(Delphi DLL) GMail IMAP Authentication using OAuth2 Access Token

Demonstrates how to do IMAP OAuth2 authentication for GMail (or any other IMAP mail server supporting OAuth2 authentication). This example assumes an OAuth2 access token was previously obtained.

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, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
json: HCkJsonObject;
success: Boolean;
accessToken: PWideChar;
imap: HCkImap;

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

// See Get GMail IMAP OAuth2 Access Token for Desktop App 
// for sample code showing how to obtain a GMail IMAP read/write access token.

// In this example, our access token was previously saved to the following file which contains JSON like this:
// 	{
// 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
// 	 "token_type": "Bearer",
// 	 "expires_in": 3600,
// 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
// 	}
// 
json := CkJsonObject_Create();
success := CkJsonObject_LoadFile(json,'qa_data/tokens/_gmailFullAccess.json');
if (success <> True) then
  begin
    Memo1.Lines.Add('Failed to load GMail access token file.');
    Exit;
  end;
accessToken := CkJsonObject__stringOf(json,'access_token');

// Do OAuth2 authentication by using the access token as the password in the Login method below...
imap := CkImap_Create();

CkImap_putSsl(imap,True);
CkImap_putPort(imap,993);

// Connect to the GMail IMAP server.
success := CkImap_Connect(imap,'imap.gmail.com');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
    Exit;
  end;

// Indicate that XOAUTH2 authentication is to be used:
CkImap_putAuthMethod(imap,'XOAUTH2');

// Login
// Use the email address of the GMail account that granted authorization.
success := CkImap_Login(imap,'user@gmail.com',accessToken);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkImap__lastErrorText(imap));
  end
else
  begin
    Memo1.Lines.Add('Successfully authenticated with GMail IMAP using XOAUTH2!');
  end;

CkJsonObject_Dispose(json);
CkImap_Dispose(imap);

end;