mirrored from git://git.moodle.org/moodle.git
/
auth.php
465 lines (418 loc) · 21.5 KB
/
auth.php
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
use auth_lti\local\ltiadvantage\entity\user_migration_claim;
defined('MOODLE_INTERNAL') || die();
require_once($CFG->libdir.'/authlib.php');
require_once($CFG->libdir.'/accesslib.php');
/**
* LTI Authentication plugin.
*
* @package auth_lti
* @copyright 2016 Mark Nelson <markn@moodle.com>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class auth_plugin_lti extends \auth_plugin_base {
/**
* @var int constant representing the automatic account provisioning mode.
* On first launch, for a previously unbound user, this mode dictates that a new Moodle account will be created automatically
* for the user and bound to their platform credentials {iss, sub}.
*/
public const PROVISIONING_MODE_AUTO_ONLY = 1;
/**
* @var int constant representing the prompt for new or existing provisioning mode.
* On first launch, for a previously unbound user, the mode dictates that the launch user will be presented with an options
* view, allowing them to select either 'link an existing account' or 'create a new account for me'.
*/
public const PROVISIONING_MODE_PROMPT_NEW_EXISTING = 2;
/**
* @var int constant representing the prompt for existing only provisioning mode.
* On first launch, for a previously unbound user, the mode dictates that the launch user will be presented with a view allowing
* them to link an existing account only. This is useful for situations like deep linking, where an existing account is needed.
*/
public const PROVISIONING_MODE_PROMPT_EXISTING_ONLY = 3;
/**
* Constructor.
*/
public function __construct() {
$this->authtype = 'lti';
}
/**
* Users can not log in via the traditional login form.
*
* @param string $username The username
* @param string $password The password
* @return bool Authentication success or failure
*/
public function user_login($username, $password) {
return false;
}
/**
* Authenticate the user based on the unique {iss, sub} tuple present in the OIDC JWT.
*
* This method ensures a Moodle user account has been found or is created, that the user is linked to the relevant
* LTI Advantage credentials (iss, sub) and that the user account is logged in.
*
* Launch code can therefore rely on this method to get a session before doing things like calling require_login().
*
* This method supports two workflows:
* 1. Automatic account provisioning - where the complete_login() call will ALWAYS create/find a user and return to
* calling code directly. No user interaction is required.
*
* 2. Manual account provisioning - where the complete_login() call will redirect ONLY ONCE to a login page,
* where the user can decide whether to use an automatically provisioned account, or bind an existing user account.
* When the decision has been made, the relevant account is bound and the user is redirected back to $returnurl.
* Once an account has been bound via this selection process, subsequent calls to complete_login() will return to
* calling code directly. Any calling code must provide its $returnurl to support the return from the account
* selection process and must also take care to cache any JWT data appropriately, since the return will not inlude
* that information.
*
* Which workflow is chosen depends on the roles present in the JWT.
* For teachers/admins, manual provisioning will take place. These user type are likely to have existing accounts.
* For learners, automatic provisioning will take place.
*
* Migration of legacy users is supported, however, only for the Learner role (automatic provisioning). Admins and
* teachers are likely to have existing accounts and we want them to be able to select and bind these, rather than
* binding an automatically provisioned legacy account which doesn't represent their real user account.
*
* The JWT data must be verified elsewhere. The code here assumes its integrity/authenticity.
*
* @param array $launchdata the JWT data provided in the link launch.
* @param moodle_url $returnurl the local URL to return to if authentication workflows are required.
* @param int $provisioningmode the desired account provisioning mode, which controls the auth flow for unbound users.
* @param array $legacyconsumersecrets an array of secrets used by the legacy consumer if a migration claim exists.
* @throws coding_exception if the specified provisioning mode is invalid.
*/
public function complete_login(array $launchdata, moodle_url $returnurl, int $provisioningmode,
array $legacyconsumersecrets = []): void {
// The platform user is already linked with a user account.
if ($this->get_user_binding($launchdata['iss'], $launchdata['sub'])) {
$user = $this->find_or_create_user_from_launch($launchdata);
if (isloggedin()) {
// If a different user is currently logged in, authenticate the linked user instead.
global $USER;
if ($USER->id !== $user->id) {
complete_user_login($user);
}
// If the linked user is already logged in, skip the call to complete_user_login() because this affects deep linking
// workflows on sites publishing and consuming resources on the same site, due to the regenerated sesskey.
