contact-forms / phpseclib-crypt / Base.php

Base.php in Contact Forms by Cimatti 2.3.0, at phpseclib-crypt/Base.php

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1	<?php
2	/**
3	* phpseclib Crypt_Base - Third-party library
4	* @package phpseclib
5	*/
6	if ( ! defined( 'ABSPATH' ) ) exit;
7
8	// phpcs:disable WordPress.Security.EscapeOutput, WordPress.NamingConventions.PrefixAllGlobals, Generic.PHP.ForbiddenFunctions, WordPress.PHP.DevelopmentFunctions, WordPress.WP.AlternativeFunctions -- Third-party cryptographic library
9
10	/**
11	* Base Class for all Crypt_* cipher classes
12	*
13	* PHP versions 4 and 5
14	*
15	* Internally for phpseclib developers:
16	* If you plan to add a new cipher class, please note following rules:
17	*
18	* - The new Crypt_* cipher class should extend Crypt_Base
19	*
20	* - Following methods are then required to be overridden/overloaded:
21	*
22	* - _encryptBlock()
23	*
24	* - _decryptBlock()
25	*
26	* - _setupKey()
27	*
28	* - All other methods are optional to be overridden/overloaded
29	*
30	* - Look at the source code of the current ciphers how they extend Crypt_Base
31	* and take one of them as a start up for the new cipher class.
32	*
33	* - Please read all the other comments/notes/hints here also for each class var/method
34	*
35	* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
36	* of this software and associated documentation files (the "Software"), to deal
37	* in the Software without restriction, including without limitation the rights
38	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
39	* copies of the Software, and to permit persons to whom the Software is
40	* furnished to do so, subject to the following conditions:
41	*
42	* The above copyright notice and this permission notice shall be included in
43	* all copies or substantial portions of the Software.
44	*
45	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
46	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
47	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
48	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
49	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
50	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
51	* THE SOFTWARE.
52	*
53	* @category Crypt
54	* @package Crypt_Base
55	* @author Jim Wigginton <terrafrost@php.net>
56	* @author Hans-Juergen Petrich <petrich@tronic-media.com>
57	* @copyright 2007 Jim Wigginton
58	* @license http://www.opensource.org/licenses/mit-license.html MIT License
59	* @link http://phpseclib.sourceforge.net
60	*/
61
62	/**#@+
63	* @access public
64	* @see self::encrypt()
65	* @see self::decrypt()
66	*/
67	/**
68	* Encrypt / decrypt using the Counter mode.
69	*
70	* Set to -1 since that's what Crypt/Random.php uses to index the CTR mode.
71	*
72	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29
73	*/
74	define('CRYPT_MODE_CTR', -1);
75	/**
76	* Encrypt / decrypt using the Electronic Code Book mode.
77	*
78	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29
79	*/
80	define('CRYPT_MODE_ECB', 1);
81	/**
82	* Encrypt / decrypt using the Code Book Chaining mode.
83	*
84	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29
85	*/
86	define('CRYPT_MODE_CBC', 2);
87	/**
88	* Encrypt / decrypt using the Cipher Feedback mode.
89	*
90	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29
91	*/
92	define('CRYPT_MODE_CFB', 3);
93	/**
94	* Encrypt / decrypt using the Output Feedback mode.
95	*
96	* @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29
97	*/
98	define('CRYPT_MODE_OFB', 4);
99	/**
100	* Encrypt / decrypt using streaming mode.
101	*/
102	define('CRYPT_MODE_STREAM', 5);
103	/*#@-/
104
105	/**#@+
106	* @access private
107	* @see self::Crypt_Base()
108	* @internal These constants are for internal use only
109	*/
110	/**
111	* Base value for the internal implementation $engine switch
112	*/
113	define('CRYPT_ENGINE_INTERNAL', 1);
114	/**
115	* Base value for the mcrypt implementation $engine switch
116	*/
117	define('CRYPT_ENGINE_MCRYPT', 2);
118	/**
119	* Base value for the OpenSSL implementation $engine switch
120	*/
121	define('CRYPT_ENGINE_OPENSSL', 3);
122	/*#@-/
123
124	/**
125	* Base Class for all Crypt_* cipher classes
126	*
127	* @package Crypt_Base
128	* @author Jim Wigginton <terrafrost@php.net>
129	* @author Hans-Juergen Petrich <petrich@tronic-media.com>
130	* @access public
131	*/
132	#[AllowDynamicProperties]
133	class Crypt_Base
134	{
135	/**
136	* The Encryption Mode
137	*
138	* @see self::Crypt_Base()
139	* @var int
140	* @access private
141	*/
142	var $mode;
143
144	/**
145	* The Block Length of the block cipher
146	*
147	* @var int
148	* @access private
149	*/
150	var $block_size = 16;
151
152	/**
153	* The Key
154	*
155	* @see self::setKey()
156	* @var string
157	* @access private
158	*/
159	var $key = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
160
161	/**
162	* The Initialization Vector
163	*
164	* @see self::setIV()
165	* @var string
166	* @access private
167	*/
168	var $iv;
169
170	/**
171	* A "sliding" Initialization Vector
172	*
173	* @see self::enableContinuousBuffer()
174	* @see self::_clearBuffers()
175	* @var string
176	* @access private
177	*/
178	var $encryptIV;
179
180	/**
181	* A "sliding" Initialization Vector
182	*
183	* @see self::enableContinuousBuffer()
184	* @see self::_clearBuffers()
185	* @var string
186	* @access private
187	*/
188	var $decryptIV;
189
190	/**
191	* Continuous Buffer status
192	*
193	* @see self::enableContinuousBuffer()
194	* @var bool
195	* @access private
196	*/
197	var $continuousBuffer = false;
198
199	/**
200	* Encryption buffer for CTR, OFB and CFB modes
201	*
202	* @see self::encrypt()
203	* @see self::_clearBuffers()
204	* @var array
205	* @access private
206	*/
207	var $enbuffer;
208
209	/**
210	* Decryption buffer for CTR, OFB and CFB modes
211	*
212	* @see self::decrypt()
213	* @see self::_clearBuffers()
214	* @var array
215	* @access private
216	*/
217	var $debuffer;
218
219	/**
220	* mcrypt resource for encryption
221	*
222	* The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
223	* Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
224	*
225	* @see self::encrypt()
226	* @var resource
227	* @access private
228	*/
229	var $enmcrypt;
230
231	/**
232	* mcrypt resource for decryption
233	*
234	* The mcrypt resource can be recreated every time something needs to be created or it can be created just once.
235	* Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode.
236	*
237	* @see self::decrypt()
238	* @var resource
239	* @access private
240	*/
241	var $demcrypt;
242
243	/**
244	* Does the enmcrypt resource need to be (re)initialized?
245	*
246	* @see Crypt_Twofish::setKey()
247	* @see Crypt_Twofish::setIV()
248	* @var bool
249	* @access private
250	*/
251	var $enchanged = true;
252
253	/**
254	* Does the demcrypt resource need to be (re)initialized?
255	*
256	* @see Crypt_Twofish::setKey()
257	* @see Crypt_Twofish::setIV()
258	* @var bool
259	* @access private
260	*/
261	var $dechanged = true;
262
263	/**
264	* mcrypt resource for CFB mode
265	*
266	* mcrypt's CFB mode, in (and only in) buffered context,
267	* is broken, so phpseclib implements the CFB mode by it self,
268	* even when the mcrypt php extension is available.
269	*
270	* In order to do the CFB-mode work (fast) phpseclib
271	* use a separate ECB-mode mcrypt resource.
272	*
273	* @link http://phpseclib.sourceforge.net/cfb-demo.phps
274	* @see self::encrypt()
275	* @see self::decrypt()
276	* @see self::_setupMcrypt()
277	* @var resource
278	* @access private
279	*/
280	var $ecb;
281
282	/**
283	* Optimizing value while CFB-encrypting
284	*
285	* Only relevant if $continuousBuffer enabled
286	* and $engine == CRYPT_ENGINE_MCRYPT
287	*
288	* It's faster to re-init $enmcrypt if
289	* $buffer bytes > $cfb_init_len than
290	* using the $ecb resource furthermore.
291	*
292	* This value depends of the chosen cipher
293	* and the time it would be needed for it's
294	* initialization [by mcrypt_generic_init()]
295	* which, typically, depends on the complexity
296	* on its internaly Key-expanding algorithm.
297	*
298	* @see self::encrypt()
299	* @var int
300	* @access private
301	*/
302	var $cfb_init_len = 600;
303
304	/**
305	* Does internal cipher state need to be (re)initialized?
306	*
307	* @see self::setKey()
308	* @see self::setIV()
309	* @see self::disableContinuousBuffer()
310	* @var bool
311	* @access private
312	*/
313	var $changed = true;
314
315	/**
316	* Padding status
317	*
318	* @see self::enablePadding()
319	* @var bool
320	* @access private
321	*/
322	var $padding = true;
323
324	/**
325	* Is the mode one that is paddable?
326	*
327	* @see self::Crypt_Base()
328	* @var bool
329	* @access private
330	*/
331	var $paddable = false;
332
333	/**
334	* Holds which crypt engine internaly should be use,
335	* which will be determined automatically on __construct()
336	*
337	* Currently available $engines are:
338	* - CRYPT_ENGINE_OPENSSL (very fast, php-extension: openssl, extension_loaded('openssl') required)
339	* - CRYPT_ENGINE_MCRYPT (fast, php-extension: mcrypt, extension_loaded('mcrypt') required)
340	* - CRYPT_ENGINE_INTERNAL (slower, pure php-engine, no php-extension required)
341	*
342	* @see self::_setEngine()
343	* @see self::encrypt()
344	* @see self::decrypt()
345	* @var int
346	* @access private
347	*/
348	var $engine;
349
350	/**
351	* Holds the preferred crypt engine
352	*
353	* @see self::_setEngine()
354	* @see self::setPreferredEngine()
355	* @var int
356	* @access private
357	*/
358	var $preferredEngine;
359
360	/**
361	* The mcrypt specific name of the cipher
362	*
363	* Only used if $engine == CRYPT_ENGINE_MCRYPT
364	*
365	* @link http://www.php.net/mcrypt_module_open
366	* @link http://www.php.net/mcrypt_list_algorithms
367	* @see self::_setupMcrypt()
368	* @var string
369	* @access private
370	*/
371	var $cipher_name_mcrypt;
372
373	/**
374	* The openssl specific name of the cipher
375	*
376	* Only used if $engine == CRYPT_ENGINE_OPENSSL
377	*
378	* @link http://www.php.net/openssl-get-cipher-methods
379	* @var string
380	* @access private
381	*/
382	var $cipher_name_openssl;
383
384	/**
385	* The openssl specific name of the cipher in ECB mode
386	*
387	* If OpenSSL does not support the mode we're trying to use (CTR)
388	* it can still be emulated with ECB mode.
389	*
390	* @link http://www.php.net/openssl-get-cipher-methods
391	* @var string
392	* @access private
393	*/
394	var $cipher_name_openssl_ecb;
395
396	/**
397	* The default salt used by setPassword()
398	*
399	* @see self::setPassword()
400	* @var string
401	* @access private
402	*/
403	var $password_default_salt = 'phpseclib/salt';
404
405	/**
406	* The namespace used by the cipher for its constants.
407	*
408	* ie: AES.php is using CRYPT_AES_MODE_* for its constants
409	* so $const_namespace is AES
410	*
411	* DES.php is using CRYPT_DES_MODE_* for its constants
412	* so $const_namespace is DES... and so on
413	*
414	* All CRYPT_<$const_namespace>_MODE_* are aliases of
415	* the generic CRYPT_MODE_* constants, so both could be used
416	* for each cipher.
