(Delphi DLL) IMAP SSH Tunneling (Port Forwarding)

Demonstrates how to setup and use an SSH tunnel for IMAP.

Note: This example requires Chilkat v11.0.0 or greater.

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, Imap, Email;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
imap: HCkImap;
sshHostname: PWideChar;
sshPort: Integer;
msgCount: Integer;
upperBound: Integer;
email: HCkEmail;
i: Integer;
bUid: Boolean;

begin
success := False;

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

imap := CkImap_Create();

// The SSH hostname may be a hostname or an 
// IP address, such as "192.168.1.108".
// The port is typically 22 (the standard port for SSH).
sshHostname := 'www.mysshserver.com';
sshPort := 22;

// Connect to an SSH server and establish the SSH tunnel:
success := CkImap_SshOpenTunnel(imap,sshHostname,sshPort);
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Authenticate with the SSH server via a login/password
// or with a public key.
// This example demonstrates SSH password authentication.
// Note: This is not authenticating with the IMAP server, it is
// for authenticating with the SSH server, which is separate.
success := CkImap_SshAuthenticatePw(imap,'mySshLogin','mySshPassword');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// OK, the SSH tunnel is setup.  The IMAP component may
// be used exactly the same as usual, except all communications
// are sent through the SSH tunnel.

// Connect to an IMAP server via the SSH tunnel.
// Because the SSH tunnel has been previously setup,
// this does not establish a direct connection with the IMAP
// server.  It directs the SSH server to establish the connection.

// In this example, the IMAP server requires SSL/TLS.  The TLS connection
// will be enclosed within the SSH tunnel.
CkImap_putSsl(imap,True);
CkImap_putPort(imap,993);
success := CkImap_Connect(imap,'imap.my-imap-server.com');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Authenticate with the IMAP server via the SSH tunnel.
success := CkImap_Login(imap,'myLogin','myPassword');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Select an IMAP mailbox
success := CkImap_SelectMailbox(imap,'Inbox');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// How many messages in Inbox?
msgCount := CkImap_getNumMessages(imap);
if (msgCount = 0) then
  begin
    Memo1.Lines.Add('No messages found.');
    Exit;
  end;

upperBound := 10;
if (msgCount < upperBound) then
  begin
    upperBound := msgCount;
  end;

// Download up to the 1st 10 messages.
email := CkEmail_Create();

bUid := False;
for i := 1 to upperBound do
  begin

    success := CkImap_FetchEmail(imap,False,i,bUid,email);
    if (success = False) then
      begin
        Memo1.Lines.Add(CkImap__lastErrorText(imap));
        Exit;
      end;

    Memo1.Lines.Add(CkEmail__from(email));
    Memo1.Lines.Add(CkEmail__subject(email));
    Memo1.Lines.Add('----');
  end;

// Disconnect from the IMAP server.
// The SSH tunnel remains open.
success := CkImap_Disconnect(imap);
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// It is possible to re-use the existing SSH tunnel for the next connection:
success := CkImap_Connect(imap,'imap.my-imap-server2.com');
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Review the LastErrorText to see that the connection was made via the SSH tunnel:
Memo1.Lines.Add(CkImap__lastErrorText(imap));

success := CkImap_Disconnect(imap);
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Finally, close the SSH tunnel.
success := CkImap_SshCloseTunnel(imap);
if (success = False) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

Memo1.Lines.Add('IMAP SSH tunneling example completed.');

CkImap_Dispose(imap);
CkEmail_Dispose(email);

end;