worker / lib / PHPSecLib / Crypt / AES.php

AES.php in ManageWP Worker 3.9.28, at lib/PHPSecLib/Crypt/AES.php

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1	<?php
2	/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
3
4	/**
5	* Pure-PHP implementation of AES.
6	*
7	* Uses mcrypt, if available, and an internal implementation, otherwise.
8	*
9	* PHP versions 4 and 5
10	*
11	* If {@link Crypt_AES::setKeyLength() setKeyLength()} isn't called, it'll be calculated from
12	* {@link Crypt_AES::setKey() setKey()}. ie. if the key is 128-bits, the key length will be 128-bits. If it's 136-bits
13	* it'll be null-padded to 160-bits and 160 bits will be the key length until {@link Crypt_Rijndael::setKey() setKey()}
14	* is called, again, at which point, it'll be recalculated.
15	*
16	* Since Crypt_AES extends Crypt_Rijndael, some functions are available to be called that, in the context of AES, don't
17	* make a whole lot of sense. {@link Crypt_AES::setBlockLength() setBlockLength()}, for instance. Calling that function,
18	* however possible, won't do anything (AES has a fixed block length whereas Rijndael has a variable one).
19	*
20	* Here's a short example of how to use this library:
21	* <code>
22	* <?php
23	* include('Crypt/AES.php');
24	*
25	* $aes = new Crypt_AES();
26	*
27	* $aes->setKey('abcdefghijklmnop');
28	*
29	* $size = 10 * 1024;
30	* $plaintext = '';
31	* for ($i = 0; $i < $size; $i++) {
32	* $plaintext.= 'a';
33	* }
34	*
35	* echo $aes->decrypt($aes->encrypt($plaintext));
36	* ?>
37	* </code>
38	*
39	* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
40	* of this software and associated documentation files (the "Software"), to deal
41	* in the Software without restriction, including without limitation the rights
42	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
43	* copies of the Software, and to permit persons to whom the Software is
44	* furnished to do so, subject to the following conditions:
45	*
46	* The above copyright notice and this permission notice shall be included in
47	* all copies or substantial portions of the Software.
48	*
49	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
50	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
51	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
52	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
53	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
54	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
55	* THE SOFTWARE.
56	*
57	* @category Crypt
58	* @package Crypt_AES
59	* @author Jim Wigginton <terrafrost@php.net>
60	* @copyright MMVIII Jim Wigginton
61	* @license http://www.opensource.org/licenses/mit-license.html MIT License
62	* @link http://phpseclib.sourceforge.net
63	*/
64
65	/**
66	* Include Crypt_Rijndael
67	*/
68	if (!class_exists('Crypt_Rijndael')) {
69	require_once 'Rijndael.php';
70	}
71
72	/**#@+
73	* @access public
74	* @see Crypt_AES::encrypt()
75	* @see Crypt_AES::decrypt()
76	*/
77	/**
78	* Encrypt / decrypt using the Counter mode.
79	*
80	* Set to -1 since that's what Crypt/Random.php uses to index the CTR mode.
81	*
82	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29
83	*/
84	define('CRYPT_AES_MODE_CTR', -1);
85	/**
86	* Encrypt / decrypt using the Electronic Code Book mode.
87	*
88	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
89	*/
90	define('CRYPT_AES_MODE_ECB', 1);
91	/**
92	* Encrypt / decrypt using the Code Book Chaining mode.
93	*
94	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
95	*/
96	define('CRYPT_AES_MODE_CBC', 2);
97	/**
98	* Encrypt / decrypt using the Cipher Feedback mode.
99	*
100	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
101	*/
102	define('CRYPT_AES_MODE_CFB', 3);
103	/**
104	* Encrypt / decrypt using the Cipher Feedback mode.
105	*
106	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
107	*/
108	define('CRYPT_AES_MODE_OFB', 4);
109	/*#@-/
110
111	/**#@+
112	* @access private
113	* @see Crypt_AES::Crypt_AES()
114	*/
115	/**
116	* Toggles the internal implementation
117	*/
118	define('CRYPT_AES_MODE_INTERNAL', 1);
119	/**
120	* Toggles the mcrypt implementation
121	*/
122	define('CRYPT_AES_MODE_MCRYPT', 2);
123	/*#@-/
124
125	/**
126	* Pure-PHP implementation of AES.
