Add CI_Security::get_random_bytes() for CSRF & XSS token generation
diff --git a/system/core/Security.php b/system/core/Security.php
index bb06705..bc224e7 100755
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -77,7 +77,7 @@
*
* @var string
*/
- protected $_xss_hash = '';
+ protected $_xss_hash;
/**
* CSRF Hash
@@ -86,7 +86,7 @@
*
* @var string
*/
- protected $_csrf_hash = '';
+ protected $_csrf_hash;
/**
* CSRF Expire time
@@ -227,7 +227,7 @@
{
// Nothing should last forever
unset($_COOKIE[$this->_csrf_cookie_name]);
- $this->_csrf_hash = '';
+ $this->_csrf_hash = NULL;
}
$this->_csrf_set_hash();
@@ -538,9 +538,12 @@
*/
public function xss_hash()
{
- if ($this->_xss_hash === '')
+ if ($this->_xss_hash === NULL)
{
- $this->_xss_hash = md5(uniqid(mt_rand()));
+ $rand = $this->get_random_bytes(16);
+ $this->_xss_hash = ($rand === FALSE)
+ ? md5(uniqid(mt_rand(), TRUE))
+ : bin2hex($rand);
}
return $this->_xss_hash;
@@ -549,6 +552,46 @@
// --------------------------------------------------------------------
/**
+ * Get random bytes
+ *
+ * @param int $length Output length
+ * @return string
+ */
+ public function get_random_bytes($length)
+ {
+ if (empty($length) OR ! ctype_digit($length))
+ {
+ return FALSE;
+ }
+
+ // Unfortunately, none of the following PRNGs is guaranteed to exist ...
+ if (defined(MCRYPT_DEV_URANDOM) && ($output = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM)) !== FALSE)
+ {
+ return $output;
+ }
+
+
+ if (is_readable('/dev/urandom') && ($fp = fopen('/dev/urandom', 'rb')) !== FALSE)
+ {
+ $output = fread($fp, $length);
+ fclose($fp);
+ if ($output !== FALSE)
+ {
+ return $output;
+ }
+ }
+
+ if (function_exists('openssl_random_pseudo_bytes'))
+ {
+ return openssl_random_pseudo_bytes($length);
+ }
+
+ return FALSE;
+ }
+
+ // --------------------------------------------------------------------
+
+ /**
* HTML Entities Decode
*
* A replacement for html_entity_decode()
@@ -915,7 +958,7 @@
*/
protected function _csrf_set_hash()
{
- if ($this->_csrf_hash === '')
+ if ($this->_csrf_hash === NULL)
{
// If the cookie exists we will use its value.
// We don't necessarily want to regenerate it with
@@ -927,7 +970,11 @@
return $this->_csrf_hash = $_COOKIE[$this->_csrf_cookie_name];
}
- $this->_csrf_hash = md5(uniqid(mt_rand(), TRUE));
+ $rand = $this->get_random_bytes(16);
+ $this->_csrf_hash = ($rand === FALSE)
+ ? md5(uniqid(mt_rand(), TRUE))
+ : bin2hex($rand);
+
$this->csrf_set_cookie();
}