| 1 | <?php |
| 2 | /*************************************************************************** |
| 3 | * Copyright (C) 2003-2010 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 | /** Authentication level. |
| 23 | * Only AUTH_PUBLIC is mandatory. The others are defined as useful values, |
| 24 | * but can be overwritten by others auth levels definitions. |
| 25 | */ |
| 26 | define('AUTH_SUID', -1); |
| 27 | define('AUTH_PUBLIC', 0); |
| 28 | define('AUTH_COOKIE', 5); |
| 29 | define('AUTH_MDP', 10); |
| 30 | |
| 31 | |
| 32 | /** The PlSession is a wrapper around the user session management. |
| 33 | */ |
| 34 | abstract class PlSession |
| 35 | { |
| 36 | /** Build a new session object. |
| 37 | * If a session is already started, this just wraps the session... if no |
| 38 | * session is currently started, this set the base session variables. |
| 39 | * * auth contains the current authentication level. The level is |
| 40 | * an integer that grows with the security of the authentication |
| 41 | * method. |
| 42 | * * perms contains the current permission flags of the user. This flags |
| 43 | * depends on the category of the user. |
| 44 | * * challenge contains a random uniq id for authentication. |
| 45 | * * xsrf_token contains a random uniq id for xsrf prevention. |
| 46 | * * user contains a reference to the current user. |
| 47 | */ |
| 48 | public function __construct() |
| 49 | { |
| 50 | $this->create(); |
| 51 | } |
| 52 | |
| 53 | /** Build the session structure with system fields. |
| 54 | */ |
| 55 | private function fillSession() |
| 56 | { |
| 57 | S::bootstrap('user', null); |
| 58 | S::bootstrap('auth', AUTH_PUBLIC); |
| 59 | S::bootstrap('challenge', sha1(uniqid(rand(), true))); |
| 60 | S::bootstrap('xsrf_token', rand_url_id()); |
| 61 | S::bootstrap('perms', new PlFlagSet()); |
| 62 | } |
| 63 | |
| 64 | /** Write current session and close it. |
| 65 | */ |
| 66 | public function close() |
| 67 | { |
| 68 | session_write_close(); |
| 69 | } |
| 70 | |
| 71 | /** Create a new session |
| 72 | */ |
| 73 | private function create() |
| 74 | { |
| 75 | session_start(); |
| 76 | $this->fillSession(); |
| 77 | } |
| 78 | |
| 79 | /** Kill the current session. |
| 80 | */ |
| 81 | public function destroy() |
| 82 | { |
| 83 | session_destroy(); |
| 84 | unset($_SESSION); |
| 85 | $this->create(); |
| 86 | } |
| 87 | |
| 88 | /** Check if the user has at least the given authentication level. |
| 89 | */ |
| 90 | public function checkAuth($level) |
| 91 | { |
| 92 | return S::i('auth') >= $level; |
| 93 | } |
| 94 | |
| 95 | /** Check if the user has the given permissions. |
| 96 | */ |
| 97 | public function checkPerms($perms) |
| 98 | { |
| 99 | return S::v('perms')->hasFlagCombination($perms); |
| 100 | } |
| 101 | |
| 102 | /** Run authentication procedure to reach at least the given level. |
| 103 | */ |
| 104 | public function start($level) |
| 105 | { |
| 106 | if ($this->checkAuth($level)) { |
| 107 | return true; |
| 108 | } |
| 109 | $user = $this->doAuth($level); |
| 110 | if (is_null($user)) { |
| 111 | return false; |
| 112 | } |
| 113 | if (!$this->checkAuth($level)) { |
| 114 | $this->destroy(); |
| 115 | return false; |
| 116 | } |
| 117 | if ($this->startSessionAs($user, $level)) { |
| 118 | if (is_null(S::v('user'))) { |
| 119 | S::set('user', $user); |
| 120 | } |
| 121 | return true; |
| 122 | } else { |
| 123 | $this->destroy(); |
| 124 | } |
| 125 | return false; |
| 126 | } |
| 127 | |
| 128 | |
| 129 | /*** Abstract methods ***/ |
| 130 | |
| 131 | /** Function that check authentication at build time of the session object. |
| 132 | * This is useful to perform authentication from a cookie or when coming |