417	*
418	* Example:
419	* $aes = new Crypt_AES(CRYPT_AES_MODE_CFB); // $aes will operate in cfb mode
420	* $aes = new Crypt_AES(CRYPT_MODE_CFB); // identical
421	*
422	* @see self::Crypt_Base()
423	* @var string
424	* @access private
425	*/
426	var $const_namespace;
427
428	/**
429	* The name of the performance-optimized callback function
430	*
431	* Used by encrypt() / decrypt()
432	* only if $engine == CRYPT_ENGINE_INTERNAL
433	*
434	* @see self::encrypt()
435	* @see self::decrypt()
436	* @see self::_setupInlineCrypt()
437	* @see self::$use_inline_crypt
438	* @var Callback
439	* @access private
440	*/
441	var $inline_crypt;
442
443	/**
444	* Holds whether performance-optimized $inline_crypt() can/should be used.
445	*
446	* @see self::encrypt()
447	* @see self::decrypt()
448	* @see self::inline_crypt
449	* @var mixed
450	* @access private
451	*/
452	var $use_inline_crypt;
453
454	/**
455	* If OpenSSL can be used in ECB but not in CTR we can emulate CTR
456	*
457	* @see self::_openssl_ctr_process()
458	* @var bool
459	* @access private
460	*/
461	var $openssl_emulate_ctr = false;
462
463	/**
464	* Determines what options are passed to openssl_encrypt/decrypt
465	*
466	* @see self::isValidEngine()
467	* @var mixed
468	* @access private
469	*/
470	var $openssl_options;
471
472	/**
473	* Has the key length explicitly been set or should it be derived from the key, itself?
474	*
475	* @see self::setKeyLength()
476	* @var bool
477	* @access private
478	*/
479	var $explicit_key_length = false;
480
481	/**
482	* Don't truncate / null pad key
483	*
484	* @see self::_clearBuffers()
485	* @var bool
486	* @access private
487	*/
488	var $skip_key_adjustment = false;
489
490	/**
491	* Default Constructor.
492	*
493	* Determines whether or not the mcrypt extension should be used.
494	*
495	* $mode could be:
496	*
497	* - CRYPT_MODE_ECB
498	*
499	* - CRYPT_MODE_CBC
500	*
501	* - CRYPT_MODE_CTR
502	*
503	* - CRYPT_MODE_CFB
504	*
505	* - CRYPT_MODE_OFB
506	*
507	* (or the alias constants of the chosen cipher, for example for AES: CRYPT_AES_MODE_ECB or CRYPT_AES_MODE_CBC ...)
508	*
509	* If not explicitly set, CRYPT_MODE_CBC will be used.
510	*
511	* @param int $mode
512	* @access public
513	*/
514	function __construct($mode = CRYPT_MODE_CBC)
515	{
516	// $mode dependent settings
517	switch ($mode) {
518	case CRYPT_MODE_ECB:
519	$this->paddable = true;
520	$this->mode = CRYPT_MODE_ECB;
521	break;
522	case CRYPT_MODE_CTR:
523	case CRYPT_MODE_CFB:
524	case CRYPT_MODE_OFB:
525	case CRYPT_MODE_STREAM:
526	$this->mode = $mode;
527	break;
528	case CRYPT_MODE_CBC:
529	default:
530	$this->paddable = true;
531	$this->mode = CRYPT_MODE_CBC;
532	}
533
534	$this->_setEngine();
535
536	// Determining whether inline crypting can be used by the cipher
537	if ($this->use_inline_crypt !== false) {
538	$this->use_inline_crypt = version_compare(PHP_VERSION, '5.3.0') >= 0 \|\| function_exists('create_function');
539	}
540	}
541
542	/**
543	* PHP4 compatible Default Constructor.
544	*
545	* @see self::__construct()
546	* @param int $mode
547	* @access public
548	*/
549	function Crypt_Base($mode = CRYPT_MODE_CBC)
550	{
551	$this->__construct($mode);
552	}
553
554	/**
555	* Sets the initialization vector. (optional)
556	*
557	* SetIV is not required when CRYPT_MODE_ECB (or ie for AES: CRYPT_AES_MODE_ECB) is being used. If not explicitly set, it'll be assumed
558	* to be all zero's.
559	*
560	* @access public
561	* @param string $iv
562	* @internal Can be overwritten by a sub class, but does not have to be
563	*/
564	function setIV($iv)
565	{
566	if ($this->mode == CRYPT_MODE_ECB) {
567	return;
568	}
569
570	$this->iv = $iv;
571	$this->changed = true;
572	}
573
574	/**
575	* Sets the key length.
576	*
577	* Keys with explicitly set lengths need to be treated accordingly
578	*
579	* @access public
580	* @param int $length
581	*/
582	function setKeyLength($length)
583	{
584	$this->explicit_key_length = true;
585	$this->changed = true;
586	$this->_setEngine();
587	}
588
589	/**
590	* Returns the current key length in bits
591	*
592	* @access public
593	* @return int
594	*/
595	function getKeyLength()
596	{
597	return $this->key_length << 3;
598	}
599
600	/**
601	* Returns the current block length in bits
602	*
603	* @access public
604	* @return int
605	*/
606	function getBlockLength()
607	{
608	return $this->block_size << 3;
609	}
610
611	/**
612	* Sets the key.
613	*
614	* The min/max length(s) of the key depends on the cipher which is used.
615	* If the key not fits the length(s) of the cipher it will paded with null bytes
616	* up to the closest valid key length. If the key is more than max length,
617	* we trim the excess bits.
618	*
619	* If the key is not explicitly set, it'll be assumed to be all null bytes.
620	*
621	* @access public
622	* @param string $key
623	* @internal Could, but not must, extend by the child Crypt_* class
624	*/
625	function setKey($key)
626	{
627	if (!$this->explicit_key_length) {
628	$this->setKeyLength(strlen($key) << 3);
629	$this->explicit_key_length = false;
630	}
631
632	$this->key = $key;
633	$this->changed = true;
634	$this->_setEngine();
635	}
636
637	/**
638	* Sets the password.
639	*
640	* Depending on what $method is set to, setPassword()'s (optional) parameters are as follows:
641	* {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2} or pbkdf1:
642	* $hash, $salt, $count, $dkLen
643	*
644	* Where $hash (default = sha1) currently supports the following hashes: see: Crypt/Hash.php
645	*
646	* @see Crypt/Hash.php
647	* @param string $password
648	* @param string $method
649	* @return bool
650	* @access public
651	* @internal Could, but not must, extend by the child Crypt_* class
652	*/
653	function setPassword($password, $method = 'pbkdf2')
654	{
655	$key = '';
656
657	switch ($method) {
658	default: // 'pbkdf2' or 'pbkdf1'
659	$func_args = func_get_args();
660
661	// Hash function
662	$hash = isset($func_args[2]) ? $func_args[2] : 'sha1';
663
664	// WPA and WPA2 use the SSID as the salt
665	$salt = isset($func_args[3]) ? $func_args[3] : $this->password_default_salt;
666
667	// RFC2898#section-4.2 uses 1,000 iterations by default
668	// WPA and WPA2 use 4,096.
669	$count = isset($func_args[4]) ? $func_args[4] : 1000;
670
671	// Keylength
672	if (isset($func_args[5]) && $func_args[5] > 0) {
673	$dkLen = $func_args[5];
674	} else {
675	$dkLen = $method == 'pbkdf1' ? 2 * $this->key_length : $this->key_length;
676	}
677
678	switch (true) {
679	case $method == 'pbkdf1':
680	if (!class_exists('Crypt_Hash')) {
681	include_once 'Hash.php';
682	}
683	$hashObj = new Crypt_Hash();
684	$hashObj->setHash($hash);
685	if ($dkLen > $hashObj->getLength()) {
686	user_error('Derived key too long');
687	return false;
688	}
689	$t = $password . $salt;
690	for ($i = 0; $i < $count; ++$i) {
691	$t = $hashObj->hash($t);
692	}
693	$key = substr($t, 0, $dkLen);
694
695	$this->setKey(substr($key, 0, $dkLen >> 1));
696	$this->setIV(substr($key, $dkLen >> 1));
697
698	return true;
699	// Determining if php[>=5.5.0]'s hash_pbkdf2() function avail- and useable
700	case !function_exists('hash_pbkdf2'):
701	case !function_exists('hash_algos'):
702	case !in_array($hash, hash_algos()):
703	if (!class_exists('Crypt_Hash')) {
704	include_once 'Hash.php';
705	}
706	$i = 1;
707	$hmac = new Crypt_Hash();
708	$hmac->setHash($hash);
709	$hmac->setKey($password);
710	while (strlen($key) < $dkLen) {
711	$f = $u = $hmac->hash($salt . pack('N', $i++));
712	for ($j = 2; $j <= $count; ++$j) {
713	$u = $hmac->hash($u);
714	$f^= $u;
715	}
716	$key.= $f;
717	}
718	$key = substr($key, 0, $dkLen);
719	break;
720	default:
721	$key = hash_pbkdf2($hash, $password, $salt, $count, $dkLen, true);
722	}
723	}
724
725	$this->setKey($key);
726
727	return true;
728	}
729
730	/**
731	* Encrypts a message.
732	*
733	* $plaintext will be padded with additional bytes such that it's length is a multiple of the block size. Other cipher
734	* implementations may or may not pad in the same manner. Other common approaches to padding and the reasons why it's
735	* necessary are discussed in the following
736	* URL:
737	*
738	* {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html}
739	*
740	* An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does.
741	* strlen($plaintext) will still need to be a multiple of the block size, however, arbitrary values can be added to make it that
742	* length.
743	*
744	* @see self::decrypt()
745	* @access public
746	* @param string $plaintext
747	* @return string $ciphertext
748	* @internal Could, but not must, extend by the child Crypt_* class
749	*/
750	function encrypt($plaintext)
751	{
752	if ($this->paddable) {
753	$plaintext = $this->_pad($plaintext);
754	}
755
756	if ($this->engine === CRYPT_ENGINE_OPENSSL) {
757	if ($this->changed) {
758	$this->_clearBuffers();
759	$this->changed = false;
760	}
761	switch ($this->mode) {
762	case CRYPT_MODE_STREAM:
763	return openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options);
764	case CRYPT_MODE_ECB:
765	$result = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options);
766	return !defined('OPENSSL_RAW_DATA') ? substr($result, 0, -$this->block_size) : $result;
767	case CRYPT_MODE_CBC:
768	$result = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $this->encryptIV);
769	if (!defined('OPENSSL_RAW_DATA')) {
770	$result = substr($result, 0, -$this->block_size);
771	}
772	if ($this->continuousBuffer) {
773	$this->encryptIV = substr($result, -$this->block_size);
774	}
775	return $result;
776	case CRYPT_MODE_CTR:
777	return $this->_openssl_ctr_process($plaintext, $this->encryptIV, $this->enbuffer);
778	case CRYPT_MODE_CFB:
779	// cfb loosely routines inspired by openssl's:
780	// {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1}
781	$ciphertext = '';
782	if ($this->continuousBuffer) {
783	$iv = &$this->encryptIV;
784	$pos = &$this->enbuffer['pos'];
785	} else {
786	$iv = $this->encryptIV;
787	$pos = 0;
788	}
789	$len = strlen($plaintext);
790	$i = 0;
791	if ($pos) {
792	$orig_pos = $pos;
793	$max = $this->block_size - $pos;
794	if ($len >= $max) {
795	$i = $max;
796	$len-= $max;
797	$pos = 0;
798	} else {
799	$i = $len;
800	$pos+= $len;
801	$len = 0;
802	}
803	// ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
804	$ciphertext = substr($iv, $orig_pos) ^ $plaintext;
805	$iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
806	$plaintext = substr($plaintext, $i);
807	}
808
809	$overflow = $len % $this->block_size;
810
811	if ($overflow) {
812	$ciphertext.= openssl_encrypt(substr($plaintext, 0, -$overflow) . str_repeat("\0", $this->block_size), $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv);
813	$iv = $this->_string_pop($ciphertext, $this->block_size);
814
815	$size = $len - $overflow;
816	$block = $iv ^ substr($plaintext, -$overflow);
817	$iv = substr_replace($iv, $block, 0, $overflow);
818	$ciphertext.= $block;
819	$pos = $overflow;
820	} elseif ($len) {
821	$ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv);
822	$iv = substr($ciphertext, -$this->block_size);
823	}
824
825	return $ciphertext;
826	case CRYPT_MODE_OFB:
827	return $this->_openssl_ofb_process($plaintext, $this->encryptIV, $this->enbuffer);
828	}
829	}
830
831	if ($this->engine === CRYPT_ENGINE_MCRYPT) {
832	if ($this->changed) {
833	$this->_setupMcrypt();
834	$this->changed = false;
835	}
836	if ($this->enchanged) {
837	@mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
838	$this->enchanged = false;
839	}
840
841	// re: {@link http://phpseclib.sourceforge.net/cfb-demo.phps}
842	// using mcrypt's default handing of CFB the above would output two different things. using phpseclib's
843	// rewritten CFB implementation the above outputs the same thing twice.
