SFTP server

Launching an SFTP server 

Simply create an instance of FileServer, bind it to a port, add a private key and at least one user with a path to their root directory. Then start it, and the fully working SFTP server is ready:

// create a server instance
var server = new FileServer();

// bind SFTP (runs over SSH) to port 22
server.Bind(22, FileServerProtocol.Sftp);

// load a server private key from encrypted 'serverkey.ppk' file
server.Keys.Add(new SshPrivateKey("server-key.ppk", "password"));

// add a user (specify username, password and virtual root path)
server.Users.Add("user01", "password", @"c:\data\user01");

// start the server in the background
server.Start();

' create a server instance
Dim server = New FileServer()

' bind SFTP (runs over SSH) to port 22
server.Bind(22, FileServerProtocol.Sftp)

' load a server private key from encrypted 'serverkey.ppk' file
server.Keys.Add(New SshPrivateKey("server-key.ppk", "password"))

' add a user (specify username, password and virtual root path)
server.Users.Add("user01", "password", "c:\data\user01")

' start the server in the background
server.Start()

See also

• User authentication and management
• Access rights
• Private keys
• SSH server
• FTP server

SFTP v3 and v4 

Rebex File Server supports SFTP v3 (the most commonly supported version of SFTP) and a subset of SFTP v4 (which adds some useful features).

Virtual file system 

Rebex File Server presents a virtual file system to each user. This makes it simple to configure it so that no sensitive or unwanted data are revealed - just confine each user to a specific directory (and its subtree) in the filesystem.

Tracking uploads and downloads 

Rebex File Server enables tracking of uploaded and downloaded files. To get notified when a file is uploaded or downloaded, register FileServer.FileUploaded event or FileServer.FileDownloaded event, respectively.

server.FileUploaded += server_FileUploaded;
server.FileDownloaded += server_FileDownloaded;

AddHandler server.FileUploaded, AddressOf Me.server_FileUploaded
AddHandler server.FileDownloaded, AddressOf Me.server_FileUploaded

Both events provide various information about the transfer, such as details about the user transferring the file, relative path from the user's root directory, bytes transferred, and so on.

void server_FileDownloaded(object sender, FileTransferredEventArgs e)
{
    Console.WriteLine("User '{0}' downloaded file '{1}', bytes transferred: {2}",
        e.User.Name, e.FullPath, e.BytesTransferred);
}

void server_FileUploaded(object sender, FileTransferredEventArgs e)
{
    Console.WriteLine("User '{0}' uploaded file '{1}', bytes transferred: {2}",
        e.User.Name, e.FullPath, e.BytesTransferred);
}

Private Sub server_FileDownloaded(ByVal sender As Object, ByVal e As FileTransferredEventArgs)
    Console.WriteLine("User '{0}' downloaded file '{1}', bytes transferred: {2}",
                      e.User.Name, e.FullPath, e.BytesTransferred)
End Sub

Private Sub server_FileUploaded(ByVal sender As Object, ByVal e As FileTransferredEventArgs)
    Console.WriteLine("User '{0}' uploaded file '{1}', bytes transferred: {2}",
                      e.User.Name, e.FullPath, e.BytesTransferred)
End Sub

Server-side file hash calculation 

Rebex File Server supports the check-file protocol extension that makes it possible for SFTP clients to request the server to calculate a hash of a specified file or a part of it. The client can then compare the server's hash value with the hash of a loacl file to determine whether the files are identical.

See how to use hashing on the SFTP client side with Rebex SFTP library.

Server-side file copying 

Rebex File Server supports the copy-data protocol extension, which makes it possible for compatible SFTP clients to copy files directly on the server without having to download and upload the data again. This reduces network traffic and speeds up remote file copies, especially for large files.

The extension can be used, for example, with the copy command in the OpenSSH SFTP client.

Compatible with popular SFTP clients 

Our SFTP server is compatible with popular third-party SFTP clients such as WinSCP, FileZilla, OpenSSH's sftp command.

It's a perfect companion to our SFTP client library, but it works with any third-party client that supports SSH2 and SFTP v3 or SFTP v4.