Myth\Auth\LocalAuthentication

Complexity

Total Complexity

87

Size/Duplication

Total Lines	926
Duplicated Lines	5.62 %

Coupling/Cohesion

Components	1
Dependencies	2

Importance

Changes	5
Bugs	1	Features	0

24 Methods

Rating	Name	Duplication	Size	Complexity
B	__construct()	0	26	4
B	logout()	0	30	5
B	isLoggedIn()	0	29	4
B	viaRemember()	0	37	4
B	registerUser()	0	36	4
B	activateUser()	5	26	4
A	activateUserById()	5	12	2
A	user()	0	4	1
A	id()	0	9	3
D	isThrottled()	0	101	14
B	remindUser()	0	31	3
B	login()	5	40	5
C	validate()	6	82	11
C	resetPassword()	11	69	7
A	changeStatus()	0	4	1
A	useModel()	0	11	3
A	error()	0	9	2
A	purgeLoginAttempts()	10	10	1
A	purgeRememberTokens()	10	10	1
A	rememberUser()	0	10	2
B	refreshRememberCookie()	0	36	2
A	invalidateRememberCookie()	0	16	1
B	loginUser()	0	33	2
A	setHeaders()	0	6	1

<?php namespace Myth\Auth;
/**
 * Sprint
 *
 * A set of power tools to enhance the CodeIgniter framework and provide consistent workflow.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package     Sprint
 * @author      Lonnie Ezell
 * @copyright   Copyright 2014-2015, New Myth Media, LLC (http://newmythmedia.com)
 * @license     http://opensource.org/licenses/MIT  (MIT)
 * @link        http://sprintphp.com
 * @since       Version 1.0
 */

use Myth\Auth\AuthenticateInterface;
use Myth\Events\Events;

/**
 * Class LocalAuthentication
 *
 * Provides most of the Authentication that web applications would need,
 * at least as far as local authentication goes. It does NOT provide
 * social authentication through third-party applications.
 *
 * The system attempts to incorporate as many of the ideas and best practices
 * set forth in the following documents:
 *
 *  - http://stackoverflow.com/questions/549/the-definitive-guide-to-form-based-website-authentication
 *  - https://www.owasp.org/index.php/Guide_to_Authentication
 *
 * todo: Set the error string for all error states here.
 *
 * @package Myth\Auth
 */
class LocalAuthentication implements AuthenticateInterface {

    protected $ci;

    protected $user = null;

    public $user_model = null;

    public $error = null;

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

    public function __construct( $ci=null )
    {
        if ($ci)
        {
            $this->ci= $ci;
        }
        else
        {
            $this->ci =& get_instance();
        }

        // Get our compatibility password file loaded up.
        if (! function_exists('password_hash'))
        {
            require_once dirname(__FILE__) .'password.php';
        }

        if (empty($this->ci->session))
        {
            $this->ci->load->library('session');
        }

        $this->ci->config->load('auth');
        $this->ci->load->model('auth/login_model');
        $this->ci->load->language('auth/auth');
    }

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

    /**
     * Attempt to log a user into the system.
     *
     * $credentials is an array of key/value pairs needed to log the user in.
     * This is often email/password, or username/password.
     *
     * @param array $credentials
     * @param bool  $remember
     * @return bool|mixed
     */
    public function login($credentials, $remember=false)
    {
        $user = $this->validate($credentials, true);

        // If the user is throttled due to too many invalid logins
        // or the system is under attack, kick them back.
        // We need to test for this after validation because we
        // don't want it to affect a valid login.

        // If throttling time is above zero, we can't allow
        // logins now.
        $time = (int)$this->isThrottled($user);
        if ($time > 0)

This code seems to be duplicated across your project.

