diff options
Diffstat (limited to 'system')
| -rw-r--r-- | system/libraries/Security.php | 620 |
1 files changed, 351 insertions, 269 deletions
diff --git a/system/libraries/Security.php b/system/libraries/Security.php index 58db4e79c..ceef9779c 100644 --- a/system/libraries/Security.php +++ b/system/libraries/Security.php @@ -22,44 +22,44 @@ * @subpackage Libraries * @category Security * @author ExpressionEngine Dev Team - * @link http://codeigniter.com/user_guide/libraries/sessions.html + * @link http://codeigniter.com/user_guide/libraries/security.html */ class CI_Security { - - public $xss_hash = ''; - public $csrf_hash = ''; - public $csrf_expire = 7200; // Two hours (in seconds) - public $csrf_token_name = 'ci_csrf_token'; - public $csrf_cookie_name = 'ci_csrf_token'; + + protected $_xss_hash = ''; + protected $_csrf_hash = ''; + protected $_csrf_expire = 7200; // Two hours (in seconds) + protected $_csrf_token_name = 'ci_csrf_token'; + protected $_csrf_cookie_name = 'ci_csrf_token'; /* never allowed, string replacement */ - public $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 */ - public $never_allowed_regex = array( - "javascript\s*:" => '[removed]', - "expression\s*(\(|&\#40;)" => '[removed]', // CSS and IE - "vbscript\s*:" => '[removed]', // IE, surprise! - "Redirect\s+302" => '[removed]' - ); + protected $_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 */ + protected $_never_allowed_regex = array( + "javascript\s*:" => '[removed]', + "expression\s*(\(|&\#40;)" => '[removed]', // CSS and IE + "vbscript\s*:" => '[removed]', // IE, surprise! + "Redirect\s+302" => '[removed]' + ); + + /** + * Constructor + */ public function __construct() { - $this->csrf_token_name = (config_item('csrf_token_name')) ? config_item('csrf_token_name') : 'csrf_token_name'; - $this->csrf_cookie_name = (config_item('csrf_cookie_name')) ? config_item('csrf_cookie_name') : 'csrf_cookie_name'; - $this->csrf_expire = (config_item('csrf_expire')) ? config_item('csrf_expire') : 7200; - // Append application specific cookie prefix to token name - $this->csrf_cookie_name = (config_item('cookie_prefix')) ? config_item('cookie_prefix').$this->csrf_token_name : $this->csrf_token_name; + $this->_csrf_cookie_name = (config_item('cookie_prefix')) ? config_item('cookie_prefix').$this->_csrf_token_name : $this->_csrf_token_name; // Set the CSRF hash $this->_csrf_set_hash(); @@ -72,8 +72,7 @@ class CI_Security { /** * Verify Cross Site Request Forgery Protection * - * @access public - * @return null + * @return object */ public function csrf_verify() { @@ -84,26 +83,30 @@ class CI_Security { } // Do the tokens exist in both the _POST and _COOKIE arrays? - if ( ! isset($_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])) { $this->csrf_show_error(); } // Do the tokens match? - if ($_POST[$this->csrf_token_name] != $_COOKIE[$this->csrf_cookie_name]) + if ($_POST[$this->_csrf_token_name] != $_COOKIE[$this->_csrf_cookie_name]) { $this->csrf_show_error(); } - // We kill this since we're done and we don't want to polute the _POST array - unset($_POST[$this->csrf_token_name]); + // We kill this since we're done and we don't want to + // polute the _POST array + unset($_POST[$this->_csrf_token_name]); // Nothing should last forever - unset($_COOKIE[$this->csrf_cookie_name]); + unset($_COOKIE[$this->_csrf_cookie_name]); $this->_csrf_set_hash(); $this->csrf_set_cookie(); log_message('debug', "CSRF token verified "); + + return $this; } // -------------------------------------------------------------------- @@ -111,57 +114,68 @@ class CI_Security { /** * Set Cross Site Request Forgery Protection Cookie * - * @access public - * @return null + * @return object */ public function csrf_set_cookie() { - $expire = time() + $this->csrf_expire; + $expire = time() + $this->_csrf_expire; $secure_cookie = (config_item('cookie_secure') === TRUE) ? 