gnu-social/plugins/TwitterBridge/actions/twitterauthorization.php

<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Class for doing OAuth authentication against Twitter
 *
 * @category  Plugin
 * @package   GNUsocial
 * @author    Zach Copley <zach@status.net>
 * @author    Julien C <chaumond@gmail.com>
 * @copyright 2009-2010 StatusNet, Inc.
 * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
 */

defined('GNUSOCIAL') || die();

require_once dirname(__DIR__) . '/twitter.php';
require_once INSTALLDIR . '/lib/util/oauthclient.php';

/**
 * Class for doing OAuth authentication against Twitter
 *
 * Peforms the OAuth "dance" between StatusNet and Twitter -- requests a token,
 * authorizes it, and exchanges it for an access token.  It also creates a link
 * (Foreign_link) between the StatusNet user and Twitter user and stores the
 * access token and secret in the link.
 *
 * @category  Plugin
 * @package   GNUsocial
 * @author    Zach Copley <zach@status.net>
 * @author    Julien C <chaumond@gmail.com>
 * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
 */
class TwitterauthorizationAction extends FormAction
{
    public $twuid        = null;
    public $tw_fields    = null;
    public $access_token = null;
    public $verifier     = null;

    protected $needLogin = false;   // authorization page can also be used to create a new user

    protected function doPreparation()
    {
        $this->oauth_token = $this->arg('oauth_token');
        $this->verifier    = $this->arg('oauth_verifier');

        if ($this->scoped instanceof Profile) {
            try {
                $flink = Foreign_link::getByUserID($this->scoped->getID(), TWITTER_SERVICE);
                $fuser = $flink->getForeignUser();

                // If there's already a foreign link record and a foreign user
                // (no exceptions were thrown when fetching either of them...)
                // it means the accounts are already linked, and this is unecessary.
                // So go back.

                common_redirect(common_local_url('twittersettings'));
            } catch (NoResultException $e) {
                // but if we don't have a foreign user linked, let's continue authorization procedure.
            }
        }
    }

    protected function doPost()
    {
        // User was not logged in to StatusNet before

        $this->twuid = $this->trimmed('twuid');

        $this->tw_fields = array('screen_name' => $this->trimmed('tw_fields_screen_name'),
                                 'fullname' => $this->trimmed('tw_fields_fullname'));

        $this->access_token = new OAuthToken($this->trimmed('access_token_key'), $this->trimmed('access_token_secret'));

        if ($this->arg('create')) {
            common_debug('TwitterBridgeDebug - POST with create');
            if (!$this->boolean('license')) {
                // TRANS: Form validation error displayed when the checkbox to agree to the license has not been checked.
                throw new ClientException(_m('You cannot register if you do not agree to the license.'));
            }
            $this->createNewUser();
        } elseif ($this->arg('connect')) {
            common_debug('TwitterBridgeDebug - POST with connect');
            $this->connectNewUser();
        } else {
            common_debug('TwitterBridgeDebug - ' . print_r($this->args, true));
            // TRANS: Form validation error displayed when an unhandled error occurs.
            throw new ClientException(_m('No known action for POST.'));
        }
    }

    /**
     * Asks Twitter for a request token, and then redirects to Twitter
     * to authorize it.
     */
    protected function authorizeRequestToken()
    {
        try {
            // Get a new request token and authorize it
            $client  = new TwitterOAuthClient();
            $req_tok = $client->getTwitterRequestToken();

            // Sock the request token away in the session temporarily
            $_SESSION['twitter_request_token']        = $req_tok->key;
            $_SESSION['twitter_request_token_secret'] = $req_tok->secret;

            $auth_link = $client->getTwitterAuthorizeLink($req_tok, $this->boolean('signin'));
        } catch (OAuthClientException $e) {
            $msg = sprintf(
                'OAuth client error - code: %1s, msg: %2s',
                $e->getCode(),
                $e->getMessage()
            );
            common_log(LOG_INFO, 'Twitter bridge - ' . $msg);
            // TRANS: Server error displayed when linking to a Twitter account fails.
            throw new ServerException(_m('Could not link your Twitter account.'));
        }

        common_redirect($auth_link);
    }

    /**
     * Called when Twitter returns an authorized request token. Exchanges
     * it for an access token and stores it.
     *
     * @return void
     */
    private function saveAccessToken(): void
    {
        // Check to make sure Twitter returned the same request
        // token we sent them

        if ($_SESSION['twitter_request_token'] != $this->oauth_token) {
            // TRANS: Server error displayed when linking to a Twitter account fails because of an incorrect oauth_token.
            throw new ServerException(_m('Could not link your Twitter account: oauth_token mismatch.'));
        }

        $twitter_user = null;

        try {
            $client = new TwitterOAuthClient($_SESSION['twitter_request_token'], $_SESSION['twitter_request_token_secret']);

