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1 | <?php |
2 | /* | |
3 | +--------------------------------------------------------------------+ | |
fee14197 | 4 | | CiviCRM version 5 | |
6a488035 | 5 | +--------------------------------------------------------------------+ |
6b83d5bd | 6 | | Copyright CiviCRM LLC (c) 2004-2019 | |
6a488035 TO |
7 | +--------------------------------------------------------------------+ |
8 | | This file is a part of CiviCRM. | | |
9 | | | | |
10 | | CiviCRM is free software; you can copy, modify, and distribute it | | |
11 | | under the terms of the GNU Affero General Public License | | |
12 | | Version 3, 19 November 2007 and the CiviCRM Licensing Exception. | | |
13 | | | | |
14 | | CiviCRM is distributed in the hope that it will be useful, but | | |
15 | | WITHOUT ANY WARRANTY; without even the implied warranty of | | |
16 | | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | | |
17 | | See the GNU Affero General Public License for more details. | | |
18 | | | | |
19 | | You should have received a copy of the GNU Affero General Public | | |
20 | | License and the CiviCRM Licensing Exception along | | |
21 | | with this program; if not, contact CiviCRM LLC | | |
22 | | at info[AT]civicrm[DOT]org. If you have questions about the | | |
23 | | GNU Affero General Public License or the licensing of CiviCRM, | | |
24 | | see the CiviCRM license FAQ at http://civicrm.org/licensing | | |
25 | +--------------------------------------------------------------------+ | |
d25dd0ee | 26 | */ |
6a488035 TO |
27 | |
28 | /** | |
29 | * | |
30 | * @package CRM | |
6b83d5bd | 31 | * @copyright CiviCRM LLC (c) 2004-2019 |
6a488035 TO |
32 | */ |
33 | ||
34 | /** | |
35 | * A utility which signs and verifies a list of key-value pairs | |
36 | * | |
37 | * FIXME: Add TTL support? | |
38 | * | |
39 | * @code | |
40 | * $signer = new CRM_Utils_Signer('myprivatekey', array('param1','param2')); | |
41 | * $params = array( | |
42 | * 'param1' => 'hello', | |
43 | * 'param2' => 'world', | |
44 | * ); | |
45 | * $token = $signer->sign($params); | |
46 | * ... | |
47 | * assertTrue($signer->validate($token, $params)); | |
48 | * @endcode | |
49 | */ | |
50 | class CRM_Utils_Signer { | |
51 | /** | |
52 | * Expected length of the salt | |
53 | * | |
54 | * @var int | |
55 | */ | |
56 | const SALT_LEN = 4; | |
57 | ||
58 | /** | |
59 | * Instantiate a signature-processor | |
60 | * | |
5a4f6742 CW |
61 | * @param string $secret |
62 | * private. | |
63 | * @param array $paramNames | |
77855840 | 64 | * Array, fields which should be part of the signature. |
6a488035 | 65 | */ |
00be9182 | 66 | public function __construct($secret, $paramNames) { |
6714d8d2 SL |
67 | // ensure consistent serialization of payloads |
68 | sort($paramNames); | |
6a488035 TO |
69 | $this->secret = $secret; |
70 | $this->paramNames = $paramNames; | |
6714d8d2 SL |
71 | // chosen to be valid in URLs but not in salt or md5 |
72 | $this->signDelim = "_"; | |
6a488035 TO |
73 | $this->defaultSalt = CRM_Utils_String::createRandom(self::SALT_LEN, CRM_Utils_String::ALPHANUMERIC); |
74 | } | |
75 | ||
76 | /** | |
77 | * Generate a signature for a set of key-value pairs | |
78 | * | |
5a4f6742 | 79 | * @param array $params |
77855840 | 80 | * Array, key-value pairs. |
5a4f6742 CW |
81 | * @param string $salt |
82 | * the salt (if known) or NULL (for auto-generated). | |
6a488035 TO |
83 | * @return string, the full public token representing the signature |
84 | */ | |
00be9182 | 85 | public function sign($params, $salt = NULL) { |
be2fb01f | 86 | $message = []; |
6a488035 | 87 | $message['secret'] = $this->secret; |
be2fb01f | 88 | $message['payload'] = []; |
6a488035 TO |
89 | if (empty($salt)) { |
90 | $message['salt'] = $this->createSalt(); | |
0db6c3e1 TO |
91 | } |
92 | else { | |
e7292422 | 93 | $message['salt'] = $salt; |
6a488035 TO |
94 | } |
95 | // recall: paramNames is pre-sorted for stability | |
96 | foreach ($this->paramNames as $paramName) { | |
97 | if (isset($params[$paramName])) { | |
98 | if (is_numeric($params[$paramName])) { | |
99 | $params[$paramName] = (string) $params[$paramName]; | |
100 | } | |
0db6c3e1 | 101 | } |
50bfb460 SB |
102 | else { |
103 | // $paramName is not included or ===NULL | |
6a488035 TO |
104 | $params[$paramName] = ''; |
105 | } | |
e7292422 TO |
106 | $message['payload'][$paramName] = $params[$paramName]; |
107 | } | |
6a488035 TO |
108 | $token = $message['salt'] . $this->signDelim . md5(serialize($message)); |
109 | return $token; | |
110 | } | |
111 | ||
112 | /** | |
113 | * Determine whether a token represents a proper signature for $params | |
114 | * | |
5a4f6742 CW |
115 | * @param string $token |
116 | * the full public token representing the signature. | |
117 | * @param array $params | |
77855840 | 118 | * Array, key-value pairs. |
f4aaa82a EM |
119 | * |
120 | * @throws Exception | |
6a488035 TO |
121 | * @return bool, TRUE iff all $paramNames for the submitted validate($params) and the original sign($params) |
122 | */ | |
00be9182 | 123 | public function validate($token, $params) { |
6a488035 TO |
124 | list ($salt, $signature) = explode($this->signDelim, $token); |
125 | if (strlen($salt) != self::SALT_LEN) { | |
ed6a28a1 | 126 | throw new Exception("Token contains invalid salt [" . urlencode($token) . "]"); |
6a488035 TO |
127 | } |
128 | $newToken = $this->sign($params, $salt); | |
129 | return ($token == $newToken); | |
130 | } | |
131 | ||
5bc392e6 EM |
132 | /** |
133 | * @return string | |
134 | */ | |
00be9182 | 135 | public function createSalt() { |
6a488035 TO |
136 | // It would be more secure to generate a new value but liable to run this |
137 | // many times on certain admin pages; so instead we'll re-use the hash. | |
138 | return $this->defaultSalt; | |
139 | } | |
96025800 | 140 | |
6a488035 | 141 | } |