diff options
author | Phil Sturgeon <email@philsturgeon.co.uk> | 2011-08-15 01:15:12 +0200 |
---|---|---|
committer | Phil Sturgeon <email@philsturgeon.co.uk> | 2011-08-15 01:15:12 +0200 |
commit | 08d186492af82a7087c0a45a80b7e8d469c83292 (patch) | |
tree | 795ecf075e524e4a33d98a90580eb4dcabf80040 /system/core/Security.php | |
parent | 2369e77dcd716c772576c1f982e9446785db819d (diff) | |
parent | 07b53422f8d61e6b0b7e6479b0de92ad1a1ce05e (diff) |
Merge pull request #52 from waldmeister/develop
Added some docs to CI core files
Diffstat (limited to 'system/core/Security.php')
-rwxr-xr-x[-rw-r--r--] | system/core/Security.php | 131 |
1 files changed, 87 insertions, 44 deletions
diff --git a/system/core/Security.php b/system/core/Security.php index 3617cadcc..dcc680a11 100644..100755 --- a/system/core/Security.php +++ b/system/core/Security.php @@ -25,14 +25,49 @@ * @link http://codeigniter.com/user_guide/libraries/security.html */ class CI_Security { - + + /** + * Random Hash for protecting URLs + * + * @var string + * @access protected + */ protected $_xss_hash = ''; + /** + * Random Hash for Cross Site Request Forgery Protection Cookie + * + * @var string + * @access protected + */ protected $_csrf_hash = ''; - protected $_csrf_expire = 7200; // Two hours (in seconds) + /** + * Expiration time for Cross Site Request Forgery Protection Cookie + * Defaults to two hours (in seconds) + * + * @var int + * @access protected + */ + protected $_csrf_expire = 7200; + /** + * Token name for Cross Site Request Forgery Protection Cookie + * + * @var string + * @access protected + */ protected $_csrf_token_name = 'ci_csrf_token'; + /** + * Cookie name for Cross Site Request Forgery Protection Cookie + * + * @var string + * @access protected + */ protected $_csrf_cookie_name = 'ci_csrf_token'; - - /* never allowed, string replacement */ + /** + * List of never allowed strings + * + * @var array + * @access protected + */ protected $_never_allowed_str = array( 'document.cookie' => '[removed]', 'document.write' => '[removed]', @@ -46,13 +81,19 @@ class CI_Security { ); /* never allowed, regex replacement */ + /** + * List of never allowed regex replacement + * + * @var array + * @access protected + */ protected $_never_allowed_regex = array( "javascript\s*:" => '[removed]', "expression\s*(\(|&\#40;)" => '[removed]', // CSS and IE "vbscript\s*:" => '[removed]', // IE, surprise! "Redirect\s+302" => '[removed]' ); - + /** * Constructor */ @@ -95,7 +136,7 @@ class CI_Security { } // Do the tokens exist in both the _POST and _COOKIE arrays? - if ( ! isset($_POST[$this->_csrf_token_name]) OR + if ( ! isset($_POST[$this->_csrf_token_name]) OR ! isset($_COOKIE[$this->_csrf_cookie_name])) { $this->csrf_show_error(); @@ -107,7 +148,7 @@ class CI_Security { $this->csrf_show_error(); } - // We kill this since we're done and we don't want to + // We kill this since we're done and we don't want to // polute the _POST array unset($_POST[$this->_csrf_token_name]); @@ -117,7 +158,7 @@ class CI_Security { $this->csrf_set_cookie(); log_message('debug', "CSRF token verified "); - + return $this; } @@ -146,7 +187,7 @@ class CI_Security { setcookie($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 $this; } @@ -165,9 +206,9 @@ class CI_Security { // -------------------------------------------------------------------- /** - * Get CSRF Hash + * Get CSRF Hash * - * Getter Method + * Getter Method * * @return string self::_csrf_hash */ @@ -215,6 +256,7 @@ class CI_Security { * http://ha.ckers.org/xss.html * * @param mixed string or array + * @param bool * @return string */ public function xss_clean($str, $is_image = FALSE) @@ -263,7 +305,7 @@ 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'), $str); /* @@ -276,7 +318,7 @@ class CI_Security { * * This prevents strings like this: ja vascript * NOTE: we deal with spaces between characters later. - * NOTE: preg_replace was found to be amazingly slow here on + * NOTE: preg_replace was found to be amazingly slow here on * large blocks of data, so we use str_replace. */ @@ -304,8 +346,8 @@ class CI_Security { */ if ($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 + // 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); } @@ -321,10 +363,10 @@ class CI_Security { * These words are compacted back to their correct state. */ $words = array( - 'javascript', 'expression', 'vbscript', 'script', + 'javascript', 'expression', 'vbscript', 'script', 'applet', 'alert', 'document', 'write', 'cookie', 'window' ); - + foreach ($words as $word) { $temp = ''; @@ -341,8 +383,8 @@ class CI_Security { /* * Remove disallowed Javascript in links or img tags - * We used to do some version comparisons and use of stripos for