127	*
128	* @author Jim Wigginton <terrafrost@php.net>
129	* @version 0.1.0
130	* @access public
131	* @package Crypt_AES
132	*/
133	class Crypt_AES extends Crypt_Rijndael {
134	/**
135	* mcrypt resource for encryption
136	*
137	* The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
138	* Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
139	*
140	* @see Crypt_AES::encrypt()
141	* @var String
142	* @access private
143	*/
144	var $enmcrypt;
145
146	/**
147	* mcrypt resource for decryption
148	*
149	* The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
150	* Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
151	*
152	* @see Crypt_AES::decrypt()
153	* @var String
154	* @access private
155	*/
156	var $demcrypt;
157
158	/**
159	* mcrypt resource for CFB mode
160	*
161	* @see Crypt_AES::encrypt()
162	* @see Crypt_AES::decrypt()
163	* @var String
164	* @access private
165	*/
166	var $ecb;
167
168	/**
169	* Default Constructor.
170	*
171	* Determines whether or not the mcrypt extension should be used. $mode should only, at present, be
172	* CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC. If not explictly set, CRYPT_AES_MODE_CBC will be used.
173	*
174	* @param optional Integer $mode
175	* @return Crypt_AES
176	* @access public
177	*/
178	function Crypt_AES($mode = CRYPT_AES_MODE_CBC)
179	{
180	if ( !defined('CRYPT_AES_MODE') ) {
181	switch (true) {
182	case extension_loaded('mcrypt') && in_array('rijndael-128', mcrypt_list_algorithms()):
183	define('CRYPT_AES_MODE', CRYPT_AES_MODE_MCRYPT);
184	break;
185	default:
186	define('CRYPT_AES_MODE', CRYPT_AES_MODE_INTERNAL);
187	}
188	}
189
190	switch ( CRYPT_AES_MODE ) {
191	case CRYPT_AES_MODE_MCRYPT:
192	switch ($mode) {
193	case CRYPT_AES_MODE_ECB:
194	$this->paddable = true;
195	$this->mode = MCRYPT_MODE_ECB;
196	break;
197	case CRYPT_AES_MODE_CTR:
198	// ctr doesn't have a constant associated with it even though it appears to be fairly widely
199	// supported. in lieu of knowing just how widely supported it is, i've, for now, opted not to
200	// include a compatibility layer. the layer has been implemented but, for now, is commented out.
201	$this->mode = 'ctr';
202	//$this->mode = in_array('ctr', mcrypt_list_modes()) ? 'ctr' : CRYPT_AES_MODE_CTR;
203	break;
204	case CRYPT_AES_MODE_CFB:
205	$this->mode = 'ncfb';
206	break;
207	case CRYPT_AES_MODE_OFB:
208	$this->mode = MCRYPT_MODE_NOFB;
209	break;
210	case CRYPT_AES_MODE_CBC:
211	default:
212	$this->paddable = true;
213	$this->mode = MCRYPT_MODE_CBC;
214	}
215
216	break;
217	default:
218	switch ($mode) {
219	case CRYPT_AES_MODE_ECB:
220	$this->paddable = true;
221	$this->mode = CRYPT_RIJNDAEL_MODE_ECB;
222	break;
223	case CRYPT_AES_MODE_CTR:
224	$this->mode = CRYPT_RIJNDAEL_MODE_CTR;
225	break;
226	case CRYPT_AES_MODE_CFB:
227	$this->mode = CRYPT_RIJNDAEL_MODE_CFB;
228	break;
229	case CRYPT_AES_MODE_OFB:
230	$this->mode = CRYPT_RIJNDAEL_MODE_OFB;
231	break;
232	case CRYPT_AES_MODE_CBC:
233	default:
234	$this->paddable = true;
235	$this->mode = CRYPT_RIJNDAEL_MODE_CBC;
236	}
237	}
238
239	if (CRYPT_AES_MODE == CRYPT_AES_MODE_INTERNAL) {
240	parent::Crypt_Rijndael($this->mode);
241	}
242
243	}
244
245	/**
246	* Dummy function
247	*
248	* Since Crypt_AES extends Crypt_Rijndael, this function is, technically, available, but it doesn't do anything.
249	*
250	* @access public
251	* @param Integer $length
252	*/
253	function setBlockLength($length)
254	{
255	return;
256	}
257
258	/**
259	* Sets the initialization vector. (optional)
260	*
261	* SetIV is not required when CRYPT_RIJNDAEL_MODE_ECB is being used. If not explictly set, it'll be assumed
262	* to be all zero's.