844	if ($this->mode == CRYPT_MODE_CFB && $this->continuousBuffer) {
845	$block_size = $this->block_size;
846	$iv = &$this->encryptIV;
847	$pos = &$this->enbuffer['pos'];
848	$len = strlen($plaintext);
849	$ciphertext = '';
850	$i = 0;
851	if ($pos) {
852	$orig_pos = $pos;
853	$max = $block_size - $pos;
854	if ($len >= $max) {
855	$i = $max;
856	$len-= $max;
857	$pos = 0;
858	} else {
859	$i = $len;
860	$pos+= $len;
861	$len = 0;
862	}
863	$ciphertext = substr($iv, $orig_pos) ^ $plaintext;
864	$iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
865	$this->enbuffer['enmcrypt_init'] = true;
866	}
867	if ($len >= $block_size) {
868	if ($this->enbuffer['enmcrypt_init'] === false \|\| $len > $this->cfb_init_len) {
869	if ($this->enbuffer['enmcrypt_init'] === true) {
870	@mcrypt_generic_init($this->enmcrypt, $this->key, $iv);
871	$this->enbuffer['enmcrypt_init'] = false;
872	}
873	$ciphertext.= @mcrypt_generic($this->enmcrypt, substr($plaintext, $i, $len - $len % $block_size));
874	$iv = substr($ciphertext, -$block_size);
875	$len%= $block_size;
876	} else {
877	while ($len >= $block_size) {
878	$iv = @mcrypt_generic($this->ecb, $iv) ^ substr($plaintext, $i, $block_size);
879	$ciphertext.= $iv;
880	$len-= $block_size;
881	$i+= $block_size;
882	}
883	}
884	}
885
886	if ($len) {
887	$iv = @mcrypt_generic($this->ecb, $iv);
888	$block = $iv ^ substr($plaintext, -$len);
889	$iv = substr_replace($iv, $block, 0, $len);
890	$ciphertext.= $block;
891	$pos = $len;
892	}
893
894	return $ciphertext;
895	}
896
897	$ciphertext = @mcrypt_generic($this->enmcrypt, $plaintext);
898
899	if (!$this->continuousBuffer) {
900	@mcrypt_generic_init($this->enmcrypt, $this->key, $this->encryptIV);
901	}
902
903	return $ciphertext;
904	}
905
906	if ($this->changed) {
907	$this->_setup();
908	$this->changed = false;
909	}
910	if ($this->use_inline_crypt) {
911	$inline = $this->inline_crypt;
912	return $inline('encrypt', $this, $plaintext);
913	}
914
915	$buffer = &$this->enbuffer;
916	$block_size = $this->block_size;
917	$ciphertext = '';
918	switch ($this->mode) {
919	case CRYPT_MODE_ECB:
920	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
921	$ciphertext.= $this->_encryptBlock(substr($plaintext, $i, $block_size));
922	}
923	break;
924	case CRYPT_MODE_CBC:
925	$xor = $this->encryptIV;
926	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
927	$block = substr($plaintext, $i, $block_size);
928	$block = $this->_encryptBlock($block ^ $xor);
929	$xor = $block;
930	$ciphertext.= $block;
931	}
932	if ($this->continuousBuffer) {
933	$this->encryptIV = $xor;
934	}
935	break;
936	case CRYPT_MODE_CTR:
937	$xor = $this->encryptIV;
938	if (strlen($buffer['ciphertext'])) {
939	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
940	$block = substr($plaintext, $i, $block_size);
941	if (strlen($block) > strlen($buffer['ciphertext'])) {
942	$buffer['ciphertext'].= $this->_encryptBlock($xor);
943	}
944	$this->_increment_str($xor);
945	$key = $this->_string_shift($buffer['ciphertext'], $block_size);
946	$ciphertext.= $block ^ $key;
947	}
948	} else {
949	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
950	$block = substr($plaintext, $i, $block_size);
951	$key = $this->_encryptBlock($xor);
952	$this->_increment_str($xor);
953	$ciphertext.= $block ^ $key;
954	}
955	}
956	if ($this->continuousBuffer) {
957	$this->encryptIV = $xor;
958	if ($start = strlen($plaintext) % $block_size) {
959	$buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext'];
960	}
961	}
962	break;
963	case CRYPT_MODE_CFB:
964	// cfb loosely routines inspired by openssl's:
965	// {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1}
966	if ($this->continuousBuffer) {
967	$iv = &$this->encryptIV;
968	$pos = &$buffer['pos'];
969	} else {
970	$iv = $this->encryptIV;
971	$pos = 0;
972	}
973	$len = strlen($plaintext);
974	$i = 0;
975	if ($pos) {
976	$orig_pos = $pos;
977	$max = $block_size - $pos;
978	if ($len >= $max) {
979	$i = $max;
980	$len-= $max;
981	$pos = 0;
982	} else {
983	$i = $len;
984	$pos+= $len;
985	$len = 0;
986	}
987	// ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
988	$ciphertext = substr($iv, $orig_pos) ^ $plaintext;
989	$iv = substr_replace($iv, $ciphertext, $orig_pos, $i);
990	}
991	while ($len >= $block_size) {
992	$iv = $this->_encryptBlock($iv) ^ substr($plaintext, $i, $block_size);
993	$ciphertext.= $iv;
994	$len-= $block_size;
995	$i+= $block_size;
996	}
997	if ($len) {
998	$iv = $this->_encryptBlock($iv);
999	$block = $iv ^ substr($plaintext, $i);
1000	$iv = substr_replace($iv, $block, 0, $len);
1001	$ciphertext.= $block;
1002	$pos = $len;
1003	}
1004	break;
1005	case CRYPT_MODE_OFB:
1006	$xor = $this->encryptIV;
1007	if (strlen($buffer['xor'])) {
1008	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
1009	$block = substr($plaintext, $i, $block_size);
1010	if (strlen($block) > strlen($buffer['xor'])) {
1011	$xor = $this->_encryptBlock($xor);
1012	$buffer['xor'].= $xor;
1013	}
1014	$key = $this->_string_shift($buffer['xor'], $block_size);
1015	$ciphertext.= $block ^ $key;
1016	}
1017	} else {
1018	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
1019	$xor = $this->_encryptBlock($xor);
1020	$ciphertext.= substr($plaintext, $i, $block_size) ^ $xor;
1021	}
1022	$key = $xor;
1023	}
1024	if ($this->continuousBuffer) {
1025	$this->encryptIV = $xor;
1026	if ($start = strlen($plaintext) % $block_size) {
1027	$buffer['xor'] = substr($key, $start) . $buffer['xor'];
1028	}
1029	}
1030	break;
1031	case CRYPT_MODE_STREAM:
1032	$ciphertext = $this->_encryptBlock($plaintext);
1033	break;
1034	}
1035
1036	return $ciphertext;
1037	}
1038
1039	/**
1040	* Decrypts a message.
1041	*
1042	* If strlen($ciphertext) is not a multiple of the block size, null bytes will be added to the end of the string until
1043	* it is.
1044	*
1045	* @see self::encrypt()
1046	* @access public
1047	* @param string $ciphertext
1048	* @return string $plaintext
1049	* @internal Could, but not must, extend by the child Crypt_* class
1050	*/
1051	function decrypt($ciphertext)
1052	{
1053	if ($this->paddable) {
1054	// we pad with chr(0) since that's what mcrypt_generic does. to quote from {@link http://www.php.net/function.mcrypt-generic}:
1055	// "The data is padded with "\0" to make sure the length of the data is n * blocksize."
