Completed
Push — development ( fd35b5...2c05ec )
by Nils
07:23
created

Core::xorBin()   A

Complexity

Conditions 3
Paths 3

Size

Total Lines 23
Code Lines 12

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
cc 3
eloc 12
nc 3
nop 2
dl 0
loc 23
rs 9.0856
c 0
b 0
f 0
1
<?php
2
/*
3
 * Author: Ryan Gilfether
4
 * URL: http://www.gilfether.com/phpCrypt
5
 * Date: March 26, 2013
6
 * Copyright (C) 2013 Ryan Gilfether
7
 *
8
 * This file is part of phpCrypt
9
 *
10
 * phpCrypt is free software; you can redistribute it and/or modify
11
 * it under the terms of the GNU General Public License as published by
12
 * the Free Software Foundation; either version 3 of the License, or
13
 * (at your option) any later version
14
 *
15
 * This program is distributed in the hope that it will be useful,
16
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18
 * GNU General Public License for more details.
19
 *
20
 * You should have received a copy of the GNU General Public License
21
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
22
 */
23
24
namespace PHP_Crypt;
25
26
/**
27
 * A base class that should not be used directly. It is intended as a base
28
 * object that should be extended and provides tools that child objects may use.
29
 *
30
 * @author Ryan Gilfether
31
 * @link http://www.gilfether.com/phpcrypt
32
 * @copyright 2013 Ryan Gilfether
33
 */
34
class Core
35
{
36
    /** @type integer HASH_LEN The length of md5() hash string */
37
    const HASH_LEN = 16;
38
39
40
    /**
41
     * Constructor
42
     *
43
     */
44
    protected function __construct()
45
    {
46
47
    }
48
49
50
    /**
51
     * Destructor
52
     *
53
     */
54
    protected function __destruct()
55
    {
56
57
    }
58
59
60
    /**
61
     * Convert hexidecimal to a binary string (ex: "00110110")
62
     *
63
     * @param string $hex A string containing a hexidecimal number
64
     * @return string A string representation of a binary
65
     */
66
    public static function hex2Bin($hex)
67
    {
68
        // if we do not have an even number of hex characters
69
        // append a 0 to the beginning to make it even
70
        if (strlen($hex) % 2) {
71
                    $hex = "0$hex";
72
        }
73
74
        $parts = str_split($hex, 2);
75
        $parts = array_map(function($v) {
76
                $v = base_convert($v, 16, 2);
77
                return str_pad($v, 8, "0", STR_PAD_LEFT);
78
        }, $parts);
79
80
        return implode("", $parts);
81
    }
82
83
84
    /**
85
     * Convert hex to a string
86
     *
87
     * @param string $hex A string representation of Hex (IE: "1a2b3c" not 0x1a2b3c)
88
     * @return string a string
89
     */
90
    public static function hex2Str($hex)
91
    {
92
        // php version >= 5.4 have a hex2bin function, use it
93
        // if it exists
94
        if (function_exists("hex2bin")) {
95
                    return hex2bin($hex);
96
        }
97
98
        $parts = str_split($hex, 2);
99
        $parts = array_map(function($v) {
100
                return chr(Core::hex2Dec($v));
101
        }, $parts);
102
103
        return implode("", $parts);
104
    }
105
106
107
    /**
108
     * Converts Hex to Decimal
109
     * This function just calls php's hexdec() function,  but I
110
     * encapsulated it in this function to keep things uniform
111
     * and have all possible conversion function available in
112
     * the Cipher class
113
     *
114
     * @param string $hex A hex number to convert to decimal
115
     * @return integer A decimal number
116
     */
117
    public static function hex2Dec($hex)
118
    {
119
        return hexdec($hex);
120
    }
121
122
123
    /**
124
     * Convert binary string (ie 00110110) to hex
125
     *
126
     * @param string $bin A binary string
127
     * @return string A string representation of hexidecimal number
128
     */
129
    public static function bin2Hex($bin)
130
    {
131
        $parts = str_split($bin, 8);
132
133
        $parts = array_map(function($v) {
134
            $v = str_pad($v, 8, "0", STR_PAD_LEFT);
135
            $v = dechex(bindec($v));
136
            return str_pad($v, 2, "0", STR_PAD_LEFT);
137
        }, $parts);
138
139
        return implode("", $parts);
140
    }
141
142
143
    /**
144
     * Converts a binary representation (ie 01101011)  back to a string
145
     *
146
     * @param string $bin a binary representation string
147
     * @return string A string of characters representing the binary
148
     */
149
    public static function bin2Str($bin)
150
    {
151
        $hex = self::bin2Hex($bin);
152
        return self::hex2Str($hex);
153
    }
154
155
156
    /**
157
     * Convert a binary string (ie: 01101011) to a decimal number
158
     *
159
     * @param string A string representation of a binary number
160
     * @param string $bin
161
     * @return integer The number converted from the binary string
162
     */
163
    public static function bin2Dec($bin)
164
    {
165
        return bindec($bin);
166
    }
167
168
169
    /**
170
     * Convert a string to hex
171
