← All changes | phpseclib-crypt/Hash.php +202 -105 1.2 → 1.9.2 View file →

		@@ -1,6 +1,5 @@
1	1	<?php
2		-/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
3	2
4	3	/**
5	4	* Pure-PHP implementations of keyed-hash message authentication codes (HMACs) and various cryptographic hashing functions.
6	5	*
		@@ -5,22 +4,22 @@
5	4	* Pure-PHP implementations of keyed-hash message authentication codes (HMACs) and various cryptographic hashing functions.
6	5	*
7	6	* Uses hash() or mhash() if available and an internal implementation, otherwise. Currently supports the following:
8	7	*
9		- * md2, md5, md5-96, sha1, sha1-96, sha256, sha384, and sha512
	8	+ * md2, md5, md5-96, sha1, sha1-96, sha256, sha256-96, sha384, and sha512, sha512-96
10	9	*
11		- * If {@link Crypt_Hash::setKey() setKey()} is called, {@link Crypt_Hash::hash() hash()} will return the HMAC as opposed to
	10	+ * If {@link self::setKey() setKey()} is called, {@link self::hash() hash()} will return the HMAC as opposed to
12	11	* the hash. If no valid algorithm is provided, sha1 will be used.
13	12	*
14	13	* PHP versions 4 and 5
15	14	*
16		- * {@internal The variable names are the same as those in
	15	+ * {@internal The variable names are the same as those in
17	16	* {@link http://tools.ietf.org/html/rfc2104#section-2 RFC2104}.}}
18	17	*
19	18	* Here's a short example of how to use this library:
20	19	* <code>
21	20	* <?php
22		- * include('Crypt/Hash.php');
	21	+ * include 'Crypt/Hash.php';
23	22	*
24	23	* $hash = new Crypt_Hash('sha1');
25	24	*
26	25	* $hash->setKey('abcdefg');
		@@ -34,12 +33,12 @@
34	33	* in the Software without restriction, including without limitation the rights
35	34	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
36	35	* copies of the Software, and to permit persons to whom the Software is
37	36	* furnished to do so, subject to the following conditions:
38		- *
	37	+ *
39	38	* The above copyright notice and this permission notice shall be included in
40	39	* all copies or substantial portions of the Software.
41		- *
	40	+ *
42	41	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
43	42	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
44	43	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
45	44	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
		@@ -46,20 +45,19 @@
46	45	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
47	46	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
48	47	* THE SOFTWARE.
49	48	*
50		- * @category Crypt
51		- * @package Crypt_Hash
52		- * @author Jim Wigginton <terrafrost@php.net>
53		- * @copyright MMVII Jim Wigginton
54		- * @license http://www.opensource.org/licenses/mit-license.html MIT License
55		- * @version $Id: Hash.php,v 1.6 2009/11/23 23:37:07 terrafrost Exp $
56		- * @link http://phpseclib.sourceforge.net
	49	+ * @category Crypt
	50	+ * @package Crypt_Hash
	51	+ * @author Jim Wigginton <terrafrost@php.net>
	52	+ * @copyright 2007 Jim Wigginton
	53	+ * @license http://www.opensource.org/licenses/mit-license.html MIT License
	54	+ * @link http://phpseclib.sourceforge.net
57	55	*/
58	56
59	57	/**#@+
60	58	* @access private
61		- * @see Crypt_Hash::Crypt_Hash()
	59	+ * @see self::Crypt_Hash()
62	60	*/
63	61	/**
64	62	* Toggles the internal implementation
65	63	*/
		@@ -76,19 +74,28 @@
76	74
77	75	/**
78	76	* Pure-PHP implementations of keyed-hash message authentication codes (HMACs) and various cryptographic hashing functions.
