Pascal (Lazarus/Delphi)

SSH Keyboard Authentication

See more SSH Examples

Demonstrates how to implement keyboard authentication with an SSH server. 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,
  Chilkat.Xml;

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

procedure RunDemo;
var
  success: Boolean;
  ssh: TSsh;
  hostname: string;
  port: Integer;
  xmlResponse: string;
  xml: TXml;

begin
  success := False;

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

  ssh := TSsh.Create;

  //  Set some timeouts, in milliseconds:
  ssh.ConnectTimeoutMs := 5000;
  ssh.IdleTimeoutMs := 15000;

  //  Connect to the SSH server.  
  //  The standard SSH port = 22
  //  The hostname may be a hostname or IP address.
  hostname := 'sftp.example.com';
  port := 22;
  success := ssh.Connect(hostname,port);
  if (success <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  Begin keyboard authentication..
  xmlResponse := ssh.StartKeyboardAuth('myLogin');
  if (ssh.LastMethodSuccess <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  If a user authentication banner was received, then your app
  //  may display it prior to prompting for the password.
  WriteLn('UserAuthBanner: ' + ssh.UserAuthBanner);

  xml := TXml.Create;

  success := xml.LoadXml(xmlResponse);
  //  Assume LoadXml succeeds for the example..
  if (xml.HasChildWithTag('success') = True) then
    begin
      WriteLn('No password required, already authenticated.');
      Exit;
    end;
  if (xml.HasChildWithTag('error') = True) then
    begin
      WriteLn('Authentication already failed.');
      Exit;
    end;

  //  See the online reference documentation for Chilkat SSH.
  //  The XML returned by StartKeyboardAuth will contain an infoRequest
  //  with one or more prompts that your application may choose to display.

  //  Call ContinueKeyboardAuth, passing in the whatever information is requires (such as the password).
  //  Typically, keyboard authentication requires one call to ContinueKeyboardAuth 
  //  using the password.  Theoretically, the SSH server could prompt for additional pieces
  //  of information.  The authentication is completed when the XML returned contains
  //  either a "success" or "error" child node.

  //  This example asumes only one call to ContinueKeyboardAuth is required.
  xmlResponse := ssh.ContinueKeyboardAuth('myPassword');
  if (ssh.LastMethodSuccess <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  success := xml.LoadXml(xmlResponse);
  //  Assume LoadXml succeeds for the example..
  if (xml.HasChildWithTag('success') = True) then
    begin
      WriteLn('SSH Keyboard Authentication Successful!');
      Exit;
    end;
  if (xml.HasChildWithTag('error') = True) then
    begin
      WriteLn('Authentication failed.');
      Exit;
    end;


  ssh.Free;
  xml.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.