     * This function calls the PHP bin2hex(), and is here
172
     * for consistency with the other string functions
173
     *
174
     * @param string $str A string
175
     * @return string A string representation of hexidecimal number
176
     */
177
    public static function str2Hex($str)
178
    {
179
        return bin2hex($str);
180
    }
181
182
183
    /**
184
     * Convert a string of characters to a decimal number
185
     *
186
     * @param string $str The string to convert to decimal
187
     * @return integer The integer converted from the string
188
     */
189
    public static function str2Dec($str)
190
    {
191
        $hex = self::str2Hex($str);
192
        return self::hex2Dec($hex);
193
    }
194
195
196
    /**
197
     * Converts a string to binary representation (ie 01101011)
198
     *
199
     * @param string $str A string
200
     * @return string A binary representation of the the string
201
     */
202
    public static function str2Bin($str)
203
    {
204
        $hex = self::str2Hex($str);
205
        $parts = str_split($hex, 2);
206
207
        $parts = array_map(function($v) {
208
            return Core::hex2Bin($v);
209
        }, $parts);
210
211
        return implode("", $parts);
212
    }
213
214
215
    /**
216
     * Converts Decimal to Hex
217
     * This function just calls php's dechex() function,  but I
218
     * encapsulated it in this function to keep things uniform
219
     * and have all possible conversion function available in
220
     * the Cipher class
221
     *
222
     * The parameter $req_bytes will pad the return hex with NULL (00)
223
     * until the hex represents the number of bytes given to $req_bytes
224
     * This is because dechex() drops null bytes from the Hex, which may
225
     * be needed in some cases
226
     *
227
     * @param integer $dec A decimal number to convert
228
     * @param integer $req_bytes Optional, forces the string to be at least
229
     *	$req_bytes in size, this is needed because on occasion left most null bytes
230
     *	are dropped in dechex(), causing the string to have a shorter byte
231
     *	size than the initial integer.
232
     * @return string A hexidecimal representation of the decimal number
233
     */
234
    public static function dec2Hex($dec, $req_bytes = 0)
235
    {
236
        $hex = dechex($dec);
237
238
        // if we do not have an even number of hex characters
239
        // append a 0 to the beginning. dechex() drops leading 0's
240
        if (strlen($hex) % 2) {
241
                    $hex = "0$hex";
242
        }
243
244
        // if the number of bytes in the hex is less than
245
        // what we need it to be, add null bytes to the
246
        // front of the hex to padd it to the required size
247
        if (($req_bytes * 2) > strlen($hex)) {
248
                    $hex = str_pad($hex, ($req_bytes * 2), "0", STR_PAD_LEFT);
249
        }
250
251
        return $hex;
252
    }
253
254
255
    /**
256
     * Converts Decimal to Binary
257
     * This function just calls php's decbin() function,  but I
258
     * encapsulated it in this function to keep things uniform
259
     * and have all possible conversion function available in
260
     * the Cipher class
261
     *
262
     * @param integer $dec A decimal number to convert
263
     * @param integer $req_bytes Optional, forces the string to be at least
264
     *	$req_bytes in size, this is needed because on occasion left most null bytes
265
     *	are dropped in dechex(), causing the string to have a shorter byte
266
     *	size than the initial integer.
267
     * @return string A binary representation of the decimal number
268
     */
269
    public static function dec2Bin($dec, $req_bytes = 0)
270
    {
271
        $hex = self::dec2Hex($dec, $req_bytes);
272
        return self::hex2Bin($hex);
273
    }
274
275
276
    /**
277
     * Convert a decimal to a string of bytes
278
     *
279
     * @param integer $dec A decimal number
280
     * @param integer $req_bytes Optional, forces the string to be at least
281
     *	$req_bytes in size, this is needed because on occasion left most null bytes
282
     *	are dropped in dechex(), causing the string to have a shorter byte
283
     *	size than the initial integer.
284
     * @return string A string with the number of bytes equal to $dec
285
     */
286
    public static function dec2Str($dec, $req_bytes = 0)
287
    {
288
        $hex = self::dec2Hex($dec, $req_bytes);
289
        return self::hex2Str($hex);
290
    }
291
292
293
    /**
294
     * XORs two binary strings (representation of binary, ie 01101011),
295
     * assumed to be equal length
296
     *
297
     * @param string $a A string that represents binary
298
     * @param string $b A string that represents binary
299
     * @return string A representation of binary
300
     */
301
    public static function xorBin($a, $b)
302
    {
303
        $len_a = strlen($a);
304
        $len_b = strlen($b);
305
        $width = $len_a;
0 ignored issues
show
Unused Code introduced by
$width is not used, you could remove the assignment.