            // Exchange the request token for an access token
            $atok = $client->getTwitterAccessToken($this->verifier);

            // Test the access token and get the user's Twitter info
            $client       = new TwitterOAuthClient($atok->key, $atok->secret);
            $twitter_user = $client->verifyCredentials();
        } catch (OAuthClientException $e) {
            $msg = sprintf(
                'OAuth client error - code: %1$s, msg: %2$s',
                $e->getCode(),
                $e->getMessage()
            );
            common_log(LOG_INFO, 'Twitter bridge - ' . $msg);
            // TRANS: Server error displayed when linking to a Twitter account fails.
            throw new ServerException(_m('Could not link your Twitter account.'));
        }

        if ($this->scoped instanceof Profile) {
            // Save the access token and Twitter user info

            $this->saveForeignLink($this->scoped->getID(), $twitter_user->id, $atok);
            save_twitter_user($twitter_user->id, $twitter_user->screen_name);
        } else {
            $this->twuid = $twitter_user->id;
            $this->tw_fields = array("screen_name" => $twitter_user->screen_name,
                                     "fullname" => $twitter_user->name);
            $this->access_token = $atok;
            $this->tryLogin();
            return;
        }

        // Clean up the the mess we made in the session

        unset($_SESSION['twitter_request_token']);
        unset($_SESSION['twitter_request_token_secret']);

        if (common_logged_in()) {
            common_redirect(common_local_url('twittersettings'));
        }
    }

    /**
     * Saves a Foreign_link between Twitter user and local user,
     * which includes the access token and secret.
     *
     * @param int        $user_id StatusNet user ID
     * @param int        $twuid   Twitter user ID
     * @param OAuthToken $token   the access token to save
     *
     * @return void
     */
    private function saveForeignLink(
        int $user_id,
        int $twuid,
        OAuthToken $access_token
    ): void {
        $flink = new Foreign_link();

        $flink->user_id = $user_id;
        $flink->service = TWITTER_SERVICE;

        // delete stale flink, if any
        $result = $flink->find(true);

        if (!empty($result)) {
            $flink->safeDelete();
        }

        $flink->user_id     = $user_id;
        $flink->foreign_id  = $twuid;
        $flink->service     = TWITTER_SERVICE;

        $creds = TwitterOAuthClient::packToken($access_token);

        $flink->credentials = DB_DataObject_Cast::blob($creds);
        $flink->created     = common_sql_now();

        // Defaults: noticesync on, everything else off

        $flink->set_flags(true, false, false, false, false);

        $flink_id = $flink->insert();

        // We want to make sure we got a numerical >0 value, not just failed the insert (which would be === false)
        if (empty($flink_id)) {
            common_log_db_error($flink, 'INSERT', __FILE__);
            // TRANS: Server error displayed when linking to a Twitter account fails.
            throw new ServerException(_m('Could not link your Twitter account.'));
        }
    }

    public function getInstructions()
    {
        // TRANS: Page instruction. %s is the StatusNet sitename.
        return sprintf(_m('This is the first time you have logged into %s so we must connect your Twitter account to a local account. You can either create a new account, or connect with your existing account, if you have one.'), common_config('site', 'name'));
    }

    public function title()
    {
        // TRANS: Page title.
        return _m('Twitter Account Setup');
    }

    public function showPage()
    {
        // $this->oauth_token is only populated once Twitter authorizes our
        // request token. If it's empty we're at the beginning of the auth
        // process
        if (empty($this->error)) {
            if (empty($this->oauth_token)) {
                // authorizeRequestToken either throws an exception or redirects
                $this->authorizeRequestToken();
            } else {
                $this->saveAccessToken();
            }
        }

        parent::showPage();
    }

    /**
     * @fixme much of this duplicates core code, which is very fragile.
     * Should probably be replaced with an extensible mini version of
     * the core registration form.
     */
    public function showContent()
    {
        $this->elementStart('form', array('method' => 'post',
                                          'id' => 'form_settings_twitter_connect',
                                          'class' => 'form_settings',
                                          'action' => common_local_url('twitterauthorization')));
        $this->elementStart('fieldset', array('id' => 'settings_twitter_connect_options'));
        // TRANS: Fieldset legend.
        $this->element('legend', null, _m('Connection options'));

        $this->hidden('access_token_key', $this->access_token->key);
        $this->hidden('access_token_secret', $this->access_token->secret);
        $this->hidden('twuid', $this->twuid);
        $this->hidden('tw_fields_screen_name', $this->tw_fields['screen_name']);
        $this->hidden('tw_fields_name', $this->tw_fields['fullname']);
        $this->hidden('token', common_session_token());

