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88a4c51b FB |
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 | ||
47fa97fe FB |
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_PUBLIC', 0); | |
27 | define('AUTH_COOKIE', 1); | |
28 | define('AUTH_MDP', 2); | |
29 | ||
88a4c51b FB |
30 | |
31 | /** The PlSession is a wrapper around the user session management. | |
32 | */ | |
33 | abstract class PlSession | |
34 | { | |
35 | /** Build a new session object. | |
36 | * If a session is already started, this just wraps the session... if no | |
37 | * session is currently started, this set the base session variables. | |
38 | * * auth contains the current authentication level. The level is | |
39 | * an integer that grows with the security of the authentication | |
40 | * method. | |
41 | * * perms contains the current permission flags of the user. This flags | |
42 | * depends on the category of the user. | |
43 | * * challenge contains a random uniq id for authentication. | |
44 | * * xsrf_token contains a random uniq id for xsrf prevention. | |
45 | * * user contains a reference to the current user. | |
46 | */ | |
47 | public function __construct() | |
48 | { | |
c0799142 | 49 | $this->create(); |
88a4c51b FB |
50 | } |
51 | ||
52 | /** Build the session structure with system fields. | |
53 | */ | |
54 | private function fillSession() | |
55 | { | |
56 | S::bootstrap('user', null); | |
57 | S::bootstrap('auth', AUTH_PUBLIC); | |
58 | S::bootstrap('challenge', sha1(uniqid(rand(), true))); | |
59 | S::bootstrap('xsrf_token', rand_url_id()); | |
60 | S::bootstrap('perms', new PlFlagSet()); | |
61 | } | |
62 | ||
63 | /** Write current session and close it. | |
64 | */ | |
65 | public function close() | |
66 | { | |
67 | session_write_close(); | |
68 | } | |
69 | ||
c0799142 FB |
70 | /** Create a new session |
71 | */ | |
72 | private function create() | |
73 | { | |
74 | session_start(); | |
75 | $this->fillSession(); | |
76 | } | |
77 | ||
88a4c51b FB |
78 | /** Kill the current session. |
79 | */ | |
80 | public function destroy() | |
81 | { | |
82 | session_destroy(); | |
83 | unset($_SESSION); | |
c0799142 | 84 | $this->create(); |
88a4c51b FB |
85 | } |
86 | ||
87 | /** Check if the user has at least the given authentication level. | |
88 | */ | |
89 | public function checkAuth($level) | |
90 | { | |
91 | return S::i('auth') >= $level; | |
92 | } | |
93 | ||
94 | /** Check if the user has the given permissions. | |
95 | */ | |
96 | public function checkPerms($perms) | |
97 | { | |
98 | return S::v('perms')->hasFlagCombination($perms); | |
99 | } | |
100 | ||
101 | /** Run authentication procedure to reach at least the given level. | |
102 | */ | |
103 | public function start($level) | |
104 | { | |
c0799142 | 105 | $backup = S::i($level); |
88a4c51b FB |
106 | if ($this->checkAuth($level)) { |
107 | return true; | |
108 | } | |
109 | $user = $this->doAuth($level); | |
c0799142 FB |
110 | if (is_null($user)) { |
111 | return false; | |
112 | } | |
113 | if (!$this->checkAuth($level)) { | |
114 | $this->destroy(); | |
88a4c51b FB |
115 | return false; |
116 | } | |
117 | if ($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 | ||
c0799142 FB |
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 | ||
88a4c51b FB |
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, $level); | |
161 | ||
162 | ||
163 | /*** SUID management ***/ | |
164 | ||
165 | /** Start a new SUID session. | |
166 | */ | |
167 | public function startSUID($user) | |
168 | { | |
732e5855 | 169 | if (S::has('suid')) { |
88a4c51b FB |
170 | return false; |
171 | } | |
732e5855 FB |
172 | $backup = $_SESSION; |
173 | $_SESSION = array(); | |
88a4c51b FB |
174 | $this->fillSession(); |
175 | S::set('suid', $backup); | |
176 | if (!$this->startSessionAs($user, -1)) { | |
177 | $this->stopSUID(); | |
178 | return false; | |
179 | } | |
732e5855 | 180 | S::set('user', $user); |
88a4c51b FB |
181 | return true; |
182 | } | |
183 | ||
184 | /** Stop a SUID session | |
185 | */ | |
186 | public function stopSUID() | |
187 | { | |
732e5855 | 188 | if (!S::has('suid')) { |
88a4c51b FB |
189 | return false; |
190 | } | |
732e5855 | 191 | $_SESSION = $_SESSION['suid']; |
88a4c51b FB |
192 | return true; |
193 | } | |
194 | ||
195 | ||
196 | /*** Thresholds ***/ | |
197 | ||
198 | /** Minimum level of authentication that is considered as sure. | |
199 | */ | |
200 | abstract public function sureLevel(); | |
201 | } | |
202 | ||
203 | // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8: | |
204 | ?> |