1056	$ciphertext = str_pad($ciphertext, strlen($ciphertext) + ($this->block_size - strlen($ciphertext) % $this->block_size) % $this->block_size, chr(0));
1057	}
1058
1059	if ($this->engine === CRYPT_ENGINE_OPENSSL) {
1060	if ($this->changed) {
1061	$this->_clearBuffers();
1062	$this->changed = false;
1063	}
1064	switch ($this->mode) {
1065	case CRYPT_MODE_STREAM:
1066	$plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options);
1067	break;
1068	case CRYPT_MODE_ECB:
1069	if (!defined('OPENSSL_RAW_DATA')) {
1070	$ciphertext.= openssl_encrypt('', $this->cipher_name_openssl_ecb, $this->key, true);
1071	}
1072	$plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options);
1073	break;
1074	case CRYPT_MODE_CBC:
1075	if (!defined('OPENSSL_RAW_DATA')) {
1076	$padding = str_repeat(chr($this->block_size), $this->block_size) ^ substr($ciphertext, -$this->block_size);
1077	$ciphertext.= substr(openssl_encrypt($padding, $this->cipher_name_openssl_ecb, $this->key, true), 0, $this->block_size);
1078	$offset = 2 * $this->block_size;
1079	} else {
1080	$offset = $this->block_size;
1081	}
1082	$plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $this->decryptIV);
1083	if ($this->continuousBuffer) {
1084	$this->decryptIV = substr($ciphertext, -$offset, $this->block_size);
1085	}
1086	break;
1087	case CRYPT_MODE_CTR:
1088	$plaintext = $this->_openssl_ctr_process($ciphertext, $this->decryptIV, $this->debuffer);
1089	break;
1090	case CRYPT_MODE_CFB:
1091	// cfb loosely routines inspired by openssl's:
1092	// {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1}
1093	$plaintext = '';
1094	if ($this->continuousBuffer) {
1095	$iv = &$this->decryptIV;
1096	$pos = &$this->buffer['pos'];
1097	} else {
1098	$iv = $this->decryptIV;
1099	$pos = 0;
1100	}
1101	$len = strlen($ciphertext);
1102	$i = 0;
1103	if ($pos) {
1104	$orig_pos = $pos;
1105	$max = $this->block_size - $pos;
1106	if ($len >= $max) {
1107	$i = $max;
1108	$len-= $max;
1109	$pos = 0;
1110	} else {
1111	$i = $len;
1112	$pos+= $len;
1113	$len = 0;
1114	}
1115	// ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $this->blocksize
1116	$plaintext = substr($iv, $orig_pos) ^ $ciphertext;
1117	$iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
1118	$ciphertext = substr($ciphertext, $i);
1119	}
1120	$overflow = $len % $this->block_size;
1121	if ($overflow) {
1122	$plaintext.= openssl_decrypt(substr($ciphertext, 0, -$overflow), $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv);
1123	if ($len - $overflow) {
1124	$iv = substr($ciphertext, -$overflow - $this->block_size, -$overflow);
1125	}
1126	$iv = openssl_encrypt(str_repeat("\0", $this->block_size), $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv);
1127	$plaintext.= $iv ^ substr($ciphertext, -$overflow);
1128	$iv = substr_replace($iv, substr($ciphertext, -$overflow), 0, $overflow);
1129	$pos = $overflow;
1130	} elseif ($len) {
1131	$plaintext.= openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, $this->openssl_options, $iv);
1132	$iv = substr($ciphertext, -$this->block_size);
1133	}
1134	break;
1135	case CRYPT_MODE_OFB:
1136	$plaintext = $this->_openssl_ofb_process($ciphertext, $this->decryptIV, $this->debuffer);
1137	}
1138
1139	return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
1140	}
1141
1142	if ($this->engine === CRYPT_ENGINE_MCRYPT) {
1143	$block_size = $this->block_size;
1144	if ($this->changed) {
1145	$this->_setupMcrypt();
1146	$this->changed = false;
1147	}
1148	if ($this->dechanged) {
1149	@mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
1150	$this->dechanged = false;
1151	}
1152
1153	if ($this->mode == CRYPT_MODE_CFB && $this->continuousBuffer) {
1154	$iv = &$this->decryptIV;
1155	$pos = &$this->debuffer['pos'];
1156	$len = strlen($ciphertext);
1157	$plaintext = '';
1158	$i = 0;
1159	if ($pos) {
1160	$orig_pos = $pos;
1161	$max = $block_size - $pos;
1162	if ($len >= $max) {
1163	$i = $max;
1164	$len-= $max;
1165	$pos = 0;
1166	} else {
1167	$i = $len;
1168	$pos+= $len;
1169	$len = 0;
1170	}
1171	// ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
1172	$plaintext = substr($iv, $orig_pos) ^ $ciphertext;
1173	$iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
1174	}
1175	if ($len >= $block_size) {
1176	$cb = substr($ciphertext, $i, $len - $len % $block_size);
1177	$plaintext.= @mcrypt_generic($this->ecb, $iv . $cb) ^ $cb;
1178	$iv = substr($cb, -$block_size);
1179	$len%= $block_size;
1180	}
1181	if ($len) {
1182	$iv = @mcrypt_generic($this->ecb, $iv);
1183	$plaintext.= $iv ^ substr($ciphertext, -$len);
1184	$iv = substr_replace($iv, substr($ciphertext, -$len), 0, $len);
1185	$pos = $len;
1186	}
1187
1188	return $plaintext;
1189	}
1190
1191	$plaintext = @mdecrypt_generic($this->demcrypt, $ciphertext);
1192
1193	if (!$this->continuousBuffer) {
1194	@mcrypt_generic_init($this->demcrypt, $this->key, $this->decryptIV);
1195	}
1196
1197	return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
1198	}
1199
1200	if ($this->changed) {
1201	$this->_setup();
1202	$this->changed = false;
1203	}
1204	if ($this->use_inline_crypt) {
1205	$inline = $this->inline_crypt;
1206	return $inline('decrypt', $this, $ciphertext);
1207	}
1208
1209	$block_size = $this->block_size;
1210
1211	$buffer = &$this->debuffer;
1212	$plaintext = '';
1213	switch ($this->mode) {
1214	case CRYPT_MODE_ECB:
1215	for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
1216	$plaintext.= $this->_decryptBlock(substr($ciphertext, $i, $block_size));
1217	}
1218	break;
1219	case CRYPT_MODE_CBC:
1220	$xor = $this->decryptIV;
1221	for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
1222	$block = substr($ciphertext, $i, $block_size);
1223	$plaintext.= $this->_decryptBlock($block) ^ $xor;
1224	$xor = $block;
1225	}
1226	if ($this->continuousBuffer) {
1227	$this->decryptIV = $xor;
1228	}
1229	break;
1230	case CRYPT_MODE_CTR:
1231	$xor = $this->decryptIV;
1232	if (strlen($buffer['ciphertext'])) {
1233	for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
1234	$block = substr($ciphertext, $i, $block_size);
1235	if (strlen($block) > strlen($buffer['ciphertext'])) {
1236	$buffer['ciphertext'].= $this->_encryptBlock($xor);
1237	$this->_increment_str($xor);
1238	}
1239	$key = $this->_string_shift($buffer['ciphertext'], $block_size);
1240	$plaintext.= $block ^ $key;
1241	}
1242	} else {
1243	for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
1244	$block = substr($ciphertext, $i, $block_size);
1245	$key = $this->_encryptBlock($xor);
1246	$this->_increment_str($xor);
1247	$plaintext.= $block ^ $key;
1248	}
1249	}
1250	if ($this->continuousBuffer) {
1251	$this->decryptIV = $xor;
1252	if ($start = strlen($ciphertext) % $block_size) {
1253	$buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext'];
1254	}
1255	}
1256	break;
1257	case CRYPT_MODE_CFB:
1258	if ($this->continuousBuffer) {
1259	$iv = &$this->decryptIV;
1260	$pos = &$buffer['pos'];
1261	} else {
1262	$iv = $this->decryptIV;
1263	$pos = 0;
1264	}
1265	$len = strlen($ciphertext);
1266	$i = 0;
1267	if ($pos) {
1268	$orig_pos = $pos;
1269	$max = $block_size - $pos;
1270	if ($len >= $max) {
1271	$i = $max;
1272	$len-= $max;
1273	$pos = 0;
1274	} else {
1275	$i = $len;
1276	$pos+= $len;
1277	$len = 0;
1278	}
1279	// ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize
1280	$plaintext = substr($iv, $orig_pos) ^ $ciphertext;
1281	$iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i);
1282	}
1283	while ($len >= $block_size) {
1284	$iv = $this->_encryptBlock($iv);
1285	$cb = substr($ciphertext, $i, $block_size);
1286	$plaintext.= $iv ^ $cb;
1287	$iv = $cb;
1288	$len-= $block_size;
1289	$i+= $block_size;
1290	}
1291	if ($len) {
1292	$iv = $this->_encryptBlock($iv);
1293	$plaintext.= $iv ^ substr($ciphertext, $i);
1294	$iv = substr_replace($iv, substr($ciphertext, $i), 0, $len);
1295	$pos = $len;
1296	}
1297	break;
1298	case CRYPT_MODE_OFB:
1299	$xor = $this->decryptIV;
1300	if (strlen($buffer['xor'])) {
1301	for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
1302	$block = substr($ciphertext, $i, $block_size);
1303	if (strlen($block) > strlen($buffer['xor'])) {
1304	$xor = $this->_encryptBlock($xor);
1305	$buffer['xor'].= $xor;
1306	}
1307	$key = $this->_string_shift($buffer['xor'], $block_size);
1308	$plaintext.= $block ^ $key;
1309	}
1310	} else {
1311	for ($i = 0; $i < strlen($ciphertext); $i+=$block_size) {
1312	$xor = $this->_encryptBlock($xor);
1313	$plaintext.= substr($ciphertext, $i, $block_size) ^ $xor;
1314	}
1315	$key = $xor;
1316	}
1317	if ($this->continuousBuffer) {
1318	$this->decryptIV = $xor;
1319	if ($start = strlen($ciphertext) % $block_size) {
1320	$buffer['xor'] = substr($key, $start) . $buffer['xor'];
1321	}
1322	}
1323	break;
1324	case CRYPT_MODE_STREAM:
1325	$plaintext = $this->_decryptBlock($ciphertext);
1326	break;
1327	}
1328	return $this->paddable ? $this->_unpad($plaintext) : $plaintext;
1329	}
1330
1331	/**
1332	* OpenSSL CTR Processor
1333	*
1334	* PHP's OpenSSL bindings do not operate in continuous mode so we'll wrap around it. Since the keystream
1335	* for CTR is the same for both encrypting and decrypting this function is re-used by both Crypt_Base::encrypt()
1336	* and Crypt_Base::decrypt(). Also, OpenSSL doesn't implement CTR for all of it's symmetric ciphers so this
1337	* function will emulate CTR with ECB when necessary.
1338	*
1339	* @see self::encrypt()
1340	* @see self::decrypt()
1341	* @param string $plaintext
1342	* @param string $encryptIV
1343	* @param array $buffer
1344	* @return string
1345	* @access private
1346	*/
1347	function _openssl_ctr_process($plaintext, &$encryptIV, &$buffer)
1348	{
1349	$ciphertext = '';
1350
1351	$block_size = $this->block_size;
1352	$key = $this->key;
1353
1354	if ($this->openssl_emulate_ctr) {
1355	$xor = $encryptIV;
1356	if (strlen($buffer['ciphertext'])) {
1357	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
1358	$block = substr($plaintext, $i, $block_size);
1359	if (strlen($block) > strlen($buffer['ciphertext'])) {
1360	$result = openssl_encrypt($xor, $this->cipher_name_openssl_ecb, $key, $this->openssl_options);
1361	$result = !defined('OPENSSL_RAW_DATA') ? substr($result, 0, -$this->block_size) : $result;
1362	$buffer['ciphertext'].= $result;
1363	}
1364	$this->_increment_str($xor);
1365	$otp = $this->_string_shift($buffer['ciphertext'], $block_size);
1366	$ciphertext.= $block ^ $otp;
1367	}
1368	} else {
1369	for ($i = 0; $i < strlen($plaintext); $i+=$block_size) {
1370	$block = substr($plaintext, $i, $block_size);
1371	$otp = openssl_encrypt($xor, $this->cipher_name_openssl_ecb, $key, $this->openssl_options);
1372	$otp = !defined('OPENSSL_RAW_DATA') ? substr($otp, 0, -$this->block_size) : $otp;
1373	$this->_increment_str($xor);
1374	$ciphertext.= $block ^ $otp;
1375	}
1376	}
1377	if ($this->continuousBuffer) {
1378	$encryptIV = $xor;
1379	if ($start = strlen($plaintext) % $block_size) {
1380	$buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext'];
1381	}
1382	}
1383
1384	return $ciphertext;
1385	}
1386
1387	if (strlen($buffer['ciphertext'])) {
1388	$ciphertext = $plaintext ^ $this->_string_shift($buffer['ciphertext'], strlen($plaintext));
1389	$plaintext = substr($plaintext, strlen($ciphertext));
1390
1391	if (!strlen($plaintext)) {
1392	return $ciphertext;
1393	}
1394	}
1395
1396	$overflow = strlen($plaintext) % $block_size;
1397	if ($overflow) {
1398	$plaintext2 = $this->_string_pop($plaintext, $overflow); // ie. trim $plaintext to a multiple of $block_size and put rest of $plaintext in $plaintext2
1399	$encrypted = openssl_encrypt($plaintext . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV);
1400	$temp = $this->_string_pop($encrypted, $block_size);
1401	$ciphertext.= $encrypted . ($plaintext2 ^ $temp);
1402	if ($this->continuousBuffer) {
1403	$buffer['ciphertext'] = substr($temp, $overflow);
1404	$encryptIV = $temp;
1405	}
1406	} elseif (!strlen($buffer['ciphertext'])) {
1407	$ciphertext.= openssl_encrypt($plaintext . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV);
1408	$temp = $this->_string_pop($ciphertext, $block_size);
1409	if ($this->continuousBuffer) {
1410	$encryptIV = $temp;
1411	}
1412	}
1413	if ($this->continuousBuffer) {
1414	if (!defined('OPENSSL_RAW_DATA')) {
1415	$encryptIV.= openssl_encrypt('', $this->cipher_name_openssl_ecb, $key, $this->openssl_options);
1416	}
1417	$encryptIV = openssl_decrypt($encryptIV, $this->cipher_name_openssl_ecb, $key, $this->openssl_options);
1418	if ($overflow) {
1419	$this->_increment_str($encryptIV);
1420	}
1421	}
1422
1423	return $ciphertext;
1424	}
1425
1426	/**
1427	* OpenSSL OFB Processor
1428	*
1429	* PHP's OpenSSL bindings do not operate in continuous mode so we'll wrap around it. Since the keystream
1430	* for OFB is the same for both encrypting and decrypting this function is re-used by both Crypt_Base::encrypt()
1431	* and Crypt_Base::decrypt().