79	77	*
	78	+ * @package Crypt_Hash
80	79	* @author Jim Wigginton <terrafrost@php.net>
81		- * @version 0.1.0
82	80	* @access public
83		- * @package Crypt_Hash
84	81	*/
85		-class Crypt_Hash {
	82	+class Crypt_Hash
	83	+{
86	84	/**
	85	+ * Hash Parameter
	86	+ *
	87	+ * @see self::setHash()
	88	+ * @var int
	89	+ * @access private
	90	+ */
	91	+ var $hashParam;
	92	+
	93	+ /**
87	94	* Byte-length of compression blocks / key (Internal HMAC)
88	95	*
89		- * @see Crypt_Hash::setAlgorithm()
90		- * @var Integer
	96	+ * @see self::setAlgorithm()
	97	+ * @var int
91	98	* @access private
92	99	*/
93	100	var $b;
94	101
		@@ -94,10 +101,10 @@
94	101
95	102	/**
96	103	* Byte-length of hash output (Internal HMAC)
97	104	*
98		- * @see Crypt_Hash::setHash()
99		- * @var Integer
	105	+ * @see self::setHash()
	106	+ * @var int
100	107	* @access private
101	108	*/
102	109	var $l = false;
103	110
		@@ -103,10 +110,10 @@
103	110
104	111	/**
105	112	* Hash Algorithm
106	113	*
107		- * @see Crypt_Hash::setHash()
108		- * @var String
	114	+ * @see self::setHash()
	115	+ * @var string
109	116	* @access private
110	117	*/
111	118	var $hash;
112	119
		@@ -112,19 +119,28 @@
112	119
113	120	/**
114	121	* Key
115	122	*
116		- * @see Crypt_Hash::setKey()
117		- * @var String
	123	+ * @see self::setKey()
	124	+ * @var string
118	125	* @access private
119	126	*/
120	127	var $key = false;
121	128
122	129	/**
	130	+ * Computed Key
	131	+ *
	132	+ * @see self::_computeKey()
	133	+ * @var string
	134	+ * @access private
	135	+ */
	136	+ var $computedKey = false;
	137	+
	138	+ /**
123	139	* Outer XOR (Internal HMAC)
124	140	*
125		- * @see Crypt_Hash::setKey()
126		- * @var String
	141	+ * @see self::setKey()
	142	+ * @var string
127	143	* @access private
128	144	*/
129	145	var $opad;
130	146
		@@ -130,10 +146,10 @@
130	146
131	147	/**
132	148	* Inner XOR (Internal HMAC)
133	149	*
134		- * @see Crypt_Hash::setKey()
135		- * @var String
	150	+ * @see self::setKey()
	151	+ * @var string
136	152	* @access private
137	153	*/
138	154	var $ipad;
139	155
		@@ -139,15 +155,15 @@
139	155
140	156	/**
141	157	* Default Constructor.
142	158	*
143		- * @param optional String $hash
	159	+ * @param string $hash
144	160	* @return Crypt_Hash
145	161	* @access public
146	162	*/
147		- function Crypt_Hash($hash = 'sha1')
	163	+ function __construct($hash = 'sha1')
148	164	{
149		- if ( !defined('CRYPT_HASH_MODE') ) {
	165	+ if (!defined('CRYPT_HASH_MODE')) {
150	166	switch (true) {
151	167	case extension_loaded('hash'):
152	168	define('CRYPT_HASH_MODE', CRYPT_HASH_MODE_HASH);
153	169	break;
		@@ -162,32 +178,97 @@
162	178	$this->setHash($hash);
163	179	}
164	180
165	181	/**
	182	+ * PHP4 compatible Default Constructor.
	183	+ *
	184	+ * @see self::__construct()
	185	+ * @param int $mode
	186	+ * @access public
	187	+ */
	188	+ function Crypt_Hash($hash = 'sha1')
	189	+ {
	190	+ $this->__construct($hash);
	191	+ }
	192	+
	193	+ /**
166	194	* Sets the key for HMACs
167	195	*
168	196	* Keys can be of any length.
169	197	*
170	198	* @access public
171		- * @param String $key
	199	+ * @param string $key
172	200	*/
173	201	function setKey($key = false)
174	202	{
175	203	$this->key = $key;
	204	+ $this->_computeKey();
176	205	}
177	206
178	207	/**
	208	+ * Pre-compute the key used by the HMAC
	209	+ *
	210	+ * Quoting http://tools.ietf.org/html/rfc2104#section-2, "Applications that use keys longer than B bytes
	211	+ * will first hash the key using H and then use the resultant L byte string as the actual key to HMAC."
