<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.2.4 or newer
 *
 * NOTICE OF LICENSE
 *
 * Licensed under the Open Software License version 3.0
 *
 * This source file is subject to the Open Software License (OSL 3.0) that is
 * bundled with this package in the files license.txt / license.rst.  It is
 * also available through the world wide web at this URL:
 * http://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to obtain it
 * through the world wide web, please send an email to
 * licensing@ellislab.com so we can send you a copy immediately.
 *
 * @package		CodeIgniter
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2013, EllisLab, Inc. (http://ellislab.com/)
 * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Security Class
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Security
 * @author		EllisLab Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/security.html
 */
class Dili_Security {

    /**
     * XSS Hash
     *
     * Random Hash for protecting URLs.
     *
     * @var	string
     */
    protected $_xss_hash =	'';

    /**
     * CSRF Hash
     *
     * Random hash for Cross Site Request Forgery protection cookie
     *
     * @var	string
     */
    protected $_csrf_hash =	'';

    /**
     * CSRF Expire time
     *
     * Expiration time for Cross Site Request Forgery protection cookie.
     * Defaults to two hours (in seconds).
     *
     * @var	int
     */
    protected $_csrf_expire =	7200;

    /**
     * CSRF Token name
     *
     * Token name for Cross Site Request Forgery protection cookie.
     *
     * @var	string
     */
    protected $_csrf_token_name =	'ci_csrf_token';

    /**
     * CSRF Cookie name
     *
     * Cookie name for Cross Site Request Forgery protection cookie.
     *
     * @var	string
     */
    protected $_csrf_cookie_name =	'ci_csrf_token';

    /**
     * List of never allowed strings
     *
     * @var	array
     */
    protected $_never_allowed_str =	array(
        'document.cookie'	=> '[removed]',
        'document.write'	=> '[removed]',
        '.parentNode'		=> '[removed]',
        '.innerHTML'		=> '[removed]',
        'window.location'	=> '[removed]',
        '-moz-binding'		=> '[removed]',
        '<!--'				=> '&lt;!--',
        '-->'				=> '--&gt;',
        '<![CDATA['			=> '&lt;![CDATA[',
        '<comment>'			=> '&lt;comment&gt;'
    );

    /**
     * List of never allowed regex replacements
     *
     * @var	array
     */
    protected $_never_allowed_regex = array(
        '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?
        if (config_item('csrf_protection') === TRUE)
        {
            // CSRF config
            foreach (array('csrf_expire', 'csrf_token_name', 'csrf_cookie_name') as $key)
            {
                if (FALSE !== ($val = config_item($key)))
                {
                    $this->{'_'.$key} = $val;
                }
            }

            // Append application specific cookie prefix
            if (config_item('cookie_prefix'))
            {
                $this->_csrf_cookie_name = config_item('cookie_prefix').$this->_csrf_cookie_name;
            }

            // Set the CSRF hash
            $this->_csrf_set_hash();
        }

        log_message('debug', 'Security Class Initialized');
    }

    // --------------------------------------------------------------------

    /**
     * CSRF Verify
     *
     * @return	CI_Security
     */
    public function csrf_verify()
    {
        // If it's not a POST request we will set the CSRF cookie
        if (strtoupper($_SERVER['REQUEST_METHOD']) !== 'POST')
        {
            return $this->csrf_set_cookie();
        }

        // Check if URI has been whitelisted from CSRF checks
        if ($exclude_uris = config_item('csrf_exclude_uris'))
        {
            $uri = load_class('URI', 'core');
            if (in_array($uri->uri_string(), $exclude_uris))
            {
                return $this;
            }
        }

        // Do the tokens exist in both the _POST and _COOKIE arrays?
        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();
        }

        // We kill this since we're done and we don't want to polute the _POST array
        unset($_POST[$this->_csrf_token_name]);

        // Regenerate on every submission?
        if (config_item('csrf_regenerate'))
        {
            // Nothing should last forever
            unset($_COOKIE[$this->_csrf_cookie_name]);
            $this->_csrf_hash = '';
        }

