Верификация JWT сертификатом CryptoPro

Помогите, пожалуйста, решить проблему. Пытаюсь верифицировать JWT, но безуспешно.

private boolean verifyJwt(String token, X509Certificate certificate) {
    boolean result = false;
    String[] parts = token.split("\\.");
    byte[] tokenSign = Base64.getDecoder().decode(parts[2].getBytes(StandardCharsets.UTF_8));
    String head = parts[0];
    String payload = parts[1];
    String headWithPayload = head + "." + payload;
    try {
        Signature signature = Signature.getInstance((certificate).getSigAlgName());
        byte[] msgBytes = headWithPayload.getBytes(StandardCharsets.UTF_8);
        PublicKey publicKey = certificate.getPublicKey();
        signature.initVerify(publicKey);
        signature.update(msgBytes);
        result = signature.verify(tokenSign);
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
        throw new RuntimeException(e);
    } catch (InvalidKeyException e) {
        e.printStackTrace();
        throw new RuntimeException(e);
    } catch (SignatureException e) {
        e.printStackTrace();
        throw new RuntimeException(e);
    }
    return result;
}

private void signJWT(InputStream dataInputStream, OutputStream signOutputStream)  throws Exception{
    InputStream inputStream = dataInputStream;
    String jwt = new BufferedReader(new InputStreamReader(inputStream)).lines().collect(Collectors.joining("\n"));
    String[] parts = jwt.split("\\.");
    String dataForSign = parts[0] + "." + parts[1];
    byte[] dataBytes = dataForSign.getBytes(StandardCharsets.UTF_8);
    byte[] finalData = computeDigestWithStream(inputStream, JCP.GOST_DIGEST_2012_256_NAME, "JCSP");
    Signature signatureProcessor;
    try {
        signatureProcessor = Signature.getInstance(this.algorithmSign, this.providerSign);
        PrivateKey privateKey = getInnerPrivateKey();
        signatureProcessor.initSign(privateKey);
        signatureProcessor.update(finalData);
        byte[] signData = signatureProcessor.sign();
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        out.write(signData);
        String signature1 = Base64.getUrlEncoder().withoutPadding().encodeToString(out.toByteArray());
        String result = parts[0] + "." + parts[1] + "." + signature1;
        signOutputStream.write(signature1.getBytes());
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    } catch (SignatureException e) {
        e.printStackTrace();
    } catch (NoSuchProviderException e) {
        e.printStackTrace();
    }
}

private byte[] computeDigestWithStream(InputStream dataSteam, String algName, String provider) throws Exception {
    final MessageDigest digest = MessageDigest.getInstance(algName, provider);
    final DigestInputStream digestStream =  new DigestInputStream(dataSteam, digest);
    while (digestStream.available() != 0)
        digestStream.read();
    return digest.digest();
}

    private PrivateKey getInnerPrivateKey() throws KeyStoreException, IOException,
CertificateException, NoSuchAlgorithmException, UnrecoverableKeyException {
    String STORE_TYPE = "Aktiv Rutoken";
    String storePath = "/opt/cert.keystore";
    String alias = "01234567-0123-0123-0123-0123456789012";
    String STORE_PASS = "01234567";
    final KeyStore keyStore = KeyStore.getInstance(STORE_TYPE);
    final File file = new File(storePath);
    if (!file.exists()) {
       throw new FileNotFoundException("File " + STORE_TYPE + " not found while retrieving private key");
    }
    keyStore.load(new FileInputStream(file), STORE_PASS.toCharArray());
    return (PrivateKey) keyStore.getKey(alias, STORE_PASS.toCharArray());
}

Т.е. после выполнения метода signJWT() подпись успешно возвращается, но при попытки проверить эту же подпись на этом же сертификате с помощью метода verifyJwt() возвращается false.