        // Only allow new account creation if site is not flagged invite-only
        if (!common_config('site', 'inviteonly')) {
            $this->elementStart('fieldset');
            $this->element(
                'legend',
                null,
                // TRANS: Fieldset legend.
                _m('Create new account')
            );
            $this->element(
                'p',
                null,
                // TRANS: Sub form introduction text.
                _m('Create a new user with this nickname.')
            );
            $this->elementStart('ul', 'form_data');

            // Hook point for captcha etc
            Event::handle('StartRegistrationFormData', array($this));

            $this->elementStart('li');
            // TRANS: Field label.
            $this->input(
                'newname',
                _m('New nickname'),
                $this->username ?: '',
                // TRANS: Field title for nickname field.
                _m('1-64 lowercase letters or numbers, no punctuation or spaces.')
            );
            $this->elementEnd('li');
            $this->elementStart('li');
            // TRANS: Field label.
            $this->input(
                'email',
                _m('LABEL', 'Email'),
                $this->getEmail(),
                // TRANS: Field title for e-mail address field.
                _m('Used only for updates, announcements, and password recovery')
            );
            $this->elementEnd('li');

            // Hook point for captcha etc
            Event::handle('EndRegistrationFormData', array($this));

            $this->elementEnd('ul');
            // TRANS: Button text for creating a new StatusNet account in the Twitter connect page.
            $this->submit('create', _m('BUTTON', 'Create'));
            $this->elementEnd('fieldset');
        }

        $this->elementStart('fieldset');
        $this->element(
            'legend',
            null,
            // TRANS: Fieldset legend.
            _m('Connect existing account')
        );
        $this->element(
            'p',
            null,
            // TRANS: Sub form introduction text.
            _m('If you already have an account, login with your username and password to connect it to your Twitter account.')
        );
        $this->elementStart('ul', 'form_data');
        $this->elementStart('li');
        // TRANS: Field label.
        $this->input('nickname', _m('Existing nickname'));
        $this->elementEnd('li');
        $this->elementStart('li');
        // TRANS: Field label.
        $this->password('password', _m('Password'));
        $this->elementEnd('li');
        $this->elementEnd('ul');
        $this->elementEnd('fieldset');

        $this->elementStart('fieldset');
        $this->element(
            'legend',
            null,
            // TRANS: Fieldset legend.
            _m('License')
        );
        $this->elementStart('ul', 'form_data');
        $this->elementStart('li');
        $this->element('input', array('type' => 'checkbox',
                                      'id' => 'license',
                                      'class' => 'checkbox',
                                      'name' => 'license',
                                      'value' => 'true'));
        $this->elementStart('label', array('class' => 'checkbox', 'for' => 'license'));
        // TRANS: Text for license agreement checkbox.
        // TRANS: %s is the license as configured for the StatusNet site.
        $message = _m('My text and files are available under %s ' .
                     'except this private data: password, ' .
                     'email address, IM address, and phone number.');
        $link = '<a href="' .
                htmlspecialchars(common_config('license', 'url')) .
                '">' .
                htmlspecialchars(common_config('license', 'title')) .
                '</a>';
        $this->raw(sprintf(htmlspecialchars($message), $link));
        $this->elementEnd('label');
        $this->elementEnd('li');
        $this->elementEnd('ul');
        $this->elementEnd('fieldset');
        // TRANS: Button text for connecting an existing StatusNet account in the Twitter connect page..
        $this->submit('connect', _m('BUTTON', 'Connect'));
        $this->elementEnd('fieldset');
        $this->elementEnd('form');
    }

    /**
     * Get specified e-mail from the form, or the invite code.
     *
     * @return string
     */
    private function getEmail(): string
    {
        $email = $this->trimmed('email');
        if (!empty($email)) {
            return $email;
        }

        // Terrible hack for invites...
        if (common_config('site', 'inviteonly')) {
            $code = $_SESSION['invitecode'];
            if ($code) {
                $invite = Invitation::getKV($code);

                if ($invite && $invite->address_type == 'email') {
                    return $invite->address;
                }
            }
        }
        return '';
    }

    protected function createNewUser()
    {
        common_debug('TwitterBridgeDebug - createNewUser');
        if (!Event::handle('StartRegistrationTry', array($this))) {
            common_debug('TwitterBridgeDebug - StartRegistrationTry failed');
            // TRANS: Client error displayed when trying to create a new user but a plugin aborted the process.
            throw new ClientException(_m('Registration of new user was aborted, maybe you failed a captcha?'));
        }

        if (common_config('site', 'closed')) {
            common_debug('TwitterBridgeDebug - site is closed for registrations');
            // TRANS: Client error displayed when trying to create a new user while creating new users is not allowed.
            throw new ClientException(_m('Registration not allowed.'));
        }

        $invite = null;

        if (common_config('site', 'inviteonly')) {
            common_debug('TwitterBridgeDebug - site is inviteonly');
            $code = $_SESSION['invitecode'];
            if (empty($code)) {
                // TRANS: Client error displayed when trying to create a new user while creating new users is not allowed.
                throw new ClientException(_m('Registration not allowed.'));
            }

