RandomLib fix for PHP 7.1 which does not have mcrypt anymore

MyRandomFactory.php

<?php

use RandomLib\Factory;

class MyRandomFactory extends Factory {

	public function __construct() {
		parent::__construct();
		$this->mixers = [];
		$this->registerMixer('OpenSSLMixer', OpenSSLMixer::class);
//		debug($this->getMixers());
	}

}
 

OpenSSLMixer.php

<?php

use RandomLib\AbstractMixer;
use SecurityLib\Strength;

class OpenSSLMixer extends AbstractMixer implements RandomLib\Mixer {

	/**
	 * Get the block size (the size of the individual blocks used for the mixing)
	 *
	 * @return int The block size
	 */
	protected function getPartSize() {
		return 128/8;
	}

	/**
	 * Mix 2 parts together using one method
	 *
	 * @param string $part1 The first part to mix
	 * @param string $part2 The second part to mix
	 *
	 * @return string The mixed data
	 */
	protected function mixParts1($part1, $part2) {
		return $this->encryptBlock($part1, $part2);
	}

	/**
	 * Mix 2 parts together using another different method
	 *
	 * @param string $part1 The first part to mix
	 * @param string $part2 The second part to mix
	 *
	 * @return string The mixed data
	 */
	protected function mixParts2($part1, $part2) {
		return $this->encryptBlock($part2, $part1);
	}

	/**
	 * Return an instance of Strength indicating the strength of the mixer
	 *
	 * @return \SecurityLib\Strength An instance of one of the strength classes
	 */
	public static function getStrength() {
		return new Strength(Strength::MEDIUM);
	}

	/**
	 * Test to see if the mixer is available
	 *
	 * @return bool If the mixer is available on the system
	 */
	public static function test() {
//		debug('openssl_encrypt', function_exists('openssl_encrypt'));
		return function_exists('openssl_encrypt');
	}

	private function encryptBlock($part2, $part1) {
		$iv = openssl_random_pseudo_bytes(16);
		return openssl_encrypt($part2, "aes-256-cbc", $part1, OPENSSL_RAW_DATA, $iv);
	}

}