SecureRandom::getArray() - Code Metrics - Inspection of "Simplify getArray" - Riimu/Kit-SecureRandom - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 99ba41...afbd03 )

by Riikka

created 2017-07-11 17:03 UTC

SecureRandom::getArray() A

↳ Parent: SecureRandom

Complexity

Conditions	3
Paths	3

Size

Total Lines	21
Code Lines	13

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	14
CRAP Score	3

Importance

Changes

Metric	Value
dl	0
loc	21
ccs	14
cts	14
cp	1
rs	9.3142
c	0
b	0
f	0
cc	3
eloc	13
nc	3
nop	2
crap	3

<?php

namespace Riimu\Kit\SecureRandom;

use Riimu\Kit\SecureRandom\Generator\Generator;
use Riimu\Kit\SecureRandom\Generator\NumberGenerator;

/**
 * Library for normalizing bytes returned by secure random byte generators.
 *
 * SecureRandom takes bytes generated by secure random byte generators and
 * normalizes (i.e. provides even distribution) for other common usages, such
 * as generation of integers, floats and randomizing arrays.
 *
 * @author Riikka Kalliomäki <[email protected]>
 * @copyright Copyright (c) 2014, Riikka Kalliomäki
 * @license http://opensource.org/licenses/mit-license.php MIT License
 */
class SecureRandom
{
    /** @var Generator The secure random byte generator used to generate bytes */
    private $generator;

    /** @var string[] List of default generators */
    private static $defaultGenerators = [
        '\Riimu\Kit\SecureRandom\Generator\Internal',
        '\Riimu\Kit\SecureRandom\Generator\RandomReader',
        '\Riimu\Kit\SecureRandom\Generator\Mcrypt',
        '\Riimu\Kit\SecureRandom\Generator\OpenSSL',
    ];

    /**
     * Creates a new instance of SecureRandom.
     *
     * You can either provide a generator to use for generating random bytes or
     * give null as the argument to use default generators. If null is provided,
     * the constructor will attempt to create the random byte generators in the
     * following order until it finds one that is supported:
     *
     * - Internal
     * - RandomReader
     * - Mcrypt
     * - OpenSSL
     *
     * Note that since most cases require non-blocking random generation, the
     * default generators use /dev/urandom as the random source. If you do not
     * think this provides enough security, create the desired random generator
     * using /dev/random as the source.
     *
     * @param Generator|null $generator Random byte generator or null for default
     * @throws GeneratorException If the provided or default generators are not supported
     */
    public function __construct(Generator $generator = null)
    {
        if ($generator === null) {
            $generator = $this->getDefaultGenerator();
        } elseif (!$generator->isSupported()) {
            throw new GeneratorException('The provided secure random byte generator is not supported by the system');
        }

        $this->generator = $generator;
    }

    /**
     * Returns the first supported default secure random byte generator.
     * @return Generator Supported secure random byte generator
     * @throws GeneratorException If none of the default generators are supported
     */
    private function getDefaultGenerator()
    {
        foreach (self::$defaultGenerators as $generator) {
            $generator = new $generator();

            if ($generator->isSupported()) {
                return $generator;
            }
        }

        throw new GeneratorException('Default secure random byte generators are not supported by the system');
    }

    /**
     * Returns a number of random bytes.
     * @param int $count Number of random bytes to return
     * @return string Randomly generated bytes
     * @throws \InvalidArgumentException If the count is invalid
     */
    public function getBytes($count)
    {
        $count = (int) $count;

        if ($count < 0) {
            throw new \InvalidArgumentException('Number of bytes must be 0 or more');
        } elseif ($count === 0) {
            return '';
        }

        return $this->generator->getBytes($count);
    }

    /**
     * Returns a random number between 0 and the limit.
     * @param int $limit Maximum random number
     * @return int Random number between 0 and the limit
     */
    private function getNumber($limit)
    {
        if ($limit === 0) {
            return 0;
        } elseif ($this->generator instanceof NumberGenerator) {
            return $this->generator->getNumber(0, $limit);
        }

        return $this->getByteNumber($limit);
    }

    /**
     * Returns a random number generated using the random byte generator.
     * @param int $limit Maximum value for the random number
     * @return int The generated random number between 0 and the limit
     */
    private function getByteNumber($limit)
    {
        for ($bits = 1, $mask = 1; $limit >> $bits > 0; $bits++) {
            $mask |= 1 << $bits;
        }