	212	+ *
	213	+ * As documented in https://www.reddit.com/r/PHP/comments/9nct2l/symfonypolyfill_hash_pbkdf2_correct_fix_for/
	214	+ * when doing an HMAC multiple times it's faster to compute the hash once instead of computing it during
	215	+ * every call
	216	+ *
	217	+ * @access private
	218	+ */
	219	+ function _computeKey()
	220	+ {
	221	+ if ($this->key === false) {
	222	+ $this->computedKey = false;
	223	+ return;
	224	+ }
	225	+
	226	+ if (strlen($this->key) <= $this->b) {
	227	+ $this->computedKey = $this->key;
	228	+ return;
	229	+ }
	230	+
	231	+ switch ($mode) {
	232	+ case CRYPT_HASH_MODE_MHASH:
	233	+ $this->computedKey = mhash($this->hash, $this->key);
	234	+ break;
	235	+ case CRYPT_HASH_MODE_HASH:
	236	+ $this->computedKey = hash($this->hash, $this->key, true);
	237	+ break;
	238	+ case CRYPT_HASH_MODE_INTERNAL:
	239	+ $this->computedKey = call_user_func($this->hash, $this->key);
	240	+ }
	241	+ }
	242	+
	243	+ /**
	244	+ * Gets the hash function.
	245	+ *
	246	+ * As set by the constructor or by the setHash() method.
	247	+ *
	248	+ * @access public
	249	+ * @return string
	250	+ */
	251	+ function getHash()
	252	+ {
	253	+ return $this->hashParam;
	254	+ }
	255	+
	256	+ /**
179	257	* Sets the hash function.
180	258	*
181	259	* @access public
182		- * @param String $hash
	260	+ * @param string $hash
183	261	*/
184	262	function setHash($hash)
185	263	{
186		- $hash = strtolower($hash);
	264	+ $this->hashParam = $hash = strtolower($hash);
187	265	switch ($hash) {
188	266	case 'md5-96':
189	267	case 'sha1-96':
	268	+ case 'sha256-96':
	269	+ case 'sha512-96':
	270	+ $hash = substr($hash, 0, -3);
190	271	$this->l = 12; // 96 / 8 = 12
191	272	break;
192	273	case 'md2':
193	274	case 'md5':
		@@ -206,9 +287,28 @@
206	287	$this->l = 64;
207	288	}
208	289
209	290	switch ($hash) {
	291	+ case 'md2-96':
210	292	case 'md2':
	293	+ $this->b = 16;
	294	+ case 'md5-96':
	295	+ case 'sha1-96':
	296	+ case 'sha224-96':
	297	+ case 'sha256-96':
	298	+ case 'md2':
	299	+ case 'md5':
	300	+ case 'sha1':
	301	+ case 'sha224':
	302	+ case 'sha256':
	303	+ $this->b = 64;
	304	+ break;
	305	+ default:
	306	+ $this->b = 128;
	307	+ }
	308	+
	309	+ switch ($hash) {
	310	+ case 'md2':
211	311	$mode = CRYPT_HASH_MODE == CRYPT_HASH_MODE_HASH && in_array('md2', hash_algos()) ?
212	312	CRYPT_HASH_MODE_HASH : CRYPT_HASH_MODE_INTERNAL;
213	313	break;
214	314	case 'sha384':
		@@ -218,13 +318,12 @@
218	318	default:
219	319	$mode = CRYPT_HASH_MODE;
220	320	}
221	321
222		- switch ( $mode ) {
	322	+ switch ($mode) {
223	323	case CRYPT_HASH_MODE_MHASH:
224	324	switch ($hash) {
225	325	case 'md5':
226		- case 'md5-96':
227	326	$this->hash = MHASH_MD5;
228	327	break;
229	328	case 'sha256':
230	329	$this->hash = MHASH_SHA256;
		@@ -229,17 +328,16 @@
229	328	case 'sha256':
230	329	$this->hash = MHASH_SHA256;
231	330	break;