This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.

$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}

Both the $myVar assignment in line 1 and the $higher assignment in line 2 are dead. The first because $myVar is never used and the second because $higher is always overwritten for every possible time line.

Loading history...
306
307
        // first determine if the two binary strings are the same length,
308
        // and if not get them to the same length
309
        if ($len_a > $len_b)
310
        {
311
            $width = $len_a;
312
            $b = str_pad($b, $width, "0", STR_PAD_LEFT);
313
        } else if ($len_a < $len_b)
314
        {
315
            $width = $len_b;
316
            $a = str_pad($a, $width, "0", STR_PAD_LEFT);
317
        }
318
319
        // fortunately PHP knows how to XOR each byte in a string
320
        // so we don't have to loop to do it
321
        $bin = self::bin2Str($a) ^ self::bin2Str($b);
322
        return self::str2Bin($bin);
323
    }
324
325
326
    /**
327
     * ExclusiveOR hex values. Supports an unlimited number of parameters.
328
     * The values are string representations of hex values
329
     * IE: "0a1b2c3d" not 0x0a1b2c3d
330
     *
331
     * @param string Unlimited number parameters, each a string representation of hex
332
     * @return string A string representation of the result in Hex
333
     */
334
    public static function xorHex()
335
    {
336
        $hex   = func_get_args();
337
        $count = func_num_args();
338
339
        // we need a minimum of 2 values
340
        if ($count < 2) {
341
                    return false;
0 ignored issues
show
Bug Best Practice introduced by
The return type of return false; (false) is incompatible with the return type documented by PHP_Crypt\Core::xorHex of type string.

If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.

Let’s take a look at an example:

class Author {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

abstract class Post {
    public function getAuthor() {
        return 'Johannes';
    }
}

class BlogPost extends Post {
    public function getAuthor() {
        return new Author('Johannes');
    }
}

class ForumPost extends Post { /* ... */ }

function my_function(Post $post) {
    echo strtoupper($post->getAuthor());
}

Our function my_function expects a Post object, and outputs the author of the post. The base class Post returns a simple string and outputting a simple string will work just fine. However, the child class BlogPost which is a sub-type of Post instead decided to return an object, and is therefore violating the SOLID principles. If a BlogPost were passed to my_function, PHP would not complain, but ultimately fail when executing the strtoupper call in its body.

Loading history...
342
        }
343
344
        // first get all hex values to an even number
345
        array_walk($hex, function(&$val, $i) {
0 ignored issues
show
Unused Code introduced by
The parameter $i is not used and could be removed.

This check looks from parameters that have been defined for a function or method, but which are not used in the method body.

