Extend CI to allow http_only cookie

<?php

class MY_Session extends CI_Session
{
    private $cookie_http_only = 0;

    /**
     * Session Constructor
     *
     * The constructor runs the session routines automatically
     * whenever the class is instantiated.
     */
    public function __construct($params = array())
    {
        log_message('debug', "Session Class Initialized");

        // Set the super object to a local variable for use throughout the class
        $this->CI =& get_instance();

        // Set all the session preferences, which can either be set
        // manually via the $params array above or via the config file
        foreach (array('sess_encrypt_cookie', 'sess_use_database', 'sess_table_name', 'sess_expiration', 'sess_expire_on_close', 'sess_match_ip', 'sess_match_useragent', 'sess_cookie_name', 'cookie_path', 'cookie_domain', 'cookie_secure', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key', 'cookie_http_only') as $key)
        {
            $this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key);
        }

        if ($this->encryption_key == '')
        {
            show_error('In order to use the Session class you are required to set an encryption key in your config file.');
        }

        // Load the string helper so we can use the strip_slashes() function
        $this->CI->load->helper('string');

        // Do we need encryption? If so, load the encryption class
        if ($this->sess_encrypt_cookie == TRUE)
        {
            $this->CI->load->library('encrypt');
        }

        // Are we using a database?  If so, load it
        if ($this->sess_use_database === TRUE AND $this->sess_table_name != '')
        {
            $this->CI->load->database();
        }

        // Set the "now" time.  Can either be GMT or server time, based on the
        // config prefs.  We use this to set the "last activity" time
        $this->now = $this->_get_time();

        // Set the session length. If the session expiration is
        // set to zero we'll set the expiration two years from now.
        if ($this->sess_expiration == 0)
        {
            $this->sess_expiration = (60*60*24*365*2);
        }

        // Set the cookie name
        $this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name;

        // Run the Session routine. If a session doesn't exist we'll
        // create a new one.  If it does, we'll update it.
        if ( ! $this->sess_read())
        {
            $this->sess_create();
        }
        else
        {
            $this->sess_update();
        }

        // Delete 'old' flashdata (from last request)
        $this->_flashdata_sweep();

        // Mark all new flashdata as old (data will be deleted before next request)
        $this->_flashdata_mark();

        // Delete expired sessions if necessary
        $this->_sess_gc();

        log_message('debug', "Session routines successfully run");
    }

    function _set_cookie($cookie_data = NULL)
    {
        if (is_null($cookie_data))
        {
            $cookie_data = $this->userdata;
        }

        // Serialize the userdata for the cookie
        $cookie_data = $this->_serialize($cookie_data);

        if ($this->sess_encrypt_cookie == TRUE)
        {
            $cookie_data = $this->CI->encrypt->encode($cookie_data);
        }

        $cookie_data .= hash_hmac('sha1', $cookie_data, $this->encryption_key);

        $expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time();

        // Set the cookie
        setcookie(
            $this->sess_cookie_name,
            $cookie_data,
            $expire,
            $this->cookie_path,
            $this->cookie_domain,
            $this->cookie_secure,
            $this->cookie_http_only
        );
    }
}