        $bytes = (int) ceil($bits / 8);

        do {
            $result = hexdec(bin2hex($this->generator->getBytes($bytes))) & $mask;
        } while ($result > $limit);

        return $result;
    }

    /**
     * Returns a random integer between two positive integers (inclusive).
     * @param int $min Minimum limit
     * @param int $max Maximum limit
     * @return int Random integer between minimum and maximum limit
     * @throws \InvalidArgumentException If the limits are invalid
     */
    public function getInteger($min, $max)
    {
        $min = (int) $min;
        $max = (int) $max;

        if ($this->isOutOfBounds($min, 0, $max)) {
            throw new \InvalidArgumentException('Invalid minimum or maximum value');
        }

        return $min + $this->getNumber($max - $min);
    }

    /**
     * Tells if the given number is not within given limits (inclusive).
     * @param int $number The number to test
     * @param int $min The minimum allowed limit
     * @param int $max The maximum allowed limit
     * @return bool True if the number is out of bounds, false if within bounds
     */
    private function isOutOfBounds($number, $min, $max)
    {
        return $number < $min || $max < $number;
    }

    /**
     * Returns a random float between 0 and 1 (excluding the number 1).
     * @return float Random float between 0 and 1 (excluding 1)
     */
    public function getRandom()
    {
        $bytes = $this->generator->getBytes(7);
        $result = 0.0;

        for ($i = 0; $i < 6; $i++) {
            $result = (ord($bytes[$i]) + $result) / 256;
        }

        $result = ((ord($bytes[6]) & 0b00011111) + $result) / 32;

        return $result;
    }

    /**
     * Returns a random float between 0 and 1 (inclusive).
     * @return float Random float between 0 and 1 (inclusive)
     */
    public function getFloat()
    {
        return (float) ($this->getNumber(PHP_INT_MAX) / PHP_INT_MAX);
    }

    /**
     * Returns a number of randomly selected elements from the array.
     *
     * This method returns randomly selected elements from the array. The number
     * of elements is determined by by the second argument. The elements are
     * returned in random order but the keys are preserved.
     *
     * @param array $array Array of elements
     * @param int $count Number of elements to return from the array
     * @return array Randomly selected elements in random order
     * @throws \InvalidArgumentException If the count is invalid
     */
    public function getArray(array $array, $count)
    {
        $count = (int) $count;
        $size = count($array);

        if ($this->isOutOfBounds($count, 0, $size)) {
            throw new \InvalidArgumentException('Invalid number of elements');
        }

        $result = [];
        $keys = array_keys($array);

        for ($i = 0; $i < $count; $i++) {
            $last = $size - $i - 1;
            $index = $this->getNumber($last);
            $result[$keys[$index]] = $array[$keys[$index]];
            $keys[$index] = $keys[$last];
        }

        return $result;
    }

    /**
     * Returns one randomly selected value from the array.
     * @param array $array The array to choose from
     * @return mixed One randomly selected value from the array
     * @throws \InvalidArgumentException If the array is empty
     */
    public function choose(array $array)
    {
        if (count($array) < 1) {
            throw new \InvalidArgumentException('Array must have at least one value');
        }

        $result = array_slice($array, $this->getNumber(count($array) - 1), 1);

        return current($result);
    }

    /**
     * Returns the array with the elements reordered in a random order.
     * @param array $array The array to shuffle
     * @return array The provided array with elements in a random order
     */
    public function shuffle(array $array)
    {
        return $this->getArray($array, count($array));
    }

    /**
     * Returns a random sequence of values.
     *
     * If a string is provided as the first argument, the method returns a
     * string with characters selected from the provided string. The length of
     * the returned string is determined by the second argument.
     *
     * If an array is provided as the first argument, the method returns an
     * array with elements selected from the provided array. The size of the
     * returned array is determined by the second argument.
     *
     * The functionality is similar to getArray(), except for the fact that the
     * returned value can contain the same character or element multiple times.
     * If the same character or element appears multiple times in the provided
     * argument, it will increase the relative chance of it appearing in the
     * returned value.
     *
     * @param string|array $choices Values to choose from
     * @param int $length Length of the sequence
     * @return array|string The generated random sequence
     * @throws \InvalidArgumentException If the choices or length is invalid
     */
    public function getSequence($choices, $length)
    {
        $length = (int) $length;

        if ($length < 0) {
            throw new \InvalidArgumentException('Invalid sequence length');
        }

        if (is_array($choices)) {
            return $this->getSequenceValues(array_values($choices), $length);
        }

        return implode($this->getSequenceValues(str_split((string) $choices), $length));
    }