Loading history...
346
            if (strlen($val) % 2) {
347
                            $val = "0".$val;
348
            }
349
        });
350
351
        $res = 0;
352
        for ($i = 0; $i < $count; ++$i)
353
        {
354
            // if this is the first loop, set the 'result' to the first
355
            // hex value
356
            if ($i == 0) {
357
                            $res = $hex[0];
358
            } else
359
            {
360
                // to make the code easier to follow
361
                $h1 = $res;
362
                $h2 = $hex[$i];
363
364
                // get lengths
365
                $len1 = strlen($h1);
366
                $len2 = strlen($h2);
367
368
                // now check that both hex values are the same length,
369
                // if not pad them with 0's until they are
370
                if ($len1 > $len2) {
371
                                    $h2 = str_pad($h2, $len1, "0", STR_PAD_LEFT);
372
                } else if ($len1 < $len2) {
373
                                    $h1 = str_pad($h1, $len2, "0", STR_PAD_LEFT);
374
                }
375
376
                // PHP knows how to XOR each byte in a string, so convert the
377
                // hex to a string, XOR, and convert back
378
                $res = self::hex2Str($h1) ^ self::hex2Str($h2);
379
                $res = self::str2Hex($res);
380
            }
381
        }
382
383
        return $res;
384
    }
385
386
387
    /**
388
     * Forces an integer to be signed
389
     *
390
     * @param integer $int An integer
391
     * @return integer An signed integer
392
     */
393
    public static function sInt($int)
394
    {
395
        $arr = unpack("i", pack("i", $int));
396
        return $arr[1];
397
    }
398
399
400
    /**
401
     * Forces an integer to be unsigned
402
     *
403
     * @param integer $int A signed integer
404
     * @return integer An unsigned integer
405
     */
406
    public static function uInt($int)
407
    {
408
        $arr = unpack("I", pack("I", $int));
409
        $ret = $arr[1];
410
411
        // On 32 bit platforms unpack() and pack() do not convert
412
        // from signed to unsigned properly all the time, it will return
413
        // the same negative number given to it, the work around is
414
        // to use sprintf().
415
        // Tested with php 5.3.x on Windows XP & Linux 32bit
416
        if ($ret < 0) {
417
                    $ret = sprintf("%u", $ret) + 0;
418
        }
419
        // convert from string to int
420
421
        return $ret;
422
    }
423
424
425
    /**
426
     * Forces an integer to be a 32 bit signed integer
427
     *
428
     * @param integer $int An integer
429
     * @return integer An signed 32 bit integer
430
     */
431 View Code Duplication
    public static function sInt32($int)
0 ignored issues
show
Duplication introduced by
This method seems to be duplicated in your project.

Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation.

You can also find more detailed suggestions in the “Code” section of your repository.

Loading history...
432
    {
433
        if (PHP_INT_SIZE === 4) {
434
            // 32 bit
435
            return self::sInt($int);
436
        } else // PHP_INT_SIZE === 8 // 64 bit
437
        {
438
            $arr = unpack("l", pack("l", $int));
439
            return $arr[1];
440
        }
441
    }
442
443
444
    /**
445
     * Force an integer to be a 32 bit unsigned integer
446
     *
447
     * @param integer $int An integer
448
     * @return integer An unsigned 32 bit integer
449
     */
450 View Code Duplication
    public static function uInt32($int)
0 ignored issues
show
Duplication introduced by
This method seems to be duplicated in your project.

Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation.

You can also find more detailed suggestions in the “Code” section of your repository.

Loading history...
451
    {
452
        if (PHP_INT_SIZE === 4) {
453
            // 32 bit
454
            return self::uInt($int);
455
        } else // PHP_INT_SIZE === 8  // 64 bit
456
        {
457
            $arr = unpack("L", pack("L", $int));
458
            return $arr[1];
459
        }
460
    }
461
462
463
    /**
464
     * Converts an integer to the value for an signed char
465
     *
466
     * @param integer $int The integer to convert to a signed char
467
     * @return integer A signed integer, representing a signed char
468
     */
469
    public static function sChar($int)
470
    {
471
        $arr = unpack("c", pack("c", $int));
472
        return $arr[1];
473
    }
474
475
476
    /**
477
     * Converts an integer to the value for an unsigned char
478
     *
479
     * @param integer $int The integer to convert to a unsigned char
480
     * @return integer An unsigned integer, representing a unsigned char
481
     */
482
    public static function uChar($int)
483
    {
484
        $arr = unpack("C", pack("C", $int));
485
        return $arr[1];
486
    }
487
488
489
    /**
490
     * Rotates bits Left, appending the bits pushed off the left onto the right
491
     *
492
     * @param integer $shifts The number of shifts left to make
493
     * @return integer The resulting value from the rotation
494
     */
495
    public static function rotBitsLeft32($i, $shifts)
496
    {
497
        if ($shifts <= 0) {
498
                    return $i;
499
        }
500
501
        $shifts &= 0x1f; /* higher rotates would not bring anything */
502
503
        // this is causing problems on 32 bit platform
504
        //return self::uInt32(($i << $shifts) | ($i >> (32 - $shifts)));
0 ignored issues
show
Unused Code Comprehensibility introduced by
65% of this comment could be valid code. Did you maybe forget this after debugging?