1 : 0; - setcookie($this->csrf_cookie_name, $this->csrf_hash, $expire, config_item('cookie_path'), config_item('cookie_domain'), $secure_cookie); + if ($secure_cookie) + { + $req = isset($_SERVER['HTTPS']) ? $_SERVER['HTTPS'] : FALSE; + + if ( ! $req OR $req == 'off') + { + return FALSE; + } + } + + setcookie($this->_csrf_cookie_name, $this->_csrf_hash, $expire, config_item('cookie_path'), config_item('cookie_domain'), $secure_cookie); log_message('debug', "CRSF cookie Set"); + + return $this; } // -------------------------------------------------------------------- /** - * Set Cross Site Request Forgery Protection Cookie + * Show CSRF Error * - * @access private - * @return null + * @return void */ - private function _csrf_set_hash() + public function csrf_show_error() { - if ($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]) AND $_COOKIE[$this->csrf_cookie_name] != '') - { - $this->csrf_hash = $_COOKIE[$this->csrf_cookie_name]; - } - else - { - $this->csrf_hash = md5(uniqid(rand(), TRUE)); - } - } + show_error('The action you have requested is not allowed.'); + } - return $this->csrf_hash; + // -------------------------------------------------------------------- + + /** + * Get CSRF Hash + * + * Getter Method + * + * @return string self::_csrf_hash + */ + public function get_csrf_hash() + { + return $this->_csrf_hash; } // -------------------------------------------------------------------- /** - * Show CSRF Error + * Get CSRF Token Name * - * @access public - * @return null + * Getter Method + * + * @return string self::csrf_token_name */ - public function csrf_show_error() + public function get_csrf_token_name() { - show_error('The action you have requested is not allowed.'); + return $this->_csrf_token_name; } // -------------------------------------------------------------------- @@ -188,7 +202,6 @@ class CI_Security { * harvested from examining vulnerabilities in other programs: * http://ha.ckers.org/xss.html * - * @access public * @param mixed string or array * @return string */ @@ -213,35 +226,8 @@ class CI_Security { */ $str = remove_invisible_characters($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); + // Validate Entities in URLs + $str = $this->_validate_entities($str); /* * URL Decode @@ -265,7 +251,7 @@ class CI_Security { */ $str = preg_replace_callback("/[a-z]+=([\'\"]).*?\\1/si", array($this, '_convert_attribute'), $str); - + $str = preg_replace_callback("/<\w+.*?(?=>|<|$)/si", array($this, '_decode_entity'), $str); /* @@ -278,9 +264,8 @@ class CI_Security { * * This prevents strings like this: ja vascript * NOTE: we deal with spaces between characters later. - * NOTE: preg_replace was found to be amazingly slow here on large blocks of data, - * so we use str_replace. - * + * NOTE: preg_replace was found to be amazingly slow here on + * large blocks of data, so we use str_replace. */ if (strpos($str, "\t") !== FALSE) @@ -293,34 +278,23 @@ class CI_Security { */ $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); - } + // Remove Strings that are never allowed + $str = $this->_do_never_allowed($str); /* * Makes PHP tags safe * - * Note: XML tags are inadvertently replaced too: + * Note: XML tags are inadvertently replaced too: * - * <?xml + * <?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. + // 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 @@ -333,9 +307,12 @@ class CI_Security { * * 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'); + $words = array( + 'javascript', 'expression', 'vbscript', 'script', + 'applet', 'alert', 'document', 'write', 'cookie', 'window' + ); + foreach ($words as $word) { $temp = ''; @@ -352,8 +329,9 @@ class CI_Security { /* * 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 + * 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 { @@ -374,30 +352,12 @@ class CI_Security { $str = preg_replace("#<(/*)(script|xss)(.*?)\>#si", '[removed]', $str); } } - while ($original != $str); + while($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); + // Remove evil attributes such as style, onclick and xmlns + $str = $this->_remove_evil_attributes($str, $is_image); /* * Sanitize naughty HTML elements @@ -407,7 +367,6 @@ class CI_Security { * * 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); @@ -423,45 +382,28 @@ class CI_Security { * * 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); - } + // Final clean up + // This adds a bit of extra precaution in case + // something got through the above filters + $str = $this->_do_never_allowed($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. + * 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 == $converted_string) - { - return TRUE; - } - else - { - return FALSE; - } + return ($str == $converted_string) ? TRUE: FALSE; } log_message('debug', "XSS Filtering completed"); @@ -473,59 +415,208 @@ class CI_Security { /** * Random Hash for protecting URLs * - * @access public * @return string */ public function xss_hash() { - if ($this->xss_hash == '') + if ($this->_xss_hash == '') { if (phpversion() >= 4.2) + { mt_srand(); + } else + { mt_srand(hexdec(substr(md5(microtime()), -8)) & 0x7fffffff); + } - $this->xss_hash = md5(time() + mt_rand(0, 1999999999)); + $this->_xss_hash = md5(time() + mt_rand(0, 1999999999)); } - return $this->xss_hash; + return $this->_xss_hash; } // -------------------------------------------------------------------- /** + * HTML Entities Decode + * + * This function is a replacement for html_entity_decode() + * + * In some versions of PHP the native function does not work + * when UTF-8 is the specified character set, so this gives us + * a work-around. More info here: + * http://bugs.php.net/bug.php?id=25670 + * + * NOTE: html_entity_decode() has a bug in some PHP versions when UTF-8 is the + * character set, and the PHP developers said they were not back porting the + * fix to versions other than PHP 5.x. + * + * @param string + * @param string + * @return string + */ + public function entity_decode($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')) + { + $str = html_entity_decode($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 $str; + } + + // -------------------------------------------------------------------- + + /** + * Filename Security + * + * @param string + * @return string + */ + public function sanitize_filename($str, $relative_path = FALSE) + { + $bad = array( + "../", + "<!--", + "-->", + "<", + ">", + "'", + '"', + '&', + '$', + '#', + '{', + '}', + '[', + ']', + '=', + ';', + '?', + "%20", + "%22", + "%3c", // < + "%253c", // < + "%3e", // > + "%0e", // > + "%28", // ( + "%29", // ) + "%2528", // ( + "%26", // & + "%24", // $ + "%3f", // ? + "%3b", // ; + "%3d" // = + ); + + if ( ! $relative_path) + { + $bad[] = './'; + $bad[] = '/'; + } + + $str = remove_invisible_characters($str, FALSE); + return stripslashes(str_replace($bad, '', $str)); + } + + // ---------------------------------------------------------------- + + /** * Compact Exploded Words * * Callback function for xss_clean() to remove whitespace from * things like j a v a s c r i p t * - * @access private * @param type * @return type */ - private function _compact_exploded_words($matches) + protected function _compact_exploded_words($matches) { return preg_replace('/\s+/s', '', $matches[1]).$matches[2]; } // -------------------------------------------------------------------- + + /* + * Remove Evil HTML Attributes (like evenhandlers and style) + * + * It removes the evil attribute and either: + * - Everything up until a space + * For example, everything between the pipes: + * <a |style=document.write('hello');alert('world');| class=link> + * - Everything inside the quotes + * For example, everything between the pipes: + * <a |style="document.write('hello'); alert('world');"| class="link"> + * + * @param string $str The string to check + * @param boolean $is_image TRUE if this is an image + * @return string The string with the evil attributes removed + */ + protected function _remove_evil_attributes($str, $is_image) + { + // All javascript event handlers (e.g. onload, onclick, onmouseover), style, and xmlns + $evil_attributes = array('on\w*', 'style', 'xmlns'); + + if ($is_image === TRUE) + { + /* + * Adobe Photoshop puts XML metadata into JFIF images, + * including namespacing, so we have to allow this for images. + */ + unset($evil_attributes[array_search('xmlns', $evil_attributes)]); + } + + do { + $str = preg_replace( + "#<(/?[^><]+?)([^A-Za-z\-])(".implode('|', $evil_attributes).")(\s*=\s*)([\"][^>]*?[\"]|[\'][^>]*?[\']|[^>]*?)([\s><])([><]*)#i", + "<$1$6", + $str, -1, $count + ); + } while ($count); + + return $str; + } + + // -------------------------------------------------------------------- /** * Sanitize Naughty HTML * * Callback function for xss_clean() to remove naughty HTML elements * - * @access private * @param array * @return string */ - private function _sanitize_naughty_html($matches) + protected 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]); + $str .