            $invite = Invitation::getKV('code', $code);

            if (!$invite instanceof Invite) {
                common_debug('TwitterBridgeDebug - and we failed the invite code test');
                // TRANS: Client error displayed when trying to create a new user with an invalid invitation code.
                throw new ClientException(_m('Not a valid invitation code.'));
            }
        }

        common_debug('TwitterBridgeDebug - trying our nickname: '.$this->trimmed('newname'));
        // Nickname::normalize throws exception if the nickname is taken
        $nickname = Nickname::normalize($this->trimmed('newname'), true);

        $fullname = trim($this->tw_fields['fullname']);

        $args = array('nickname' => $nickname, 'fullname' => $fullname);

        if (!empty($invite)) {
            $args['code'] = $invite->code;
        }

        $email = $this->getEmail();
        if (!empty($email)) {
            $args['email'] = $email;
        }

        common_debug(
            'TwitterBridgeDebug - registering user with args:'
            . var_export($args, true)
        );
        $user = User::register($args);

        common_debug(
            'TwitterBridgeDebug - registered the user and saving twitter user'
        );
        save_twitter_user($this->twuid, $this->tw_fields['screen_name']);

        common_debug(
            'TwitterBridgeDebug - saving foreign link after creating new '
            . 'local user ' . $user->id
        );

        $this->saveForeignLink(
            $user->id,
            $this->twuid,
            $this->access_token
        );

        common_set_user($user);
        common_real_login(true);

        common_debug('TwitterBridge Plugin - ' .
                     "Registered new user $user->id from Twitter user $this->twuid");

        Event::handle('EndRegistrationTry', array($this));

        common_redirect(common_local_url('showstream', array('nickname' => $user->nickname)), 303);
    }

    private function connectNewUser(): void
    {
        $nickname = $this->trimmed('nickname');
        $password = $this->trimmed('password');

        if (!common_check_user($nickname, $password)) {
            // TRANS: Form validation error displayed when connecting an existing user to a Twitter user fails because
            // TRANS: the provided username and/or password are incorrect.
            throw new ClientException(_m('Invalid username or password.'));
        }

        $user = User::getKV('nickname', $nickname);

        if ($user instanceof User) {
            common_debug('TwitterBridge Plugin - ' .
                         "Legit user to connect to Twitter: $nickname");
        }

        // throws exception on failure
        $this->saveForeignLink(
            $user->id,
            $this->twuid,
            $this->access_token
        );

        save_twitter_user($this->twuid, $this->tw_fields['screen_name']);

        common_debug('TwitterBridge Plugin - ' .
                     "Connected Twitter user $this->twuid to local user $user->id");

        common_set_user($user);
        common_real_login(true);

        $this->goHome($user->nickname);
    }

    private function connectUser(): void
    {
        $user = common_current_user();

        $result = $this->flinkUser($user->id, $this->twuid);

        if (empty($result)) {
            // TRANS: Server error displayed connecting a user to a Twitter user has failed.
            $this->serverError(_m('Error connecting user to Twitter.'));
        }

        common_debug('TwitterBridge Plugin - ' .
                     "Connected Twitter user $this->twuid to local user $user->id");

        // Return to Twitter connection settings tab
        common_redirect(common_local_url('twittersettings'), 303);
    }

    protected function tryLogin()
    {
        common_debug('TwitterBridge Plugin - ' .
                     "Trying login for Twitter user $this->twuid.");

        try {
            $flink = Foreign_link::getByForeignID($this->twuid, TWITTER_SERVICE);
            $user = $flink->getUser();

            common_debug('TwitterBridge Plugin - ' .
                         "Logged in Twitter user $flink->foreign_id as user $user->id ($user->nickname)");

            common_set_user($user);
            common_real_login(true);
            $this->goHome($user->nickname);
        } catch (NoResultException $e) {
            // Either no Foreign_link was found or not the user connected to it.
            // Let's just continue to allow creating or logging in as a new user.
        }
        common_debug("TwitterBridge Plugin - No flink found for twuid: {$this->twuid} - new user");

        // FIXME: what do we want to do here? I forgot
        return;
        throw new ServerException(_m('No foreign link found for Twitter user'));
    }

    private function goHome(string $nickname): void
    {
        $url = common_get_returnto();
        if ($url) {
            // We don't have to return to it again
            common_set_returnto(null);
        } else {
            $url = common_local_url(
                'all',
                ['nickname' => $nickname]
            );
        }

        common_redirect($url, 303);
    }

    private function bestNewNickname(): ?string
    {
        try {
            return Nickname::normalize($this->tw_fields['fullname'], true);
        } catch (NicknameException $e) {
            return null;
        }
    }
}