Sometimes obsolete code just ends up commented out instead of removed. In this case it is better to remove the code once you have checked you do not need it.

The code might also have been commented out for debugging purposes. In this case it is vital that someone uncomments it again or your project may behave in very unexpected ways in production.

This check looks for comments that seem to be mostly valid code and reports them.

Loading history...
505
506
        // so lets cheat: convert to binary string, rotate left, and
507
        // convert back to decimal
508
        $i = self::dec2Bin(self::uInt32($i), 4);
509
        $i = substr($i, $shifts).substr($i, 0, $shifts);
510
        return self::bin2Dec($i);
511
512
    }
513
514
515
    /**
516
     * Rotates bits right, appending the bits pushed off the right onto the left
517
     *
518
     * @param integer $shifts The number of shifts right to make
519
     * @return integer The resulting value from the rotation
520
     */
521
    public static function rotBitsRight32($i, $shifts)
522
    {
523
        if ($shifts <= 0) {
524
                    return $i;
525
        }
526
527
        $shifts &= 0x1f; /* higher rotates would not bring anything */
528
529
        // this might cause problems on 32 bit platforms since rotBitsLeft32 was
530
        // having a problem with some bit shifts on 32 bits
531
        // return self::uInt32(($i >> $shifts) | ($i << (32 - $shifts)));
0 ignored issues
show
Unused Code Comprehensibility introduced by
63% of this comment could be valid code. Did you maybe forget this after debugging?

Sometimes obsolete code just ends up commented out instead of removed. In this case it is better to remove the code once you have checked you do not need it.

The code might also have been commented out for debugging purposes. In this case it is vital that someone uncomments it again or your project may behave in very unexpected ways in production.

This check looks for comments that seem to be mostly valid code and reports them.

Loading history...
532
533
        // so lets cheat: convert to binary string, rotate right,
534
        // and convert back to decimal
535
        $i = self::dec2Bin($i, 4);
536
        $i = substr($i, (-1 * $shifts)).substr($i, 0, (-1 * $shifts));
537
        return self::bin2Dec($i);
538
    }
539
540
541
    /**
542
     * Create a string of random bytes, used for creating an IV
543
     * and a random key. See PHP_Crypt::createKey() and PHP_Crypt::createIV()
544
     * There are 4 ways to auto generate random bytes by setting $src parameter
545
     * PHP_Crypt::RAND - Default, uses mt_rand()
546
     * PHP_Crypt::RAND_DEV_RAND - Unix only, uses /dev/random
547
     * PHP_Crypt::RAND_DEV_URAND - Unix only, uses /dev/urandom
548
     * PHP_Crypt::RAND_WIN_COM - Windows only, uses Microsoft's CAPICOM SDK
549
     *
550
     * @param string $src Optional, Use the $src to create the random bytes
551
     * 	by default PHP_Crypt::RAND is used when $src is not specified
552
     * @param integer $byte_len The length of the byte string to create
553
     * @return string A random string of bytes
554
     */
555
    public static function randBytes($src = PHP_Crypt::RAND, $byte_len = PHP_Crypt::RAND_DEFAULT_SZ)
556
    {
557
        $bytes = "";
558
        $err_msg = "";
559
560
        if ($src == PHP_Crypt::RAND_DEV_RAND)
561
        {
562 View Code Duplication
            if (file_exists(PHP_Crypt::RAND_DEV_RAND)) {
563
                            $bytes = file_get_contents(PHP_CRYPT::RAND_DEV_RAND, false, null, 0, $byte_len);
564
            } else {
565
                            $err_msg = PHP_Crypt::RAND_DEV_RAND." not found";
566
            }
567
        } else if ($src == PHP_Crypt::RAND_DEV_URAND)
568
        {
569 View Code Duplication
            if (file_exists(PHP_Crypt::RAND_DEV_URAND)) {
570
                            $bytes = file_get_contents(PHP_CRYPT::RAND_DEV_URAND, false, null, 0, $byte_len);
571
            } else {
572
                            $err_msg = PHP_Crypt::RAND_DEV_URAND." not found";
573
            }
574
        } else if ($src == PHP_Crypt::RAND_WIN_COM)
575
        {
576
            if (extension_loaded('com_dotnet'))
577
            {
578
                // http://msdn.microsoft.com/en-us/library/aa388176(VS.85).aspx
579
                try
580
                {
581
                    // request a random number in $byte_len bytes, returned
582
                    // as base_64 encoded string. This is because PHP munges the
583
                    // binary data on Windows
584
                    $com = @new \COM("CAPICOM.Utilities.1");
585
                    $bytes = $com->GetRandom($byte_len, 0);
586
                } catch (Exception $e)
0 ignored issues
show
Bug introduced by
The class PHP_Crypt\Exception does not exist. Did you forget a USE statement, or did you not list all dependencies?