232	331	case 'sha1':
233		- case 'sha1-96':
234	332	default:
235	333	$this->hash = MHASH_SHA1;
236	334	}
	335	+ $this->_computeKey();
237	336	return;
238	337	case CRYPT_HASH_MODE_HASH:
239	338	switch ($hash) {
240	339	case 'md5':
241		- case 'md5-96':
242	340	$this->hash = 'md5';
243	341	return;
244	342	case 'md2':
245	343	case 'sha256':
		@@ -247,43 +345,38 @@
247	345	case 'sha512':
248	346	$this->hash = $hash;
249	347	return;
250	348	case 'sha1':
251		- case 'sha1-96':
252	349	default:
253	350	$this->hash = 'sha1';
254	351	}
	352	+ $this->_computeKey();
255	353	return;
256	354	}
257	355
258	356	switch ($hash) {
259	357	case 'md2':
260		- $this->b = 16;
261		- $this->hash = array($this, '_md2');
262		- break;
	358	+ $this->hash = array($this, '_md2');
	359	+ break;
263	360	case 'md5':
264		- case 'md5-96':
265		- $this->b = 64;
266		- $this->hash = array($this, '_md5');
267		- break;
	361	+ $this->hash = array($this, '_md5');
	362	+ break;
268	363	case 'sha256':
269		- $this->b = 64;
270		- $this->hash = array($this, '_sha256');
271		- break;
	364	+ $this->hash = array($this, '_sha256');
	365	+ break;
272	366	case 'sha384':
273	367	case 'sha512':
274		- $this->b = 128;
275		- $this->hash = array($this, '_sha512');
276		- break;
	368	+ $this->hash = array($this, '_sha512');
	369	+ break;
277	370	case 'sha1':
278		- case 'sha1-96':
279	371	default:
280		- $this->b = 64;
281		- $this->hash = array($this, '_sha1');
	372	+ $this->hash = array($this, '_sha1');
282	373	}
283	374
284	375	$this->ipad = str_repeat(chr(0x36), $this->b);
285	376	$this->opad = str_repeat(chr(0x5C), $this->b);
	377	+
	378	+ $this->_computeKey();
286	379	}
287	380
288	381	/**
289	382	* Compute the HMAC.
		@@ -288,10 +381,10 @@
288	381	/**
289	382	* Compute the HMAC.
290	383	*
291	384	* @access public
292		- * @param String $text
293		- * @return String
	385	+ * @param string $text
	386	+ * @return string
294	387	*/
295	388	function hash($text)
296	389	{
297	390	$mode = is_array($this->hash) ? CRYPT_HASH_MODE_INTERNAL : CRYPT_HASH_MODE;
		@@ -296,32 +389,26 @@
296	389	{
297	390	$mode = is_array($this->hash) ? CRYPT_HASH_MODE_INTERNAL : CRYPT_HASH_MODE;
298	391
299	392	if (!empty($this->key) || is_string($this->key)) {
300		- switch ( $mode ) {
	393	+ switch ($mode) {
301	394	case CRYPT_HASH_MODE_MHASH:
302		- $output = mhash($this->hash, $text, $this->key);
	395	+ $output = mhash($this->hash, $text, $this->computedKey);
303	396	break;
304	397	case CRYPT_HASH_MODE_HASH:
305		- $output = hash_hmac($this->hash, $text, $this->key, true);
	398	+ $output = hash_hmac($this->hash, $text, $this->computedKey, true);
306	399	break;
307	400	case CRYPT_HASH_MODE_INTERNAL:
308		- /* "Applications that use keys longer than B bytes will first hash the key using H and then use the
309		- resultant L byte string as the actual key to HMAC."