        {
            $this->error = sprintf(lang('auth.throttled'), $time);
            return false;
        }

        if (! $user)
        {
            if (empty($this->error))
            {
                // We need to set an error if there is no one
                $this->error = lang('auth.invalid_user');
            }
            $this->user = null;
            return $user;
        }       

        $this->loginUser($user);

        if ($remember)
        {
            $this->rememberUser($user);
        }

        Events::trigger('didLogin', [$user]);

        return true;
    }

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

    /**
     * Validates user login information without logging them in.
     *
     * $credentials is an array of key/value pairs needed to log the user in.
     * This is often email/password, or username/password.
     *
     * @param $credentials
     * @param bool $return_user
     * @return mixed
     */
    public function validate($credentials, $return_user=false)
    {
        // Get ip address
        $ip_address = $this->ci->input->ip_address();

        // We do not want to force case-sensitivity on things
        // like username and email for usability sake.
        if (! empty($credentials['email']))
        {
            $credentials['email'] = strtolower($credentials['email']);
        }

        // Can't validate without a password.
        if (empty($credentials['password']) || count($credentials) < 2)
        {
            $this->ci->login_model->recordLoginAttempt($ip_address);
            return null;
        }

        $password = $credentials['password'];
        unset($credentials['password']);

        // We should only be allowed 1 single other credential to
        // test against.
        if (count($credentials) > 1)
        {
            $this->error = lang('auth.too_many_credentials');
            $this->ci->login_model->recordLoginAttempt($ip_address);
            return false;
        }

        // Ensure that the fields are allowed validation fields
        if (! in_array(key($credentials), config_item('auth.valid_fields')) )
        {
            $this->error = lang('auth.invalid_credentials');
            $this->ci->login_model->recordLoginAttempt($ip_address);
            return false;
        }

        // Can we find a user with those credentials?
        $user = $this->user_model->as_array()
                                 ->where($credentials)
                                 ->first();

        if (! $user)

This code seems to be duplicated across your project.

        {
            $this->error = lang('auth.invalid_user');
            $this->ci->login_model->recordLoginAttempt($ip_address);
            return false;
        }

        // Now, try matching the passwords.
        $result =  password_verify($password, $user['password_hash']);

        if (! $result)
        {
            $this->error = lang('auth.invalid_password');
            $this->ci->login_model->recordLoginAttempt($ip_address, $user['id']);
            return false;
        }

        // Check to see if the password needs to be rehashed.
        // This would be due to the hash algorithm or hash
        // cost changing since the last time that a user
        // logged in.
        if (password_needs_rehash($user['password_hash'], PASSWORD_DEFAULT, ['cost' => config_item('auth.hash_cost')] ))
        {
            $new_hash = Password::hashPassword($password);
            $this->user_model->skip_validation()
                             ->update($user['id'], ['password_hash' => $new_hash]);
            unset($new_hash);
        }

        // Is the user active?
        if (! $user['active'])
        {
            $this->error = lang('auth.inactive_account');
            return false;
        }

        return $return_user ? $user : true;
    }

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

    /**
     * Logs a user out and removes all session information.
     *
     * @return mixed
     */
    public function logout()
    {
        $this->ci->load->helper('cookie');

        if (! Events::trigger('beforeLogout', [$this->user]))
        {
            return false;
        }

        // Destroy the session data - but ensure a session is still
        // available for flash messages, etc.
        if (isset($_SESSION))
        {
            foreach ( $_SESSION as $key => $value )
            {
                $_SESSION[ $key ] = NULL;
                unset( $_SESSION[ $key ] );
            }
        }
        // Also, regenerate the session ID for a touch of added safety.
        $this->ci->session->sess_regenerate(true);

        // Take care of any rememberme functionality.
        if (config_item('auth.allow_remembering'))
        {
            $token = get_cookie('remember');

            $this->invalidateRememberCookie($this->user['email'], $token);
        }
    }

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

    /**
     * Checks whether a user is logged in or not.
     *
     * @return bool
     */
    public function isLoggedIn()
    {
        $id = $this->ci->session->userdata('logged_in');

        if (! $id)
        {
            return false;
        }

        // If the user var hasn't been filled in, we need to fill it in,
        // since this method will typically be used as the only method
        // to determine whether a user is logged in or not.
        if (! $this->user)
        {
            $this->user = $this->user_model->as_array()
                                           ->find_by('id', (int)$id);

            if (empty($this->user))
            {
                return false;
            }
        }