        $this->_csrf_set_hash();
        $this->csrf_set_cookie();

        log_message('debug', 'CSRF token verified');
        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * CSRF Set Cookie
     *
     * @codeCoverageIgnore
     * @return	CI_Security
     */
    public function csrf_set_cookie()
    {
        $expire = time() + $this->_csrf_expire;
        $secure_cookie = (bool) config_item('cookie_secure');

        if ($secure_cookie && ! is_https())
        {
            return FALSE;
        }

        setcookie(
            $this->_csrf_cookie_name,
            $this->_csrf_hash,
            $expire,
            config_item('cookie_path'),
            config_item('cookie_domain'),
            $secure_cookie,
            config_item('cookie_httponly')
        );
        log_message('debug', 'CRSF cookie Set');

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Show CSRF Error
     *
     * @return	void
     */
    public function csrf_show_error()
    {
        show_error('The action you have requested is not allowed.');
    }

    // --------------------------------------------------------------------

    /**
     * Get CSRF Hash
     *
     * @see		CI_Security::$_csrf_hash
     * @return 	string	CSRF hash
     */
    public function get_csrf_hash()
    {
        return $this->_csrf_hash;
    }

    // --------------------------------------------------------------------

    /**
     * Get CSRF Token Name
     *
     * @see		CI_Security::$_csrf_token_name
     * @return	string	CSRF token name
     */
    public function get_csrf_token_name()
    {
        return $this->_csrf_token_name;
    }

    // --------------------------------------------------------------------

    /**
     * XSS Clean
     *
     * Sanitizes data so that Cross Site Scripting Hacks can be
     * 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: Should only be used to deal with data upon submission.
     *	 It's not something that should be used for general
     *	 runtime processing.
     *
     * @link	http://channel.bitflux.ch/wiki/XSS_Prevention
     * 		Based in part on some code and ideas from Bitflux.
     *
     * @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	string|string[]	$str		Input data
     * @param 	bool		$is_image	Whether the input is an image
     * @return	string
     */
    public function xss_clean($str, $is_image = FALSE)
    {
        // Is the string an array?
        if (is_array($str))
        {
            while (list($key) = each($str))
            {
                $str[$key] = $this->xss_clean($str[$key]);
            }

            return $str;
        }

        // Remove Invisible Characters and validate entities in URLs
        $str = $this->_validate_entities(remove_invisible_characters($str));

        /*
         * URL Decode
         *
         * Just in case stuff like this is submitted:
         *
         * <a href="http://%77%77%77%2E%67%6F%6F%67%6C%65%2E%63%6F%6D">Google</a>
         *
         * Note: Use rawurldecode() so it does not remove plus signs
         */
        $str = rawurldecode($str);

        /*
         * Convert character entities to ASCII
         *
         * This permits our tests below to work reliably.
         * We only convert entities that are within tags since
         * these are the ones that will pose security problems.
         */
        $str = preg_replace_callback("/[a-z]+=([\'\"]).*?\\1/si", array($this, '_convert_attribute'), $str);
        $str = preg_replace_callback('/<\w+.*/si', array($this, '_decode_entity'), $str);

        // Remove Invisible Characters Again!
        $str = remove_invisible_characters($str);

        /*
         * Convert all tabs to spaces
         *
         * 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.
         */
        $str = str_replace("\t", ' ', $str);

        // Capture converted string for later comparison
        $converted_string = $str;

        // Remove Strings that are never allowed
        $str = $this->_do_never_allowed($str);

        /*
         * Makes PHP tags safe
         *
         * Note: XML tags are inadvertently replaced too:
         *
         * <?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.
            $str = preg_replace('/<\?(php)/i', '&lt;?\\1', $str);
        }
        else
        {
            $str = str_replace(array('<?', '?'.'>'), array('&lt;?', '?&gt;'), $str);
        }