1432	*
1433	* @see self::encrypt()
1434	* @see self::decrypt()
1435	* @param string $plaintext
1436	* @param string $encryptIV
1437	* @param array $buffer
1438	* @return string
1439	* @access private
1440	*/
1441	function _openssl_ofb_process($plaintext, &$encryptIV, &$buffer)
1442	{
1443	if (strlen($buffer['xor'])) {
1444	$ciphertext = $plaintext ^ $buffer['xor'];
1445	$buffer['xor'] = substr($buffer['xor'], strlen($ciphertext));
1446	$plaintext = substr($plaintext, strlen($ciphertext));
1447	} else {
1448	$ciphertext = '';
1449	}
1450
1451	$block_size = $this->block_size;
1452
1453	$len = strlen($plaintext);
1454	$key = $this->key;
1455	$overflow = $len % $block_size;
1456
1457	if (strlen($plaintext)) {
1458	if ($overflow) {
1459	$ciphertext.= openssl_encrypt(substr($plaintext, 0, -$overflow) . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV);
1460	$xor = $this->_string_pop($ciphertext, $block_size);
1461	if ($this->continuousBuffer) {
1462	$encryptIV = $xor;
1463	}
1464	$ciphertext.= $this->_string_shift($xor, $overflow) ^ substr($plaintext, -$overflow);
1465	if ($this->continuousBuffer) {
1466	$buffer['xor'] = $xor;
1467	}
1468	} else {
1469	$ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $key, $this->openssl_options, $encryptIV);
1470	if ($this->continuousBuffer) {
1471	$encryptIV = substr($ciphertext, -$block_size) ^ substr($plaintext, -$block_size);
1472	}
1473	}
1474	}
1475
1476	return $ciphertext;
1477	}
1478
1479	/**
1480	* phpseclib <-> OpenSSL Mode Mapper
1481	*
1482	* May need to be overwritten by classes extending this one in some cases
1483	*
1484	* @return int
1485	* @access private
1486	*/
1487	function _openssl_translate_mode()
1488	{
1489	switch ($this->mode) {
1490	case CRYPT_MODE_ECB:
1491	return 'ecb';
1492	case CRYPT_MODE_CBC:
1493	return 'cbc';
1494	case CRYPT_MODE_CTR:
1495	return 'ctr';
1496	case CRYPT_MODE_CFB:
1497	return 'cfb';
1498	case CRYPT_MODE_OFB:
1499	return 'ofb';
1500	}
1501	}
1502
1503	/**
1504	* Pad "packets".
1505	*
1506	* Block ciphers working by encrypting between their specified [$this->]block_size at a time
1507	* If you ever need to encrypt or decrypt something that isn't of the proper length, it becomes necessary to
1508	* pad the input so that it is of the proper length.
1509	*
1510	* Padding is enabled by default. Sometimes, however, it is undesirable to pad strings. Such is the case in SSH,
1511	* where "packets" are padded with random bytes before being encrypted. Unpad these packets and you risk stripping
1512	* away characters that shouldn't be stripped away. (SSH knows how many bytes are added because the length is
1513	* transmitted separately)
1514	*
1515	* @see self::disablePadding()
1516	* @access public
1517	*/
1518	function enablePadding()
1519	{
1520	$this->padding = true;
1521	}
1522
1523	/**
1524	* Do not pad packets.
1525	*
1526	* @see self::enablePadding()
1527	* @access public
1528	*/
1529	function disablePadding()
1530	{
1531	$this->padding = false;
1532	}
1533
1534	/**
1535	* Treat consecutive "packets" as if they are a continuous buffer.
1536	*
1537	* Say you have a 32-byte plaintext $plaintext. Using the default behavior, the two following code snippets
1538	* will yield different outputs:
1539	*
1540	* <code>
1541	* echo $rijndael->encrypt(substr($plaintext, 0, 16));
1542	* echo $rijndael->encrypt(substr($plaintext, 16, 16));
1543	* </code>
1544	* <code>
1545	* echo $rijndael->encrypt($plaintext);
1546	* </code>
1547	*
1548	* The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates
1549	* another, as demonstrated with the following:
1550	*
1551	* <code>
1552	* $rijndael->encrypt(substr($plaintext, 0, 16));
1553	* echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16)));
1554	* </code>
1555	* <code>
1556	* echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16)));
1557	* </code>
1558	*
1559	* With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different
1560	* outputs. The reason is due to the fact that the initialization vector's change after every encryption /
1561	* decryption round when the continuous buffer is enabled. When it's disabled, they remain constant.
1562	*
1563	* Put another way, when the continuous buffer is enabled, the state of the Crypt_*() object changes after each
1564	* encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that
1565	* continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them),
1566	* however, they are also less intuitive and more likely to cause you problems.
1567	*
1568	* @see self::disableContinuousBuffer()
1569	* @access public
1570	* @internal Could, but not must, extend by the child Crypt_* class
1571	*/
1572	function enableContinuousBuffer()
1573	{
1574	if ($this->mode == CRYPT_MODE_ECB) {
1575	return;
1576	}
1577
1578	$this->continuousBuffer = true;
1579
1580	$this->_setEngine();
1581	}
1582
1583	/**
1584	* Treat consecutive packets as if they are a discontinuous buffer.
1585	*
1586	* The default behavior.
1587	*
1588	* @see self::enableContinuousBuffer()
1589	* @access public
1590	* @internal Could, but not must, extend by the child Crypt_* class
1591	*/
1592	function disableContinuousBuffer()
1593	{
1594	if ($this->mode == CRYPT_MODE_ECB) {
1595	return;
1596	}
1597	if (!$this->continuousBuffer) {
1598	return;
1599	}
1600
1601	$this->continuousBuffer = false;
1602	$this->changed = true;
1603
1604	$this->_setEngine();
1605	}
1606
1607	/**
1608	* Test for engine validity
1609	*
1610	* @see self::Crypt_Base()
1611	* @param int $engine
1612	* @access public
1613	* @return bool
1614	*/
1615	function isValidEngine($engine)
1616	{
1617	switch ($engine) {
1618	case CRYPT_ENGINE_OPENSSL:
1619	if ($this->mode == CRYPT_MODE_STREAM && $this->continuousBuffer) {
1620	return false;
1621	}
1622	$this->openssl_emulate_ctr = false;
1623	$result = $this->cipher_name_openssl &&
1624	extension_loaded('openssl') &&
1625	// PHP 5.3.0 - 5.3.2 did not let you set IV's
1626	version_compare(PHP_VERSION, '5.3.3', '>=');
1627	if (!$result) {
1628	return false;
1629	}
1630
1631	// prior to PHP 5.4.0 OPENSSL_RAW_DATA and OPENSSL_ZERO_PADDING were not defined. instead of expecting an integer
1632	// $options openssl_encrypt expected a boolean $raw_data.
1633	if (!defined('OPENSSL_RAW_DATA')) {
1634	$this->openssl_options = true;
1635	} else {
1636	$this->openssl_options = OPENSSL_RAW_DATA \| OPENSSL_ZERO_PADDING;
1637	}
1638
1639	$methods = openssl_get_cipher_methods();
1640	if (in_array($this->cipher_name_openssl, $methods)) {
1641	return true;
1642	}
1643	// not all of openssl's symmetric cipher's support ctr. for those
1644	// that don't we'll emulate it
1645	switch ($this->mode) {
1646	case CRYPT_MODE_CTR:
1647	if (in_array($this->cipher_name_openssl_ecb, $methods)) {
1648	$this->openssl_emulate_ctr = true;
1649	return true;
1650	}
1651	}
1652	return false;
1653	case CRYPT_ENGINE_MCRYPT:
1654	return $this->cipher_name_mcrypt &&
1655	extension_loaded('mcrypt') &&
1656	in_array($this->cipher_name_mcrypt, @mcrypt_list_algorithms());
1657	case CRYPT_ENGINE_INTERNAL:
1658	return true;
1659	}
1660
1661	return false;
1662	}
1663
1664	/**
1665	* Sets the preferred crypt engine
1666	*
1667	* Currently, $engine could be:
1668	*
1669	* - CRYPT_ENGINE_OPENSSL [very fast]
1670	*
1671	* - CRYPT_ENGINE_MCRYPT [fast]
1672	*
1673	* - CRYPT_ENGINE_INTERNAL [slow]
1674	*
1675	* If the preferred crypt engine is not available the fastest available one will be used
1676	*
1677	* @see self::Crypt_Base()
1678	* @param int $engine
1679	* @access public
1680	*/
1681	function setPreferredEngine($engine)
1682	{
1683	switch ($engine) {
1684	//case CRYPT_ENGINE_OPENSSL:
1685	case CRYPT_ENGINE_MCRYPT:
1686	case CRYPT_ENGINE_INTERNAL:
1687	$this->preferredEngine = $engine;
1688	break;
1689	default:
1690	$this->preferredEngine = CRYPT_ENGINE_OPENSSL;
1691	}
1692
1693	$this->_setEngine();
1694	}
1695
1696	/**
1697	* Returns the engine currently being utilized
1698	*
1699	* @see self::_setEngine()
1700	* @access public
1701	*/
1702	function getEngine()
1703	{
1704	return $this->engine;
1705	}
1706
1707	/**
1708	* Sets the engine as appropriate
1709	*
1710	* @see self::Crypt_Base()
1711	* @access private
1712	*/
1713	function _setEngine()
1714	{
1715	$this->engine = null;
1716
1717	$candidateEngines = array(
1718	$this->preferredEngine,
1719	CRYPT_ENGINE_OPENSSL,
1720	CRYPT_ENGINE_MCRYPT
1721	);
1722	foreach ($candidateEngines as $engine) {
1723	if ($this->isValidEngine($engine)) {
1724	$this->engine = $engine;
1725	break;
1726	}
1727	}
1728	if (!$this->engine) {
1729	$this->engine = CRYPT_ENGINE_INTERNAL;
1730	}
1731
1732	if ($this->engine != CRYPT_ENGINE_MCRYPT && $this->enmcrypt) {
1733	// Closing the current mcrypt resource(s). _mcryptSetup() will, if needed,
1734	// (re)open them with the module named in $this->cipher_name_mcrypt
1735	@mcrypt_module_close($this->enmcrypt);
1736	@mcrypt_module_close($this->demcrypt);
1737	$this->enmcrypt = null;
1738	$this->demcrypt = null;
1739
1740	if ($this->ecb) {
1741	@mcrypt_module_close($this->ecb);
1742	$this->ecb = null;
1743	}
1744	}
1745
1746	$this->changed = true;
1747	}
1748
1749	/**
1750	* Encrypts a block
1751	*
1752	* @access private
1753	* @param string $in
1754	* @return string
1755	* @internal Must be extended by the child Crypt_* class
1756	*/
1757	function _encryptBlock($in)
1758	{
1759	user_error((version_compare(PHP_VERSION, '5.0.0', '>=') ? __METHOD__ : __FUNCTION__) . '() must extend by class ' . get_class($this), E_USER_ERROR);
1760	}
1761
1762	/**
1763	* Decrypts a block
1764	*
1765	* @access private
1766	* @param string $in
1767	* @return string
1768	* @internal Must be extended by the child Crypt_* class
1769	*/
1770	function _decryptBlock($in)
1771	{
1772	user_error((version_compare(PHP_VERSION, '5.0.0', '>=') ? __METHOD__ : __FUNCTION__) . '() must extend by class ' . get_class($this), E_USER_ERROR);
1773	}
1774
1775	/**
1776	* Setup the key (expansion)
1777	*
1778	* Only used if $engine == CRYPT_ENGINE_INTERNAL
1779	*
1780	* @see self::_setup()
1781	* @access private
1782	* @internal Must be extended by the child Crypt_* class
1783	*/
1784	function _setupKey()
1785	{
1786	user_error((version_compare(PHP_VERSION, '5.0.0', '>=') ? __METHOD__ : __FUNCTION__) . '() must extend by class ' . get_class($this), E_USER_ERROR);
1787	}
1788
1789	/**
1790	* Setup the CRYPT_ENGINE_INTERNAL $engine
1791	*
1792	* (re)init, if necessary, the internal cipher $engine and flush all $buffers
1793	* Used (only) if $engine == CRYPT_ENGINE_INTERNAL
1794	*
1795	* _setup() will be called each time if $changed === true
1796	* typically this happens when using one or more of following public methods:
1797	*
1798	* - setKey()
1799	*
1800	* - setIV()
1801	*
1802	* - disableContinuousBuffer()
1803	*
1804	* - First run of encrypt() / decrypt() with no init-settings
1805	*
1806	* @see self::setKey()
1807	* @see self::setIV()
1808	* @see self::disableContinuousBuffer()
1809	* @access private
1810	* @internal _setup() is always called before en/decryption.
