detectDefaultPseudoRandomStringGenerator()   B
last analyzed

Complexity

Conditions 5
Paths 4

Size

Total Lines 18
Code Lines 8

Duplication

Lines 0
Ratio 0 %

Importance

Changes 1
Bugs 0 Features 0
Metric Value
c 1
b 0
f 0
dl 0
loc 18
rs 8.8571
cc 5
eloc 8
nc 4
nop 0
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<?php
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/**
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 * Copyright 2016 Facebook, Inc.
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 *
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 * You are hereby granted a non-exclusive, worldwide, royalty-free license to
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 * use, copy, modify, and distribute this software in source code or binary
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 * form for use in connection with the web services and APIs provided by
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 * Facebook.
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 *
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 * As with any software that integrates with the Facebook platform, your use
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 * of this software is subject to the Facebook Developer Principles and
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 * Policies [http://developers.facebook.com/policy/]. This copyright notice
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 * shall be included in all copies or substantial portions of the software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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 * DEALINGS IN THE SOFTWARE.
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 *
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 */
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namespace Facebook\PseudoRandomString;
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use Facebook\Exceptions\FacebookSDKException;
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use InvalidArgumentException;
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class PseudoRandomStringGeneratorFactory
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{
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    private function __construct()
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    {
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        // a factory constructor should never be invoked
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    }
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    /**
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     * Pseudo random string generator creation.
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     *
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     * @param PseudoRandomStringGeneratorInterface|string|null $generator
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     *
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     * @throws InvalidArgumentException If the pseudo random string generator must be set to "mcrypt", "openssl", or "urandom", or be an instance of Facebook\PseudoRandomString\PseudoRandomStringGeneratorInterface.
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     *
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     * @return PseudoRandomStringGeneratorInterface
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     */
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    public static function createPseudoRandomStringGenerator($generator)
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    {
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        if (!$generator) {
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            return self::detectDefaultPseudoRandomStringGenerator();
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        }
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        if ($generator instanceof PseudoRandomStringGeneratorInterface) {
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            return $generator;
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        }
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        if ('mcrypt' === $generator) {
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            return new McryptPseudoRandomStringGenerator();
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        }
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        if ('openssl' === $generator) {
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            return new OpenSslPseudoRandomStringGenerator();
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        }
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        if ('urandom' === $generator) {
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            return new UrandomPseudoRandomStringGenerator();
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        }
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        throw new InvalidArgumentException('The pseudo random string generator must be set to "mcrypt", "openssl", or "urandom", or be an instance of Facebook\PseudoRandomString\PseudoRandomStringGeneratorInterface');
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    }
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    /**
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     * Detects which pseudo-random string generator to use.
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     *
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     * @throws FacebookSDKException If unable to detect a cryptographically secure pseudo-random string generator.
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     *
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     * @return PseudoRandomStringGeneratorInterface
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     */
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    private static function detectDefaultPseudoRandomStringGenerator()
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    {
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        // Since openssl_random_pseudo_bytes() can sometimes return non-cryptographically
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        // secure pseudo-random strings (in rare cases), we check for mcrypt_create_iv() first.
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        if (function_exists('mcrypt_create_iv')) {
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            return new McryptPseudoRandomStringGenerator();
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        }
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        if (function_exists('openssl_random_pseudo_bytes')) {
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            return new OpenSslPseudoRandomStringGenerator();
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        }
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        if (!ini_get('open_basedir') && is_readable('/dev/urandom')) {
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            return new UrandomPseudoRandomStringGenerator();
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        }
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        throw new FacebookSDKException('Unable to detect a cryptographically secure pseudo-random string generator.');
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    }
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}
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