    /**
     * Returns the selected list of values for the sequence.
     * @param array $values List of possible values
     * @param int $length Number of values to return
     * @return array Selected list of values for the sequence
     * @throws \InvalidArgumentException If the value set is empty
     */
    private function getSequenceValues(array $values, $length)
    {
        if ($length < 1) {
            return [];
        }

        if (count($values) < 1) {
            throw new \InvalidArgumentException('Cannot generate sequence from empty value set');
        }

        $size = count($values);
        $result = [];

        for ($i = 0; $i < $length; $i++) {
            $result[] = $values[$this->getNumber($size - 1)];
        }

        return $result;
    }

    /**
     * Returns a random UUID version 4 identifier.
     * @return string A random UUID identifier
     */
    public function getUuid()
    {
        $integers = array_map(function ($bytes) {
            return hexdec(bin2hex($bytes));
        }, str_split($this->generator->getBytes(16), 2));

        $integers[3] &= 0x0FFF;
        $integers[4] = $integers[4] & 0x3FFF | 0x8000;

        return vsprintf('%04x%04x-%04x-4%03x-%04x-%04x%04x%04x', $integers);
    }
}


1		<?php
2
3		namespace Riimu\Kit\SecureRandom;
4
5		use Riimu\Kit\SecureRandom\Generator\Generator;
6		use Riimu\Kit\SecureRandom\Generator\NumberGenerator;
7
8		/**
9		* Library for normalizing bytes returned by secure random byte generators.
10		*
11		* SecureRandom takes bytes generated by secure random byte generators and
12		* normalizes (i.e. provides even distribution) for other common usages, such
13		* as generation of integers, floats and randomizing arrays.
14		*
15		* @author Riikka Kalliomäki <[email protected]>
16		* @copyright Copyright (c) 2014, Riikka Kalliomäki
17		* @license http://opensource.org/licenses/mit-license.php MIT License
18		*/
19		class SecureRandom
20		{
21		/** @var Generator The secure random byte generator used to generate bytes */
22		private $generator;
23
24		/** @var string[] List of default generators */
25		private static $defaultGenerators = [
26		'\Riimu\Kit\SecureRandom\Generator\Internal',
27		'\Riimu\Kit\SecureRandom\Generator\RandomReader',
28		'\Riimu\Kit\SecureRandom\Generator\Mcrypt',
29		'\Riimu\Kit\SecureRandom\Generator\OpenSSL',
30		];
31
32		/**
33		* Creates a new instance of SecureRandom.
34		*
35		* You can either provide a generator to use for generating random bytes or
36		* give null as the argument to use default generators. If null is provided,
37		* the constructor will attempt to create the random byte generators in the
38		* following order until it finds one that is supported:
39		*
40		* - Internal
41		* - RandomReader
42		* - Mcrypt
43		* - OpenSSL
44		*
45		* Note that since most cases require non-blocking random generation, the
46		* default generators use /dev/urandom as the random source. If you do not
47		* think this provides enough security, create the desired random generator
48		* using /dev/random as the source.
49		*
50		* @param Generator\|null $generator Random byte generator or null for default
51		* @throws GeneratorException If the provided or default generators are not supported
52		*/
53	98	public function __construct(Generator $generator = null)
54		{
55	98	if ($generator === null) {
56	6	$generator = $this->getDefaultGenerator();
57	93	} elseif (!$generator->isSupported()) {
58	3	throw new GeneratorException('The provided secure random byte generator is not supported by the system');
59		}
60
61	92	$this->generator = $generator;
62	92	}
63
64		/**
65		* Returns the first supported default secure random byte generator.
66		* @return Generator Supported secure random byte generator
67		* @throws GeneratorException If none of the default generators are supported
68		*/
69	6	private function getDefaultGenerator()
70		{
71	6	foreach (self::$defaultGenerators as $generator) {
72	3	$generator = new $generator();
73
74	3	if ($generator->isSupported()) {
75	3	return $generator;
76		}
77	2	}
78
79	3	throw new GeneratorException('Default secure random byte generators are not supported by the system');