PHP5, - * but it is dog slow compared to these simplified non-capturing + * We used to do some version comparisons and use of stripos for PHP5, + * but it is dog slow compared to these simplified non-capturing * preg_match(), especially if the pattern exists in the string */ do @@ -405,11 +447,11 @@ class CI_Security { /* * Images are Handled in a Special Way - * - Essentially, we want to know that after all of the character - * conversion is done whether any unwanted, likely XSS, code was found. + * - Essentially, we want to know that after all of the character + * conversion is done whether any unwanted, likely XSS, code was found. * If not, we return TRUE, as the image is clean. - * However, if the string post-conversion does not matched the - * string post-removal of XSS, then it fails, as there was unwanted XSS + * However, if the string post-conversion does not matched the + * string post-removal of XSS, then it fails, as there was unwanted XSS * code found and removed/changed during processing. */ @@ -478,7 +520,7 @@ class CI_Security { // correctly. html_entity_decode() does not convert entities without // semicolons, so we are left with our own little solution here. Bummer. - if (function_exists('html_entity_decode') && + if (function_exists('html_entity_decode') && (strtolower($charset) != 'utf-8')) { $str = html_entity_decode($str, ENT_COMPAT, $charset); @@ -505,6 +547,7 @@ class CI_Security { * Filename Security * * @param string + * @param bool * @return string */ public function sanitize_filename($str, $relative_path = FALSE) @@ -542,7 +585,7 @@ class CI_Security { "%3b", // ; "%3d" // = ); - + if ( ! $relative_path) { $bad[] = './'; @@ -570,7 +613,7 @@ class CI_Security { } // -------------------------------------------------------------------- - + /* * Remove Evil HTML Attributes (like evenhandlers and style) * @@ -578,7 +621,7 @@ class CI_Security { * - Everything up until a space * For example, everything between the pipes: * <a |style=document.write('hello');alert('world');| class=link> - * - Everything inside the quotes + * - Everything inside the quotes * For example, everything between the pipes: * <a |style="document.write('hello'); alert('world');"| class="link"> * @@ -594,12 +637,12 @@ class CI_Security { if ($is_image === TRUE) { /* - * Adobe Photoshop puts XML metadata into JFIF images, + * 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", @@ -607,10 +650,10 @@ class CI_Security { $str, -1, $count ); } while ($count); - + return $str; } - + // -------------------------------------------------------------------- /** @@ -627,7 +670,7 @@ class CI_Security { $str = '<'.$matches[1].$matches[2].$matches[3]; // encode captured opening or closing brace to prevent recursive vectors - $str .= str_replace(array('>', '<'), array('>', '<'), + $str .= str_replace(array('>', '<'), array('>', '<'), $matches[4]); return $str; @@ -649,7 +692,7 @@ class CI_Security { protected function _js_link_removal($match) { $attributes = $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1])); - + return str_replace($match[1], preg_replace("#href=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si", "", $attributes), $match[0]); } @@ -669,7 +712,7 @@ class CI_Security { protected function _js_img_removal($match) { $attributes = $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1])); - + return str_replace($match[1], preg_replace("#src=.*?(alert\(|alert&\#40;|javascript\:|livescript\:|mocha\:|charset\=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si", "", $attributes), $match[0]); } @@ -729,13 +772,13 @@ class CI_Security { } // -------------------------------------------------------------------- - + /** * Validate URL entities * * Called by xss_clean() * - * @param string + * @param string * @return string */ protected function _validate_entities($str) @@ -743,9 +786,9 @@ class CI_Security { /* * Protect GET variables in URLs */ - + // 901119URL5918AMP18930PROTECT8198 - + $str = preg_replace('|\&([a-z\_0-9\-]+)\=([a-z\_0-9\-]+)|i', $this->xss_hash()."\\1=\\2", $str); /* @@ -769,7 +812,7 @@ class CI_Security { * Un-Protect GET variables in URLs */ $str = str_replace($this->xss_hash(), '&', $str); - + return $str; } @@ -794,7 +837,7 @@ class CI_Security { { $str = preg_replace("#".$key."#i", $val, $str); } - + return $str; } @@ -809,16 +852,16 @@ class CI_Security { { if ($this->_csrf_hash == '') { - // If the cookie exists we will use it's value. + // 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 + // each page load since a page could contain embedded // sub-pages causing this feature to fail - if (isset($_COOKIE[$this->_csrf_cookie_name]) && + 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)); } |