Pascal (Lazarus/Delphi)

GMail IMAP Authentication using OAuth2 Access Token

See more GMail SMTP/IMAP/POP Examples

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. 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.Imap,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  json: TJsonObject;
  accessToken: string;
  imap: TImap;

begin
  success := False;

  //  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 := TJsonObject.Create;
  success := json.LoadFile('qa_data/tokens/_gmailFullAccess.json');
  if (success <> True) then
    begin
      WriteLn('Failed to load GMail access token file.');
      Exit;
    end;
  accessToken := json.StringOf('access_token');

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

  imap.Ssl := True;
  imap.Port := 993;

  //  Connect to the GMail IMAP server.
  success := imap.Connect('imap.gmail.com');
  if (success <> True) then
    begin
      WriteLn(imap.LastErrorText);
      Exit;
    end;

  //  Indicate that XOAUTH2 authentication is to be used:
  imap.AuthMethod := 'XOAUTH2';

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


  json.Free;
  imap.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.