Estoy tratando de iniciar sesión en el sitio web de instagram usando idhttp en Delphi. Utilicé herramientas de desarrollador de Google Chrome para obtener los datos y esto es lo que he intentado hasta ahora.

procedure TForm1.Button1Click(Sender: TObject);
var
  lHTTP: TIdHTTP;
  S,M : TStrings;
  IdSSL: TIdSSLIOHandlerSocketOpenSSL;
begin
  S := TStringList.Create;
  S.Add('username :' +Edit1.Text);
  S.Add('password :'+ Edit2.Text);
  lHTTP := TIdHTTP.Create(nil);
  lHTTP.ReadTimeout := 30000;
  lHTTP.HandleRedirects := True;
  IdSSL := TIdSSLIOHandlerSocketOpenSSL.Create(lHTTP);
  IdSSL.SSLOptions.Method := sslvTLSv1;
  IdSSL.SSLOptions.Mode := sslmClient;
  lHTTP.IOHandler := IdSSL;
  lHTTP.Request.CustomHeaders.Add('x-csrftoken:'+ Edit3.Text);
  lHTTP.Request.CustomHeaders.Add('x-instagram-ajax:1');
  lHTTP.Request.CustomHeaders.Add(' x-requested-with:XMLHttpRequest');
  lHTTP.Request.CustomHeaders.Add('referer:https://www.instagram.com/');
  lHTTP.Request.ContentType := 'application/x-www-form-urlencoded';
  lHTTP.Request.UserAgent := 'Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.76 Mobile Safari/537.36';
  lHTTP.Post('https://www.instagram.com/accounts/login/ajax/', S);
  Memo1.Lines.Add(lHTTP.Request.ToString);
end;

Obtengo el token de acceso manualmente por ahora, solo para probar el código. yo obtengoHTTP/1.1 403 Forbidden. !

ACTUALIZAR

Esta es la información de las cookies.

Response Headers
set-cookie:csrftoken=e3YbQ1FobxgMGcLHRAkj****ML97psae; expires=Tue, 20-Jun-2017 19:09:21 GMT; Max-Age=31449600; Path=/
set-cookie:s_network=; expires=Tue, 21-Jun-2016 20:09:21 GMT; Max-Age=3600; Path=/
set-cookie:sessionid=IGSC3074cea6684a55981cc30d3c5222ed9e46,75db0aa4665d3f5b7ed4ae09be01b6%3AugN5uNRztrtVarx6LuheBkv5tNuaVHrL%3A%7B%22_token_ver%22%3A2%2C%22_auth_user_id%22%3A348733484%2C%22_token%22%3A%22348733484%3A6dXogo2jTCkOf29JEUxHavzxqp9iUOr4%3Aa4f855cabbd5c5d2999538a8ec9093c6a59af65e7306998a5647341bdd691158%22%2C%22asns%22%3A%7B%225.37.149.220%22%3A28885%2C%22time%22%3A1466536160%7D%2C%22_auth_user_backend%22%3A%22accounts.backends.CaseInsensitiveModelBackend%22%2C%22last_refreshed%22%3A1466536160.338314%2C%22_platform%22%3A4%2C%22_auth_user_hash%22%3A%22%22%7D; expires=Mon, 19-Sep-2016 19:09:21 GMT; httponly; Max-Age=7776000; Path=/
set-cookie:ds_user_id=348733***; expires=Mon, 19-Sep-2016 19:09:21 GMT; Max-Age=


Request Headers
set-cookie:sessionid=IGSC3074cea6684a55981cc30d3c5222ed9e4675db0aa4665d3f5b7ed4ae09be01b6%3AugN5uNRztrtVarx6LuheBkv5tNuaVHrL%3A%7B%22_token_ver%22%3A2%2C%22_auth_user_id%22%3A348***484%2C%22_token%22%3A%22348733484%3A6dXogo2jTCkOf29JEUxHavzxqp9iUOr4%3Aa4f855cabbd5c5d2999538a8ec9093c6a59af65e7306998a5647341bdd691158%22%2C%22asns%22%3A%7B%225.37.149.220%22%3A28885%2C%22time%22%3A1466536160%7D%2C%22_auth_user_backend%22%3A%22accounts.backends.CaseInsensitiveModelBackend%22%2C%22last_refreshed%22%3A1466536160.338314%2C%22_platform%22%3A4%2C%22_auth_user_hash%22%3A%22%22%7D; expires=Mon, 19-Sep-2016 19:09:21 GMT; httponly; Max-Age=7776000; Path=/
set-cookie:ds_user_id=348733***; expires=Mon, 19-Sep-2016 19:09:21 GMT; Max-Age=7776000; Path=/