classes/xorgsession.php

   1 <?php
   2 /***************************************************************************
   3  *  Copyright (C) 2003-2011 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 class XorgSession extends PlSession
  23 {
  24     const INVALID_USER = -2;
  25     const NO_COOKIE = -1;
  26     const COOKIE_SUCCESS = 0;
  27     const INVALID_COOKIE = 1;
  28
  29     public function __construct()
  30     {
  31         parent::__construct();
  32     }
  33
  34     public function startAvailableAuth()
  35     {
  36         if (!S::logged()) {
  37             switch ($this->tryCookie()) {
  38               case self::COOKIE_SUCCESS:
  39                 if (!$this->start(AUTH_COOKIE)) {
  40                     return false;
  41                 }
  42                 break;
  43
  44               case self::INVALID_USER:
  45               case self::INVALID_COOKIE:
  46                 return false;
  47             }
  48         }
  49         if ((check_ip('dangerous') && S::has('uid')) || check_account()) {
  50             S::logger()->log("view_page", $_SERVER['REQUEST_URI']);
  51         }
  52         return true;
  53     }
  54
  55     /** Check the cookie and set the associated uid in the auth_by_cookie session variable.
  56      */
  57     private function tryCookie()
  58     {
  59         S::kill('auth_by_cookie');
  60         if (Cookie::v('access') == '' || !Cookie::has('uid')) {
  61             return self::NO_COOKIE;
  62         }
  63
  64         $res = XDB::query('SELECT  uid, password
  65                              FROM  accounts
  66                             WHERE  uid = {?} AND state = \'active\'',
  67                          Cookie::i('uid'));
  68         if ($res->numRows() != 0) {
  69             list($uid, $password) = $res->fetchOneRow();
  70             if (sha1($password) == Cookie::v('access')) {
  71                 S::set('auth_by_cookie', $uid);
  72                 return self::COOKIE_SUCCESS;
  73             } else {
  74                 return self::INVALID_COOKIE;
  75             }
  76         }
  77         return self::INVALID_USER;
  78     }
  79
  80     const TEXT_INVALID_LOGIN = "Mot de passe ou nom d'utilisateur invalide";
  81     const TEXT_INVALID_PASS = "Mot de passe invalide";
  82
  83     private function checkPassword($login, User $user, $response)
  84     {
  85         if ($user === null) {
  86             Platal::page()->trigError(self::TEXT_INVALID_LOGIN);
  87             return false;
  88         } else {
  89             $password = $user->password();
  90             $expected_response = sha1("$login:$password:" . S::v('challenge'));
  91             /* Deprecates len(password) > 10 conversion. */
  92             if ($response != $expected_response) {
  93                 if (!S::logged()) {
  94                     Platal::page()->trigError(self::TEXT_INVALID_LOGIN);
  95                 } else {
  96                     Platal::page()->trigError(self::TEXT_INVALID_PASS);
  97                 }
  98                 S::logger($uid)->log('auth_fail', 'bad password');
  99                 return false;
 100             }
 101             return true;
 102         }
 103     }
 104
 105
 106     /** Check auth.
 107      */
 108     protected function doAuth($level)
 109     {
 110         global $globals;
 111
 112         /* Cookie authentication
 113          */
 114         if ($level == AUTH_COOKIE && !S::has('auth_by_cookie')) {
 115             $this->tryCookie();
 116         }
 117         if ($level == AUTH_COOKIE && S::has('auth_by_cookie')) {
 118             if (!S::logged()) {
 119                 S::set('auth', AUTH_COOKIE);
 120             }
 121             return User::getSilentWithUID(S::i('auth_by_cookie'));
 122         }
 123
 124
 125         /* We want to do auth... we must have infos from a form.
 126          */
 127         if (!Post::has('username') || !Post::has('response') || !S::has('challenge')) {
 128             return null;
 129         }
 130
 131         /** We come from an authentication form.
 132          */
 133         if (S::suid()) {
 134             $login = S::suid('uid');
 135         } else {
 136             $login = Post::v('username');
 137         }
 138
 139         $user = User::getSilent($login);
 140
 141         if (is_null($user)) {
 142             Platal::page()->trigError(self::TEXT_INVALID_LOGIN);
 143             $success = false;
 144         } else {
 145             if (S::suid()) {
 146                 $success = (S::suid('uid') == $user->id());
 147             } else {
 148                 $success = $this->checkPassword($login, $user, Post::v('response'));
 149             }
 150         }
 151
 152         if ($success) {
 153             S::set('auth', AUTH_PASSWD);
 154             S::kill('challenge');
 155             S::logger($user->id())->log('auth_ok');
 156         }
 157         return $user;
 158     }
 159
 160     protected function startSessionAs($user, $level)
 161     {
 162         if ((!is_null(S::user()) && S::user()->id() != $user->id())
 163             || (S::has('uid') && S::i('uid') != $user->id())) {
 164             return false;
 165         } else if (S::has('uid')) {
 166             return true;
 167         }
 168         if ($level == AUTH_SUID) {
 169             S::set('auth', AUTH_PASSWD);
 170         }
 171
 172         // Loads uid and hruid into the session for developement conveniance.
 173         $_SESSION = array_merge($_SESSION, array('uid' => $user->id(), 'hruid' => $user->hruid, 'token' => $user->token, 'user' => $user));
 174
 175         // Starts the session's logger, and sets up the permanent cookie.
 176         if (S::suid()) {
 177             S::logger()->log("suid_start", S::v('hruid') . ' by ' . S::suid('hruid'));
 178         } else {
 179             S::logger()->saveLastSession();
 180             Cookie::set('uid', $user->id(), 300);
 181
 182             if (S::i('auth_by_cookie') == $user->id() || Post::v('remember', 'false') == 'true') {
 183                 $this->setAccessCookie(false, S::i('auth_by_cookie') != $user->id());
 184             } else {
 185                 $this->killAccessCookie();
 186             }
 187         }
 188
 189         // Finalizes the session setup.