| 133 | * back from a authentication service. |
| 134 | * |
| 135 | * This function must NOT try to launch a new authenticatioin procedure. It |
| 136 | * just tests if the environment contains sufficient information to start |
| 137 | * a user session. |
| 138 | * |
| 139 | * This function return false if informations are available but lead to an |
| 140 | * authentication failure (invalid cookie, invalid service return data...) |
| 141 | */ |
| 142 | abstract public function startAvailableAuth(); |
| 143 | |
| 144 | /** Run the effectively authentication procedure to reach the given user. |
| 145 | * This method must return a user object (that will be used to fill the |
| 146 | * $_SESSION['user'] field). |
| 147 | * |
| 148 | * If auth failed, the function MUST return null. If auth succeed, the |
| 149 | * field $_SESSION['auth'] MUST be filled to the current effective level. |
| 150 | */ |
| 151 | abstract protected function doAuth($level); |
| 152 | |
| 153 | /** Set the session environment to the given user and authentication level. |
| 154 | * This function MUST return false if a session is already started and the |
| 155 | * user mismatch. |
| 156 | * |
| 157 | * On succes, this function MUST return true. |
| 158 | * If $level is set to -1, this means you are building a new SUID session. |
| 159 | */ |
| 160 | abstract protected function startSessionAs($user, $level); |
| 161 | |
| 162 | /** Check authentication with the given token. |
| 163 | * |
| 164 | * Token authentication is a light-weight authentication based on a user-specific token. |
| 165 | * This can be used for protocols that requires a 'cookie'-free authentication, such as |
| 166 | * RSS, iCal registration... |
| 167 | * |
| 168 | * This function returns a valid user object if authentication is successful, or null if |
| 169 | * token mismatch. |
| 170 | */ |
| 171 | abstract public function tokenAuth($login, $token); |
| 172 | |
| 173 | /** Set the permissions to the given flagset. |
| 174 | * |
| 175 | * This function sets S::set('perms') with a flagset represeting the combination of |
| 176 | * $perms and $is_admin. |
| 177 | * |
| 178 | * $perms is an abstract object representing the permissions. |
| 179 | * $is_admin is a boolean, true if the current user has site-administration rights. |
| 180 | */ |
| 181 | abstract protected function makePerms($perms, $is_admin); |
| 182 | |
| 183 | /*** SUID management ***/ |
| 184 | |
| 185 | /** Start a new SUID session. |
| 186 | */ |
| 187 | public function startSUID($user, $perms = null) |
| 188 | { |
| 189 | if (S::suid()) { |
| 190 | return false; |
| 191 | } |
| 192 | $backup = $_SESSION; |
| 193 | $_SESSION = array(); |
| 194 | $this->fillSession(); |
| 195 | S::set('suid', $backup); |
| 196 | if (!$this->startSessionAs($user, AUTH_SUID)) { |
| 197 | $this->stopSUID(); |
| 198 | return false; |
| 199 | } |
| 200 | S::set('user', $user); |
| 201 | if (!is_null($perms)) { |
| 202 | $this->makePerms($perms, false); |
| 203 | } |
| 204 | return true; |
| 205 | } |
| 206 | |
| 207 | /** Stop a SUID session |
| 208 | */ |
| 209 | public function stopSUID() |
| 210 | { |
| 211 | if (!S::suid()) { |
| 212 | return false; |
| 213 | } |
| 214 | $_SESSION = $_SESSION['suid']; |
| 215 | return true; |
| 216 | } |
| 217 | |
| 218 | |
| 219 | /*** Thresholds ***/ |
| 220 | |
| 221 | /** Minimum level of authentication that is considered as logged. |
| 222 | */ |
| 223 | abstract public function loggedLevel(); |
| 224 | |
| 225 | /** Minimum level of authentication that is considered as sure. |
| 226 | */ |
| 227 | abstract public function sureLevel(); |
| 228 | } |
| 229 | |
| 230 | // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8: |
| 231 | ?> |