<?php /** * Copyright 2017 Facebook, Inc. * * You are hereby granted a non-exclusive, worldwide, royalty-free license to * use, copy, modify, and distribute this software in source code or binary * form for use in connection with the web services and APIs provided by * Facebook. * * As with any software that integrates with the Facebook platform, your use * of this software is subject to the Facebook Developer Principles and * Policies [http://developers.facebook.com/policy/]. This copyright notice * shall be included in all copies or substantial portions of the software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. * */ namespace Facebook\PseudoRandomString; use Facebook\Exceptions\FacebookSDKException; class RandomBytesPseudoRandomStringGenerator implements PseudoRandomStringGeneratorInterface { use PseudoRandomStringGeneratorTrait; /** * @const string The error message when generating the string fails. */ const ERROR_MESSAGE = 'Unable to generate a cryptographically secure pseudo-random string from random_bytes(). '; /** * @throws FacebookSDKException */ public function __construct() { if (!function_exists('random_bytes')) { throw new FacebookSDKException( static::ERROR_MESSAGE . 'The function random_bytes() does not exist.' ); } } /** * @inheritdoc */ public function getPseudoRandomString($length) { $this->validateLength($length); return $this->binToHex(random_bytes($length), $length); } }