Pascal (Lazarus/Delphi)

Get XOAUTH2 Access Token from Google OAuth 2.0 Authorization Server

See more HTTP Examples

Obtains an OAUTH2 access token from the Google OAuth 2.0 Authorization Server. This is for Server to server applications using Google API's that need an access token. See https://developers.google.com/accounts/docs/OAuth2ServiceAccount 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.Cert,
  Chilkat.Http;

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

procedure RunDemo;
var
  success: Boolean;
  http: THttp;
  cert: TCert;
  iss: string;
  scope: string;
  oauth_sub: string;
  numSec: Integer;
  accessToken: string;

begin
  success := False;

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

  http := THttp.Create;

  //  --------------------------------------------------------------------------------
  //  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
  //  --------------------------------------------------------------------------------
  //  Begin by loading your Google service account key (.p12)
  cert := TCert.Create;
  success := cert.LoadPfxFile('c:/someDirectory/keys/chilkat25-cbd7b42afbd8.p12','notasecret');
  if (success <> True) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  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 := 'bob@yourcompany.com';

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

  accessToken := http.G_SvcOauthAccessToken(iss,scope,oauth_sub,numSec,cert);
  if (http.LastMethodSuccess <> True) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end
  else
    begin
      WriteLn('access token: ' + accessToken);
    end;

  //  The access token allows us to send unlimited emails while it's valid. Once it expires, we must obtain and use a new one.


  http.Free;
  cert.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.