static void Main(string[] args)
{
var certificateData = File.ReadAllBytes("YOUR_p7b_FILE");
var cert = new X509CertificateParser().ReadCertificate(certificateData);
//I just wanted to know if I can see the publicKey somehow
//var publicKey = cert.GetPublicKey();
var store = new Pkcs12Store(File.OpenRead("YOUR_p12_File"), "test".ToCharArray());
var privateKey = store.GetKey("THE_NAME_OF_KEY_YOU_WANT_TO_GET").Key;
var signedDataGen = new CmsSignedDataGenerator();
signedDataGen.AddSigner(privateKey, cert, CmsSignedDataGenerator.EncryptionRsa, CmsSignedDataGenerator.DigestSha512);
var zipContent = new CmsProcessableFile(new FileInfo("YOUR_DATA_FILE"));
//For me a zip
var signedData = signedDataGen.Generate(zipContent, true);
var envDataGen = new CmsEnvelopedDataGenerator();
envDataGen.AddKeyTransRecipient(cert);
var sData = new CmsProcessableByteArray(signedData.GetEncoded());
var enveloped = envDataGen.Generate(sData, CmsEnvelopedDataGenerator.DesEde3Cbc);
var dos = new DerOutputStream(File.OpenWrite("YOUR_DATA_FILE.zip.encrypted.sig)"));
var bytesToWrite = enveloped.GetEncoded();
dos.Write(bytesToWrite, 0, bytesToWrite.Length);
dos.Flush();
dos.Close();
}