Cannot upload files to FTP site using SSL encryption from C# code

I'm trying to write C# code (.NET 4.0) to upload files using FTP with a site that requires SSL encrypted communications.

Here's my code:

static void FTPUpload(string filename)
        {

            string ftpSite = (string)System.Configuration.ConfigurationManager.AppSettings["ftpSite"];
            string ftpUserName = (string)System.Configuration.ConfigurationManager.AppSettings["ftpUserName"];
            string ftpPassword = (string)System.Configuration.ConfigurationManager.AppSettings["ftpPassword"];
            string ftpEnableSSL = (string)System.Configuration.ConfigurationManager.AppSettings["EnableSSL"];

            FileInfo fileInf = new FileInfo(filename);
            string uri = "ftp://" + ftpSite + "/" + fileInf.Name;
            FtpWebRequest reqFTP;
   
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpSite + "/" + fileInf.Name));

            reqFTP.Credentials = new NetworkCredential(ftpUserName, ftpPassword);

            if (ftpEnableSSL == "true")
            {
                reqFTP.EnableSsl = true;

                ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(AcceptAllCertifications);
// see function AcceptAllCertifications below
            }

            if (ftpEnableSSL == "false") reqFTP.EnableSsl = false;
   
            reqFTP.KeepAlive = true;

            reqFTP.UsePassive = true;

            reqFTP.Method = WebRequestMethods.Ftp.UploadFile;
   
            reqFTP.UseBinary = true;

            reqFTP.ContentLength = fileInf.Length;

            int buffLength = 2048;
            byte[] buff = new byte[buffLength];
            int contentLen;
   
            FileStream fs = fileInf.OpenRead();
   
            Stream strm = reqFTP.GetRequestStream();
       
            contentLen = fs.Read(buff, 0, buffLength);
       
            while (contentLen != 0)
            {
                strm.Write(buff, 0, contentLen);
                contentLen = fs.Read(buff, 0, buffLength);
            }
            strm.Close();
            fs.Close();
        }


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

When this code runs, I get the exception message "Unable to connect to the remote server".

The line throwing the exception is Stream strm = reqFTP.GetRequestStream();

When I use this code with an FTP site (outside my network) that does not use SSL encryption, the files I create are uploaded.

When I use Filezilla to upload files to the site requiring SSL, I can upload files when I set Protocol to SFTP. Also, when I set up the site in Filezilla, I copied the user name and password out of my config file.

I need some kind of answer by 8/26. The ideal answer would be a change to my code that will allow the upload to work. The second best answer would be a free DLL that can be called from my code that can do the upload. The third choice would be a commercial DLL that can be called from my code.

Thanks for your help.
LVL 1
CRESLISAAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

David Johnson, CD, MVPOwnerCommented:
are you sure that it is ftp/s and not sftp, ftp/s uses certificates and sftp (SSH File Transfer Protocol, a network protocol for secure file transfer over secure shell ) source:wikipedia
0
CRESLISAAuthor Commented:
I don't know for sure what the site uses. But I'm able to upload using Filezilla with the sftp setting, and that's the only secure setting in that program.

Since you brought up this issue, please supply code for both methods. I assume you would not respond to this question unless you know C# code that accomplish what I'm trying to do.
0
David Johnson, CD, MVPOwnerCommented:
They are entirely different protocols and S/FTP is not natively in .net you will need a 3rd party library like:
http://www.routrek.co.jp/en/product/varaterm/granados.html
http://www.tamirgal.com/blog/page/SharpSSH.aspx
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
What were the top attacks of Q1 2018?

The Threat Lab team analyzes data from WatchGuard’s Firebox Feed, internal and partner threat intelligence, and a research honeynet, to provide insightful analysis about the top threats on the Internet. Check out our Q1 2018 report for smart, practical security advice today!

CRESLISAAuthor Commented:
This looks like the answer I need. I ran the example code with the Sharp demo and was able to upload a file. But I need to use a component in my C# program. If you have an example of how to use this in a C# program, that would be greatly appreciated.
0
CRESLISAAuthor Commented:
OK, it was easy to use. Thanks! And it worked!
0
CRESLISAAuthor Commented:
The B is because code was not supplied. But it was easy to figure out code that worked. And, since there is no A- or B+, I'm giving a B.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
C#

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.