1811	* @internal Could, but not must, extend by the child Crypt_* class
1812	*/
1813	function _setup()
1814	{
1815	$this->_clearBuffers();
1816	$this->_setupKey();
1817
1818	if ($this->use_inline_crypt) {
1819	$this->_setupInlineCrypt();
1820	}
1821	}
1822
1823	/**
1824	* Setup the CRYPT_ENGINE_MCRYPT $engine
1825	*
1826	* (re)init, if necessary, the (ext)mcrypt resources and flush all $buffers
1827	* Used (only) if $engine = CRYPT_ENGINE_MCRYPT
1828	*
1829	* _setupMcrypt() will be called each time if $changed === true
1830	* typically this happens when using one or more of following public methods:
1831	*
1832	* - setKey()
1833	*
1834	* - setIV()
1835	*
1836	* - disableContinuousBuffer()
1837	*
1838	* - First run of encrypt() / decrypt()
1839	*
1840	* @see self::setKey()
1841	* @see self::setIV()
1842	* @see self::disableContinuousBuffer()
1843	* @access private
1844	* @internal Could, but not must, extend by the child Crypt_* class
1845	*/
1846	function _setupMcrypt()
1847	{
1848	$this->_clearBuffers();
1849	$this->enchanged = $this->dechanged = true;
1850
1851	if (!isset($this->enmcrypt)) {
1852	static $mcrypt_modes = array(
1853	CRYPT_MODE_CTR => 'ctr',
1854	CRYPT_MODE_ECB => MCRYPT_MODE_ECB,
1855	CRYPT_MODE_CBC => MCRYPT_MODE_CBC,
1856	CRYPT_MODE_CFB => 'ncfb',
1857	CRYPT_MODE_OFB => MCRYPT_MODE_NOFB,
1858	CRYPT_MODE_STREAM => MCRYPT_MODE_STREAM,
1859	);
1860
1861	$this->demcrypt = @mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], '');
1862	$this->enmcrypt = @mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], '');
1863
1864	// we need the $ecb mcrypt resource (only) in MODE_CFB with enableContinuousBuffer()
1865	// to workaround mcrypt's broken ncfb implementation in buffered mode
1866	// see: {@link http://phpseclib.sourceforge.net/cfb-demo.phps}
1867	if ($this->mode == CRYPT_MODE_CFB) {
1868	$this->ecb = @mcrypt_module_open($this->cipher_name_mcrypt, '', MCRYPT_MODE_ECB, '');
1869	}
1870	} // else should mcrypt_generic_deinit be called?
1871
1872	if ($this->mode == CRYPT_MODE_CFB) {
1873	@mcrypt_generic_init($this->ecb, $this->key, str_repeat("\0", $this->block_size));
1874	}
1875	}
1876
1877	/**
1878	* Pads a string
1879	*
1880	* Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize.
1881	* $this->block_size - (strlen($text) % $this->block_size) bytes are added, each of which is equal to
1882	* chr($this->block_size - (strlen($text) % $this->block_size)
1883	*
1884	* If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless
1885	* and padding will, hence forth, be enabled.
1886	*
1887	* @see self::_unpad()
1888	* @param string $text
1889	* @access private
1890	* @return string
1891	*/
1892	function _pad($text)
1893	{
1894	$length = strlen($text);
1895
1896	if (!$this->padding) {
1897	if ($length % $this->block_size == 0) {
1898	return $text;
1899	} else {
1900	user_error("The plaintext's length ($length) is not a multiple of the block size ({$this->block_size})");
1901	$this->padding = true;
1902	}
1903	}
1904
1905	$pad = $this->block_size - ($length % $this->block_size);
1906
1907	return str_pad($text, $length + $pad, chr($pad));
1908	}
1909
1910	/**
1911	* Unpads a string.
1912	*
1913	* If padding is enabled and the reported padding length is invalid the encryption key will be assumed to be wrong
1914	* and false will be returned.
1915	*
1916	* @see self::_pad()
1917	* @param string $text
1918	* @access private
1919	* @return string
1920	*/
1921	function _unpad($text)
1922	{
1923	if (!$this->padding) {
1924	return $text;
1925	}
1926
1927	$length = ord($text[strlen($text) - 1]);
1928
1929	if (!$length \|\| $length > $this->block_size) {
1930	return false;
1931	}
1932
1933	return substr($text, 0, -$length);
1934	}
1935
1936	/**
1937	* Clears internal buffers
1938	*
1939	* Clearing/resetting the internal buffers is done everytime
1940	* after disableContinuousBuffer() or on cipher $engine (re)init
1941	* ie after setKey() or setIV()
1942	*
1943	* @access public
1944	* @internal Could, but not must, extend by the child Crypt_* class
1945	*/
1946	function _clearBuffers()
1947	{
1948	$this->enbuffer = $this->debuffer = array('ciphertext' => '', 'xor' => '', 'pos' => 0, 'enmcrypt_init' => true);
1949
1950	// mcrypt's handling of invalid's $iv:
1951	// $this->encryptIV = $this->decryptIV = strlen($this->iv) == $this->block_size ? $this->iv : str_repeat("\0", $this->block_size);
1952	$this->encryptIV = $this->decryptIV = str_pad(substr($this->iv, 0, $this->block_size), $this->block_size, "\0");
1953
1954	if (!$this->skip_key_adjustment) {
1955	$this->key = str_pad(substr($this->key, 0, $this->key_length), $this->key_length, "\0");
1956	}
1957	}
1958
1959	/**
1960	* String Shift
1961	*
1962	* Inspired by array_shift
1963	*
1964	* @param string $string
1965	* @param int $index
1966	* @access private
1967	* @return string
1968	*/
1969	function _string_shift(&$string, $index = 1)
1970	{
1971	$substr = substr($string, 0, $index);
1972	$string = substr($string, $index);
1973	return $substr;
1974	}
1975
1976	/**
1977	* String Pop
1978	*
1979	* Inspired by array_pop
1980	*
1981	* @param string $string
1982	* @param int $index
1983	* @access private
1984	* @return string
1985	*/
1986	function _string_pop(&$string, $index = 1)
1987	{
1988	$substr = substr($string, -$index);
1989	$string = substr($string, 0, -$index);
1990	return $substr;
1991	}
1992
1993	/**
1994	* Increment the current string
1995	*
1996	* @see self::decrypt()
1997	* @see self::encrypt()
1998	* @param string $var
1999	* @access private
2000	*/
2001	function _increment_str(&$var)
2002	{
2003	for ($i = 4; $i <= strlen($var); $i+= 4) {
2004	$temp = substr($var, -$i, 4);
2005	switch ($temp) {
2006	case "\xFF\xFF\xFF\xFF":
2007	$var = substr_replace($var, "\x00\x00\x00\x00", -$i, 4);
2008	break;
2009	case "\x7F\xFF\xFF\xFF":
2010	$var = substr_replace($var, "\x80\x00\x00\x00", -$i, 4);
2011	return;
2012	default:
2013	$temp = unpack('Nnum', $temp);
2014	$var = substr_replace($var, pack('N', $temp['num'] + 1), -$i, 4);
2015	return;
2016	}
2017	}
2018
2019	$remainder = strlen($var) % 4;
2020
2021	if ($remainder == 0) {
2022	return;
2023	}
2024
2025	$temp = unpack('Nnum', str_pad(substr($var, 0, $remainder), 4, "\0", STR_PAD_LEFT));
2026	$temp = substr(pack('N', $temp['num'] + 1), -$remainder);
2027	$var = substr_replace($var, $temp, 0, $remainder);
2028	}
2029
2030	/**
2031	* Setup the performance-optimized function for de/encrypt()
2032	*
2033	* Stores the created (or existing) callback function-name
2034	* in $this->inline_crypt
2035	*
2036	* Internally for phpseclib developers:
2037	*
2038	* _setupInlineCrypt() would be called only if:
2039	*
2040	* - $engine == CRYPT_ENGINE_INTERNAL and
2041	*
2042	* - $use_inline_crypt === true
2043	*
2044	* - each time on _setup(), after(!) _setupKey()
2045	*
2046	*
2047	* This ensures that _setupInlineCrypt() has always a
2048	* full ready2go initializated internal cipher $engine state
2049	* where, for example, the keys allready expanded,
2050	* keys/block_size calculated and such.
2051	*
2052	* It is, each time if called, the responsibility of _setupInlineCrypt():
2053	*
2054	* - to set $this->inline_crypt to a valid and fully working callback function
2055	* as a (faster) replacement for encrypt() / decrypt()
2056	*
2057	* - NOT to create unlimited callback functions (for memory reasons!)
2058	* no matter how often _setupInlineCrypt() would be called. At some
2059	* point of amount they must be generic re-useable.
2060	*
2061	* - the code of _setupInlineCrypt() it self,
2062	* and the generated callback code,
2063	* must be, in following order:
2064	* - 100% safe
2065	* - 100% compatible to encrypt()/decrypt()
2066	* - using only php5+ features/lang-constructs/php-extensions if
2067	* compatibility (down to php4) or fallback is provided
2068	* - readable/maintainable/understandable/commented and... not-cryptic-styled-code :-)
2069	* - >= 10% faster than encrypt()/decrypt() [which is, by the way,
2070	* the reason for the existence of _setupInlineCrypt() :-)]
2071	* - memory-nice
2072	* - short (as good as possible)
2073	*
2074	* Note: - _setupInlineCrypt() is using _createInlineCryptFunction() to create the full callback function code.