 190         $this->makePerms($user->perms, $user->is_admin);
 191         $this->securityChecks();
 192         $this->setSkin();
 193         $this->updateNbNotifs();
 194         // Only check email redirection for 'internal' users.
 195         if ($user->checkPerms(PERMS_USER)) {
 196             check_redirect();
 197         }
 198
 199         // We should not have to use this private data anymore
 200         S::kill('auth_by_cookie');
 201         return true;
 202     }
 203
 204     private function securityChecks()
 205     {
 206         $mail_subject = array();
 207         if (check_account()) {
 208             $mail_subject[] = 'Connexion d\'un utilisateur surveillé';
 209         }
 210         if (check_ip('unsafe')) {
 211             $mail_subject[] = 'Une IP surveillee a tente de se connecter';
 212             if (check_ip('ban')) {
 213                 send_warning_mail(implode(' - ', $mail_subject));
 214                 $this->destroy();
 215                 Platal::page()->kill('Une erreur est survenue lors de la procédure d\'authentification. '
 216                                     . 'Merci de contacter au plus vite '
 217                                     . '<a href="mailto:support@polytechnique.org">support@polytechnique.org</a>');
 218                 return false;
 219             }
 220         }
 221         if (count($mail_subject)) {
 222             send_warning_mail(implode(' - ', $mail_subject));
 223         }
 224     }
 225
 226     /**
 227      * The authentication schema is based on three query parameters:
 228      *   ?user=<hruid>&timestamp=<timestamp>&sig=<sig>
 229      * where:
 230      *   - hruid is the hruid of the querying user
 231      *   - timestamp is the current UNIX timestamp, which has to be within a
 232      *     given distance of the server-side UNIX timestamp
 233      *   - sig is the HMAC of "<method>#<resource>#<payload>#<timestamp>" using
 234      *     a known secret of the user as the key.
 235      *
 236      * At the moment, the shared secret of the user is the sha1 hash of its
 237      * password. This is temporary, though, until better support for tokens is
 238      * implemented in plat/al.
 239      * TODO(vzanotti): Switch to dedicated secrets for authentication.
 240      */
 241     public function apiAuth($method, $resource, $payload)
 242     {
 243         // Verify that the timestamp is within acceptable bounds.
 244         $timestamp = Env::i('timestamp', 0);
 245         if (abs($timestamp - time()) > Platal::globals()->api->timestamp_tolerance) {
 246             return null;
 247         }
 248
 249         // Retrieve the user corresponding to the forlife. Note that at the
 250         // moment, other aliases are also accepted.
 251         $user = User::getSilent(Env::s('user', ''));
 252         if (is_null($user) || !$user->isActive()) {
 253             return null;
 254         }
 255
 256         // Determine the list of tokens associated with the user. At the moment,
 257         // this is just the sha1 of the password.
 258         $tokens = array($user->password());
 259
 260         // For each token, try to validate the signature.
 261         $message = implode('#', array($method, $resource, $payload, $timestamp));
 262         $signature = Env::s('sig');
 263         foreach ($tokens as $token) {
 264             $expected_signature = hash_hmac(
 265                 Platal::globals()->api->hmac_algo, $message, $token);
 266             if ($signature == $expected_signature) {
 267                 return $user;
 268             }
 269         }
 270
 271         return null;
 272     }
 273
 274     public function tokenAuth($login, $token)
 275     {
 276         $res = XDB::query('SELECT  a.uid, a.hruid
 277                              FROM  accounts AS a
 278                             WHERE  a.token = {?} AND a.hruid = {?} AND a.state = \'active\'',
 279                           $token, $login);
 280         if ($res->numRows() == 1) {
 281             return new User(null, $res->fetchOneAssoc());
 282         }
 283         return null;
 284     }
 285
 286     protected function makePerms($perm, $is_admin)
 287     {
 288         S::set('perms', User::makePerms($perm, $is_admin));
 289     }
 290
 291     public function setSkin()
 292     {
 293         if (S::logged() && (!S::has('skin') || S::suid())) {
 294             $res = XDB::query('SELECT  skin_tpl
 295                                  FROM  accounts AS a
 296                            INNER JOIN  skins    AS s on (a.skin = s.id)
 297                                 WHERE  a.uid = {?} AND skin_tpl != \'\'', S::i('uid'));
 298             S::set('skin', $res->fetchOneCell());
 299         }
 300     }
 301
 302     public function loggedLevel()
 303     {
 304         return AUTH_COOKIE;
 305     }
 306
 307     public function sureLevel()
 308     {
 309         return AUTH_PASSWD;
 310     }
 311
 312
 313     public function updateNbNotifs()
 314     {
 315         require_once 'notifs.inc.php';
 316         $user = S::user();
 317         $n = Watch::getCount($user);
 318         S::set('notifs', $n);
 319     }
 320
 321     public function setAccessCookie($replace = false, $log = true) {
 322         if (S::suid() || ($replace && !Cookie::blank('access'))) {
 323             return;
 324         }
 325         Cookie::set('access', sha1(S::user()->password()), 300, true);
 326         if ($log) {
 327             S::logger()->log('cookie_on');
 328         }
 329     }
 330
 331     public function killAccessCookie($log = true) {
 332         Cookie::kill('access');
 333         if ($log) {
 334             S::logger()->log('cookie_off');
 335         }
 336     }
 337
 338     public function killLoginFormCookies() {
 339         Cookie::kill('uid');
 340         Cookie::kill('domain');
 341     }
 342 }
 343
 344 // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8:
 345 ?>