ParagonIE\Halite\KeyFactory::saveKeyFile PHP Method

    protected static function saveKeyFile(string $filePath, string $keyData) : bool
    {
        $saved = \file_put_contents($filePath, \Sodium\bin2hex(Halite::HALITE_VERSION_KEYS . $keyData . \Sodium\crypto_generichash(Halite::HALITE_VERSION_KEYS . $keyData, '', \Sodium\CRYPTO_GENERICHASH_BYTES_MAX)));
        return $saved !== false;
    }