        /*
         * Compact any exploded words
         *
         * 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', 'base64',
            'applet', 'alert', 'document', 'write', 'cookie', 'window'
        );

        foreach ($words as $word)
        {
            $word = implode('\s*', str_split($word)).'\s*';

            // We only want to do this when it is followed by a non-word character
            // That way valid stuff like "dealer to" does not become "dealerto"
            $str = preg_replace_callback('#('.substr($word, 0, -3).')(\W)#is', array($this, '_compact_exploded_words'), $str);
        }

        /*
         * 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
         */
        do
        {
            $original = $str;

            if (preg_match('/<a/i', $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);
            }

            if (preg_match('/script|xss/i', $str))
            {
                $str = preg_replace('#</*(?:script|xss).*?>#si', '[removed]', $str);
            }
        }
        while ($original !== $str);

        unset($original);

        // Remove evil attributes such as style, onclick and xmlns
        $str = $this->_remove_evil_attributes($str, $is_image);

        /*
         * Sanitize naughty HTML elements
         *
         * If a tag containing any of the words in the list
         * below is found, the tag gets converted to entities.
         *
         * So this: <blink>
         * Becomes: &lt;blink&gt;
         */
        $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);

        /*
         * Sanitize naughty scripting elements
         *
         * Similar to above, only instead of looking for
         * tags it looks for PHP and JavaScript commands
         * that are disallowed. Rather than removing the
         * code, it simply converts the parenthesis to entities
         * rendering the code un-executable.
         *
         * For example:	eval('some code')
         * Becomes:	eval&#40;'some code'&#41;
         */
        $str = preg_replace('#(alert|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si',
            '\\1\\2&#40;\\3&#41;',
            $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.
         */
        if ($is_image === TRUE)
        {
            return ($str === $converted_string);
        }

        log_message('debug', 'XSS Filtering completed');
        return $str;
    }

    // --------------------------------------------------------------------

    /**
     * XSS Hash
     *
     * 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 === '')
        {
            $this->_xss_hash = md5(uniqid(mt_rand()));
        }

        return $this->_xss_hash;
    }

    // --------------------------------------------------------------------

    /**
     * HTML Entities 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
     * 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.
     *
     * @link	http://php.net/html-entity-decode
     *
     * @param	string	$str		Input
     * @param	string	$charset	Character set
     * @return	string
     */
    public function entity_decode($str, $charset = NULL)
    {
        if (strpos($str, '&') === FALSE)
        {
            return $str;
        }

        if (empty($charset))
        {
            $charset = config_item('charset');
        }

        do
        {
            $matches = $matches1 = 0;

            $str = html_entity_decode($str, ENT_COMPAT, $charset);
            $str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str, -1, $matches);
            $str = preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str, -1, $matches1);
        }
        while ($matches OR $matches1);

        return $str;
    }

    // --------------------------------------------------------------------

    /**
     * Sanitize Filename
     *
     * @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'		// =
        );

        if ( ! $relative_path)
        {
            $bad[] = './';
            $bad[] = '/';
        }

        $str = remove_invisible_characters($str, FALSE);

        do
        {
            $old = $str;
            $str = str_replace($bad, '', $str);
        }
        while ($old !== $str);

        return stripslashes($str);
    }

    // ----------------------------------------------------------------

    /**
     * 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 method for xss_clean() to remove whitespace from
     * things like 'j a v a s c r i p t'.
     *
     * @used-by	CI_Security::xss_clean()
     * @param	array	$matches
     * @return	string
     */
    protected function _compact_exploded_words($matches)
    {
        return preg_replace('/\s+/s', '', $matches[1]).$matches[2];
    }

    // --------------------------------------------------------------------

    /**
     * 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:
     *
     *	<code>
     *		<a |style=document.write('hello');alert('world');| class=link>
     *	</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	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)
    {
        // All javascript event handlers (e.g. onload, onclick, onmouseover), style, and xmlns
        $evil_attributes = array('on\w*', 'style', 'xmlns', 'formaction');

        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 {
            $count = 0;
            $attribs = array();

