diff options
Diffstat (limited to 'system/core/Security.php')
| -rw-r--r--[-rwxr-xr-x] | system/core/Security.php | 331 |
1 files changed, 188 insertions, 143 deletions
diff --git a/system/core/Security.php b/system/core/Security.php index ac39ce97b..c415544b6 100755..100644 --- a/system/core/Security.php +++ b/system/core/Security.php @@ -1,4 +1,4 @@ -<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); +<?php /** * CodeIgniter * @@ -24,6 +24,7 @@ * @since Version 1.0 * @filesource */ +defined('BASEPATH') OR exit('No direct script access allowed'); /** * Security Class @@ -37,71 +38,87 @@ class CI_Security { /** - * Random Hash for protecting URLs + * XSS Hash * - * @var string + * Random Hash for protecting URLs. + * + * @var string */ - protected $_xss_hash = ''; + protected $_xss_hash = ''; /** - * Random Hash for Cross Site Request Forgery Protection Cookie + * CSRF Hash + * + * Random hash for Cross Site Request Forgery protection cookie * - * @var string + * @var string */ - protected $_csrf_hash = ''; + protected $_csrf_hash = ''; /** - * Expiration time for Cross Site Request Forgery Protection Cookie - * Defaults to two hours (in seconds) + * CSRF Expire time + * + * Expiration time for Cross Site Request Forgery protection cookie. + * Defaults to two hours (in seconds). * - * @var int + * @var int */ - protected $_csrf_expire = 7200; + protected $_csrf_expire = 7200; /** - * Token name for Cross Site Request Forgery Protection Cookie + * CSRF Token name * - * @var string + * Token name for Cross Site Request Forgery protection cookie. + * + * @var string */ - protected $_csrf_token_name = 'ci_csrf_token'; + protected $_csrf_token_name = 'ci_csrf_token'; /** - * Cookie name for Cross Site Request Forgery Protection Cookie + * CSRF Cookie name + * + * Cookie name for Cross Site Request Forgery protection cookie. * - * @var string + * @var string */ - protected $_csrf_cookie_name = 'ci_csrf_token'; + protected $_csrf_cookie_name = 'ci_csrf_token'; /** * List of never allowed strings * - * @var array + * @var array */ - protected $_never_allowed_str = array( - 'document.cookie' => '[removed]', - 'document.write' => '[removed]', - '.parentNode' => '[removed]', - '.innerHTML' => '[removed]', - 'window.location' => '[removed]', - '-moz-binding' => '[removed]', - '<!--' => '<!--', - '-->' => '-->', - '<![CDATA[' => '<![CDATA[', - '<comment>' => '<comment>' - ); + protected $_never_allowed_str = array( + 'document.cookie' => '[removed]', + 'document.write' => '[removed]', + '.parentNode' => '[removed]', + '.innerHTML' => '[removed]', + 'window.location' => '[removed]', + '-moz-binding' => '[removed]', + '<!--' => '<!--', + '-->' => '-->', + '<![CDATA[' => '<![CDATA[', + '<comment>' => '<comment>' + ); /** - * List of never allowed regex replacement + * List of never allowed regex replacements * - * @var array + * @var array */ protected $_never_allowed_regex = array( - 'javascript\s*:', - 'expression\s*(\(|&\#40;)', // CSS and IE - 'vbscript\s*:', // IE, surprise! - 'Redirect\s+302' - ); + 'javascript\s*:', + 'expression\s*(\(|&\#40;)', // CSS and IE + 'vbscript\s*:', // IE, surprise! + 'Redirect\s+302', + "([\"'])?data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?" + ); + /** + * Class constructor + * + * @return void + */ public function __construct() { // Is CSRF protection enabled? @@ -132,7 +149,7 @@ class CI_Security { // -------------------------------------------------------------------- /** - * Verify Cross Site Request Forgery Protection + * CSRF Verify * * @return object */ @@ -155,8 +172,8 @@ 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]) - OR $_POST[$this->_csrf_token_name] != $_COOKIE[$this->_csrf_cookie_name]) // Do the tokens match? + if ( ! isset($_POST[$this->_csrf_token_name], $_COOKIE[$this->_csrf_cookie_name]) + OR $_POST[$this->_csrf_token_name] !== $_COOKIE[$this->_csrf_cookie_name]) // Do the tokens match? { $this->csrf_show_error(); } @@ -182,8 +199,9 @@ class CI_Security { // -------------------------------------------------------------------- /** - * Set Cross Site Request Forgery Protection Cookie + * CSRF Set Cookie * + * @codeCoverageIgnore * @return object */ public function csrf_set_cookie() @@ -191,17 +209,17 @@ class CI_Security { $expire = time() + $this->_csrf_expire; $secure_cookie = (bool) config_item('cookie_secure'); - if ($secure_cookie && (empty($_SERVER['HTTPS']) OR strtolower($_SERVER['HTTPS']) === 'off')) + if ($secure_cookie && ! is_https()) { return