private static ASN1Set buildSignedAttributes(byte[] hash, Date dateTime, X509Certificate cert) throws Exception {
    ASN1EncodableVector v = new ASN1EncodableVector();
    v.add(new Attribute(CMSAttributes.contentType, new DERSet(PKCSObjectIdentifiers.data)));
    if (dateTime != null)
        v.add(new Attribute(CMSAttributes.signingTime, new DERSet(new Time(dateTime))));
    v.add(new Attribute(CMSAttributes.messageDigest, new DERSet(new DEROctetString(hash))));

    // CADES support section
    ASN1EncodableVector aaV2 = new ASN1EncodableVector();
    AlgorithmIdentifier algoId = new AlgorithmIdentifier(new ASN1ObjectIdentifier(CMSSignedDataGenerator.DIGEST_SHA256), null);
    aaV2.add(algoId);
    byte[] dig = SignUtils.calculateHASH(CMSSignedDataGenerator.DIGEST_SHA256, cert.getEncoded());
    aaV2.add(new DEROctetString(dig));
    Attribute cades = new Attribute(PKCSObjectIdentifiers.id_aa_signingCertificateV2, new DERSet(new DERSequence(new DERSequence(new DERSequence(aaV2)))));
    v.add(cades);

    ASN1Set signedAttributes = new DERSet(v);
    return signedAttributes;
}
 

/**
 * <a href="http://stackoverflow.com/questions/41767351/create-pkcs7-signature-from-file-digest">
 * Create pkcs7 signature from file digest
 * </a>
 * <p>
 * The OP's own <code>sign</code> method which has some errors. These
 * errors are fixed in {@link #signWithSeparatedHashing(InputStream)}.
 * </p>
 */
public byte[] signBySnox(InputStream content) throws IOException {
    // testSHA1WithRSAAndAttributeTable
    try {
        MessageDigest md = MessageDigest.getInstance("SHA1", "BC");
        List<Certificate> certList = new ArrayList<Certificate>();
        CMSTypedData msg = new CMSProcessableByteArray(IOUtils.toByteArray(content));

        certList.addAll(Arrays.asList(chain));

        Store<?> certs = new JcaCertStore(certList);

        CMSSignedDataGenerator gen = new CMSSignedDataGenerator();

        Attribute attr = new Attribute(CMSAttributes.messageDigest,
                new DERSet(new DEROctetString(md.digest(IOUtils.toByteArray(content)))));

        ASN1EncodableVector v = new ASN1EncodableVector();

        v.add(attr);

        SignerInfoGeneratorBuilder builder = new SignerInfoGeneratorBuilder(new BcDigestCalculatorProvider())
                .setSignedAttributeGenerator(new DefaultSignedAttributeTableGenerator(new AttributeTable(v)));

        AlgorithmIdentifier sha1withRSA = new DefaultSignatureAlgorithmIdentifierFinder().find("SHA1withRSA");

        CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
        InputStream in = new ByteArrayInputStream(chain[0].getEncoded());
        X509Certificate cert = (X509Certificate) certFactory.generateCertificate(in);

        gen.addSignerInfoGenerator(builder.build(
                new BcRSAContentSignerBuilder(sha1withRSA,
                        new DefaultDigestAlgorithmIdentifierFinder().find(sha1withRSA))
                                .build(PrivateKeyFactory.createKey(pk.getEncoded())),
                new JcaX509CertificateHolder(cert)));

        gen.addCertificates(certs);

        CMSSignedData s = gen.generate(new CMSAbsentContent(), false);
        return new CMSSignedData(msg, s.getEncoded()).getEncoded();

    } catch (Exception e) {
        e.printStackTrace();
        throw new IOException(e);
    }
}
 

/**
 * <a href="http://stackoverflow.com/questions/41767351/create-pkcs7-signature-from-file-digest">
 * Create pkcs7 signature from file digest
 * </a>
 * <p>
 * The OP's <code>sign</code> method after fixing some errors. The
 * OP's original method is {@link #signBySnox(InputStream)}. The
 * errors were
 * </p>
 * <ul>
 * <li>multiple attempts at reading the {@link InputStream} parameter;
 * <li>convoluted creation of final CMS container.
 * </ul>
 * <p>
 * Additionally this method uses SHA256 instead of SHA-1.
 * </p>
 */
public byte[] signWithSeparatedHashing(InputStream content) throws IOException
{
    try
    {
        // Digest generation step
        MessageDigest md = MessageDigest.getInstance("SHA256", "BC");
        byte[] digest = md.digest(IOUtils.toByteArray(content));

        // Separate signature container creation step
        List<Certificate> certList = Arrays.asList(chain);
        JcaCertStore certs = new JcaCertStore(certList);

        CMSSignedDataGenerator gen = new CMSSignedDataGenerator();

        Attribute attr = new Attribute(CMSAttributes.messageDigest,
                new DERSet(new DEROctetString(digest)));

        ASN1EncodableVector v = new ASN1EncodableVector();

        v.add(attr);

        SignerInfoGeneratorBuilder builder = new SignerInfoGeneratorBuilder(new BcDigestCalculatorProvider())
                .setSignedAttributeGenerator(new DefaultSignedAttributeTableGenerator(new AttributeTable(v)));

        AlgorithmIdentifier sha256withRSA = new DefaultSignatureAlgorithmIdentifierFinder().find("SHA256withRSA");

        CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
        InputStream in = new ByteArrayInputStream(chain[0].getEncoded());
        X509Certificate cert = (X509Certificate) certFactory.generateCertificate(in);

        gen.addSignerInfoGenerator(builder.build(
                new BcRSAContentSignerBuilder(sha256withRSA,
                        new DefaultDigestAlgorithmIdentifierFinder().find(sha256withRSA))
                                .build(PrivateKeyFactory.createKey(pk.getEncoded())),
                new JcaX509CertificateHolder(cert)));

        gen.addCertificates(certs);

        CMSSignedData s = gen.generate(new CMSAbsentContent(), false);
        return s.getEncoded();
    }
    catch (Exception e)
    {
        e.printStackTrace();
        throw new IOException(e);
    }
}