Pascal (Lazarus/Delphi)

Multi-Hop SSH (SSH Through SSH)

See more SSH Examples

Demonstrates how to SSH through one SSH server to get to another SSH server. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2

The ConnectThroughSsh method is added in Chilkat version 9.5.0.55 to accomplish this task. Technically, it should be possible to chain any number of servers using the ConnectThroughSsh multiple times:

Application => ServerSSH1 => ServerSSH2 ==> ServerSSH3 => ... => ServerSSHN

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Ssh;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  ssh1: TSsh;
  hostname: string;
  port: string;
  ssh2: TSsh;
  channelNum: Integer;

begin
  success := False;

  //  This example assumes the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  ssh1 := TSsh.Create;

  //  Hostname may be an IP address or domain name:
  hostname := '192.168.1.108';
  port := 22;

  //  Connect directly to the 1st SSH server:
  success := ssh1.Connect(hostname,port);
  if (success <> True) then
    begin
      WriteLn(ssh1.LastErrorText);
      Exit;
    end;

  //  Wait a max of 15 seconds when reading responses..
  ssh1.IdleTimeoutMs := 15000;

  //  Authenticate using login/password:
  success := ssh1.AuthenticatePw('myLogin','myPassword');
  if (success <> True) then
    begin
      WriteLn(ssh1.LastErrorText);
      Exit;
    end;

  //  Connect through the 1st SSH connection to reach a 2nd SSH server.
  //  Note: Any number of SSH connections may be simultaneously tunneled through a single
  //  existing SSH connection.
  ssh2 := TSsh.Create;
  success := ssh2.ConnectThroughSsh(ssh1,'someremoteserver.com',22);
  if (success <> True) then
    begin
      WriteLn(ssh2.LastErrorText);
      Exit;
    end;

  ssh2.IdleTimeoutMs := 15000;

  //  Authenticate with ssh2...
  success := ssh2.AuthenticatePw('myLogin2','myPassword2');
  if (success <> True) then
    begin
      WriteLn(ssh2.LastErrorText);
      Exit;
    end;

  //  The application may now is connected and authenticated with ssh2.
  //  The application can do whatever it desires just as if it was directly
  //  connected to ssh2.   For example, the application might open
  //  a session channel to send commands or start a remote shell..
  channelNum := ssh2.OpenSessionChannel();
  if (channelNum < 0) then
    begin
      WriteLn(ssh2.LastErrorText);
      Exit;
    end;

  //  ...
  //  ...
  //  ...

  //  Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
  //  The connection with ssh1 is still alive, and may be used for more connections.
  ssh2.Disconnect();

  //  ...
  //  ...
  //  ...

  ssh1.Disconnect();


  ssh1.Free;
  ssh2.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.