FTP通过FTP代理

Question

I am trying to download a file using FTP through a FTP proxy (on my side). This is script I am trying to implement in C#:

On Commandline:
ftp -i -s:get.ini CORPORATE_PROXY.com  
-----------get.ini------------
CORPORATE_PROXY_USER@CLIENT_FTP.com abc/user_name
CORPORATE_PROXY_PASSWORD 
user_name_password
cd pub/linux/knoppix
get packages.txt
bye
-----------get.ini------------

abc/user_name is my user name who was granted by permissions to FTP through my corporate proxy.

I want to implement above script in C#, but after playing with many types of code found on Internet I cannot do that.

FtpWebRequest request = FtpWebRequest.Create(new Uri(@"ftp://" + CORPORATE_PROXY.com + @"/" + Path.GetFileName(fileToUpload))) as FtpWebRequest;
request.UseBinary = true;
request.KeepAlive = false;
request.Method = WebRequestMethods.Ftp.UploadFile;
if (!string.IsNullOrEmpty(CORPORATE_PROXY_USER) && !string.IsNullOrEmpty(CORPORATE_PROXY_PASSWORD ))
    request.Credentials = new NetworkCredential(CORPORATE_PROXY_USER, CORPORATE_PROXY_PASSWORD );

//Get physical file
FileInfo fi = new FileInfo(fileToUpload);
Byte[] contents = new Byte[fi.Length];

//Read file
FileStream fs = fi.OpenRead();
fs.Read(contents, 0, Convert.ToInt32(fi.Length));
fs.Close();

request.Proxy = new WebProxy("CLIENT_FTP.com");
request.Proxy.Credentials = new NetworkCredential(abc/user_name, user_name_password);

//Write file contents to FTP server
Stream rs = request.GetRequestStream();
rs.Write(contents, 0, Convert.ToInt32(fi.Length));
rs.Close();

FtpWebResponse response = request.GetResponse() as FtpWebResponse;
string statusDescription = response.StatusDescription;
response.Close();
return statusDescription;

The main problem is that for the proxy I am using WebProxy, while I suspect I should use FTPProxy - which I cannot find anythere? Any ideas which direction should I go, or maybe WebProxy is fine?

Answer 1

Try using WebRequest instead of FtpWebRequest in your code example.

By doing so, the connection from client to proxy can be HTTP whereas the connection from proxy to destination server is FTP. The proxy will handle the protocol translation, this technique is referred to as FTP over HTTP.

It is also possible to use a native FTP Proxy where client to proxy and proxy to server connections are FTP. Make sure your proxy supports this.

The proxy offers a separate proxy port to serve native FTP proxy connections.

Answer 2

在过去，我使用Indy Project来通过FTP代理。