使用Bouncycastle编写CMS编码的PEM

Question

我使用了以下源代码并成功生成了PKCS7编码的PEM，但我需要生成基于RFC7468 https://tools.ietf.org/html/rfc7468#page-11编码的CMS。基于RFC，建议使用CMS编码的PEM。如果您知道答案，请提前帮助，谢谢。

    ContentSigner sha256Signer = new     JcaContentSignerBuilder("SHA256WITHECDSA").setProvider(new org.spongycastle.jce.provider.BouncyCastleProvider()).build(key);

    CMSTypedData     msg = new CMSProcessableByteArray(data.getBytes(charset));
    CMSSignedDataGenerator gen = new CMSSignedDataGenerator();
    gen.addSignerInfoGenerator(new JcaSignerInfoGeneratorBuilder(
            new JcaDigestCalculatorProviderBuilder().build()).build(
            sha256Signer, new X509CertificateHolder(x509Cert)));

    gen.addCertificates(certStore);
    CMSSignedData signedData = gen.generate(msg, true);
    // Generate PKCS7 PEM
    ContentInfo ci = signedData.toASN1Structure();

    StringWriter signedCertificatePEMDataStringWriter = new StringWriter();
    JcaPEMWriter pemWrt = new JcaPEMWriter(signedCertificatePEMDataStringWriter);
    pemWrt.writeObject(ci);
    pemWrt.flush();
    pemWrt.close();