Can't get SharpSSH to connect via FTP

Question

I'm having trouble making a secure FTP connection using SharpSSH. Up to now I've been using the DOS command line app MOVEit Freely to make the connection, and it connects fine:

C:\> ftps -user:ABC -password:123 xxx.xxx.xxx.mil

However, when I try to do the same thing with SharpSSH, I get an error that says either the connection timed out or the server didn't respond correctly:

Dim sftp = New Tamir.SharpSsh.Sftp("xxx.xxx.xxx.mil", "ABC", "123")
sftp.Connect()

or

Dim host = New Tamir.SharpSsh.SshStream("xxx.xxx.xxx.mil", "ABC", "123")

Any idea what I might be doing wrong, or how I could figure out what's failing?

Note that I need a secure FTP connection, so the .NET classes are not an option. I'm willing to try alternatives to SharpSSH if they exist though.

Answer 1

Hi, you are using Tamir.SharpSsh, which is a SSH library. However, it looks like you are connecting to FTPS (or FTP/SSL) server. The FTPS is completely different protocol and has nothing common with SFTP nor SSH.

Following page on our website discusses the differences between FTP, FTP/SSL, FTPS and SFTP protocols: rebex.net/secure-ftp.net/.

Brief summary follows:

• FTP plain, old, insecure file transfer protocol. Transfers clear text password over the network.

• FTPS - FTP over TLS/SSL encrypted channel. FTP and FTPS relation is similar to HTTP and HTTPS.

• FTP/SSL - same as FTPS

• SFTP - SSH File Transfer Protocol. Has nothing common with FTP (expect the name). Runs over SSH encrypted communication channel.

• Secure FTP - could be either SFTP or FTPS :-(

You may try Rebex File Transfer Pack component, which supports both SFTP and FTPS protocols (but it costs some money unlike the SharpSSH).

Connection to FTP/SSL server would look like this:

' Create an instance of the Ftp class. 
Dim ftp As New Ftp()

' Connect securely using explicit SSL. 
' Use the third argument to specify additional SSL parameters. 
ftp.Connect(hostname, 21, Nothing, FtpSecurity.Explicit)

' Connection is protected now, we can log in safely. 
ftp.Login(username, password)

Answer 2

Another great alternative (also not free) is edtFTPnet/PRO, a stable, mature library which offers full support for FTPS (and SFTP) in .NET.

Here's some sample code for connecting:

   SecureFTPConnection ftpConnection = new SecureFTPConnection();

   // setting server address and credentials
   ftpConnection.ServerAddress = "xxx.xxx.xxx.mil";
   ftpConnection.UserName = "ABC";
   ftpConnection.Password = "123";

   // select explicit FTPS
   ftpConnection.Protocol = FileTransferProtocol.FTPSExplicit;

   // switch off server validation (only do this when testing)
   ftpConnection.ServerValidation = SecureFTPServerValidationType.None;

   // connect to server
   ftpConnection.Connect();