263	*
264	* @access public
265	* @param String $iv
266	*/
267	function setIV($iv)
268	{
269	parent::setIV($iv);
270	if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) {
271	$this->changed = true;
272	}
273	}
274
275	/**
276	* Encrypts a message.
277	*
278	* $plaintext will be padded with up to 16 additional bytes. Other AES implementations may or may not pad in the
279	* same manner. Other common approaches to padding and the reasons why it's necessary are discussed in the following
280	* URL:
281	*
282	* {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
283	*
284	* An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does.
285	* strlen($plaintext) will still need to be a multiple of 16, however, arbitrary values can be added to make it that
286	* length.
287	*
288	* @see Crypt_AES::decrypt()
289	* @access public
290	* @param String $plaintext
291	*/
292	function encrypt($plaintext)
293	{
294	if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) {
295	$this->_mcryptSetup();
296
297	// re: http://phpseclib.sourceforge.net/cfb-demo.phps
298	// using mcrypt's default handing of CFB the above would output two different things. using phpseclib's
299	// rewritten CFB implementation the above outputs the same thing twice.
300	if ($this->mode == 'ncfb' && $this->continuousBuffer) {
301	$iv = &$this->encryptIV;
302	$pos = &$this->enbuffer['pos'];
303	$len = strlen($plaintext);
304	$ciphertext = '';
305	$i = 0;
306	if ($pos) {
307	$orig_pos = $pos;
308	$max = 16 - $pos;
309	if ($len >= $max) {
310	$i = $max;
311	$len-= $max;
312	$pos = 0;
313	} else {
314	$i = $len;
315	$pos+= $len;
316	$len = 0;
317	}
318	$ciphertext = substr($iv, $orig_pos) ^ $plaintext;
319	$iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
320	$this->enbuffer['enmcrypt_init'] = true;
321	}
322	if ($len >= 16) {
323	if ($this->enbuffer['enmcrypt_init'] === false \|\| $len > 280) {
324	if ($this->enbuffer['enmcrypt_init'] === true) {
325	mcrypt_generic_init($this->enmcrypt, $this->key, $iv);
326	$this->enbuffer['enmcrypt_init'] = false;
327	}
328	$ciphertext.= mcrypt_generic($this->enmcrypt, substr($plaintext, $i, $len - $len % 16));
329	$iv = substr($ciphertext, -16);
330	$len%= 16;
331	} else {
332	while ($len >= 16) {
333	$iv = mcrypt_generic($this->ecb, $iv) ^ substr($plaintext, $i, 16);
334	$ciphertext.= $iv;
335	$len-= 16;
336	$i+= 16;
337	}
338	}
339	}
340
341	if ($len) {
342	$iv = mcrypt_generic($this->ecb, $iv);
343	$block = $iv ^ substr($plaintext, -$len);
344	$iv = substr_replace($iv, $block, 0, $len);
345	$ciphertext.= $block;
346	$pos = $len;
347	}
348
349	return $ciphertext;
350	}
351
352	if ($this->paddable) {
353	$plaintext = $this->_pad($plaintext);
354	}
355
356	$ciphertext = mcrypt_generic($this->enmcrypt, $plaintext);
357
358	if (!$this->continuousBuffer) {
359	mcrypt_generic_init($this->enmcrypt, $this->key, $this->iv);
360	}
361
362	return $ciphertext;
363	}
364
365	return parent::encrypt($plaintext);
366	}
367
368	/**
369	* Decrypts a message.
370	*
371	* If strlen($ciphertext) is not a multiple of 16, null bytes will be added to the end of the string until it is.
372	*
373	* @see Crypt_AES::encrypt()
374	* @access public
375	* @param String $ciphertext
376	*/
377	function decrypt($ciphertext)
378	{
379	if ( CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT ) {
380	$this->_mcryptSetup();
381
382	if ($this->mode == 'ncfb' && $this->continuousBuffer) {
383	$iv = &$this->decryptIV;
384	$pos = &$this->debuffer['pos'];
385	$len = strlen($ciphertext);
386	$plaintext = '';
387	$i = 0;
388	if ($pos) {
389	$orig_pos = $pos;
390	$max = 16 - $pos;
391	if ($len >= $max) {
392	$i = $max;
393	$len-= $max;
394	$pos = 0;
395	} else {
396	$i = $len;
397	$pos+= $len;
398	$len = 0;
399	}
400	// ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
401	$plaintext = substr($iv, $orig_pos) ^ $ciphertext;
402	$iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
403	}
404	if ($len >= 16) {
405	$cb = substr($ciphertext, $i, $len - $len % 16);
406	$plaintext.= mcrypt_generic($this->ecb, $iv . $cb) ^ $cb;
407	$iv = substr($cb, -16);
408	$len%= 16;
409	}
410	if ($len) {
411	$iv = mcrypt_generic($this->ecb, $iv);
412	$plaintext.= $iv ^ substr($ciphertext, -$len);
413	$iv = substr_replace($iv, substr($ciphertext, -$len), 0, $len);
414	$pos = $len;
415	}
416
417	return $plaintext;
418	}
419
420	if ($this->paddable) {
421	// we pad with chr(0) since that's what mcrypt_generic does. to quote from http://php.net/function.mcrypt-generic :
422	// "The data is padded with "\0" to make sure the length of the data is n * blocksize."