} else {
complete_user_login($user);
}
// Always sync the PII, regardless of whether we're already authenticated as this user or not.
$this->update_user_account($user, $launchdata, $launchdata['iss']);
return;
}
// The platform user is not bound to a user account, check provisioning mode now.
if (!$this->is_valid_provisioning_mode($provisioningmode)) {
throw new coding_exception('Invalid account provisioning mode provided to complete_login().');
}
switch ($provisioningmode) {
case self::PROVISIONING_MODE_AUTO_ONLY:
// Automatic provisioning - this will create/migrate a user account and log the user in.
$user = $this->find_or_create_user_from_launch($launchdata, $legacyconsumersecrets);
complete_user_login($user);
$this->update_user_account($user, $launchdata, $launchdata['iss']);
break;
case self::PROVISIONING_MODE_PROMPT_NEW_EXISTING:
case self::PROVISIONING_MODE_PROMPT_EXISTING_ONLY:
default:
// Allow linking an existing account or creation of a new account via an intermediate account options page.
// Cache the relevant data and take the user to the account options page.
// Note: This mode also depends on the global auth config 'authpreventaccountcreation'. If set, only existing
// accounts can be bound in this provisioning mode.
global $SESSION;
$SESSION->auth_lti = (object)[
'launchdata' => $launchdata,
'returnurl' => $returnurl,
'provisioningmode' => $provisioningmode
];
redirect(new moodle_url('/auth/lti/login.php', [
'sesskey' => sesskey(),
]));
break;
}
}
/**
* Get a Moodle user account for the LTI user based on the user details returned by a NRPS 2 membership call.
*
* This method expects a single member structure, in array format, as defined here:
* See: https://www.imsglobal.org/spec/lti-nrps/v2p0#membership-container-media-type.
*
* This method supports migration of user accounts used in legacy launches, provided the legacy consumerkey corresponding to
* to the legacy consumer is provided. Calling code will have verified the migration claim during initial launches and should
* have the consumer key mapped to the deployment, ready to pass in.
*
* @param array $member the member data, in array format.
* @param string $iss the issuer to which the member relates.
* @param string $legacyconsumerkey optional consumer key mapped to the deployment to facilitate user migration.
* @return stdClass a Moodle user record.
*/
public function find_or_create_user_from_membership(array $member, string $iss,
string $legacyconsumerkey = ''): stdClass {
// Picture is not synced with membership-based auths because sync tasks may wish to perform slow operations like this a
// different way.
unset($member['picture']);
if ($binduser = $this->get_user_binding($iss, $member['user_id'])) {
$user = \core_user::get_user($binduser);
$this->update_user_account($user, $member, $iss);
return \core_user::get_user($user->id);
} else {
if (!empty($legacyconsumerkey)) {
// Consumer key is required to attempt user migration because legacy users were identified by a
// username consisting of the consumer key and user id.
// See the legacy \enrol_lti\helper::create_username() for details.
$legacyuserid = $member['lti11_legacy_user_id'] ?? $member['user_id'];
$username = 'enrol_lti' .
sha1($legacyconsumerkey . '::' . $legacyconsumerkey . ':' . $legacyuserid);
if ($user = \core_user::get_user_by_username($username)) {
$this->create_user_binding($iss, $member['user_id'], $user->id);
$this->update_user_account($user, $member, $iss);
return \core_user::get_user($user->id);
}
}
$user = $this->create_new_account($member, $iss);
return \core_user::get_user($user->id);
}
}
/**
* Get a Moodle user account for the LTI user corresponding to the user defined in a link launch.
*
* This method supports migration of user accounts used in legacy launches, provided the legacy consumer secrets corresponding
* to the legacy consumer are provided. If calling code wishes migration to be role-specific, it should check roles accordingly
* itself and pass relevant data in - as auth_plugin_lti::complete_login() does.
*
* @param array $launchdata all data in the decoded JWT including iss and sub.
* @param array $legacyconsumersecrets all secrets found for the legacy consumer, facilitating user migration.
* @return stdClass the Moodle user who is mapped to the platform user identified in the JWT data.