            // 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], '/');
            }

            // 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], '/');
            }

            // 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$6$7$8', $str, -1, $count);
            }
        }
        while ($count);

        return $str;
    }

    // --------------------------------------------------------------------

    /**
     * Sanitize Naughty HTML
     *
     * Callback method for xss_clean() to remove naughty HTML elements.
     *
     * @used-by	CI_Security::xss_clean()
     * @param	array	$matches
     * @return	string
     */
    protected function _sanitize_naughty_html($matches)
    {
        return '&lt;'.$matches[1].$matches[2].$matches[3] // encode opening brace
        // encode captured opening or closing brace to prevent recursive vectors:
        .str_replace(array('>', '<'), array('&gt;', '&lt;'), $matches[4]);
    }

    // --------------------------------------------------------------------

    /**
     * JS Link Removal
     *
     * 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.
     *
     * @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|data\s*:)#si',
                '',
                $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
            ),
            $match[0]);
    }

    // --------------------------------------------------------------------

    /**
     * JS Image Removal
     *
     * 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.
     *
     * @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',
                '',
                $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
            ),
            $match[0]);
    }

    // --------------------------------------------------------------------

    /**
     * Attribute Conversion
     *
     * @used-by	CI_Security::xss_clean()
     * @param	array	$match
     * @return	string
     */
    protected function _convert_attribute($match)
    {
        return str_replace(array('>', '<', '\\'), array('&gt;', '&lt;', '\\\\'), $match[0]);
    }

    // --------------------------------------------------------------------

    /**
     * Filter Attributes
     *
     * Filters tag attributes for consistency and safety.
     *
     * @used-by	CI_Security::_js_img_removal()
     * @used-by	CI_Security::_js_link_removal()
     * @param	string	$str
     * @return	string
     */
    protected function _filter_attributes($str)
    {
        $out = '';
        if (preg_match_all('#\s*[a-z\-]+\s*=\s*(\042|\047)([^\\1]*?)\\1#is', $str, $matches))
        {
            foreach ($matches[0] as $match)
            {
                $out .= preg_replace('#/\*.*?\*/#s', '', $match);
            }
        }

        return $out;
    }

    // --------------------------------------------------------------------

    /**
     * HTML Entity Decode Callback
     *
     * @used-by	CI_Security::xss_clean()
     * @param	array	$match
     * @return	string
     */
    protected function _decode_entity($match)
    {
        return $this->entity_decode($match[0], strtoupper(config_item('charset')));
    }

    // --------------------------------------------------------------------

    /**
     * Validate URL entities
     *
     * @used-by	CI_Security::xss_clean()
     * @param 	string	$str
     * @return 	string
     */
    protected function _validate_entities($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
         */
        return str_replace($this->xss_hash(), '&', $str);
    }

    // ----------------------------------------------------------------------

    /**
     * Do Never Allowed
     *
     * @used-by	CI_Security::xss_clean()
     * @param 	string
     * @return 	string
     */
    protected function _do_never_allowed($str)
    {
        $str = str_replace(array_keys($this->_never_allowed_str), $this->_never_allowed_str, $str);

        foreach ($this->_never_allowed_regex as $regex)
        {
            $str = preg_replace('#'.$regex.'#is', '[removed]', $str);
        }

        return $str;
    }

    // --------------------------------------------------------------------

    /**
     * Set CSRF Hash and Cookie
     *
     * @return	string
     */
    protected function _csrf_set_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[$this->_csrf_cookie_name]) &&
                preg_match('#^[0-9a-f]{32}$#iS', $_COOKIE[$this->_csrf_cookie_name]) === 1)
            {
                return $this->_csrf_hash = $_COOKIE[$this->_csrf_cookie_name];
            }

            $this->_csrf_hash = md5(uniqid(rand(), TRUE));
            $this->csrf_set_cookie();
        }

        return $this->_csrf_hash;
    }

}

/* End of file Security.php */
/* Location: ./system/core/Security.php */