        // If logged in, ensure cache control
        // headers are in place
        $this->setHeaders();

        return true;
    }

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

    /**
     * Attempts to log a user in based on the "remember me" cookie.
     *
     * @return bool
     */
    public function viaRemember()
    {
        if (! config_item('auth.allow_remembering'))
        {
            return false;
        }

        $this->ci->load->helper('cookie');

        if (! $token = get_cookie('remember'))
        {
            return false;
        }

        // Attempt to match the token against our auth_tokens table.
        $query = $this->ci->db->where('hash', $this->ci->login_model->hashRememberToken($token))
                              ->get('auth_tokens');

        if (! $query->num_rows())
        {
            return false;
        }

        // Grab the user
        $email = $query->row()->email;

        $user = $this->user_model->as_array()
                                 ->find_by('email', $email);

        $this->loginUser($user);

        // We only want our remember me tokens to be valid
        // for a single use.
        $this->refreshRememberCookie($user, $token);

        return true;
    }

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

    /**
     * Registers a new user and handles activation method.
     *
     * @param $user_data
     * @return bool
     */
    public function registerUser($user_data)
    {
        // Anything special needed for Activation?
        $method = config_item('auth.activation_method');

        $user_data['active'] = $method == 'auto' ? 1 : 0;

        // If via email, we need to generate a hash
        $this->ci->load->helper('string');
        $token = random_string('alnum', 24);
        $user_data['activate_hash'] = hash('sha1', config_item('auth.salt') . $token);

        // Email should NOT be case sensitive.
        if (! empty($user_data['email']))
        {
            $user_data['email'] = strtolower($user_data['email']);
        }

        // Save the user
        if (! $id = $this->user_model->insert($user_data))
        {
            $this->error = $this->user_model->error();
            return false;
        }

        $data = [
            'user_id' => $id,
            'email'   => $user_data['email'],
            'token'   => $token,
            'method'  => $method
        ];

        Events::trigger('didRegisterUser', [$data]);

        return true;
    }

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

    /**
     * Used to verify the user values and activate a user so they can
     * visit the site.
     *
     * @param $data
     * @return bool
     */
    public function activateUser($data)
    {
        $post = [
            'email'         => $data['email'],
            'activate_hash' => hash('sha1', config_item('auth.salt') . $data['code'])
        ];

        $user = $this->user_model->where($post)
                                 ->first();

        if (! $user) {
            $this->error = $this->user_model->error() ? $this->user_model->error() : lang('auth.activate_no_user');

            return false;
        }

        if (! $this->user_model->update($user->id, ['active' => 1, 'activate_hash' => null]))
        {
            $this->error = $this->user_model->error();
            return false;
        }

        Events::trigger('didActivate', [(array)$user]);

        return true;
    }

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

    /**
     * Used to allow manual activation of a user with a known ID.
     *
     * @param $id
     * @return bool
     */
    public function activateUserById($id)
    {
        if (! $this->user_model->update($id, ['active' => 1, 'activate_hash' => null]))
        {
            $this->error = $this->user_model->error();
            return false;
        }

        Events::trigger('didActivate', [$this->user_model->as_array()->find($id)]);

        return true;
    }

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

    /**
     * Grabs the current user object. Returns NULL if nothing found.
     *
     * @return array|null
     */
    public function user()
    {
        return $this->user;
    }

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

    /**
     * A convenience method to grab the current user's ID.
     *
     * @return int|null
     */
    public function id()
    {
        if (! is_array($this->user) || empty($this->user['id']))
        {
            return null;
        }

        return (int)$this->user['id'];
    }

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

    /**
     * Checks to see if the user is currently being throttled.
     *
     *  - If they are NOT, will return FALSE.
     *  - If they ARE, will return the number of seconds until they can try again.
     *
     * @param $user
     * @return mixed
     */
    public function isThrottled($user)

isThrottled uses the super-global variable $_SESSION which is generally not recommended.

