modules/openid.php

   1 <?php
   2 /***************************************************************************
   3  *  Copyright (C) 2003-2008 Polytechnique.org                              *
   4  *  http://opensource.polytechnique.org/                                   *
   5  *                                                                         *
   6  *  This program is free software; you can redistribute it and/or modify   *
   7  *  it under the terms of the GNU General Public License as published by   *
   8  *  the Free Software Foundation; either version 2 of the License, or      *
   9  *  (at your option) any later version.                                    *
  10  *                                                                         *
  11  *  This program is distributed in the hope that it will be useful,        *
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of         *
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *
  14  *  GNU General Public License for more details.                           *
  15  *                                                                         *
  16  *  You should have received a copy of the GNU General Public License      *
  17  *  along with this program; if not, write to the Free Software            *
  18  *  Foundation, Inc.,                                                      *
  19  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA                *
  20  ***************************************************************************/
  21
  22
  23 /* Definitions for the OpenId Specification
  24  * http://openid.net/specs/openid-authentication-2_0.html
  25  *
  26  * OP Endpoint URL:             https://www.polytechnique.org/openid
  27  * OP Identifier:               https://www.polytechnique.org/openid
  28  * User Identifier:             https://www.polytechnique.org/openid/{hruid}
  29  * OP-Local Identifier:         {hruid}
  30  */
  31
  32 /* This implementation supports two modes:
  33  *     - entering the OP Identifier, which can simply be 'polytechnique.org'
  34  *     - entering the User Identifier, or some URL that resolves there
  35  * In both cases, Yadis discovery is made possible through the X-XRDS-Location
  36  * header.
  37  *
  38  * In the former case, Yadis discovery is performed on /, or where it redirects;
  39  * see platal.php. It resolves to the XRDS for this OP, and User Identifier
  40  * selection is performed after forcing the user to log in. This only works for
  41  * version 2.0 of the OpenId protocol.
  42  *
  43  * In the latter cas, Yadis discovery is performed on /openid/{hruid}. It
  44  * resolves ta a user-specific XRDS. This page also features HTML-based
  45  * discovery. This works with any version of the protocol.
  46  */
  47
  48 /* Testing suite is here:
  49  * http://openidenabled.com/resources/openid-test/
  50  * It only supports User Indentifiers.
  51  *
  52  * To test OP Identifiers, download the JanRain PHP library and use the
  53  * consumer provided as an example (although it appears that a failure is
  54  * mistakenly reported: 'Server denied check_authentication').
  55  * Reading the source of the server can also help understanding the code below.
  56  */
  57
  58
  59 class OpenidModule extends PLModule
  60 {
  61     function handlers()
  62     {
  63         return array(
  64             'openid'            => $this->make_hook('openid', AUTH_PUBLIC),
  65             'openid/trust'      => $this->make_hook('trust', AUTH_COOKIE),
  66             'openid/idp_xrds'   => $this->make_hook('idp_xrds', AUTH_PUBLIC),
  67             'openid/user_xrds'  => $this->make_hook('user_xrds', AUTH_PUBLIC),
  68             'openid/melix'      => $this->make_hook('melix', AUTH_PUBLIC),
  69         );
  70     }
  71
  72     function handler_openid(&$page, $x = null)
  73     {
  74         $this->load('openid.inc.php');
  75
  76         // Spec §4.1.2: if "openid.mode" is absent, whe SHOULD assume that
  77         // the request is not an OpenId message
  78         // Thus, we try to render the discovery page
  79         if (!array_key_exists('openid_mode', $_REQUEST)) {
  80             return $this->render_discovery_page($page, get_user($x));
  81         }
  82
  83         // Now, deal with the OpenId message
  84         // Create a server and decode the request
  85         $server = init_openid_server();
  86         $request = $server->decodeRequest();
  87
  88         // In modes 'checkid_immediate' and 'checkid_setup', the request
  89         // needs some logic and can not be automatically answered by the server
