CAdESUtility.initJCPAlgorithms();

            List<X509Certificate> chain = new ArrayList<>();

            PrivateKey privateKey = CMStools.loadKey("oootf", "123456".toCharArray());
            
            Certificate cc = CMStools.loadCertificate("oootf");
            

            X509Certificate cert = (X509Certificate) cc;

            chain.add(cert);

            Store certStore = new JcaCertStore(chain);

          
            CMSSignedDataGenerator generator = new CMSSignedDataGenerator();

            ContentSigner contentSigner = new GostContentSignerProvider(
                    privateKey, JCP.PROVIDER_NAME);

            SignerInfoGenerator signerInfoGenerator = new JcaSignerInfoGeneratorBuilder(
                    new GostDigestCalculatorProvider(privateKey, JCP.PROVIDER_NAME)).build(contentSigner, cert);

            generator.addSignerInfoGenerator(signerInfoGenerator);
            generator.addCertificates(certStore);
          
            // Создаем совмещенную подпись PKCS7.            
            CMSProcessable content = new CMSProcessableByteArray(ss.getBytes());
            CMSSignedData signedData = generator.generate((CMSTypedData) content, true);

            // Сформированная подпись.
            byte[] pkcs7 = signedData.getEncoded();           
           
            return new String(Base64.getEncoder().encode(pkcs7));