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1 | <?php |
2 | /* | |
3 | +--------------------------------------------------------------------+ | |
39de6fd5 | 4 | | CiviCRM version 4.6 | |
6a488035 | 5 | +--------------------------------------------------------------------+ |
06b69b18 | 6 | | Copyright CiviCRM LLC (c) 2004-2014 | |
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 | +--------------------------------------------------------------------+ | |
26 | */ | |
27 | ||
28 | /** | |
29 | * | |
30 | * @package CRM | |
06b69b18 | 31 | * @copyright CiviCRM LLC (c) 2004-2014 |
6a488035 TO |
32 | * $Id$ |
33 | * | |
34 | */ | |
35 | ||
36 | /** | |
37 | * A utility which signs and verifies a list of key-value pairs | |
38 | * | |
39 | * FIXME: Add TTL support? | |
40 | * | |
41 | * @code | |
42 | * $signer = new CRM_Utils_Signer('myprivatekey', array('param1','param2')); | |
43 | * $params = array( | |
44 | * 'param1' => 'hello', | |
45 | * 'param2' => 'world', | |
46 | * ); | |
47 | * $token = $signer->sign($params); | |
48 | * ... | |
49 | * assertTrue($signer->validate($token, $params)); | |
50 | * @endcode | |
51 | */ | |
52 | class CRM_Utils_Signer { | |
53 | /** | |
54 | * Expected length of the salt | |
55 | * | |
56 | * @var int | |
57 | */ | |
58 | const SALT_LEN = 4; | |
59 | ||
60 | /** | |
61 | * Instantiate a signature-processor | |
62 | * | |
77855840 TO |
63 | * @param $secret |
64 | * String, private. | |
65 | * @param $paramNames | |
66 | * Array, fields which should be part of the signature. | |
6a488035 | 67 | */ |
00be9182 | 68 | public function __construct($secret, $paramNames) { |
6a488035 TO |
69 | sort($paramNames); // ensure consistent serialization of payloads |
70 | $this->secret = $secret; | |
71 | $this->paramNames = $paramNames; | |
72 | $this->signDelim = "_"; // chosen to be valid in URLs but not in salt or md5 | |
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 | * | |
77855840 TO |
79 | * @param $params |
80 | * Array, key-value pairs. | |
81 | * @param $salt | |
82 | * String, the salt (if known) or NULL (for auto-generated). | |
6a488035 TO |
83 | * @return string, the full public token representing the signature |
84 | */ | |
00be9182 | 85 | public function sign($params, $salt = NULL) { |
6a488035 TO |
86 | $message = array(); |
87 | $message['secret'] = $this->secret; | |
88 | $message['payload'] = array(); | |
89 | if (empty($salt)) { | |
90 | $message['salt'] = $this->createSalt(); | |
91 | } else { | |
e7292422 | 92 | $message['salt'] = $salt; |
6a488035 TO |
93 | } |
94 | // recall: paramNames is pre-sorted for stability | |
95 | foreach ($this->paramNames as $paramName) { | |
96 | if (isset($params[$paramName])) { | |
97 | if (is_numeric($params[$paramName])) { | |
98 | $params[$paramName] = (string) $params[$paramName]; | |
99 | } | |
100 | } else { // $paramName is not included or ===NULL | |
101 | $params[$paramName] = ''; | |
102 | } | |
e7292422 TO |
103 | $message['payload'][$paramName] = $params[$paramName]; |
104 | } | |
6a488035 TO |
105 | $token = $message['salt'] . $this->signDelim . md5(serialize($message)); |
106 | return $token; | |
107 | } | |
108 | ||
109 | /** | |
110 | * Determine whether a token represents a proper signature for $params | |
111 | * | |
77855840 TO |
112 | * @param $token |
113 | * String, the full public token representing the signature. | |
114 | * @param $params | |
115 | * Array, key-value pairs. | |
f4aaa82a EM |
116 | * |
117 | * @throws Exception | |
6a488035 TO |
118 | * @return bool, TRUE iff all $paramNames for the submitted validate($params) and the original sign($params) |
119 | */ | |
00be9182 | 120 | public function validate($token, $params) { |
6a488035 TO |
121 | list ($salt, $signature) = explode($this->signDelim, $token); |
122 | if (strlen($salt) != self::SALT_LEN) { | |
123 | throw new Exception("Invalid salt [$token]=[$salt][$signature]"); | |
124 | } | |
125 | $newToken = $this->sign($params, $salt); | |
126 | return ($token == $newToken); | |
127 | } | |
128 | ||
5bc392e6 EM |
129 | /** |
130 | * @return string | |
131 | */ | |
00be9182 | 132 | public function createSalt() { |
6a488035 TO |
133 | // It would be more secure to generate a new value but liable to run this |
134 | // many times on certain admin pages; so instead we'll re-use the hash. | |
135 | return $this->defaultSalt; | |
136 | } | |
137 | } |