FALSE; } setcookie( - $this->_csrf_cookie_name, - $this->_csrf_hash, - $expire, - config_item('cookie_path'), - config_item('cookie_domain'), + $this->_csrf_cookie_name, + $this->_csrf_hash, + $expire, + config_item('cookie_path'), + config_item('cookie_domain'), $secure_cookie, config_item('cookie_httponly') ); @@ -227,9 +245,8 @@ class CI_Security { /** * Get CSRF Hash * - * Getter Method - * - * @return string self::_csrf_hash + * @see CI_Security::$_csrf_hash + * @return string CSRF hash */ public function get_csrf_hash() { @@ -241,9 +258,8 @@ class CI_Security { /** * Get CSRF Token Name * - * Getter Method - * - * @return string self::_csrf_token_name + * @see CI_Security::$_csrf_token_name + * @return string CSRF token name */ public function get_csrf_token_name() { @@ -256,26 +272,26 @@ class CI_Security { * XSS Clean * * Sanitizes data so that Cross Site Scripting Hacks can be - * prevented. This function does a fair amount of work but + * prevented. This method 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. + * Note: 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://channel.bitflux.ch/wiki/XSS_Prevention + * @link http://channel.bitflux.ch/wiki/XSS_Prevention + * Based in part on some code and ideas from Bitflux. * - * 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 + * @link http://ha.ckers.org/xss.html + * 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. * - * @param mixed string or array - * @param bool + * @param string|string[] $str Input data + * @param bool $is_image Whether the input is an image * @return string */ public function xss_clean($str, $is_image = FALSE) @@ -352,7 +368,7 @@ class CI_Security { } else { - $str = str_replace(array('<?', '?'.'>'), array('<?', '?>'), $str); + $str = str_replace(array('<?', '?'.'>'), array('<?', '?>'), $str); } /* @@ -362,9 +378,9 @@ 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) { @@ -387,20 +403,20 @@ class CI_Security { 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)) { - $str = preg_replace_callback('#<img\s+([^>]*?)(\s?/?>|$)#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|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); @@ -461,13 +477,16 @@ class CI_Security { // -------------------------------------------------------------------- /** - * Random Hash for protecting URLs + * XSS Hash * - * @return string + * Generates the XSS hash if needed and returns it. + * + * @see CI_Security::$_xss_hash + * @return string XSS hash */ public function xss_hash() { - if ($this->_xss_hash == '') + if ($this->_xss_hash === '') { mt_srand(); $this->_xss_hash = md5(time() + mt_rand(0, 1999999999)); @@ -481,7 +500,7 @@ class CI_Security { /** * HTML Entities Decode * - * This function is a replacement for html_entity_decode() + * A replacement for html_entity_decode() * * The reason we are not using html_entity_decode() by itself is because * while it is not technically correct to leave out the semicolon @@ -489,8 +508,10 @@ class CI_Security { * 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 + * @link http://php.net/html-entity-decode + * + * @param string $str Input + * @param string $charset Character set * @return string */ public function entity_decode($str, $charset = NULL) @@ -513,32 +534,32 @@ class CI_Security { // -------------------------------------------------------------------- /** - * Filename Security + * Sanitize Filename * - * @param string - * @param bool + * @param string $str Input file name + * @param bool $relative_path Whether to preserve paths * @return string */ public function sanitize_filename($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) { @@ -553,13 +574,27 @@ class CI_Security { // ---------------------------------------------------------------- /** + * Strip Image Tags + * + * @param string $str + * @return string + */ + public function strip_image_tags($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 + * Callback method for xss_clean() to remove whitespace from + * things like 'j a v a s c r i p t'. * - * @param type - * @return type + * @used-by CI_Security::xss_clean() + * @param array $matches + * @return string */ protected function _compact_exploded_words($matches) { @@ -568,20 +603,26 @@ 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 - * For example, everything between the pipes: + * + * - Everything up until a space. For example, everything between the pipes: + * + * <code> * <a |style=document.write('hello');alert('world');| class=link> - * - Everything inside the quotes - * For example, everything between the pipes: + * </code> + * + * - Everything inside the quotes. For example, everything between the pipes: + * + * <code> * <a |style="document.write('hello'); alert('world');"| class="link"> + * </code> * - * @param string $str The string to check - * @param boolean $is_image TRUE if this is an image - * @return string The string with the evil attributes removed + * @param string $str The string to check + * @param bool $is_image Whether the input is an image + * @return string The string with the evil attributes removed */ protected function _remove_evil_attributes($str, $is_image) { @@ -602,10 +643,11 @@ class CI_Security { $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); + preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', $str, $matches, PREG_SET_ORDER); foreach ($matches as $attr) { + $attribs[] = preg_quote($attr[0], '/'); } @@ -620,7 +662,7 @@ class CI_Security { // 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$2$4$5', $str, -1, $count); + $str = preg_replace('/<(\/?[^><]+?)([^A-Za-z<>\-])(.*?)('.implode('|', $attribs).')(.*?)([\s><])([><]*)/i', '<$1 $3$5$6$7', $str, -1, $count); } } while ($count); @@ -633,9 +675,10 @@ class CI_Security { /** * Sanitize Naughty HTML * - * Callback function for xss_clean() to remove naughty HTML elements + * Callback method for xss_clean() to remove naughty HTML elements. * - * @param array + * @used-by CI_Security::xss_clean() + * @param array $matches * @return string */ protected function _sanitize_naughty_html($matches) @@ -650,18 +693,20 @@ class CI_Security { /** * JS Link Removal * - * Callback function for xss_clean() to sanitize links + * Callback method 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 + * PHP 5.2+ on link-heavy strings. * - * @param array + * @used-by CI_Security::xss_clean() + * @param array $match * @return string */ protected function _js_link_removal($match) { return str_replace($match[1], - preg_replace('#href=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si', + 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])) ), @@ -673,18 +718,20 @@ class CI_Security { /** * JS Image Removal * - * Callback function for xss_clean() to sanitize image tags + * Callback method 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 + * PHP 5.2+ on image tag heavy strings. * - * @param array + * @used-by CI_Security::xss_clean() + * @param array $match * @return string */ protected function _js_img_removal($match) { return str_replace($match[1], - preg_replace('#src=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si', + 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])) ), @@ -696,9 +743,8 @@ class CI_Security { /** * Attribute Conversion * - * Used as a callback for XSS Clean - * - * @param array + * @used-by CI_Security::xss_clean() + * @param array $match * @return string */ protected function _convert_attribute($match) @@ -711,9 +757,11 @@ class CI_Security { /** * Filter Attributes * - * Filters tag attributes for consistency and safety + * Filters tag attributes for consistency and safety. * - * @param string + * @used-by CI_Security::_js_img_removal() + * @used-by CI_Security::_js_link_removal() + * @param string $str * @return string */ protected function _filter_attributes($str) @@ -735,9 +783,8 @@ class CI_Security { /** * HTML Entity Decode Callback * - * Used as a callback for XSS Clean - * - * @param array + * @used-by CI_Security::xss_clean() + * @param array $match * @return string */ protected function _decode_entity($match) @@ -750,9 +797,8 @@ class CI_Security { /** * Validate URL entities * - * Called by xss_clean() - * - * @param string + * @used-by CI_Security::xss_clean() + * @param string $str * @return string */ protected function _validate_entities($str) @@ -790,8 +836,7 @@ class CI_Security { /** * Do Never Allowed * - * A utility function for xss_clean() - * + * @used-by CI_Security::xss_clean() * @param string * @return string */ @@ -801,7 +846,7 @@ class CI_Security { foreach ($this->_never_allowed_regex as $regex) { - $str = preg_replace('#'.$regex.'#i', '[removed]', $str); + $str = preg_replace('#'.$regex.'#is', '[removed]', $str); } return $str; @@ -810,20 +855,20 @@ class CI_Security { // -------------------------------------------------------------------- /** - * Set Cross Site Request Forgery Protection Cookie + * Set CSRF Hash and Cookie * * @return string */ protected function _csrf_set_hash() { - if ($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]; } @@ -838,4 +883,4 @@ class CI_Security { } /* End of file Security.php */ -/* Location: ./system/core/Security.php */ +/* Location: ./system/core/Security.php */
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