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.

Delphi 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
success: Boolean;
ssh1: HCkSsh;
ssh2: HCkSsh;
mailman: HCkMailMan;
email: HCkEmail;

begin
success := False;

// 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;