80		}
81
82		/**
83		* Returns a number of random bytes.
84		* @param int $count Number of random bytes to return
85		* @return string Randomly generated bytes
86		* @throws \InvalidArgumentException If the count is invalid
87		*/
88	9	public function getBytes($count)
89		{
90	9	$count = (int) $count;
91
92	9	if ($count < 0) {
93	3	throw new \InvalidArgumentException('Number of bytes must be 0 or more');
94	6	} elseif ($count === 0) {
95	3	return '';
96		}
97
98	3	return $this->generator->getBytes($count);
99		}
100
101		/**
102		* Returns a random number between 0 and the limit.
103		* @param int $limit Maximum random number
104		* @return int Random number between 0 and the limit
105		*/
106	38	private function getNumber($limit)
107		{
108	38	if ($limit === 0) {
109	12	return 0;
110	29	} elseif ($this->generator instanceof NumberGenerator) {
111	5	return $this->generator->getNumber(0, $limit);
112		}
113
114	24	return $this->getByteNumber($limit);
115		}
116
117		/**
118		* Returns a random number generated using the random byte generator.
119		* @param int $limit Maximum value for the random number
120		* @return int The generated random number between 0 and the limit
121		*/
122	24	private function getByteNumber($limit)
123		{
124	24	for ($bits = 1, $mask = 1; $limit >> $bits > 0; $bits++) {
125	24	$mask \|= 1 << $bits;
126	8	}
127
128	24	$bytes = (int) ceil($bits / 8);
129
130		do {
131	24	$result = hexdec(bin2hex($this->generator->getBytes($bytes))) & $mask;
132	24	} while ($result > $limit);
133
134	24	return $result;
135		}
136
137		/**
138		* Returns a random integer between two positive integers (inclusive).
139		* @param int $min Minimum limit
140		* @param int $max Maximum limit
141		* @return int Random integer between minimum and maximum limit
142		* @throws \InvalidArgumentException If the limits are invalid
143		*/
144	23	public function getInteger($min, $max)
145		{
146	23	$min = (int) $min;
147	23	$max = (int) $max;
148
149	23	if ($this->isOutOfBounds($min, 0, $max)) {
150	9	throw new \InvalidArgumentException('Invalid minimum or maximum value');
151		}
152
153	14	return $min + $this->getNumber($max - $min);
154		}
155
156		/**
157		* Tells if the given number is not within given limits (inclusive).
158		* @param int $number The number to test
159		* @param int $min The minimum allowed limit
160		* @param int $max The maximum allowed limit
161		* @return bool True if the number is out of bounds, false if within bounds
162		*/
163	44	private function isOutOfBounds($number, $min, $max)
164		{
165	44	return $number < $min \|\| $max < $number;
166		}
167
168		/**
169		* Returns a random float between 0 and 1 (excluding the number 1).
170		* @return float Random float between 0 and 1 (excluding 1)
171		*/
172	3	public function getRandom()
173		{
174	3	$bytes = $this->generator->getBytes(7);
175	3	$result = 0.0;
176
177	3	for ($i = 0; $i < 6; $i++) {
178	3	$result = (ord($bytes[$i]) + $result) / 256;
179	1	}
180
181	3	$result = ((ord($bytes[6]) & 0b00011111) + $result) / 32;
182
183	3	return $result;
184		}
185
186		/**
187		* Returns a random float between 0 and 1 (inclusive).
188		* @return float Random float between 0 and 1 (inclusive)
189		*/
190	3	public function getFloat()
191		{
192	3	return (float) ($this->getNumber(PHP_INT_MAX) / PHP_INT_MAX);
193		}
194
195		/**
196		* Returns a number of randomly selected elements from the array.
197		*
198		* This method returns randomly selected elements from the array. The number
199		* of elements is determined by by the second argument. The elements are
200		* returned in random order but the keys are preserved.
201		*
202		* @param array $array Array of elements
203		* @param int $count Number of elements to return from the array
204		* @return array Randomly selected elements in random order
205		* @throws \InvalidArgumentException If the count is invalid
206		*/
207	21	public function getArray(array $array, $count)
208		{
209	21	$count = (int) $count;
210	21	$size = count($array);
211
212	21	if ($this->isOutOfBounds($count, 0, $size)) {
