FTP over SSL for C#

Question

I'm using the code below (needs to be .Net 2.0) to connect on a UAT server to a customer FTP server to up/down load files. I need to connect over port 990, using a self signed certificate supplied by them. I've got the firewall rules amended to allow connection to the URI on port 990 from our UAT server.

However (! :) ) I get a timeout on the line

 Stream requestStream = request.GetRequestStream();

If I increase the timeout time it makes no difference.

I've had a look around on the web but found nothing obvious that is missing in the code.

If I use CuteFTP to connect on the UAT server then, naturally, it connect fine and I can manually do the file transfers. If I use WireShark to look at the network traffic it gets a responce from the FTP server but never does the handshake for the userid and pwd (for the code), but via CuteFTP all the network traffic is fine.

I force the return of True where it checks the certificate.

private void button4_Click(object sender, EventArgs e)
        {
            try
            {
                string completeFTPPath = ConfigurationManager.AppSettings["FTPPath"];
                // get the object used to communicate with the server.
                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(completeFTPPath);
                request.EnableSsl = true;
                request.Credentials = new NetworkCredential(ConfigurationManager.AppSettings["FtpUserName"], ConfigurationManager.AppSettings["FtpPassword"]);
                request.Method = WebRequestMethods.Ftp.UploadFile;                

                ServicePointManager.ServerCertificateValidationCallback = AcceptAllCertifications;

                // read file into byte array
                StreamReader sourceStream = new StreamReader(ConfigurationManager.AppSettings["LocalFilePath"]);
                byte[] fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());
                sourceStream.Close();
                request.ContentLength = fileContents.Length;

                // send bytes to server
                MessageBox.Show("GetRequestStream() start");
                Stream requestStream = request.GetRequestStream();
                requestStream.Write(fileContents, 0, fileContents.Length);
                requestStream.Close();
                MessageBox.Show("GetRequestStream() end");

                FtpWebResponse response = (FtpWebResponse)request.GetResponse();
                MessageBox.Show("Response status: " + response.StatusDescription);
            }
            catch (WebException we)
            {
                MessageBox.Show(we.Message);
            }
            catch (Exception exc)
            {
                MessageBox.Show(exc.Message);
            }

        }

  public bool AcceptAllCertifications(object sender, System.Security.Cryptography.X509Certificates.X509Certificate certification, System.Security.Cryptography.X509Certificates.X509Chain chain, System.Net.Security.SslPolicyErrors sslPolicyErrors)
        { return true; }

e.g. FTPPath - ftp://111.222.333.444:990/UAT/testFile.zip; FtpUserName - userID; FtpPassword = userPwd; LocalFilePath - c:\temp\testFile.zip

Anyone any ideas? As some people seem to have the above code working. TIA.

Answer 1

Being on port 990, the server is most likely supporting implicit FTPS, not the more standard explicit FTPS. It may be that implicit FTPS is not supported in FtpWebRequest (I don't know).

If so, take a look at edtFTPnet/PRO , which supports both implicit and explicit FTPS, as well as SFTP.