310		-
311		- -- http://tools.ietf.org/html/rfc2104#section-2 */
312		- $key = strlen($this->key) > $this->b ? call_user_func($this->hash, $this->key) : $this->key;
313		-
314		- $key = str_pad($key, $this->b, chr(0)); // step 1
315		- $temp = $this->ipad ^ $key; // step 2
316		- $temp .= $text; // step 3
317		- $temp = call_user_func($this->hash, $temp); // step 4
318		- $output = $this->opad ^ $key; // step 5
319		- $output.= $temp; // step 6
320		- $output = call_user_func($this->hash, $output); // step 7
	401	+ $key = str_pad($this->computedKey, $this->b, chr(0)); // step 1
	402	+ $temp = $this->ipad ^ $key; // step 2
	403	+ $temp .= $text; // step 3
	404	+ $temp = call_user_func($this->hash, $temp); // step 4
	405	+ $output = $this->opad ^ $key; // step 5
	406	+ $output.= $temp; // step 6
	407	+ $output = call_user_func($this->hash, $output); // step 7
321	408	}
322	409	} else {
323		- switch ( $mode ) {
	410	+ switch ($mode) {
324	411	case CRYPT_HASH_MODE_MHASH:
325	412	$output = mhash($this->hash, $text);
326	413	break;
327	414	case CRYPT_HASH_MODE_HASH:
		@@ -338,9 +425,9 @@
338	425	/**
339	426	* Returns the hash length (in bytes)
340	427	*
341	428	* @access public
342		- * @return Integer
	429	+ * @return int
343	430	*/
344	431	function getLength()
345	432	{
346	433	return $this->l;
		@@ -349,9 +436,9 @@
349	436	/**
350	437	* Wrapper for MD5
351	438	*
352	439	* @access private
353		- * @param String $text
	440	+ * @param string $m
354	441	*/
355	442	function _md5($m)
356	443	{
357	444	return pack('H*', md5($m));
		@@ -360,9 +447,9 @@
360	447	/**
361	448	* Wrapper for SHA1
362	449	*
363	450	* @access private
364		- * @param String $text
	451	+ * @param string $m
365	452	*/
366	453	function _sha1($m)
367	454	{
368	455	return pack('H*', sha1($m));
		@@ -373,9 +460,9 @@
373	460	*
374	461	* See {@link http://tools.ietf.org/html/rfc1319 RFC1319}.
375	462	*
376	463	* @access private
377		- * @param String $text
	464	+ * @param string $m
378	465	*/
379	466	function _md2($m)
380	467	{
381	468	static $s = array(
		@@ -449,9 +536,9 @@
449	536	*
450	537	* See {@link http://en.wikipedia.org/wiki/SHA_hash_functions#SHA-256_.28a_SHA-2_variant.29_pseudocode SHA-256 (a SHA-2 variant) pseudocode - Wikipedia}.
451	538	*
452	539	* @access private
453		- * @param String $text
	540	+ * @param string $m
454	541	*/
455	542	function _sha256($m)
456	543	{
457	544	if (extension_loaded('suhosin')) {
		@@ -493,8 +580,9 @@
493	580	}
494	581
495	582	// Extend the sixteen 32-bit words into sixty-four 32-bit words
496	583	for ($i = 16; $i < 64; $i++) {
	584	+ // @codingStandardsIgnoreStart
497	585	$s0 = $this->_rightRotate($w[$i - 15], 7) ^
498	586	$this->_rightRotate($w[$i - 15], 18) ^
499	587	$this->_rightShift( $w[$i - 15], 3);
500	588	$s1 = $this->_rightRotate($w[$i - 2], 17) ^
		@@ -499,10 +587,10 @@
499	587	$this->_rightShift( $w[$i - 15], 3);
500	588	$s1 = $this->_rightRotate($w[$i - 2], 17) ^
501	589	$this->_rightRotate($w[$i - 2], 19) ^
502	590	$this->_rightShift( $w[$i - 2], 10);
	591	+ // @codingStandardsIgnoreEnd
503	592	$w[$i] = $this->_add($w[$i - 16], $s0, $w[$i - 7], $s1);
504		-
505	593	}
506	594
507	595	// Initialize hash value for this chunk
508	596	list($a, $b, $c, $d, $e, $f, $g, $h) = $hash;
		@@ -554,14 +642,14 @@
554	642	/**
555	643	* Pure-PHP implementation of SHA384 and SHA512
556	644	*
557	645	* @access private
558		- * @param String $text
	646	+ * @param string $m
559	647	*/
560	648	function _sha512($m)
561	649	{
562	650	if (!class_exists('Math_BigInteger')) {
563		- require_once('Math/BigInteger.php');
	651	+ include_once 'BigInteger.php';
564	652	}
565	653
566	654	static $init384, $init512, $k;