213	3	throw new \InvalidArgumentException('Invalid number of elements');
214		}
215
216	18	$result = [];
217	18	$keys = array_keys($array);
218
219	18	for ($i = 0; $i < $count; $i++) {
220	9	$last = $size - $i - 1;
221	9	$index = $this->getNumber($last);
222	9	$result[$keys[$index]] = $array[$keys[$index]];
223	9	$keys[$index] = $keys[$last];
224	3	}
225
226	18	return $result;
227		}
228
229		/**
230		* Returns one randomly selected value from the array.
231		* @param array $array The array to choose from
232		* @return mixed One randomly selected value from the array
233		* @throws \InvalidArgumentException If the array is empty
234		*/
235	9	public function choose(array $array)
236		{
237	9	if (count($array) < 1) {
238	3	throw new \InvalidArgumentException('Array must have at least one value');
239		}
240
241	6	$result = array_slice($array, $this->getNumber(count($array) - 1), 1);
242
243	6	return current($result);
244		}
245
246		/**
247		* Returns the array with the elements reordered in a random order.
248		* @param array $array The array to shuffle
249		* @return array The provided array with elements in a random order
250		*/
251	6	public function shuffle(array $array)
252		{
253	6	return $this->getArray($array, count($array));
254		}
255
256		/**
257		* Returns a random sequence of values.
258		*
259		* If a string is provided as the first argument, the method returns a
260		* string with characters selected from the provided string. The length of
261		* the returned string is determined by the second argument.
262		*
263		* If an array is provided as the first argument, the method returns an
264		* array with elements selected from the provided array. The size of the
265		* returned array is determined by the second argument.
266		*
267		* The functionality is similar to getArray(), except for the fact that the
268		* returned value can contain the same character or element multiple times.
269		* If the same character or element appears multiple times in the provided
270		* argument, it will increase the relative chance of it appearing in the
271		* returned value.
272		*
273		* @param string\|array $choices Values to choose from
274		* @param int $length Length of the sequence
275		* @return array\|string The generated random sequence
276		* @throws \InvalidArgumentException If the choices or length is invalid
277		*/
278	18	public function getSequence($choices, $length)
279		{
280	18	$length = (int) $length;
281
282	18	if ($length < 0) {
283	3	throw new \InvalidArgumentException('Invalid sequence length');
284		}
285
286	15	if (is_array($choices)) {
287	12	return $this->getSequenceValues(array_values($choices), $length);
288		}
289
290	12	return implode($this->getSequenceValues(str_split((string) $choices), $length));
291		}
292
293		/**
294		* Returns the selected list of values for the sequence.
295		* @param array $values List of possible values
296		* @param int $length Number of values to return
297		* @return array Selected list of values for the sequence
298		* @throws \InvalidArgumentException If the value set is empty
299		*/
300	15	private function getSequenceValues(array $values, $length)
301		{
302	15	if ($length < 1) {
303	6	return [];
304		}
305
306	9	if (count($values) < 1) {
307	3	throw new \InvalidArgumentException('Cannot generate sequence from empty value set');
308		}
309
310	6	$size = count($values);
311	6	$result = [];
312
313	6	for ($i = 0; $i < $length; $i++) {
314	6	$result[] = $values[$this->getNumber($size - 1)];
315	2	}
316
317	6	return $result;
318		}
319
320		/**
321		* Returns a random UUID version 4 identifier.
322		* @return string A random UUID identifier
323		*/
324		public function getUuid()
325		{
326	3	$integers = array_map(function ($bytes) {
327	3	return hexdec(bin2hex($bytes));
328	3	}, str_split($this->generator->getBytes(16), 2));
329
330	3	$integers[3] &= 0x0FFF;
331	3	$integers[4] = $integers[4] & 0x3FFF \| 0x8000;
332
333	3	return vsprintf('%04x%04x-%04x-4%03x-%04x-%04x%04x%04x', $integers);
334		}
335		}
336

Riimu / Kit-SecureRandom

Push — master ( 99ba41...afbd03 )

SecureRandom::getArray() A

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like