*/
public function find_or_create_user_from_launch(array $launchdata, array $legacyconsumersecrets = []): stdClass {
if ($binduser = $this->get_user_binding($launchdata['iss'], $launchdata['sub'])) {
return \core_user::get_user($binduser);
} else {
// Is the intent to migrate a user account used in legacy launches?
if (!empty($legacyconsumersecrets)) {
try {
// Validate the migration claim and try to find a legacy user.
$usermigrationclaim = new user_migration_claim($launchdata, $legacyconsumersecrets);
$username = 'enrol_lti' .
sha1($usermigrationclaim->get_consumer_key() . '::' .
$usermigrationclaim->get_consumer_key() . ':' . $usermigrationclaim->get_user_id());
if ($user = core_user::get_user_by_username($username)) {
$this->create_user_binding($launchdata['iss'], $launchdata['sub'], $user->id);
return core_user::get_user($user->id);
}
} catch (Exception $e) {
// There was an issue validating the user migration claim. We don't want to fail auth entirely though.
// Rather, we want to fall back to new account creation and log the attempt.
debugging("There was a problem migrating the LTI user '{$launchdata['sub']}' on the platform " .
"'{$launchdata['iss']}'. The migration claim could not be validated. A new account will be created.");
}
}
// At the point of the creation, to ensure the user_created event correctly reflects the creating user of '0' (the user
// performing the action), ensure any active session is terminated and an empty session initialised.
$this->empty_session();
$user = $this->create_new_account($launchdata, $launchdata['iss']);
return core_user::get_user($user->id);
}
}
/**
* Create a binding between the LTI user, as identified by {iss, sub} tuple and the user id.
*
* @param string $iss the issuer URL identifying the platform to which to user belongs.
* @param string $sub the sub string identifying the user on the platform.
* @param int $userid the id of the Moodle user account to bind.
*/
public function create_user_binding(string $iss, string $sub, int $userid): void {
global $DB;
$timenow = time();
$issuer256 = hash('sha256', $iss);
$sub256 = hash('sha256', $sub);
if ($DB->record_exists('auth_lti_linked_login', ['issuer256' => $issuer256, 'sub256' => $sub256])) {
return;
}
$rec = [
'userid' => $userid,
'issuer' => $iss,
'issuer256' => $issuer256,
'sub' => $sub,
'sub256' => $sub256,
'timecreated' => $timenow,
'timemodified' => $timenow
];
$DB->insert_record('auth_lti_linked_login', $rec);
}
/**
* Gets the id of the linked Moodle user account for an LTI user, or null if not found.
*
* @param string $issuer the issuer to which the user belongs.
* @param string $sub the sub string identifying the user on the issuer.
* @return int|null the id of the corresponding Moodle user record, or null if not found.
*/
public function get_user_binding(string $issuer, string $sub): ?int {
global $DB;
$issuer256 = hash('sha256', $issuer);
$sub256 = hash('sha256', $sub);
try {
$binduser = $DB->get_field('auth_lti_linked_login', 'userid',
['issuer256' => $issuer256, 'sub256' => $sub256], MUST_EXIST);
} catch (\dml_exception $e) {
$binduser = null;
}
return $binduser;
}
/**
* If there's an existing session, inits an empty session.
*
* @return void
*/
protected function empty_session(): void {
if (isloggedin()) {
\core\session\manager::init_empty_session();
}
}
/**
* Check whether a provisioning mode is valid or not.
*
* @param int $mode the mode
* @return bool true if valid for use, false otherwise.
*/
protected function is_valid_provisioning_mode(int $mode): bool {
$validmodes = [
self::PROVISIONING_MODE_AUTO_ONLY,
self::PROVISIONING_MODE_PROMPT_NEW_EXISTING,
self::PROVISIONING_MODE_PROMPT_EXISTING_ONLY
];
return in_array($mode, $validmodes);
}
/**
* Create a new user account based on the user data either in the launch JWT or from a membership call.
*
* @param array $userdata the user data coming from either a launch or membership service call.
* @param string $iss the issuer to which the user belongs.
* @return stdClass a complete Moodle user record.
*/
protected function create_new_account(array $userdata, string $iss): stdClass {
global $CFG;
require_once($CFG->dirroot.'/user/lib.php');
// Launches and membership calls handle the user id differently.
// Launch uses 'sub', whereas member uses 'user_id'.