= str_replace(array('>', '<'), array('>', '<'), + $matches[4]); return $str; } @@ -540,16 +631,18 @@ class CI_Security { * and prevents PREG_BACKTRACK_LIMIT_ERROR from being triggered in * PHP 5.2+ on link-heavy strings * - * @access private * @param array * @return string */ - private function _js_link_removal($match) + 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\:|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|base64\s*,)#si", "", $attributes), $match[0]); } + // -------------------------------------------------------------------- + /** * JS Image Removal * @@ -558,14 +651,14 @@ class CI_Security { * and prevents PREG_BACKTRACK_LIMIT_ERROR from being triggered in * PHP 5.2+ on image tag heavy strings * - * @access private * @param array * @return string */ - private function _js_img_removal($match) + 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\:|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", "", $attributes), $match[0]); } // -------------------------------------------------------------------- @@ -575,11 +668,10 @@ class CI_Security { * * Used as a callback for XSS Clean * - * @access private * @param array * @return string */ - private function _convert_attribute($match) + protected function _convert_attribute($match) { return str_replace(array('>', '<', '\\'), array('>', '<', '\\\\'), $match[0]); } @@ -591,11 +683,10 @@ class CI_Security { * * Filters tag attributes for consistency and safety * - * @access private * @param string * @return string */ - private function _filter_attributes($str) + protected function _filter_attributes($str) { $out = ''; @@ -617,118 +708,109 @@ class CI_Security { * * Used as a callback for XSS Clean * - * @access private * @param array * @return string */ - private function _decode_entity($match) + protected function _decode_entity($match) { return $this->entity_decode($match[0], strtoupper(config_item('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 + * Validate URL entities * - * 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. + * Called by xss_clean() * - * @access public - * @param string - * @param string - * @return string + * @param string + * @return string */ - public function entity_decode($str, $charset='UTF-8') + protected function _validate_entities($str) { - if (stristr($str, '&') === FALSE) return $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); - // 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. + /* + * 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", $str); - if (function_exists('html_entity_decode') && (strtolower($charset) != 'utf-8' OR is_php('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); - } + /* + * 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); - // 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); + /* + * Un-Protect GET variables in URLs + */ + $str = str_replace($this->xss_hash(), '&', $str); + + return $str; + } - // Literal Entities - Slightly slow so we do another check - if (stristr($str, '&') === FALSE) + // ---------------------------------------------------------------------- + + /** + * Do Never Allowed + * + * A utility function for xss_clean() + * + * @param string + * @return string + */ + protected function _do_never_allowed($str) + { + foreach ($this->_never_allowed_str as $key => $val) { - $str = strtr($str, array_flip(get_html_translation_table(HTML_ENTITIES))); + $str = str_replace($key, $val, $str); } + foreach ($this->_never_allowed_regex as $key => $val) + { + $str = preg_replace("#".$key."#i", $val, $str); + } + return $str; } // -------------------------------------------------------------------- /** - * Filename Security + * Set Cross Site Request Forgery Protection Cookie * - * @access public - * @param string * @return string */ - public function sanitize_filename($str, $relative_path = FALSE) + protected function _csrf_set_hash() { - $bad = array( - "../", - "<!--", - "-->", - "<", - ">", - "'", - '"', - '&', - '$', - '#', - '{', - '}', - '[', - ']', - '=', - ';', - '?', - "%20", - "%22", - "%3c", // < - "%253c", // < - "%3e", // > - "%0e", // > - "%28", // ( - "%29", // ) - "%2528", // ( - "%26", // & - "%24", // $ - "%3f", // ? - "%3b", // ; - "%3d" // = - ); - - if ( ! $relative_path) + if ($this->_csrf_hash == '') { - $bad[] = './'; - $bad[] = '/'; + // If the cookie exists we will use it's value. + // We don't necessarily want to regenerate it with + // each page load since a page could contain embedded + // sub-pages causing this feature to fail + if (isset($_COOKIE[$this->_csrf_cookie_name]) && + $_COOKIE[$this->_csrf_cookie_name] != '') + { + return $this->_csrf_hash = $_COOKIE[$this->_csrf_cookie_name]; + } + + return $this->_csrf_hash = md5(uniqid(rand(), TRUE)); } - return stripslashes(str_replace($bad, '', $str)); + return $this->_csrf_hash; } } |