SSH Tunnel (Port Forwarding via direct-tcpip channel)

Demonstrates how to create an SSH tunnel to a remote hostname:port via a direct-tcpip channel.

Download Chilkat 32-bit SSH / SFTP ActiveX (.msi)

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uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATRSALib_TLB,
    CHILKATSSHLib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ssh: TChilkatSsh;
success: Integer;
hostname: String;
port: Integer;
channelNum: Integer;
httpReq: String;
caseSensitive: Integer;
matchStr: String;
responseHeader: String;
numBytesRead: Integer;
pollTimeoutMs: Integer;
htmlBody: String;

begin
//  Important: It is helpful to send the contents of the
//  ssh.LastErrorText property when requesting support.

ssh := TChilkatSsh.Create(Self);

//  Any string automatically begins a fully-functional 30-day trial.
success := ssh.UnlockComponent('Anything for 30-day trial');
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Connect to an SSH server:

//  Hostname may be an IP address or hostname:
hostname := '192.168.1.117';
port := 22;

success := ssh.Connect(hostname,port);
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Wait a max of 5 seconds when reading responses..
ssh.IdleTimeoutMs := 5000;

//  Authenticate using login/password:
success := ssh.AuthenticatePw('chilkat','myPassword');
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Open a direct-tcpip channel.  We want the SSH server to connect
//  to www.chilkatsoft.com, port 80 (i.e. the web server).
//  Data sent through the SSH tunnel is forwarded to the remote
//  host:port.  (Note: The remote host:port does not need to be
//  a web server.  It can be anything.  It can be your own
//  customer application server that listens on a port, or any
//  other type of server.)
//  When we read from the SSH channel, we'll be reading data
//  sent from the remote host:port (i.e. the web server in this
//  example).

channelNum := ssh.OpenDirectTcpIpChannel('www.chilkatsoft.com',80);
if (channelNum < 0) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Build a simple HTTP GET request for http://www.chilkatsoft.com/xyz.html
httpReq := 'GET /xyz123.html HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n';

//  Send the HTTP request:
success := ssh.ChannelSendString(channelNum,httpReq,'ansi');
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Get the HTTP response.
//  First read the HTTP response header which ends with a double CRLF.
//  Calling ChannelReceiveUntilMatch will receive until match string is seen,
//  or until a timeout occurs (IdleTimeoutMs property).  ChannelReceiveUntilMatch
//  may read beyond the match string, but it will stop reading as soon as the match
//  string is seen.
caseSensitive := 0;
matchStr := '\r\n\r\n';
success := ssh.ChannelReceiveUntilMatch(channelNum,matchStr,'ansi',caseSensitive);
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Extract the HTTP header from the receive buffer.
//  (GetReceiveTextS extracts up to and including the match string from the receive buffer)

responseHeader := ssh.GetReceivedTextS(channelNum,matchStr,'ansi');
Memo1.Lines.Add('---- HTTP Response Header ----');
Memo1.Lines.Add(responseHeader);

//  Now get the body of the HTTP response (this is the HTML content
//  of http://www.chilkatsoft.com/xyz.html
//  It's possible we've already received the entire HTTP response in the
//  call to ChannelReceiveUntilMatch.  Therefore, we'll poll for any remaining data
//  and wait a max of .2 seconds.

pollTimeoutMs := 200;
numBytesRead := ssh.ChannelPoll(channelNum,pollTimeoutMs);
//  We're not checking for an error here.
//  A return value of -2 means that no data was available and the poll simply timed out (not an error)
//  A return value of -1 indicates an error.
//  A return value greater than 0 indicates that additional data was received.

Memo1.Lines.Add('---- HTML BODY ----');

//  Extract the remainder of the accumulated data in the internal receive buffer.
//  This should be our HTML body:

htmlBody := ssh.GetReceivedText(channelNum,'ansi');
Memo1.Lines.Add(htmlBody);

//  Close the channel:
success := ssh.ChannelSendClose(channelNum);
if (success <> 1) then
  begin
    ShowMessage(ssh.LastErrorText);
    Exit;
  end;

//  Disconnect
ssh.Disconnect();
end;