$userid = !empty($userdata['sub']) ? $userdata['sub'] : $userdata['user_id'];
$user = new stdClass();
$user->username = 'enrol_lti_13_' . sha1($iss . '_' . $userid);
// If the email was stripped/not set then fill it with a default one.
// This stops the user from being redirected to edit their profile page.
$email = !empty($userdata['email']) ? $userdata['email'] :
'enrol_lti_13_' . sha1($iss . '_' . $userid) . "@example.com";
$email = \core_user::clean_field($email, 'email');
$user->email = $email;
$user->auth = 'lti';
$user->mnethostid = $CFG->mnet_localhost_id;
$user->firstname = $userdata['given_name'] ?? $userid;
$user->lastname = $userdata['family_name'] ?? $iss;
$user->password = '';
$user->confirmed = 1;
$user->id = user_create_user($user, false);
// Link this user with the LTI credentials for future use.
$this->create_user_binding($iss, $userid, $user->id);
return (object) get_complete_user_data('id', $user->id);
}
/**
* Update the personal fields of the user account, based on data present in either a launch of member sync call.
*
* @param stdClass $user the Moodle user account to update.
* @param array $userdata the user data coming from either a launch or membership service call.
* @param string $iss the issuer to which the user belongs.
*/
public function update_user_account(stdClass $user, array $userdata, string $iss): void {
global $CFG;
require_once($CFG->dirroot.'/user/lib.php');
if ($user->auth !== 'lti') {
return;
}
// Launches and membership calls handle the user id differently.
// Launch uses 'sub', whereas member uses 'user_id'.
$platformuserid = !empty($userdata['sub']) ? $userdata['sub'] : $userdata['user_id'];
$email = !empty($userdata['email']) ? $userdata['email'] :
'enrol_lti_13_' . sha1($iss . '_' . $platformuserid) . "@example.com";
$email = \core_user::clean_field($email, 'email');
$update = [
'id' => $user->id,
'firstname' => $userdata['given_name'] ?? $platformuserid,
'lastname' => $userdata['family_name'] ?? $iss,
'email' => $email
];
$userfieldstocompare = array_intersect_key((array) $user, $update);
if (!empty(array_diff($update, $userfieldstocompare))) {
user_update_user($update); // Only update if there's a change.
}
if (!empty($userdata['picture'])) {
try {
$this->update_user_picture($user->id, $userdata['picture']);
} catch (Exception $e) {
debugging("Error syncing the profile picture for user '$user->id' during LTI authentication.");
}
}
}
/**
* Update the user's picture with the image stored at $url.
*
* @param int $userid the id of the user to update.
* @param string $url the string URL where the new image can be found.
* @throws moodle_exception if there were any problems updating the picture.
*/
protected function update_user_picture(int $userid, string $url): void {
global $CFG, $DB;
require_once($CFG->libdir . '/filelib.php');
require_once($CFG->libdir . '/gdlib.php');
$fs = get_file_storage();
$context = \context_user::instance($userid, MUST_EXIST);
$fs->delete_area_files($context->id, 'user', 'newicon');
$filerecord = array(
'contextid' => $context->id,
'component' => 'user',
'filearea' => 'newicon',
'itemid' => 0,
'filepath' => '/'
);
$urlparams = array(
'calctimeout' => false,
'timeout' => 5,
'skipcertverify' => true,
'connecttimeout' => 5
);
try {
$fs->create_file_from_url($filerecord, $url, $urlparams);
} catch (\file_exception $e) {
throw new moodle_exception(get_string($e->errorcode, $e->module, $e->a));
}
$iconfile = $fs->get_area_files($context->id, 'user', 'newicon', false, 'itemid', false);
// There should only be one.
$iconfile = reset($iconfile);
// Something went wrong while creating temp file - remove the uploaded file.
if (!$iconfile = $iconfile->copy_content_to_temp()) {
$fs->delete_area_files($context->id, 'user', 'newicon');
throw new moodle_exception('There was a problem copying the profile picture to temp.');
}
// Copy file to temporary location and the send it for processing icon.
$newpicture = (int) process_new_icon($context, 'user', 'icon', 0, $iconfile);
// Delete temporary file.
@unlink($iconfile);
// Remove uploaded file.
$fs->delete_area_files($context->id, 'user', 'newicon');
// Set the user's picture.
$DB->set_field('user', 'picture', $newpicture, array('id' => $userid));
}
}