2075	* - In case of using inline crypting, _setupInlineCrypt() must extend by the child Crypt_* class.
2076	* - The following variable names are reserved:
2077	* - $_* (all variable names prefixed with an underscore)
2078	* - $self (object reference to it self. Do not use $this, but $self instead)
2079	* - $in (the content of $in has to en/decrypt by the generated code)
2080	* - The callback function should not use the 'return' statement, but en/decrypt'ing the content of $in only
2081	*
2082	*
2083	* @see self::_setup()
2084	* @see self::_createInlineCryptFunction()
2085	* @see self::encrypt()
2086	* @see self::decrypt()
2087	* @access private
2088	* @internal If a Crypt_* class providing inline crypting it must extend _setupInlineCrypt()
2089	*/
2090	function _setupInlineCrypt()
2091	{
2092	// If, for any reason, an extending Crypt_Base() Crypt_* class
2093	// not using inline crypting then it must be ensured that: $this->use_inline_crypt = false
2094	// ie in the class var declaration of $use_inline_crypt in general for the Crypt_* class,
2095	// in the constructor at object instance-time
2096	// or, if it's runtime-specific, at runtime
2097
2098	$this->use_inline_crypt = false;
2099	}
2100
2101	/**
2102	* Creates the performance-optimized function for en/decrypt()
2103	*
2104	* Internally for phpseclib developers:
2105	*
2106	* _createInlineCryptFunction():
2107	*
2108	* - merge the $cipher_code [setup'ed by _setupInlineCrypt()]
2109	* with the current [$this->]mode of operation code
2110	*
2111	* - create the $inline function, which called by encrypt() / decrypt()
2112	* as its replacement to speed up the en/decryption operations.
2113	*
2114	* - return the name of the created $inline callback function
2115	*
2116	* - used to speed up en/decryption
2117	*
2118	*
2119	*
2120	* The main reason why can speed up things [up to 50%] this way are:
2121	*
2122	* - using variables more effective then regular.
2123	* (ie no use of expensive arrays but integers $k_0, $k_1 ...
2124	* or even, for example, the pure $key[] values hardcoded)
2125	*
2126	* - avoiding 1000's of function calls of ie _encryptBlock()
2127	* but inlining the crypt operations.
2128	* in the mode of operation for() loop.
2129	*
2130	* - full loop unroll the (sometimes key-dependent) rounds
2131	* avoiding this way ++$i counters and runtime-if's etc...
2132	*
2133	* The basic code architectur of the generated $inline en/decrypt()
2134	* lambda function, in pseudo php, is:
2135	*
2136	* <code>
2137	* +----------------------------------------------------------------------------------------------+
2138	* \| callback $inline = create_function: \|
2139	* \| lambda_function_0001_crypt_ECB($action, $text) \|
2140	* \| { \|
2141	* \| INSERT PHP CODE OF: \|
2142	* \| $cipher_code['init_crypt']; // general init code. \|
2143	* \| // ie: $sbox'es declarations used for \|
2144	* \| // encrypt and decrypt'ing. \|
2145	* \| \|
2146	* \| switch ($action) { \|
2147	* \| case 'encrypt': \|
2148	* \| INSERT PHP CODE OF: \|
2149	* \| $cipher_code['init_encrypt']; // encrypt sepcific init code. \|
2150	* \| ie: specified $key or $box \|
2151	* \| declarations for encrypt'ing. \|
2152	* \| \|
2153	* \| foreach ($ciphertext) { \|
2154	* \| $in = $block_size of $ciphertext; \|
2155	* \| \|
2156	* \| INSERT PHP CODE OF: \|
2157	* \| $cipher_code['encrypt_block']; // encrypt's (string) $in, which is always: \|
2158	* \| // strlen($in) == $this->block_size \|
2159	* \| // here comes the cipher algorithm in action \|
2160	* \| // for encryption. \|
2161	* \| // $cipher_code['encrypt_block'] has to \|
2162	* \| // encrypt the content of the $in variable \|
2163	* \| \|
2164	* \| $plaintext .= $in; \|
2165	* \| } \|
2166	* \| return $plaintext; \|
2167	* \| \|
2168	* \| case 'decrypt': \|
2169	* \| INSERT PHP CODE OF: \|
2170	* \| $cipher_code['init_decrypt']; // decrypt sepcific init code \|
2171	* \| ie: specified $key or $box \|
2172	* \| declarations for decrypt'ing. \|
2173	* \| foreach ($plaintext) { \|
2174	* \| $in = $block_size of $plaintext; \|
2175	* \| \|
2176	* \| INSERT PHP CODE OF: \|
2177	* \| $cipher_code['decrypt_block']; // decrypt's (string) $in, which is always \|
2178	* \| // strlen($in) == $this->block_size \|
2179	* \| // here comes the cipher algorithm in action \|
2180	* \| // for decryption. \|
2181	* \| // $cipher_code['decrypt_block'] has to \|
2182	* \| // decrypt the content of the $in variable \|
2183	* \| $ciphertext .= $in; \|
2184	* \| } \|
2185	* \| return $ciphertext; \|
2186	* \| } \|
2187	* \| } \|
2188	* +----------------------------------------------------------------------------------------------+
2189	* </code>
2190	*
2191	* See also the Crypt_*::_setupInlineCrypt()'s for
2192	* productive inline $cipher_code's how they works.
2193	*
2194	* Structure of:
2195	* <code>
2196	* $cipher_code = array(
2197	* 'init_crypt' => (string) '', // optional
2198	* 'init_encrypt' => (string) '', // optional
2199	* 'init_decrypt' => (string) '', // optional
2200	* 'encrypt_block' => (string) '', // required
2201	* 'decrypt_block' => (string) '' // required
2202	* );
2203	* </code>
2204	*
2205	* @see self::_setupInlineCrypt()
2206	* @see self::encrypt()
2207	* @see self::decrypt()
2208	* @param array $cipher_code
2209	* @access private
2210	* @return string (the name of the created callback function)
2211	*/
2212	function _createInlineCryptFunction($cipher_code)
2213	{
2214	$block_size = $this->block_size;
2215
2216	// optional
2217	$init_crypt = isset($cipher_code['init_crypt']) ? $cipher_code['init_crypt'] : '';
2218	$init_encrypt = isset($cipher_code['init_encrypt']) ? $cipher_code['init_encrypt'] : '';
2219	$init_decrypt = isset($cipher_code['init_decrypt']) ? $cipher_code['init_decrypt'] : '';
2220	// required
2221	$encrypt_block = $cipher_code['encrypt_block'];
2222	$decrypt_block = $cipher_code['decrypt_block'];
2223
2224	// Generating mode of operation inline code,
2225	// merged with the $cipher_code algorithm
2226	// for encrypt- and decryption.
2227	switch ($this->mode) {
2228	case CRYPT_MODE_ECB:
2229	$encrypt = $init_encrypt . '
2230	$_ciphertext = "";
2231	$_plaintext_len = strlen($_text);
2232
2233	for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
2234	$in = substr($_text, $_i, '.$block_size.');
2235	'.$encrypt_block.'
2236	$_ciphertext.= $in;
2237	}
2238
2239	return $_ciphertext;
2240	';
2241
2242	$decrypt = $init_decrypt . '
2243	$_plaintext = "";
2244	$_text = str_pad($_text, strlen($_text) + ('.$block_size.' - strlen($_text) % '.$block_size.') % '.$block_size.', chr(0));
2245	$_ciphertext_len = strlen($_text);
2246
2247	for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
2248	$in = substr($_text, $_i, '.$block_size.');
2249	'.$decrypt_block.'
2250	$_plaintext.= $in;
2251	}
2252
2253	return $self->_unpad($_plaintext);
2254	';
2255	break;
2256	case CRYPT_MODE_CTR:
2257	$encrypt = $init_encrypt . '
2258	$_ciphertext = "";
2259	$_plaintext_len = strlen($_text);
2260	$_xor = $self->encryptIV;
2261	$_buffer = &$self->enbuffer;
2262	if (strlen($_buffer["ciphertext"])) {
2263	for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
2264	$_block = substr($_text, $_i, '.$block_size.');
2265	if (strlen($_block) > strlen($_buffer["ciphertext"])) {
2266	$in = $_xor;
2267	'.$encrypt_block.'
2268	$self->_increment_str($_xor);
2269	$_buffer["ciphertext"].= $in;
2270	}
2271	$_key = $self->_string_shift($_buffer["ciphertext"], '.$block_size.');
2272	$_ciphertext.= $_block ^ $_key;
2273	}
2274	} else {
2275	for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
2276	$_block = substr($_text, $_i, '.$block_size.');
2277	$in = $_xor;
2278	'.$encrypt_block.'
2279	$self->_increment_str($_xor);
2280	$_key = $in;
2281	$_ciphertext.= $_block ^ $_key;
2282	}
2283	}
2284	if ($self->continuousBuffer) {
2285	$self->encryptIV = $_xor;
2286	if ($_start = $_plaintext_len % '.$block_size.') {
2287	$_buffer["ciphertext"] = substr($_key, $_start) . $_buffer["ciphertext"];
2288	}
2289	}
2290
2291	return $_ciphertext;
2292	';
2293
2294	$decrypt = $init_encrypt . '
2295	$_plaintext = "";
2296	$_ciphertext_len = strlen($_text);
2297	$_xor = $self->decryptIV;
2298	$_buffer = &$self->debuffer;
2299
2300	if (strlen($_buffer["ciphertext"])) {
2301	for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
2302	$_block = substr($_text, $_i, '.$block_size.');
2303	if (strlen($_block) > strlen($_buffer["ciphertext"])) {
2304	$in = $_xor;
2305	'.$encrypt_block.'
2306	$self->_increment_str($_xor);
2307	$_buffer["ciphertext"].= $in;
2308	}
2309	$_key = $self->_string_shift($_buffer["ciphertext"], '.$block_size.');
2310	$_plaintext.= $_block ^ $_key;
2311	}
2312	} else {
2313	for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
2314	$_block = substr($_text, $_i, '.$block_size.');
2315	$in = $_xor;
2316	'.$encrypt_block.'
2317	$self->_increment_str($_xor);
2318	$_key = $in;
2319	$_plaintext.= $_block ^ $_key;
2320	}
2321	}
2322	if ($self->continuousBuffer) {
2323	$self->decryptIV = $_xor;
2324	if ($_start = $_ciphertext_len % '.$block_size.') {
2325	$_buffer["ciphertext"] = substr($_key, $_start) . $_buffer["ciphertext"];
2326	}
2327	}
2328
2329	return $_plaintext;
2330	';
2331	break;
2332	case CRYPT_MODE_CFB:
2333	$encrypt = $init_encrypt . '
2334	$_ciphertext = "";
2335	$_buffer = &$self->enbuffer;
2336
2337	if ($self->continuousBuffer) {
2338	$_iv = &$self->encryptIV;
2339	$_pos = &$_buffer["pos"];
2340	} else {
2341	$_iv = $self->encryptIV;
2342	$_pos = 0;
2343	}
2344	$_len = strlen($_text);
2345	$_i = 0;
2346	if ($_pos) {
2347	$_orig_pos = $_pos;
2348	$_max = '.$block_size.' - $_pos;
2349	if ($_len >= $_max) {
2350	$_i = $_max;
2351	$_len-= $_max;
2352	$_pos = 0;
2353	} else {
2354	$_i = $_len;
2355	$_pos+= $_len;
2356	$_len = 0;
2357	}
2358	$_ciphertext = substr($_iv, $_orig_pos) ^ $_text;
2359	$_iv = substr_replace($_iv, $_ciphertext, $_orig_pos, $_i);
2360	}
2361	while ($_len >= '.$block_size.') {
2362	$in = $_iv;
2363	'.$encrypt_block.';
2364	$_iv = $in ^ substr($_text, $_i, '.$block_size.');
2365	$_ciphertext.= $_iv;
2366	$_len-= '.$block_size.';
2367	$_i+= '.$block_size.';
2368	}
2369	if ($_len) {
2370	$in = $_iv;
2371	'.$encrypt_block.'