  90
  91         // Immediate mode
  92         if ($request->mode == 'checkid_immediate') {
  93
  94             // We deny immediate requests, unless:
  95             //   - the user identifier is known by the RP
  96             //   - the user is logged in
  97             //   - the user identifier matches the user logged in
  98             //   - the user and has whitelisted the site
  99             $answer = !$request->idSelect()
 100                       && S::logged()
 101                       && $request->identity == S::user()->login()
 102                       && is_trusted_site(S::user(), $request->trust_root);
 103             $response =& $request->answer($answer);
 104
 105         // Setup mode
 106         } else if ($request->mode == 'checkid_setup') {
 107
 108             // We redirect to a page where the user will authenticate
 109             // and confirm the use of his/her OpenId
 110             // Save request in session before jumping to confirmation page
 111             S::set('openid_request', serialize($request));
 112             pl_redirect('openid/trust');
 113             return;
 114
 115         // Other requests can be automatically handled by the server
 116         } else {
 117             $response =& $server->handleRequest($request);
 118         }
 119
 120         // Render response
 121         $webresponse =& $server->encodeResponse($response);
 122         $this->render_openid_response($webresponse);
 123     }
 124
 125     function handler_trust(&$page, $x = null)
 126     {
 127         $this->load('openid.inc.php');
 128
 129         // Recover request in session
 130         $request = S::v('openid_request');
 131         if (is_null($request)) {
 132             // There is no authentication information, something went wrong
 133             pl_redirect('/');
 134             return;
 135         }
 136
 137         // Unserialize the request
 138         require_once 'Auth/OpenID/Server.php';
 139         $request = unserialize($request);
 140
 141         $server = init_openid_server();
 142         $user = S::user();
 143         $identity = null;
 144         $claimed_id = null;
 145
 146         // Set the identity to the user currently logged in
 147         // if an OP Identifier was initially used
 148         if ($request->identity == Auth_OpenID_IDENTIFIER_SELECT) {
 149             $identity = $user->hruid;
 150             $claimed_id = get_user_openid_url($user);
 151         // Check that the identity matches the user currently logged in
 152         // if an User Identifier was initially used
 153         } else if ($request->identity != $user->hruid) {
 154             $response =& $request->answer(false);
 155             $webresponse =& $server->encodeResponse($response);
 156             $this->render_openid_response($webresponse);
 157             return;
 158         }
 159
 160         // Prepare Simple Registration response fields
 161         require_once 'Auth/OpenID/SReg.php';
 162         $sreg_request = Auth_OpenID_SRegRequest::fromOpenIDRequest($request);
 163         $sreg_response = Auth_OpenID_SRegResponse::extractResponse($sreg_request, get_sreg_data($user));
 164
 165         // Check the whitelist
 166         $whitelisted = is_trusted_site($user, $request->trust_root);
 167
 168         // Ask the user for confirmation
 169         if (!$whitelisted && $_SERVER['REQUEST_METHOD'] != 'POST') {
 170             $page->changeTpl('openid/trust.tpl');
 171             $page->assign('relying_party', $request->trust_root);
 172             $page->assign_by_ref('sreg_data', $sreg_response->data);
 173             return;
 174         }
 175
 176         // At this point $_SERVER['REQUEST_METHOD'] == 'POST'
 177
 178         // Add 'always trusted' sites to whitelist
 179         if (isset($_POST['trust']) && @$_POST['always']) {
 180             add_trusted_site($user, $request->trust_root);
 181         }
 182
 183         // Answer to the Relying Party
 184         if ($whitelisted || isset($_POST['trust'])) {
 185             S::kill('openid_request');
 186             $response =& $request->answer(true, null, $identity, $claimed_id);
 187
 188             // Add the simple registration response values to the OpenID
 189             // response message.
 190             $sreg_response->toMessage($response->fields);
 191
 192         } else { // !$whitelisted && !isset($_POST['trust'])
 193             S::kill('openid_request');
 194             $response =& $request->answer(false);
 195         }
 196
 197         // Generate a response to send to the user agent.
