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authorPascal Kriete <pascal@pascalkriete.com>2011-11-14 21:15:15 +0100
committerPascal Kriete <pascal@pascalkriete.com>2011-11-14 21:15:15 +0100
commitf525f10c850399700a4cce183aef55656ff44d31 (patch)
treed0250655551d773c9347573e594997e07d7280a5 /system/core/Security.php
parent44cdece942c310f5520497dbde4febc26e96c27e (diff)
parent917c3455cc70d5117daa7359f345a820154ada3e (diff)
Merge branch 'release/2.1.0'
Conflicts: user_guide/helpers/url_helper.html
Diffstat (limited to 'system/core/Security.php')
-rwxr-xr-x[-rw-r--r--]system/core/Security.php208
1 files changed, 121 insertions, 87 deletions
diff --git a/system/core/Security.php b/system/core/Security.php
index 3617cadcc..a3e227437 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]',
@@ -42,17 +77,24 @@ class CI_Security {
'-moz-binding' => '[removed]',
'<!--' => '&lt;!--',
'-->' => '--&gt;',
- '<![CDATA[' => '&lt;![CDATA['
+ '<![CDATA[' => '&lt;![CDATA[',
+ '<comment>' => '&lt;comment&gt;'
);
/* 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 +137,7 @@ 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 +149,7 @@ 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 +159,7 @@ class CI_Security {
$this->csrf_set_cookie();
log_message('debug', "CSRF token verified ");
-
+
return $this;
}
@@ -146,7 +188,7 @@ class CI_Security {
setcookie($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 $this;
}
@@ -165,9 +207,9 @@ class CI_Security {
// --------------------------------------------------------------------
/**
- * Get CSRF Hash
+ * Get CSRF Hash
*
- * Getter Method
+ * Getter Method
*
* @return string self::_csrf_hash
*/
@@ -215,6 +257,7 @@ class CI_Security {
* http://ha.ckers.org/xss.html
*
* @param mixed string or array
+ * @param bool
* @return string
*/
public function xss_clean($str, $is_image = FALSE)
@@ -263,7 +306,7 @@ 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'), $str);
/*
@@ -276,7 +319,7 @@ class CI_Security {
*
* This prevents strings like this: ja vascript
* NOTE: we deal with spaces between characters later.
- * NOTE: preg_replace was found to be amazingly slow here on
+ * NOTE: preg_replace was found to be amazingly slow here on
* large blocks of data, so we use str_replace.
*/
@@ -304,8 +347,8 @@ class CI_Security {
*/
if ($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', "&lt;?\\1", $str);
}
@@ -321,10 +364,10 @@ 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)
{
$temp = '';
@@ -341,8 +384,8 @@ class CI_Security {
/*
* Remove disallowed Javascript in links or img tags
- * We used to do some version comparisons and use of stripos for PHP5,
- * but it is dog slow compared to these simplified non-capturing
+ * We used to do some version comparisons and use of stripos for PHP5,
+ * but it is dog slow compared to these simplified non-capturing
* preg_match(), especially if the pattern exists in the string
*/
do
@@ -405,11 +448,11 @@ class CI_Security {
/*
* Images are Handled in a Special Way
- * - Essentially, we want to know that after all of the character
- * conversion is done whether any unwanted, likely XSS, code was found.
+ * - Essentially, we want to know that after all of the character
+ * conversion is done whether any unwanted, likely XSS, code was found.
* If not, we return TRUE, as the image is clean.
- * However, if the string post-conversion does not matched the
- * string post-removal of XSS, then it fails, as there was unwanted XSS
+ * However, if the string post-conversion does not matched the
+ * string post-removal of XSS, then it fails, as there was unwanted XSS
* code found and removed/changed during processing.
*/
@@ -433,15 +476,7 @@ class CI_Security {
{
if ($this->_xss_hash == '')
{
- if (phpversion() >= 4.2)
- {
- mt_srand();
- }
- else
- {
- mt_srand(hexdec(substr(md5(microtime()), -8)) & 0x7fffffff);
- }
-
+ mt_srand();
$this->_xss_hash = md5(time() + mt_rand(0, 1999999999));
}
@@ -455,14 +490,11 @@ class CI_Security {
*
* This function is a replacement for html_entity_decode()
*
- * In some versions of PHP the native function does not work
- * when UTF-8 is the specified character set, so this gives us
- * a work-around. More info here:
- * http://bugs.php.net/bug.php?id=25670
- *
- * NOTE: html_entity_decode() has a bug in some PHP versions when UTF-8 is the
- * character set, and the PHP developers said they were not back porting the
- * fix to versions other than PHP 5.x.