    {
        // Not throttling? Get outta here!
        if (! config_item('auth.allow_throttling'))
        {
            return false;
        }

        // Get user_id
        $user_id = $user ? $user['id'] : null;
        
        // Get ip address
        $ip_address = $this->ci->input->ip_address();

        // Have any attempts been made?
        $attempts = $this->ci->login_model->countLoginAttempts($ip_address, $user_id);

        // Grab the amount of time to add if the system thinks we're
        // under a distributed brute force attack.
        // Affect users that have at least 1 failure login attempt
        $dbrute_time = ($attempts === 0) ? 0 : $this->ci->login_model->distributedBruteForceTime();

        // If this user was found to possibly be under a brute
        // force attack, their account would have been banned
        // for 15 minutes.
        if ($time = isset($_SESSION['bruteBan']) ? $_SESSION['bruteBan'] : false)
        {
            // If the current time is less than the
            // the ban expiration, plus any distributed time
            // then the user can't login just yet.
            if ($time + $dbrute_time > time())
            {
                // The user is banned still...
                $this->error = lang('auth.bruteBan_notice');
                return ($time + $dbrute_time) - time();
            }

            // Still here? The the ban time is over...
            unset($_SESSION['bruteBan']);
        }

        // Grab the time of last attempt and
        // determine if we're throttled by amount of time passed.
        $last_time = $this->ci->login_model->lastLoginAttemptTime($ip_address, $user_id);

        $allowed = config_item('auth.allowed_login_attempts');

        // We're not throttling if there are 0 attempts or
        // the number is less than or equal to the allowed free attempts
        if ($attempts === 0 || $attempts <= $allowed)
        {
            // Before we can say there's nothing up here,
            // we need to check dbrute time.
            $time_left = $last_time + $dbrute_time - time();

            if ($time_left > 0)
            {
                return $time_left;
            }

            return false;
        }

        // If the number of attempts is excessive (above 100) we need
        // to check the elapsed time of all of these attacks. If they are
        // less than 1 minute it's obvious this is a brute force attack,
        // so we'll set a session flag and block that user for 15 minutes.
        if ($attempts > 100 && $this->ci->login_model->isBruteForced($ip_address, $user_id))
        {
            $this->error = lang('auth.bruteBan_notice');

            $ban_time = 60 * 15;    // 15 minutes
            $_SESSION['bruteBan'] = time() + $ban_time;
            return $ban_time;
        }

        // Get our allowed attempts out of the picture.
        $attempts = $attempts - $allowed;

        $max_time = config_item('auth.max_throttle_time');

        $add_time = 5 * pow(2, $attempts - 1);

        if ($add_time > $max_time)
        {
            $add_time = $max_time;
        }

        $next_time = $last_time + $add_time + $dbrute_time;

        $current = time();

        // We are NOT throttled if we are already
        // past the allowed time.
        if ($current > $next_time)
        {
            return false;
        }

        return $next_time - $current;
    }

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

    /**
     * Sends a password reset link email to the user associated with
     * the passed in $email.
     *
     * @param $email
     * @return mixed
     */
    public function remindUser($email)
    {
        // Emails should NOT be case sensitive.
        $email = strtolower($email);

        // Is it a valid user?
        $user = $this->user_model->find_by('email', $email);

        if (! $user)
        {
            $this->error = lang('auth.invalid_email');
            return false;
        }

        // Generate/store our codes
        $this->ci->load->helper('string');
        $token = random_string('alnum', 24);
        $hash = hash('sha1', config_item('auth.salt') .$token);

        $result = $this->user_model->update($user->id, ['reset_hash' => $hash]);

        if (! $result)
        {
            $this->error = $this->user_model->error();
            return false;
        }

