(Delphi ActiveX) Get Google API Access Token using P12 Service Account Key

Demonstrates how to get a Google API access token using a P12 service account key.

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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
pfx: TChilkatPfx;
success: Integer;
gAuth: TChilkatAuthGoogle;
iss: WideString;
scope: WideString;
oauth_sub: WideString;
numSec: Integer;
tlsSock: TChilkatSocket;

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

// --------------------------------------------------------------------------------
// For a step-by-step guide for setting up your Google Workspace service account,
// see Setup Google Workspace Account for Sending SMTP GMail from a Service Account
// --------------------------------------------------------------------------------

// First load the PKCS12 (.p12 / .pfx) into a PFX object.
pfx := TChilkatPfx.Create(Self);
success := pfx.LoadPfxFile('qa_data/pfx/chilkat25-cbd7b42afbd8.p12','notasecret');
if (success <> 1) then
  begin
    Memo1.Lines.Add(pfx.LastErrorText);
    Exit;
  end;

gAuth := TChilkatAuthGoogle.Create(Self);
success := gAuth.SetP12(pfx.ControlInterface);

// The ISS is your service account email address ending in gserviceaccount.com.
iss := 'chilkatsvc@chilkat25.iam.gserviceaccount.com';

// The scope is always the following string:
scope := 'https://mail.google.com/';

// The sub is your company email address
oauth_sub := 'info@chilkat.xyz';

// The access token is valid for this number of seconds.
numSec := 3600;

gAuth.EmailAddress := iss;
gAuth.Scope := scope;
gAuth.ExpireNumSeconds := numSec;
gAuth.SubEmailAddress := oauth_sub;

// Connect to www.googleapis.com
tlsSock := TChilkatSocket.Create(Self);
success := tlsSock.Connect('www.googleapis.com',443,1,5000);
if (success <> 1) then
  begin
    Memo1.Lines.Add(tlsSock.LastErrorText);
    Exit;
  end;

// Send the request to obtain the access token.
success := gAuth.ObtainAccessToken(tlsSock.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(gAuth.LastErrorText);
    Exit;
  end;

// Examine the access token:
Memo1.Lines.Add('Access Token: ' + gAuth.AccessToken);
end;