lookyman/u2f

<?php

namespace lookyman\U2f\Entropy;

use lookyman\U2f\Exception\EntropyException;
use lookyman\U2f\Exception\IException;

class OpenSslEntropyProvider implements IEntropyProvider
{

    public function __construct()
    {
        if (OPENSSL_VERSION_NUMBER < 0x10000000) {
            throw new EntropyException(sprintf('OpenSSL has to be at least version 1.0.0, this is %s.', OPENSSL_VERSION_TEXT), IException::ERR_OLD_OPENSSL);
        }
    }

    public function getPseudoRandomBytes($length)
    {
        $data = openssl_random_pseudo_bytes((int) $length, $strong);
        if ($data === FALSE || $strong !== TRUE) {
            throw new EntropyException('Could not get enough cryptographically strong bytes of entropy.', IException::ERR_BAD_RANDOM);
        }
        return $data;
    }

}