try {
            final Signature sign =
                    Signature.getInstance("GOST3411withGOST3410EL");
            sign.initSign((PrivateKey) key);
            sign.update(Array.readFile(file));
            signature = sign.sign();
        } catch (NoSuchAlgorithmException e) {
            err = e.toString();
        } catch (SignatureException e) {
            err = e.toString();
        } catch (InvalidKeyException e) {
            err = e.toString();
        } catch (IOException e) {
            err = e.toString();
        }