| 1 |
efrain |
1 |
<?php
|
|
|
2 |
// This file is part of Moodle - http://moodle.org/
|
|
|
3 |
//
|
|
|
4 |
// Moodle is free software: you can redistribute it and/or modify
|
|
|
5 |
// it under the terms of the GNU General Public License as published by
|
|
|
6 |
// the Free Software Foundation, either version 3 of the License, or
|
|
|
7 |
// (at your option) any later version.
|
|
|
8 |
//
|
|
|
9 |
// Moodle is distributed in the hope that it will be useful,
|
|
|
10 |
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
11 |
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
12 |
// GNU General Public License for more details.
|
|
|
13 |
//
|
|
|
14 |
// You should have received a copy of the GNU General Public License
|
|
|
15 |
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
|
|
|
16 |
|
|
|
17 |
/**
|
|
|
18 |
* Class for generating and representing a Safe Exam Browser config key.
|
|
|
19 |
*
|
|
|
20 |
* @package quizaccess_seb
|
|
|
21 |
* @author Andrew Madden <andrewmadden@catalyst-au.net>
|
|
|
22 |
* @copyright 2019 Catalyst IT
|
|
|
23 |
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
|
|
|
24 |
*/
|
|
|
25 |
|
|
|
26 |
namespace quizaccess_seb;
|
|
|
27 |
|
|
|
28 |
defined('MOODLE_INTERNAL') || die();
|
|
|
29 |
|
|
|
30 |
/**
|
|
|
31 |
* Class for generating and representing a Safe Exam Browser config key.
|
|
|
32 |
*
|
|
|
33 |
* @copyright 2020 Catalyst IT
|
|
|
34 |
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
|
|
|
35 |
*/
|
|
|
36 |
class config_key {
|
|
|
37 |
|
|
|
38 |
/** @var string $hash The Config Key hash. */
|
|
|
39 |
private $hash;
|
|
|
40 |
|
|
|
41 |
/**
|
|
|
42 |
* The config_key constructor.
|
|
|
43 |
*
|
|
|
44 |
* @param string $hash The Config Key hash.
|
|
|
45 |
*/
|
|
|
46 |
public function __construct(string $hash) {
|
|
|
47 |
$this->hash = $hash;
|
|
|
48 |
}
|
|
|
49 |
|
|
|
50 |
/**
|
|
|
51 |
* Generate the Config Key hash from an SEB Config XML string.
|
|
|
52 |
*
|
|
|
53 |
* See https://safeexambrowser.org/developer/seb-config-key.html for more information about the process.
|
|
|
54 |
*
|
|
|
55 |
* @param string $xml A PList XML string, representing SEB config.
|
|
|
56 |
* @return config_key This config key instance.
|
|
|
57 |
*/
|
|
|
58 |
public static function generate(string $xml): config_key {
|
|
|
59 |
if (!empty($xml) && !helper::is_valid_seb_config($xml)) {
|
|
|
60 |
throw new \invalid_parameter_exception('Invalid a PList XML string, representing SEB config');
|
|
|
61 |
}
|
|
|
62 |
|
|
|
63 |
$plist = new property_list($xml);
|
|
|
64 |
// Remove the key "originatorVersion" first. This key is exempted from the SEB-JSON hash (it's a special key
|
|
|
65 |
// which doesn't have any functionality, it's just meta data indicating which SEB version saved the config file).
|
|
|
66 |
$plist->delete_element('originatorVersion');
|
|
|
67 |
// Convert the plist XML of a decrypted/unencrypted SEB config file to a ordered JSON-like "SEB-JSON" object.
|
|
|
68 |
$hash = $plist->to_json();
|
|
|
69 |
// Hash the JSON with SHA256. Defaults to required Base16 encoding.
|
|
|
70 |
$hash = hash('SHA256', $hash);
|
|
|
71 |
|
|
|
72 |
return new self($hash);
|
|
|
73 |
}
|
|
|
74 |
|
|
|
75 |
/**
|
|
|
76 |
* Get the Config Key hash.
|
|
|
77 |
*
|
|
|
78 |
* @return string The Config Key hash
|
|
|
79 |
*/
|
|
|
80 |
public function get_hash(): string {
|
|
|
81 |
return $this->hash;
|
|
|
82 |
}
|
|
|
83 |
}
|