423	$ciphertext = str_pad($ciphertext, (strlen($ciphertext) + 15) & 0xFFFFFFF0, chr(0));
424	}
425
426	$plaintext = mdecrypt_generic($this->demcrypt, $ciphertext);
427
428	if (!$this->continuousBuffer) {
429	mcrypt_generic_init($this->demcrypt, $this->key, $this->iv);
430	}
431
432	return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
433	}
434
435	return parent::decrypt($ciphertext);
436	}
437
438	/**
439	* Setup mcrypt
440	*
441	* Validates all the variables.
442	*
443	* @access private
444	*/
445	function _mcryptSetup()
446	{
447	if (!$this->changed) {
448	return;
449	}
450
451	if (!$this->explicit_key_length) {
452	// this just copied from Crypt_Rijndael::_setup()
453	$length = strlen($this->key) >> 2;
454	if ($length > 8) {
455	$length = 8;
456	} else if ($length < 4) {
457	$length = 4;
458	}
459	$this->Nk = $length;
460	$this->key_size = $length << 2;
461	}
462
463	switch ($this->Nk) {
464	case 4: // 128
465	$this->key_size = 16;
466	break;
467	case 5: // 160
468	case 6: // 192
469	$this->key_size = 24;
470	break;
471	case 7: // 224
472	case 8: // 256
473	$this->key_size = 32;
474	}
475
476	$this->key = str_pad(substr($this->key, 0, $this->key_size), $this->key_size, chr(0));
477	$this->encryptIV = $this->decryptIV = $this->iv = str_pad(substr($this->iv, 0, 16), 16, chr(0));
478
479	if (!isset($this->enmcrypt)) {
480	$mode = $this->mode;
481	//$mode = $this->mode == CRYPT_AES_MODE_CTR ? MCRYPT_MODE_ECB : $this->mode;
482
483	$this->demcrypt = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', $mode, '');
484	$this->enmcrypt = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', $mode, '');
485
486	if ($mode == 'ncfb') {
487	$this->ecb = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');
488	}
489
490	} // else should mcrypt_generic_deinit be called?
491
492	mcrypt_generic_init($this->demcrypt, $this->key, $this->iv);
493	mcrypt_generic_init($this->enmcrypt, $this->key, $this->iv);
494
495	if ($this->mode == 'ncfb') {
496	mcrypt_generic_init($this->ecb, $this->key, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
497	}
498
499	$this->changed = false;
500	}
501
502	/**
503	* Treat consecutive "packets" as if they are a continuous buffer.
504	*
505	* The default behavior.
506	*
507	* @see Crypt_Rijndael::disableContinuousBuffer()
508	* @access public
509	*/
510	function enableContinuousBuffer()
511	{
512	parent::enableContinuousBuffer();
513
514	if (CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT) {
515	$this->enbuffer['enmcrypt_init'] = true;
516	$this->debuffer['demcrypt_init'] = true;
517	}
518	}
519
520	/**
521	* Treat consecutive packets as if they are a discontinuous buffer.
522	*
523	* The default behavior.
524	*
525	* @see Crypt_Rijndael::enableContinuousBuffer()
526	* @access public
527	*/
528	function disableContinuousBuffer()
529	{
530	parent::disableContinuousBuffer();
531
532	if (CRYPT_AES_MODE == CRYPT_AES_MODE_MCRYPT) {
533	mcrypt_generic_init($this->enmcrypt, $this->key, $this->iv);
534	mcrypt_generic_init($this->demcrypt, $this->key, $this->iv);
535	}
536	}
537	}
538
539	// vim: ts=4:sw=4:et:
540	// vim6: fdl=1:
541