 198         $webresponse =& $server->encodeResponse($response);
 199         $this->render_openid_response($webresponse);
 200     }
 201
 202     function handler_idp_xrds(&$page)
 203     {
 204         $this->load('openid.inc.php');
 205
 206         // Set XRDS content-type and template
 207         header('Content-type: application/xrds+xml');
 208         $page->changeTpl('openid/idp_xrds.tpl', NO_SKIN);
 209
 210         // Set variables
 211         $page->assign('type2', Auth_OpenID_TYPE_2_0_IDP);
 212         $page->assign('sreg', Auth_OpenID_SREG_URI);
 213         $page->assign('provider', get_openid_url());
 214     }
 215
 216     function handler_user_xrds(&$page, $x = null)
 217     {
 218         $this->load('openid.inc.php');
 219
 220         // Make sure the user exists
 221         $user = get_user($x);
 222         if (is_null($user)) {
 223             return PL_NOT_FOUND;
 224         }
 225
 226         // Set XRDS content-type and template
 227         header('Content-type: application/xrds+xml');
 228         $page->changeTpl('openid/user_xrds.tpl', NO_SKIN);
 229
 230         // Set variables
 231         $page->assign('type2', Auth_OpenID_TYPE_2_0);
 232         $page->assign('type1', Auth_OpenID_TYPE_1_1);
 233         $page->assign('sreg', Auth_OpenID_SREG_URI);
 234         $page->assign('provider', get_openid_url());
 235         $page->assign('local_id', $user->hruid);
 236     }
 237
 238     function handler_melix(&$page, $x = null)
 239     {
 240         $this->load('openid.inc.php');
 241         $user = get_user_by_alias($x);
 242
 243         // This will redirect to the canonic URL, which was not used
 244         // if this hook was triggered
 245         return $this->render_discovery_page(&$page, $user);
 246     }
 247
 248     //--------------------------------------------------------------------//
 249
 250     function render_discovery_page(&$page, $user)
 251     {
 252
 253         // Show the documentation if this is not the OpenId page of an user
 254         if (is_null($user)) {
 255             pl_redirect('Xorg/OpenId');
 256         }
 257
 258         // Redirect to the canonic URL if we are using an alias
 259         // There might be a risk of redirection loop here
 260         // if $_SERVER was not exactly what we expect
 261         $current_url = 'http' . (empty($_SERVER['HTTPS']) ? '' : 's') . '://'
 262                        . $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI'];
 263         $canonic_url = get_user_openid_url($user);
 264         if ($current_url != $canonic_url) {
 265             http_redirect($canonic_url);
 266         }
 267
 268         // Include X-XRDS-Location response-header for Yadis discovery
 269         header('X-XRDS-Location: ' . get_user_xrds_url($user));
 270
 271         // Select template
 272         $page->changeTpl('openid/openid.tpl');
 273
 274         // Sets the title of the html page.
 275         $page->setTitle($user->fullName());
 276
 277         // Sets the <link> tags for HTML-Based Discovery
 278         $page->addLink('openid.server openid2.provider', get_openid_url());
 279         $page->addLink('openid.delegate openid2.local_id', $user->hruid);
 280
 281         // Adds the global user property array to the display.
 282         $page->assign_by_ref('user', $user);
 283
 284         return;
 285     }
 286
 287     function render_openid_response($webresponse)
 288     {
 289         // Send HTTP response code
 290         if ($webresponse->code != AUTH_OPENID_HTTP_OK) {
 291             header(sprintf("HTTP/1.1 %d ", $webresponse->code),
 292                    true, $webresponse->code);
 293         }
 294
 295         // Send headers
 296         foreach ($webresponse->headers as $k => $v) {
 297             header("$k: $v");
 298         }
 299         header('Connection: close');
 300
 301         // Send body
 302         print $webresponse->body;
 303         exit;
 304     }
 305 }
 306
 307 // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8:
 308 ?>