Scrutinizer analyzes your composer.json/composer.lock file if available to determine the classes, and functions that are defined by your dependencies.

It seems like the listed class was neither found in your dependencies, nor was it found in the analyzed files in your repository. If you are using some other form of dependency management, you might want to disable this analysis.

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587
                {
588
                    $err_msg = "Windows COM exception: ".$e->getMessage();
589
                }
590
591
                if (!$bytes) {
592
                                    $err_msg = "Windows COM failed to create random string of bytes";
593
                }
594
            } else {
595
                            $err_msg = "The COM_DOTNET extension is not loaded";
596
            }
597
        }
598
599
        // trigger a warning if something went wrong
600
        if ($err_msg != "") {
601
                    trigger_error("$err_msg. Defaulting to PHP_Crypt::RAND", E_USER_WARNING);
602
        }
603
604
        // if the random bytes where not created properly or PHP_Crypt::RAND was
605
        // passed as the $src param, create the bytes using mt_rand(). It's not
606
        // the most secure option but we have no other choice
607
        if (strlen($bytes) < $byte_len)
608
        {
609
            $bytes = "";
610
611
            // md5() hash a random number to get a 16 byte string, keep looping
612
            // until we have a string as long or longer than the ciphers block size
613
            for ($i = 0; ($i * self::HASH_LEN) < $byte_len; ++$i) {
614
                            $bytes .= md5(mt_rand(), true);
615
            }
616
        }
617
618
        // because $bytes may have come from mt_rand() or /dev/urandom which are not
619
        // cryptographically secure, lets add another layer of 'randomness' before
620
        // the final md5() below
621
        $bytes = str_shuffle($bytes);
622
623
        // md5() the $bytes to add extra randomness. Since md5() only returns
624
        // 16 bytes, we may need to loop to generate a string of $bytes big enough for
625
        // some ciphers which have a block size larger than 16 bytes
626
        $tmp = "";
627
        $loop = ceil(strlen($bytes) / self::HASH_LEN);
628
        for ($i = 0; $i < $loop; ++$i) {
629
                    $tmp .= md5(substr($bytes, ($i * self::HASH_LEN), self::HASH_LEN), true);
630
        }
631
632
        // grab the number of bytes equal to the requested $byte_len
633
        return substr($tmp, 0, $byte_len);
634
    }
635
}
636
?>
0 ignored issues
show
Best Practice introduced by
It is not recommended to use PHP's closing tag ?> in files other than templates.

Using a closing tag in PHP files that only contain PHP code is not recommended as you might accidentally add whitespace after the closing tag which would then be output by PHP. This can cause severe problems, for example headers cannot be sent anymore.

A simple precaution is to leave off the closing tag as it is not required, and it also has no negative effects whatsoever.

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637