        Events::trigger('didRemindUser', [(array)$user, $token]);

        return true;
    }

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

    /**
     * Validates the credentials provided and, if valid, resets the password.
     *
     * The $credentials array MUST contain a 'code' key with the string to
     * hash and check against the reset_hash.
     *
     * @param $credentials
     * @param $password
     * @param $passConfirm
     * @return mixed
     */
    public function resetPassword($credentials, $password, $passConfirm)
    {
        if (empty($credentials['code']))
        {
            $this->error = lang('auth.need_reset_code');
            return false;
        }

        // Generate a hash to match against the table.
        $reset_hash = hash('sha1', config_item('auth.salt') .$credentials['code']);
        unset($credentials['code']);

        if (! empty($credentials['email']))
        {
            $credentials['email'] = strtolower($credentials['email']);
        }

        // Is there a matching user?
        $user = $this->user_model->as_array()
                                 ->where($credentials)
                                 ->first();

        // If throttling time is above zero, we can't allow
        // logins now.
        $time = (int)$this->isThrottled($user);
        if ($time > 0)

This code seems to be duplicated across your project.

        {
            $this->error = sprintf(lang('auth.throttled'), $time);
            return false;
        }

        // Get ip address
        $ip_address = $this->ci->input->ip_address();

        if (! $user)

This code seems to be duplicated across your project.

        {
            $this->error = lang('auth.reset_no_user');
            $this->ci->login_model->recordLoginAttempt($ip_address);
            return false;
        }

        // Is generated reset_hash string matches one from the table?
        if ($reset_hash !== $user['reset_hash'])
        {
            $this->error = lang('auth.reset_no_user');
            $this->ci->login_model->recordLoginAttempt($ip_address, $user['id']);
            return false;
        }

        // Update their password and reset their reset_hash
        $data = [
            'password'     => $password,
            'pass_confirm' => $passConfirm,
            'reset_hash'   => null
        ];

        if (! $this->user_model->update($user['id'], $data))
        {
            $this->error = $this->user_model->error();
            return false;
        }

        // Clear our login attempts
        $this->ci->login_model->purgeLoginAttempts($ip_address, $user['id']);

        Events::trigger('didResetPassword', [$user]);

        return true;
    }

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

    /**
     * Provides a way for implementations to allow new statuses to be set
     * on the user. The details will vary based upon implementation, but
     * will often allow for banning or suspending users.
     *
     * @param $newStatus
     * @param null $message
     * @return mixed
     */
    public function changeStatus($newStatus, $message=null)
    {
        // todo actually record new users status!
    }

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

    /**
     * Allows the consuming application to pass in a reference to the
     * model that should be used.
     *
     * The model MUST extend Myth\Models\CIDbModel.
     *
     * @param $model
     * @param bool $allow_any_parent
     * @return mixed
     */
    public function useModel($model, $allow_any_parent=false)
    {
        if (! $allow_any_parent && get_parent_class($model) != 'Myth\Models\CIDbModel')
        {
            throw new \RuntimeException('Models passed into LocalAuthenticate MUST extend Myth\Models\CIDbModel');
        }

        $this->user_model =& $model;

        return $this;
    }

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

    public function error()
    {
        if (validation_errors())
        {
            return validation_errors();
        }

        return $this->error;
    }

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

    //--------------------------------------------------------------------
    // Login Records
    //--------------------------------------------------------------------

    /**
     * Purges all login attempt records from the database.
     *
     * @param $email
     */
    public function purgeLoginAttempts($email)
    {
        // Emails should NOT be case sensitive.
        $email = strtolower($email);

        $this->ci->login_model->purgeLoginAttempts($email);

        // @todo record activity of login attempts purge.
        Events::trigger('didPurgeLoginAttempts', [$email]);
    }

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

    /**
     * Purges all remember tokens for a single user. Effectively logs
     * a user out of all devices. Intended to allow users to log themselves
     * out of all devices as a security measure.
     *
     * @param $email
     */
    public function purgeRememberTokens($email)
    {
        // Emails should NOT be case sensitive.
        $email = strtolower($email);

