Gerar SignAC

    @Override
    public boolean gerarSignAc(String cnpjCpf) throws IOException, KeyStoreException, CertificateException, NoSuchAlgorithmException, UnrecoverableEntryException, NoSuchPaddingException, InvalidKeyException, SignatureException {
        String cnpjs = CNPJ_SOFTWARE_HOUSE.concat(cnpjCpf);
        byte[] data = cnpjs.getBytes(StandardCharsets.UTF_8);
        InputStream entrada = new FileInputStream(CAMINHO_CERTIFICAO);
        KeyStore ks = KeyStore.getInstance("pkcs12");
        ks.load(entrada, SENHA_CERTIFICADO.toCharArray());
        entrada.close();
        PrivateKey privateKey = (PrivateKey) ks.getKey(ks.aliases().nextElement(), SENHA_CERTIFICADO.toCharArray());
        KeyStore.PrivateKeyEntry pkEntry = (KeyStore.PrivateKeyEntry) ks.getEntry(ks.aliases().nextElement(),
                new KeyStore.PasswordProtection(SENHA_CERTIFICADO.toCharArray()));
        if (pkEntry != null && privateKey != null) {
            Certificate cert = pkEntry.getCertificate();
            // initialize cipher to encrypt
            Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
            cipher.init(Cipher.ENCRYPT_MODE, cert.getPublicKey());
            Signature sig = Signature.getInstance("SHA256withRSA");
            sig.initSign(privateKey);
            sig.update(data);
            byte[] signData = sig.sign();
            String signDataEncrypted = Base64.getEncoder().encodeToString(signData);
            System.out.println(signDataEncrypted);
            return true;
        }
        return false;
    }