Does .NET FtpWebRequest Support both Implicit (FTPS) and explicit (FTPES)?

Question

I am being asked to support implicit and explicit FTPS (also known as FTPES). We are currently using the .NET FtpWebRequest. Does the FtpWebRequest

Answer 1

.NET Framework/FtpWebRequest supports only explicit TLS/SSL encryption. It does not support implicit TLS/SSL encryption.

I believe it's unlikely it ever will. The FTP implementation of .NET frameworks uses only standardized features of the protocol. The implicit TLS/SSL encryption was never standardized. It was introduced only as a temporary mechanism to allow using seamless encryption with FTP clients that did not support encryption. In general, there's no reason to use implicit TLS/SSL encryption. An FTP server that supports implicit TLS/SSL encryption only, is broken, imo. Note that RFC 2228 [FTP Security Extensions] was introduced over 20 years ago!

---

Anyway, if you need to use the implicit TLS/SSL encryption, you have to use a 3rd party FTP library.

With WinSCP .NET assembly, it's easy:

// Set up session options
SessionOptions sessionOptions = new SessionOptions
{
    Protocol = Protocol.Ftp,
    UserName = "username",
    Password = "password",
    FtpSecure = FtpSecure.Implicit,
};

using (Session session = new Session())
{
    // Connect
    session.Open(sessionOptions);

    // Your code
}

You can have WinSCP GUI generate a C# FTP code template, like the one above, for you.

(I'm the author of WinSCP)