(Delphi DLL) SMTP over Multiple Hop SSH

Demonstrates how to send email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => SmtpServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, MailMan, Email, Ssh;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ssh1: HCkSsh;
success: Boolean;
ssh2: HCkSsh;
mailman: HCkMailMan;
email: HCkEmail;

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

ssh1 := CkSsh_Create();

// Connect directly to the 1st SSH server.
success := CkSsh_Connect(ssh1,'serverssh1.com',22);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh1));
    Exit;
  end;

// Authenticate using login/password:
success := CkSsh_AuthenticatePw(ssh1,'ssh1Login','ssh1Password');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh1));
    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 := CkSsh_Create();
success := CkSsh_ConnectThroughSsh(ssh2,ssh1,'serverssh2.com',22);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh2));
    Exit;
  end;

// Authenticate with ssh2...
success := CkSsh_AuthenticatePw(ssh2,'ssh2Login','ssh2Password');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(ssh2));
    Exit;
  end;

mailman := CkMailMan_Create();

// Tell the mailman object to connect to the SMTP server though the ssh2 tunnel (which itself is routed through ssh1).
// The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => SMTPServer
success := CkMailMan_UseSsh(mailman,ssh2);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Set the SMTP server.
CkMailMan_putSmtpHost(mailman,'smtp.someserver.com');

// Set the SMTP login/password (if required)
CkMailMan_putSmtpUsername(mailman,'myUsername');
CkMailMan_putSmtpPassword(mailman,'myPassword');

// Create a new email object
email := CkEmail_Create();

CkEmail_putSubject(email,'This is a test');
CkEmail_putBody(email,'This is a test');
CkEmail_putFrom(email,'Chilkat Support <support@chilkatsoft.com>');
success := CkEmail_AddTo(email,'Chilkat Admin','admin@chilkatsoft.com');

success := CkMailMan_SendEmail(mailman,email);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Close the connection with the server.  This closes the tunnel through ssh2.
success := CkMailMan_CloseSmtpConnection(mailman);
if (success <> True) then
  begin
    Memo1.Lines.Add('Connection to SMTP server not closed cleanly.');
  end;

Memo1.Lines.Add('Mail Sent!');

// 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.
CkSsh_Disconnect(ssh2);

CkSsh_Disconnect(ssh1);

CkSsh_Dispose(ssh1);
CkSsh_Dispose(ssh2);
CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);

end;