+ * The reason we are not using html_entity_decode() by itself is because
+ * while it is not technically correct to leave out the semicolon
+ * at the end of an entity most browsers will still interpret the entity
+ * correctly. html_entity_decode() does not convert entities without
+ * semicolons, so we are left with our own little solution here. Bummer.
*
* @param string
* @param string
@@ -470,33 +502,14 @@ class CI_Security {
*/
public function entity_decode($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;
}
- return $str;
+ $str = html_entity_decode($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)', $str);
}
// --------------------------------------------------------------------
@@ -505,6 +518,7 @@ class CI_Security {
* Filename Security
*
* @param string
+ * @param bool
* @return string
*/
public function sanitize_filename($str, $relative_path = FALSE)
@@ -542,7 +556,7 @@ class CI_Security {
"%3b", // ;
"%3d" // =
);
-
+
if ( ! $relative_path)
{
$bad[] = './';
@@ -570,7 +584,7 @@ class CI_Security {
}
// --------------------------------------------------------------------
-
+
/*
* Remove Evil HTML Attributes (like evenhandlers and style)
*
@@ -578,7 +592,7 @@ class CI_Security {
* - Everything up until a space
* For example, everything between the pipes:
* <a |style=document.write('hello');alert('world');| class=link>
- * - Everything inside the quotes
+ * - Everything inside the quotes
* For example, everything between the pipes:
* <a |style="document.write('hello'); alert('world');"| class="link">
*
@@ -589,7 +603,7 @@ class CI_Security {
protected function _remove_evil_attributes($str, $is_image)
{
// All javascript event handlers (e.g. onload, onclick, onmouseover), style, and xmlns
- $evil_attributes = array('on\w*', 'style', 'xmlns');
+ $evil_attributes = array('on\w*', 'style', 'xmlns', 'formaction');
if ($is_image === TRUE)
{
@@ -601,16 +615,36 @@ class CI_Security {
}
do {
- $str = preg_replace(
- "#<(/?[^><]+?)([^A-Za-z\-])(".implode('|', $evil_attributes).")(\s*=\s*)([\"][^>]*?[\"]|[\'][^>]*?[\']|[^>]*?)([\s><])([><]*)#i",
- "<$1$6",
- $str, -1, $count
- );
+ $count = 0;
+ $attribs = array();
+
+ // find occurrences of illegal attribute strings without quotes
+ preg_match_all("/(".implode('|', $evil_attributes).")\s*=\s*([^\s]*)/is", $str, $matches, PREG_SET_ORDER);
+
+ foreach ($matches as $attr)
+ {
+ $attribs[] = preg_quote($attr[0], '/');
+ }
+
+ // find occurrences of illegal attribute strings with quotes (042 and 047 are octal quotes)
+ preg_match_all("/(".implode('|', $evil_attributes).")\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is", $str, $matches, PREG_SET_ORDER);
+
+ foreach ($matches as $attr)
+ {
+ $attribs[] = preg_quote($attr[0], '/');
+ }
+
+ // 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, $count);
+ }
+
} while ($count);
return $str;
}
-
+
// --------------------------------------------------------------------
/**
@@ -627,7 +661,7 @@ class CI_Security {
$str = '&lt;'.$matches[1].$matches[2].$matches[3];
// encode captured opening or closing brace to prevent recursive vectors
- $str .= str_replace(array('>', '<'), array('&gt;', '&lt;'),
+ $str .= str_replace(array('>', '<'), array('&gt;', '&lt;'),
$matches[4]);
return $str;
@@ -649,7 +683,7 @@ class CI_Security {
protected function _js_link_removal($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), $match[0]);
}
@@ -669,7 +703,7 @@ class CI_Security {
protected function _js_img_removal($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), $match[0]);
}
@@ -729,13 +763,13 @@ class CI_Security {
}
// --------------------------------------------------------------------
-
+
/**
* Validate URL entities
*
* Called by xss_clean()
*
- * @param string
+ * @param string
* @return string
*/
protected function _validate_entities($str)
@@ -743,9 +777,9 @@ 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 +803,7 @@ class CI_Security {
* Un-Protect GET variables in URLs
*/
$str = str_replace($this->xss_hash(), '&', $str);
-
+
return $str;
}
@@ -794,7 +828,7 @@ class CI_Security {
{
$str = preg_replace("#".$key."#i", $val, $str);
}
-
+
return $str;
}
@@ -809,16 +843,16 @@ class CI_Security {
{
if ($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));
}