gnu-social/lib/apiauth.php

<?php
/**
 * StatusNet, the distributed open-source microblogging tool
 *
 * Base class for API actions that require authentication
 *
 * PHP version 5
 *
 * LICENCE: This program 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.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @category  API
 * @package   StatusNet
 * @author    Adrian Lang <mail@adrianlang.de>
 * @author    Brenda Wallace <shiny@cpan.org>
 * @author    Craig Andrews <candrews@integralblue.com>
 * @author    Dan Moore <dan@moore.cx>
 * @author    Evan Prodromou <evan@status.net>
 * @author    mEDI <medi@milaro.net>
 * @author    Sarven Capadisli <csarven@status.net>
 * @author    Zach Copley <zach@status.net>
 * @copyright 2009-2010 StatusNet, Inc.
 * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link      http://status.net/
 */

if (!defined('STATUSNET')) {
    exit(1);
}

require_once INSTALLDIR . '/lib/apioauth.php';

/**
 * Actions extending this class will require auth
 *
 * @category API
 * @package  StatusNet
 * @author   Zach Copley <zach@status.net>
 * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link     http://status.net/
 */

class ApiAuthAction extends ApiAction
{
    var $auth_user_nickname = null;
    var $auth_user_password = null;

    /**
     * Take arguments for running, looks for an OAuth request,
     * and outputs basic auth header if needed
     *
     * @param array $args $_REQUEST args
     *
     * @return boolean success flag
     *
     */

    function prepare($args)
    {
        parent::prepare($args);

        // NOTE: $this->auth_user has to get set in prepare(), not handle(),
        // because subclasses do stuff with it in their prepares.

        $oauthReq = $this->getOAuthRequest();

        if (!$oauthReq) {
            if ($this->requiresAuth()) {
                $this->checkBasicAuthUser(true);
            } else {
                // Check to see if a basic auth user is there even
                // if one's not required
                $this->checkBasicAuthUser(false);
            }
        } else {
            $this->checkOAuthRequest($oauthReq);
        }

        // Reject API calls with the wrong access level

        if ($this->isReadOnly($args) == false) {
            if ($this->access != self::READ_WRITE) {
                $msg = _('API resource requires read-write access, ' .
                         'but you only have read access.');
                $this->clientError($msg, 401, $this->format);
                exit;
            }
        }

        return true;
    }

    /**
     * Determine whether the request is an OAuth request.
     * This is to avoid doign any unnecessary DB lookups.
     *
     * @return mixed the OAuthRequest or false
     */

    function getOAuthRequest()
    {
        ApiOauthAction::cleanRequest();

        $req  = OAuthRequest::from_request();

        $consumer    = $req->get_parameter('oauth_consumer_key');
        $accessToken = $req->get_parameter('oauth_token');

        // XXX: Is it good enough to assume it's not meant to be an
        // OAuth request if there is no consumer or token? --Z

        if (empty($consumer) || empty($accessToken)) {
            return false;
        }

        return $req;
    }

    /**
     * Verifies the OAuth request signature, sets the auth user
     * and access type (read-only or read-write)
     *
     * @param OAuthRequest $request the OAuth Request
     *
     * @return nothing
     */

    function checkOAuthRequest($request)
    {
        $datastore   = new ApiStatusNetOAuthDataStore();
        $server      = new OAuthServer($datastore);
        $hmac_method = new OAuthSignatureMethod_HMAC_SHA1();

        $server->add_signature_method($hmac_method);

        try {

            $server->verify_request($request);

            $consumer     = $request->get_parameter('oauth_consumer_key');
            $access_token = $request->get_parameter('oauth_token');

            $app = Oauth_application::getByConsumerKey($consumer);

            if (empty($app)) {
                common_log(LOG_WARNING,
                           'Couldn\'t find the OAuth app for consumer key: ' .
                           $consumer);
                throw new OAuthException('No application for that consumer key.');
            }

            // set the source attr

            $this->source = $app->name;

            $appUser = Oauth_application_user::staticGet('token', $access_token);

            if (!empty($appUser)) {

                // If access_type == 0 we have either a request token
                // or a bad / revoked access token

                if ($appUser->access_type != 0) {

                    // Set the access level for the api call

                    $this->access = ($appUser->access_type & Oauth_application::$writeAccess)
                      ? self::READ_WRITE : self::READ_ONLY;

                    // Set the auth user

                    if (Event::handle('StartSetApiUser', array(&$user))) {
                        $this->auth_user = User::staticGet('id', $appUser->profile_id);
                        Event::handle('EndSetApiUser', array($user));
                    }

