|javascript\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si", "", $attributes), $match[0]); + } + + /** + * JS Image Removal + * + * Callback function for xss_clean() to sanitize image tags + * This limits the PCRE backtracks, making it more performance friendly + * and prevents PREG_BACKTRACK_LIMIT_ERROR from being triggered in + * PHP 5.2+ on image tag heavy strings + * + * @access private + * @param array + * @return string + */ + function _js_img_removal($match) + { + $attributes = $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1])); + return str_replace($match[1], preg_replace("#src=.*?(alert\(|alert&\#40;|javascript\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si", "", $attributes), $match[0]); + } + + // -------------------------------------------------------------------- + + /** + * Attribute Conversion + * + * Used as a callback for XSS Clean + * + * @access public + * @param array + * @return string + */ + function _convert_attribute($match) + { + return str_replace(array('>', '<', '\\'), array('>', '<', '\\\\'), $match[0]); + } + + // -------------------------------------------------------------------- + + /** + * HTML Entity Decode Callback + * + * Used as a callback for XSS Clean + * + * @access public + * @param array + * @return string + */ + function _html_entity_decode_callback($match) + { + $CFG =& load_class('Config'); + $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*[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 $str; + } + + // -------------------------------------------------------------------- + + /** + * Filter Attributes + * + * Filters tag attributes for consistency and safety + * + * @access public + * @param string + * @return string + */ + function _filter_attributes($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); + } + } + + return $out; + } + + // -------------------------------------------------------------------- + +} +// END Input class + +/* End of file Input.php */ +/* Location: ./system/libraries/Input.php */
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