contact-forms / phpseclib-crypt / AES.php

AES.php in Contact Forms by Cimatti 1.9.2, at phpseclib-crypt/AES.php

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1	<?php
2
3	/**
4	* Pure-PHP implementation of AES.
5	*
6	* Uses mcrypt, if available/possible, and an internal implementation, otherwise.
7	*
8	* PHP versions 4 and 5
9	*
10	* NOTE: Since AES.php is (for compatibility and phpseclib-historical reasons) virtually
11	* just a wrapper to Rijndael.php you may consider using Rijndael.php instead of
12	* to save one include_once().
13	*
14	* If {@link self::setKeyLength() setKeyLength()} isn't called, it'll be calculated from
15	* {@link self::setKey() setKey()}. ie. if the key is 128-bits, the key length will be 128-bits. If it's 136-bits
16	* it'll be null-padded to 192-bits and 192 bits will be the key length until {@link self::setKey() setKey()}
17	* is called, again, at which point, it'll be recalculated.
18	*
19	* Since Crypt_AES extends Crypt_Rijndael, some functions are available to be called that, in the context of AES, don't
20	* make a whole lot of sense. {@link self::setBlockLength() setBlockLength()}, for instance. Calling that function,
21	* however possible, won't do anything (AES has a fixed block length whereas Rijndael has a variable one).
22	*
23	* Here's a short example of how to use this library:
24	* <code>
25	* <?php
26	* include 'Crypt/AES.php';
27	*
28	* $aes = new Crypt_AES();
29	*
30	* $aes->setKey('abcdefghijklmnop');
31	*
32	* $size = 10 * 1024;
33	* $plaintext = '';
34	* for ($i = 0; $i < $size; $i++) {
35	* $plaintext.= 'a';
36	* }
37	*
38	* echo $aes->decrypt($aes->encrypt($plaintext));
39	* ?>
40	* </code>
41	*
42	* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
43	* of this software and associated documentation files (the "Software"), to deal
44	* in the Software without restriction, including without limitation the rights
45	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
46	* copies of the Software, and to permit persons to whom the Software is
47	* furnished to do so, subject to the following conditions:
48	*
49	* The above copyright notice and this permission notice shall be included in
50	* all copies or substantial portions of the Software.
51	*
52	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
53	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
54	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
55	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
56	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
57	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
58	* THE SOFTWARE.
59	*
60	* @category Crypt
61	* @package Crypt_AES
62	* @author Jim Wigginton <terrafrost@php.net>
63	* @copyright 2008 Jim Wigginton
64	* @license http://www.opensource.org/licenses/mit-license.html MIT License
65	* @link http://phpseclib.sourceforge.net
66	*/
67
68	/**
69	* Include Crypt_Rijndael
70	*/
71	if (!class_exists('Crypt_Rijndael')) {
72	include_once 'Rijndael.php';
73	}
74
75	/**#@+
76	* @access public
77	* @see self::encrypt()
78	* @see self::decrypt()
79	*/
80	/**
81	* Encrypt / decrypt using the Counter mode.
82	*
83	* Set to -1 since that's what Crypt/Random.php uses to index the CTR mode.
84	*
85	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29
86	*/
87	define('CRYPT_AES_MODE_CTR', CRYPT_MODE_CTR);
88	/**
89	* Encrypt / decrypt using the Electronic Code Book mode.
90	*
91	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
92	*/
93	define('CRYPT_AES_MODE_ECB', CRYPT_MODE_ECB);
94	/**
95	* Encrypt / decrypt using the Code Book Chaining mode.
96	*
97	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
98	*/
99	define('CRYPT_AES_MODE_CBC', CRYPT_MODE_CBC);
100	/**
101	* Encrypt / decrypt using the Cipher Feedback mode.
102	*
103	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
104	*/
105	define('CRYPT_AES_MODE_CFB', CRYPT_MODE_CFB);
106	/**
107	* Encrypt / decrypt using the Cipher Feedback mode.
108	*
109	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
110	*/
111	define('CRYPT_AES_MODE_OFB', CRYPT_MODE_OFB);
112	/*#@-/
113
114	/**
115	* Pure-PHP implementation of AES.
116	*
117	* @package Crypt_AES
118	* @author Jim Wigginton <terrafrost@php.net>
119	* @access public
120	*/
121	class Crypt_AES extends Crypt_Rijndael
122	{
123	/**
124	* The namespace used by the cipher for its constants.
125	*
126	* @see Crypt_Base::const_namespace
127	* @var string
128	* @access private
129	*/
130	var $const_namespace = 'AES';
131
132	/**
133	* Dummy function
134	*
135	* Since Crypt_AES extends Crypt_Rijndael, this function is, technically, available, but it doesn't do anything.
136	*
137	* @see Crypt_Rijndael::setBlockLength()
138	* @access public
139	* @param int $length
140	*/
141	function setBlockLength($length)
142	{
143	return;
144	}
145
146	/**
147	* Sets the key length
148	*
149	* Valid key lengths are 128, 192, and 256. If the length is less than 128, it will be rounded up to
150	* 128. If the length is greater than 128 and invalid, it will be rounded down to the closest valid amount.
151	*
152	* @see Crypt_Rijndael:setKeyLength()
153	* @access public
154	* @param int $length
155	*/
156	function setKeyLength($length)
157	{
158	switch ($length) {
159	case 160:
160	$length = 192;
161	break;
162	case 224:
163	$length = 256;
164	}
165	parent::setKeyLength($length);
166	}
167
168	/**
169	* Sets the key.
170	*
171	* Rijndael supports five different key lengths, AES only supports three.
172	*
173	* @see Crypt_Rijndael:setKey()
174	* @see setKeyLength()
175	* @access public
176	* @param string $key
177	*/
178	function setKey($key)
179	{
180	parent::setKey($key);
181
182	if (!$this->explicit_key_length) {
183	$length = strlen($key);
184	switch (true) {
185	case $length <= 16:
186	$this->key_length = 16;
187	break;
188	case $length <= 24:
189	$this->key_length = 24;
190	break;
191	default:
192	$this->key_length = 32;
193	}
194	$this->_setEngine();
195	}
196	}
197	}
198