567	655
		@@ -567,13 +655,13 @@
567	655
568	656	if (!isset($k)) {
569	657	// Initialize variables
570	658	$init384 = array( // initial values for SHA384
571		- 'cbbb9d5dc1059ed8', '629a292a367cd507', '9159015a3070dd17', '152fecd8f70e5939',
	659	+ 'cbbb9d5dc1059ed8', '629a292a367cd507', '9159015a3070dd17', '152fecd8f70e5939',
572	660	'67332667ffc00b31', '8eb44a8768581511', 'db0c2e0d64f98fa7', '47b5481dbefa4fa4'
573	661	);
574	662	$init512 = array( // initial values for SHA512
575		- '6a09e667f3bcc908', 'bb67ae8584caa73b', '3c6ef372fe94f82b', 'a54ff53a5f1d36f1',
	663	+ '6a09e667f3bcc908', 'bb67ae8584caa73b', '3c6ef372fe94f82b', 'a54ff53a5f1d36f1',
576	664	'510e527fade682d1', '9b05688c2b3e6c1f', '1f83d9abfb41bd6b', '5be0cd19137e2179'
577	665	);
578	666
579	667	for ($i = 0; $i < 8; $i++) {
		@@ -737,12 +825,12 @@
737	825	/**
738	826	* Right Rotate
739	827	*
740	828	* @access private
741		- * @param Integer $int
742		- * @param Integer $amt
743		- * @see _sha256()
744		- * @return Integer
	829	+ * @param int $int
	830	+ * @param int $amt
	831	+ * @see self::_sha256()
	832	+ * @return int
745	833	*/
746	834	function _rightRotate($int, $amt)
747	835	{
748	836	$invamt = 32 - $amt;
		@@ -753,12 +841,12 @@
753	841	/**
754	842	* Right Shift
755	843	*
756	844	* @access private
757		- * @param Integer $int
758		- * @param Integer $amt
759		- * @see _sha256()
760		- * @return Integer
	845	+ * @param int $int
	846	+ * @param int $amt
	847	+ * @see self::_sha256()
	848	+ * @return int
761	849	*/
762	850	function _rightShift($int, $amt)
763	851	{
764	852	$mask = (1 << (32 - $amt)) - 1;
		@@ -768,11 +856,11 @@
768	856	/**
769	857	* Not
770	858	*
771	859	* @access private
772		- * @param Integer $int
773		- * @see _sha256()
774		- * @return Integer
	860	+ * @param int $int
	861	+ * @see self::_sha256()
	862	+ * @return int
775	863	*/
776	864	function _not($int)
777	865	{
778	866	return ~$int & 0xFFFFFFFF;
		@@ -783,12 +871,11 @@
783	871	*
784	872	* _sha256() adds multiple unsigned 32-bit integers. Since PHP doesn't support unsigned integers and since the
785	873	* possibility of overflow exists, care has to be taken. Math_BigInteger() could be used but this should be faster.
786	874	*
787		- * @param String $string
788		- * @param optional Integer $index
789		- * @return String
790		- * @see _sha256()
	875	+ * @param int $...
	876	+ * @return int
	877	+ * @see self::_sha256()
791	878	* @access private
792	879	*/
793	880	function _add()
794	881	{
		@@ -802,9 +889,19 @@
802	889	foreach ($arguments as $argument) {
803	890	$result+= $argument < 0 ? ($argument & 0x7FFFFFFF) + 0x80000000 : $argument;
804	891	}
805	892
806		- return fmod($result, $mod);
	893	+ switch (true) {
	894	+ case is_int($result):
	895	+ // PHP 5.3, per http://php.net/releases/5_3_0.php, introduced "more consistent float rounding"
	896	+ case version_compare(PHP_VERSION, '5.3.0') >= 0 && (php_uname('m') & "\xDF\xDF\xDF") != 'ARM':
	897	+ // PHP_OS & "\xDF\xDF\xDF" == strtoupper(substr(PHP_OS, 0, 3)), but a lot faster
	898	+ case (PHP_OS & "\xDF\xDF\xDF") === 'WIN':
	899	+ return fmod($result, $mod);
	900	+ }
	901	+
	902	+ return (fmod($result, 0x80000000) & 0x7FFFFFFF) |
	903	+ ((fmod(floor($result / 0x80000000), 2) & 1) << 31);
807	904	}
808	905
809	906	/**
810	907	* String Shift
		@@ -810,11 +907,11 @@
810	907	* String Shift
811	908	*
812	909	* Inspired by array_shift
813	910	*
814		- * @param String $string
815		- * @param optional Integer $index
816		- * @return String
	911	+ * @param string $string
	912	+ * @param int $index
	913	+ * @return string
817	914	* @access private
818	915	*/
819	916	function _string_shift(&$string, $index = 1)
820	917	{