        $this->ci->login_model->purgeRememberTokens($email);

        // todo record activity of remember me purges.
        Events::trigger('didPurgeRememberTokens', [$email]);
    }

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

    //--------------------------------------------------------------------
    // Protected Methods
    //--------------------------------------------------------------------

    /**
     * Check if Allow Persistent Login Cookies is enable
     *
     * @param $user
     */
    protected function rememberUser($user)
    {
        if (! config_item('auth.allow_remembering'))
        {
            log_message('debug', 'Auth library set to refuse "Remember Me" functionality.');
            return false;
        }

        $this->refreshRememberCookie($user);
    }

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

    /**
     * Invalidates the current rememberme cookie/database entry, creates
     * a new one, stores it and returns the new value.
     *
     * @param $user
     * @param null $token
     * @return mixed
     */
    protected function refreshRememberCookie($user, $token=null)
    {
        $this->ci->load->helper('cookie');

        // If a token is passed in, we know we're removing the
        // old one.
        if (! empty($token))
        {
            $this->invalidateRememberCookie($user['email'], $token);
        }

        $new_token = $this->ci->login_model->generateRememberToken($user);

        // Save the token to the database.
        $data = [
            'email'   => $user['email'],
            'hash'    => sha1(config_item('auth.salt') . $new_token),
            'created' => date('Y-m-d H:i:s')
        ];

        $this->ci->db->insert('auth_tokens', $data);

        // Create the cookie
        set_cookie(
            'remember',                             // Cookie Name
            $new_token,                             // Value
            config_item('auth.remember_length'),    // # Seconds until it expires
            config_item('cookie_domain'),
            config_item('cookie_path'),
            config_item('cookie_prefix'),
            false,                                  // Only send over HTTPS?
            true                                    // Hide from Javascript?
        );

        return $new_token;
    }

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

    /**
     * Deletes any current remember me cookies and database entries.
     *
     * @param $email
     * @param $token
     * @return string The new token (not the hash).
     */
    protected function invalidateRememberCookie($email, $token)
    {
        // Emails should NOT be case sensitive.
        $email = strtolower($email);

        // Remove from the database
        $this->ci->login_model->deleteRememberToken($email, $token);

        // Remove the cookie
        delete_cookie(
            'remember',
            config_item('cookie_domain'),
            config_item('cookie_path'),
            config_item('cookie_prefix')
        );
    }

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

    /**
     * Handles the nitty gritty of actually logging our user into the system.
     * Does NOT perform the authentication, just sets the system up so that
     * it knows we're here.
     *
     * @param $user
     */
    protected function loginUser($user)
    {
        // Save the user for later access
        $this->user = $user;

        // Get ip address
        $ip_address = $this->ci->input->ip_address();

        // Regenerate the session ID to help protect
        // against session fixation
        $this->ci->session->sess_regenerate();

        // Let the session know that we're logged in.
        $this->ci->session->set_userdata('logged_in', $user['id']);

        // Clear our login attempts
        $this->ci->login_model->purgeLoginAttempts($ip_address, $user['id']);

        // Record a new Login
        $this->ci->login_model->recordLogin($user);

        // If logged in, ensure cache control
        // headers are in place
        $this->setHeaders();

        // We'll give a 20% chance to need to do a purge since we
        // don't need to purge THAT often, it's just a maintenance issue.
        // to keep the table from getting out of control.
        if (mt_rand(1, 100) < 20)
        {
            $this->ci->login_model->purgeOldRememberTokens();
        }
    }

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

    /**
     * Sets the headers to ensure that pages are not cached when a user
     * is logged in, helping to protect against logging out and then
     * simply hitting the Back button on the browser and getting private
     * information because the page was loaded from cache.
     */
    protected function setHeaders()
    {
        $this->ci->output->set_header('Cache-Control: no-store, no-cache, must-revalidate');
        $this->ci->output->set_header('Cache-Control: post-check=0, pre-check=0');
        $this->ci->output->set_header('Pragma: no-cache');
    }

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


}