2372	$_iv = $in;
2373	$_block = $_iv ^ substr($_text, $_i);
2374	$_iv = substr_replace($_iv, $_block, 0, $_len);
2375	$_ciphertext.= $_block;
2376	$_pos = $_len;
2377	}
2378	return $_ciphertext;
2379	';
2380
2381	$decrypt = $init_encrypt . '
2382	$_plaintext = "";
2383	$_buffer = &$self->debuffer;
2384
2385	if ($self->continuousBuffer) {
2386	$_iv = &$self->decryptIV;
2387	$_pos = &$_buffer["pos"];
2388	} else {
2389	$_iv = $self->decryptIV;
2390	$_pos = 0;
2391	}
2392	$_len = strlen($_text);
2393	$_i = 0;
2394	if ($_pos) {
2395	$_orig_pos = $_pos;
2396	$_max = '.$block_size.' - $_pos;
2397	if ($_len >= $_max) {
2398	$_i = $_max;
2399	$_len-= $_max;
2400	$_pos = 0;
2401	} else {
2402	$_i = $_len;
2403	$_pos+= $_len;
2404	$_len = 0;
2405	}
2406	$_plaintext = substr($_iv, $_orig_pos) ^ $_text;
2407	$_iv = substr_replace($_iv, substr($_text, 0, $_i), $_orig_pos, $_i);
2408	}
2409	while ($_len >= '.$block_size.') {
2410	$in = $_iv;
2411	'.$encrypt_block.'
2412	$_iv = $in;
2413	$cb = substr($_text, $_i, '.$block_size.');
2414	$_plaintext.= $_iv ^ $cb;
2415	$_iv = $cb;
2416	$_len-= '.$block_size.';
2417	$_i+= '.$block_size.';
2418	}
2419	if ($_len) {
2420	$in = $_iv;
2421	'.$encrypt_block.'
2422	$_iv = $in;
2423	$_plaintext.= $_iv ^ substr($_text, $_i);
2424	$_iv = substr_replace($_iv, substr($_text, $_i), 0, $_len);
2425	$_pos = $_len;
2426	}
2427
2428	return $_plaintext;
2429	';
2430	break;
2431	case CRYPT_MODE_OFB:
2432	$encrypt = $init_encrypt . '
2433	$_ciphertext = "";
2434	$_plaintext_len = strlen($_text);
2435	$_xor = $self->encryptIV;
2436	$_buffer = &$self->enbuffer;
2437
2438	if (strlen($_buffer["xor"])) {
2439	for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
2440	$_block = substr($_text, $_i, '.$block_size.');
2441	if (strlen($_block) > strlen($_buffer["xor"])) {
2442	$in = $_xor;
2443	'.$encrypt_block.'
2444	$_xor = $in;
2445	$_buffer["xor"].= $_xor;
2446	}
2447	$_key = $self->_string_shift($_buffer["xor"], '.$block_size.');
2448	$_ciphertext.= $_block ^ $_key;
2449	}
2450	} else {
2451	for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
2452	$in = $_xor;
2453	'.$encrypt_block.'
2454	$_xor = $in;
2455	$_ciphertext.= substr($_text, $_i, '.$block_size.') ^ $_xor;
2456	}
2457	$_key = $_xor;
2458	}
2459	if ($self->continuousBuffer) {
2460	$self->encryptIV = $_xor;
2461	if ($_start = $_plaintext_len % '.$block_size.') {
2462	$_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"];
2463	}
2464	}
2465	return $_ciphertext;
2466	';
2467
2468	$decrypt = $init_encrypt . '
2469	$_plaintext = "";
2470	$_ciphertext_len = strlen($_text);
2471	$_xor = $self->decryptIV;
2472	$_buffer = &$self->debuffer;
2473
2474	if (strlen($_buffer["xor"])) {
2475	for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
2476	$_block = substr($_text, $_i, '.$block_size.');
2477	if (strlen($_block) > strlen($_buffer["xor"])) {
2478	$in = $_xor;
2479	'.$encrypt_block.'
2480	$_xor = $in;
2481	$_buffer["xor"].= $_xor;
2482	}
2483	$_key = $self->_string_shift($_buffer["xor"], '.$block_size.');
2484	$_plaintext.= $_block ^ $_key;
2485	}
2486	} else {
2487	for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
2488	$in = $_xor;
2489	'.$encrypt_block.'
2490	$_xor = $in;
2491	$_plaintext.= substr($_text, $_i, '.$block_size.') ^ $_xor;
2492	}
2493	$_key = $_xor;
2494	}
2495	if ($self->continuousBuffer) {
2496	$self->decryptIV = $_xor;
2497	if ($_start = $_ciphertext_len % '.$block_size.') {
2498	$_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"];
2499	}
2500	}
2501	return $_plaintext;
2502	';
2503	break;
2504	case CRYPT_MODE_STREAM:
2505	$encrypt = $init_encrypt . '
2506	$_ciphertext = "";
2507	'.$encrypt_block.'
2508	return $_ciphertext;
2509	';
2510	$decrypt = $init_decrypt . '
2511	$_plaintext = "";
2512	'.$decrypt_block.'
2513	return $_plaintext;
2514	';
2515	break;
2516	// case CRYPT_MODE_CBC:
2517	default:
2518	$encrypt = $init_encrypt . '
2519	$_ciphertext = "";
2520	$_plaintext_len = strlen($_text);
2521
2522	$in = $self->encryptIV;
2523
2524	for ($_i = 0; $_i < $_plaintext_len; $_i+= '.$block_size.') {
2525	$in = substr($_text, $_i, '.$block_size.') ^ $in;
2526	'.$encrypt_block.'
2527	$_ciphertext.= $in;
2528	}
2529
2530	if ($self->continuousBuffer) {
2531	$self->encryptIV = $in;
2532	}
2533
2534	return $_ciphertext;
2535	';
2536
2537	$decrypt = $init_decrypt . '
2538	$_plaintext = "";
2539	$_text = str_pad($_text, strlen($_text) + ('.$block_size.' - strlen($_text) % '.$block_size.') % '.$block_size.', chr(0));
2540	$_ciphertext_len = strlen($_text);
2541
2542	$_iv = $self->decryptIV;
2543
2544	for ($_i = 0; $_i < $_ciphertext_len; $_i+= '.$block_size.') {
2545	$in = $_block = substr($_text, $_i, '.$block_size.');
2546	'.$decrypt_block.'
2547	$_plaintext.= $in ^ $_iv;
2548	$_iv = $_block;
2549	}
2550
2551	if ($self->continuousBuffer) {
2552	$self->decryptIV = $_iv;
2553	}
2554
2555	return $self->_unpad($_plaintext);
2556	';
2557	break;
2558	}
2559
2560	// Create the $inline function and return its name as string. Ready to run!
2561	if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
2562	eval('$func = function ($_action, &$self, $_text) { ' . $init_crypt . 'if ($_action == "encrypt") { ' . $encrypt . ' } else { ' . $decrypt . ' } };');
2563	return $func;
2564	}
2565
2566	return create_function('$_action, &$self, $_text', $init_crypt . 'if ($_action == "encrypt") { ' . $encrypt . ' } else { ' . $decrypt . ' }');
2567	}
2568
2569	/**
2570	* Holds the lambda_functions table (classwide)
2571	*
2572	* Each name of the lambda function, created from
2573	* _setupInlineCrypt() && _createInlineCryptFunction()
2574	* is stored, classwide (!), here for reusing.
2575	*
2576	* The string-based index of $function is a classwide
2577	* unique value representing, at least, the $mode of
2578	* operation (or more... depends of the optimizing level)
2579	* for which $mode the lambda function was created.
2580	*
2581	* @access private
2582	* @return array &$functions
2583	*/
2584	function &_getLambdaFunctions()
2585	{
2586	static $functions = array();
2587	return $functions;
2588	}
2589
2590	/**
2591	* Generates a digest from $bytes
2592	*
2593	* @see self::_setupInlineCrypt()
2594	* @access private
2595	* @param $bytes
2596	* @return string
2597	*/
2598	function _hashInlineCryptFunction($bytes)
2599	{
2600	if (!defined('CRYPT_BASE_WHIRLPOOL_AVAILABLE')) {
2601	define('CRYPT_BASE_WHIRLPOOL_AVAILABLE', (bool)(extension_loaded('hash') && in_array('whirlpool', hash_algos())));
2602	}
2603
2604	$result = '';
2605	$hash = $bytes;
2606
2607	switch (true) {
2608	case CRYPT_BASE_WHIRLPOOL_AVAILABLE:
2609	foreach (str_split($bytes, 64) as $t) {
2610	$hash = hash('whirlpool', $hash, true);
2611	$result .= $t ^ $hash;
2612	}
2613	return $result . hash('whirlpool', $hash, true);
2614	default:
2615	$len = strlen($bytes);
2616	for ($i = 0; $i < $len; $i+=20) {
2617	$t = substr($bytes, $i, 20);
2618	$hash = pack('H*', sha1($hash));
2619	$result .= $t ^ $hash;
2620	}
2621	return $result . pack('H*', sha1($hash));
2622	}
2623	}
2624
2625	/**
2626	* Convert float to int
2627	*
2628	* On 32-bit Linux installs running PHP < 5.3 converting floats to ints doesn't always work
2629	*
2630	* @access private
2631	* @param string $x
2632	* @return int
2633	*/
2634	function safe_intval($x)
2635	{
2636	switch (true) {
2637	case is_int($x):
2638	// PHP 5.3, per http://php.net/releases/5_3_0.php, introduced "more consistent float rounding"
2639	case version_compare(PHP_VERSION, '5.3.0') >= 0 && (php_uname('m') & "\xDF\xDF\xDF") != 'ARM':
2640	// PHP_OS & "\xDF\xDF\xDF" == strtoupper(substr(PHP_OS, 0, 3)), but a lot faster
2641	case (PHP_OS & "\xDF\xDF\xDF") === 'WIN':
2642	return $x;
2643	}
2644	return (fmod($x, 0x80000000) & 0x7FFFFFFF) \|
2645	((fmod(floor($x / 0x80000000), 2) & 1) << 31);
2646	}
2647
2648	/**
2649	* eval()'able string for in-line float to int
2650	*
2651	* @access private
2652	* @return string
2653	*/
2654	function safe_intval_inline()
2655	{
2656	// on 32-bit linux systems with PHP < 5.3 float to integer conversion is bad
2657	switch (true) {
2658	case defined('PHP_INT_SIZE') && PHP_INT_SIZE == 8:
2659	case version_compare(PHP_VERSION, '5.3.0') >= 0 && (php_uname('m') & "\xDF\xDF\xDF") != 'ARM':
2660	case (PHP_OS & "\xDF\xDF\xDF") === 'WIN':
2661	return '%s';
2662	break;
2663	default:
2664	$safeint = '(is_int($temp = %s) ? $temp : (fmod($temp, 0x80000000) & 0x7FFFFFFF) \| ';
2665	return $safeint . '((fmod(floor($temp / 0x80000000), 2) & 1) << 31))';
2666	}
2667	}
2668	}
2669