OFTPServer Component

Properties   Methods   Events   Configuration Settings   Errors  

The OFTPServer component implements the server side of the Odette File Transfer Protocol.

Syntax

nsoftware.IPWorksEDI.Oftpserver

Remarks

The OFTPServer component implements an OFTP server. It is a lightweight server that supports version 1.2, 1.3, 1.4, and 2.0 of OFTP.

Sending and Receiving Files

To use the component first decide if you will support TLS/SSL connections or not. If UseSSL is set to true, all clients will be expected to connect in TLS/SSL. If UseSSL is set to false (default), all clients are expected to connect in plaintext. If UseSSL is true, only clients that support Version 2.0 of the protocol can connect.

Once you have decided whether or not to support TLS/SSL, specify the port you wish the server to listen on in LocalPort. By default this value is 3305.

Next, specify values for ServerSSIDCode, ServerSFIDCode, ServerPassword.

Then set Listening to true to start listening for incoming requests.

When a client connects, you will have an opportunity to authenticate the client before continuing the connection. This is done when the AcceptConnection event fires. Within this event you can validate that the connecting client has access based on rules you determine. If you wish to reject the connection set the Accept parameter to false. Within this event you can also specify the directory to which files sent by the client to the server are saved. It is necessary to specify the directory within this event, as the client can start sending files as soon as the connection is complete. To specify the download directory set the DownloadDirectory field. For instance:

oftpserver1.Connections[e.ConnectionId].DownloadDirectory = "C:\\Downloads";

When the connection is complete, the client may send files. If the client does send a file the AcceptFile event will fire and you will have the opportunity to reject the file by setting the Accept parameter of the event. In addition you will have a chance to change the filename by setting the Filename parameter if desired.

After the client has sent all the files it is configured to send, it will pass control to the server. At that time the ReadyToSend event will fire, and the ReadyToSend field will be set to true. After this, you can either end the session with the client by calling Logoff or send files to the client. To send files to the client simply call the SendFile method with the specified parameters.

TLS/SSL Notes

When UseSSL is set to true, the server must be configured with a TLS/SSL certificate before it is started. Set SSLCert to a valid certificate with corresponding private key before setting Listening to true. This may be a PFX file, PEM key, or a certificate in a windows certificate store. See the SSLCert property for more information.

After SSLCert is set to a valid certificate and Listening is set to true, when a client connects the SSLStatus event will fire during the TLS/SSL negotiation. This is purely informational, if there is an error the Error event will fire.

If you want to require TLS/SSL client authentication, set SSLAuthenticateClients to true before setting Listening to true. This will force clients to present a certificate during TLS/SSL negotiation to be used for authorization. In this case the SSLClientAuthentication event will fire and you must set the Accept parameter within the event to true in order to accept the client's certificate and proceed with the connection.

Example Code

Oftpserver server = new Oftpserver();

server.OnAcceptConnection += new Oftpserver.OnAcceptConnectionHandler(server_OnAcceptConnection);
server.OnAcceptFile += new Oftpserver.OnAcceptFileHandler(server_OnAcceptFile);
server.OnReadyToSend += new Oftpserver.OnReadyToSendHandler(server_OnReadyToSend);
server.OnPITrail += new Oftpserver.OnPITrailHandler(server_OnPITrail);
server.OnError += new Oftpserver.OnErrorHandler(server_OnError);

server.ServerSSIDCode = "SERVERSSID";
server.ServerSFIDCode = "SERVERSFID";
server.ServerPassword = "SERVER";

server.Listening = true;

...
//Within the main loop of the application call server.DoEvents() in a loop
//to process events.

//When the ReadyToSend event fires the server can then send files to the client. To do this call the SendFile method from a worker thread.
//Alternatively, monitor the server.Connections[<ConnectionId>].ReadyToSend field to determine when files can be sent.

void server_OnAcceptConnection(object sender, OftpserverAcceptConnectionEventArgs e)
{
  server.Connections[e.ConnectionId].DownloadDirectory = myIncomingDir;
}

void server_OnAcceptFile(object sender, OftpserverAcceptFileEventArgs e)
{
  //e.Accept = false; //To reject a file set e.Accept to false
}

void server_OnPITrail(object sender, OftpserverPITrailEventArgs e)
{
  string direction = "";

  if(e.Direction == 0)
    direction = "CLIENT";
  else
    direction = "SERVER";

  Console.WriteLine(direction + ": " + e.CommandId + ": " + e.CommandDescription);
}

void server_OnError(object sender, OftpserverErrorEventArgs e)
{
  Console.WriteLine("Error: " + e.ErrorCode + ": " + e.Description);
}