S/MIME Enveloped Messages C#

Question

I am new to BouncyCastle Crypto and cryptography. I downloaded the code and looking to create S/MIME encrypted Enveloped Messages using C#. I searched online and I see there are lot of examples using Java but don't see any examples using C#. Could you please let me know if there are any links for documentation or examples? Thanks for any suggestions.

Answer 1

Unfortunately, the C# version does not implement S/MIME, although it does implement much of the underlying CMS formats. The reason, at least at the time the majority of it was ported from Java, was the absence of any equivalent to the JavaMail API for .NET.

Answer 2

Just to update this, but I've started working with Peter Dettman and the BouncyCastle .NET project and the situation has now changed.

I've written an open source (MIT) library called MimeKit which is a complete MIME parser (and generator) library which uses BouncyCastle for S/MIME and PGP support.

It has full support for all of the S/MIME v3.2 features, including application/pkcs7-mime; smime-type=compressed-data which is not supported by any other library out there.

For S/MIME digital signatures, both application/pkcs7-mime; smime-type=signed-data and multipart/signed are supported for both sending and receiving.

I've also built an open source (MIT) library on top of MimeKit called MailKit which implements SMTP, POP3, and IMAP support.