Question

We need to move off traditional FTP for security purposes (it transmits it’s passwords unencrypted). I am hearing SSH touted as the obvious alternative. However I have been driving FTP from an ASP.NET program interface to automate my web-site development, which is now quite a highly web-enabled process.

Can anyone recommend a secure way to transfer files around which has a program interface that I can drive from ASP.NET?

Answer 1

the question has three subquestions:

1) choosing the secure transfer protocol

The secure version of old FTP exists – it’s called FTP/SSL (plain old FTP over SSL encrypted channel). Maybe you can still use your old deployment infrastructure – just check whether it supports the FTPS or FTP/SSL.

You can check details about FTP, FTP/SSL and SFTP differences at http://www.rebex.net/secure-ftp.net/ page.

2) SFTP or FTP/SSL server for Windows

When you choose whether to use SFTP or FTPS you have to deploy the proper server. For FTP/SSL we use the Gene6 (http://www.g6ftpserver.com/) on several servers without problems. There is plenty of FTP/SSL Windows servers so use whatever you want. The situation is a bit more complicated with SFTP server for Windows – there is only a few working implementations. The Bitvise WinHTTPD looks quite promising (http://www.bitvise.com/winsshd).

3) Internet File Transfer Component for ASP.NET

Last part of the solution is secure file transfer from asp.net. There is several components on the market. I would recommend the Rebex File Transfer Pack – it supports both FTP (and FTP/SSL) and SFTP (SSH File Transfer).

Following code shows how to upload a file to the server via SFTP. The code is taken from our Rebex SFTP tutorial page.

// create client, connect and log in  Sftp client = new Sftp(); client.Connect(hostname); client.Login(username, password);  // upload the 'test.zip' file to the current directory at the server  client.PutFile(@'c:\data\test.zip', 'test.zip');  // upload the 'index.html' file to the specified directory at the server  client.PutFile(@'c:\data\index.html', '/wwwroot/index.html');  // download the 'test.zip' file from the current directory at the server  client.GetFile('test.zip', @'c:\data\test.zip');  // download the 'index.html' file from the specified directory at the server  client.GetFile('/wwwroot/index.html', @'c:\data\index.html');  // upload a text using a MemoryStream  string message = 'Hello from Rebex SFTP for .NET!'; byte[] data = System.Text.Encoding.Default.GetBytes(message); System.IO.MemoryStream ms = new System.IO.MemoryStream(data); client.PutFile(ms, 'message.txt'); 

Martin