                    $msg = "API OAuth authentication for user '%s' (id: %d) on behalf of " .
                      "application '%s' (id: %d) with %s access.";

                    common_log(LOG_INFO, sprintf($msg,
                                                 $this->auth_user->nickname,
                                                 $this->auth_user->id,
                                                 $app->name,
                                                 $app->id,
                                                 ($this->access = self::READ_WRITE) ?
                                                 'read-write' : 'read-only'
                                                 ));
                } else {
                    throw new OAuthException('Bad access token.');
                }
            } else {

                // Also should not happen

                throw new OAuthException('No user for that token.');
            }

        } catch (OAuthException $e) {
            common_log(LOG_WARNING, 'API OAuthException - ' . $e->getMessage());
            $this->showAuthError();
            exit;
        }
    }

    /**
     * Does this API resource require authentication?
     *
     * @return boolean true
     */

    function requiresAuth()
    {
        return true;
    }

    /**
     * Check for a user specified via HTTP basic auth. If there isn't
     * one, try to get one by outputting the basic auth header.
     *
     * @return boolean true or false
     */

    function checkBasicAuthUser($required = true)
    {
        $this->basicAuthProcessHeader();

        $realm = common_config('api', 'realm');

        if (empty($realm)) {
            $realm = common_config('site', 'name') . ' API';
        }

        if (empty($this->auth_user_nickname) && $required) {
            header('WWW-Authenticate: Basic realm="' . $realm . '"');

            // show error if the user clicks 'cancel'

            $this->showAuthError();
            exit;

        } else {

            $user = common_check_user($this->auth_user_nickname,
                                      $this->auth_user_password);

            if (Event::handle('StartSetApiUser', array(&$user))) {

                if (!empty($user)) {
                    $this->auth_user = $user;
                }

                Event::handle('EndSetApiUser', array($user));
            }

            // By default, basic auth users have rw access

            $this->access = self::READ_WRITE;

            if (empty($this->auth_user) && ($required || isset($_SERVER['PHP_AUTH_USER']))) {

                // basic authentication failed

                list($proxy, $ip) = common_client_ip();

                $msg = sprintf(_('Failed API auth attempt, nickname = %1$s, ' .
                         'proxy = %2$s, ip = %3$s'),
                               $this->auth_user_nickname,
                               $proxy,
                               $ip);
                common_log(LOG_WARNING, $msg);
                $this->showAuthError();
                exit;
            }
        }
    }

    /**
     * Read the HTTP headers and set the auth user.  Decodes HTTP_AUTHORIZATION
     * param to support basic auth when PHP is running in CGI mode.
     *
     * @return void
     */

    function basicAuthProcessHeader()
    {
        $authHeaders = array('AUTHORIZATION',
                             'HTTP_AUTHORIZATION',
                             'REDIRECT_HTTP_AUTHORIZATION'); // rewrite for CGI
        $authorization_header = null;
        foreach ($authHeaders as $header) {
            if (isset($_SERVER[$header])) {
                $authorization_header = $_SERVER[$header];
                break;
            }
        }

        if (isset($_SERVER['PHP_AUTH_USER'])) {
            $this->auth_user_nickname = $_SERVER['PHP_AUTH_USER'];
            $this->auth_user_password = $_SERVER['PHP_AUTH_PW'];
        } elseif (isset($authorization_header)
            && strstr(substr($authorization_header, 0, 5), 'Basic')) {

            // Decode the HTTP_AUTHORIZATION header on php-cgi server self
            // on fcgid server the header name is AUTHORIZATION

            $auth_hash = base64_decode(substr($authorization_header, 6));
            list($this->auth_user_nickname,
                 $this->auth_user_password) = explode(':', $auth_hash);

            // Set all to null on a empty basic auth request

            if (empty($this->auth_user_nickname)) {
                $this->auth_user_nickname = null;
                $this->auth_password = null;
            }
        }
    }

    /**
     * Output an authentication error message.  Use XML or JSON if one
     * of those formats is specified, otherwise output plain text
     *
     * @return void
     */

    function showAuthError()
    {
        header('HTTP/1.1 401 Unauthorized');
        $msg = 'Could not authenticate you.';

        if ($this->format == 'xml') {
            header('Content-Type: application/xml; charset=utf-8');
            $this->startXML();
            $this->elementStart('hash');
            $this->element('error', null, $msg);
            $this->element('request', null, $_SERVER['REQUEST_URI']);
            $this->elementEnd('hash');
            $this->endXML();
        } elseif ($this->format == 'json') {
            header('Content-Type: application/json; charset=utf-8');
            $error_array = array('error' => $msg,
                                 'request' => $_SERVER['REQUEST_URI']);
            print(json_encode($error_array));
        } else {
            header('Content-type: text/plain');
            print "$msg\n";
        }
    }

}