Bitrix API: does advanced management of rights to elements and sections of infoblocks through the API exist?

Question

API

Due to the large number of users and sections of infoblocks to which rights must be divided among them, it became necessary to create a separate interface in the form of a matrix that allows you to switch the access mode to the corresponding section with one click. Searches on the Internet led only to the CIBlockRights, CIBlockSectionRights and CIBlockElementRights classes, the description of which was not found anywhere. Understanding these by no means independent classes seems to me a rather costly task. Please help me figure out how to add / remove the rights of a specific user to a specific section using the API?

Answer 1

Found a solution. Thanks vtyrtov .
I threw a function that changes the user's rights to the section:

function chmodSectionAccess($bid, $sid, $uid, $tid, $mod){
  $bid = intval($bid); // идентификатор инфоблока
  $sid = intval($sid);  // идентификатор раздела
  $uid = intval($uid); // идентификатор пользователя
  $tid = intval($tid); // идентификатор уровня доступа
  $mod = ($mod === "Y"); // дать/убрать (Y|N) права на раздел 
  
  if ($bid > 0 && $sid > 0 && $uid > 0 && $tid > 0) {
    
// получаем текущий массив прав
    $ob = new CIBlockSectionRights($bid, $sid);
    $ar = $ob->GetRights(); 
    
    if ($mod) { 
// дополняем в массив новый элемент
      $ar["n0"] = array(
        "GROUP_CODE" =>"U" . $uid,
        "TASK_ID" => $tid,
        "XML_ID" => "API"
      );
    } else {
      // находим совпадающее со входными данными и исключаем из массива
      foreach($ar as $i => $r) {
        if ($r["GROUP_CODE"] === "U" . $uid && 
          $r["TASK_ID"] === $tid) unset($ar[$i]);
      }
    }
// записываем новые права из массива (другие не наследуемые будут удалены)
    $ob->SetRights($ar); 
    
    return true;
  } else {
    return false;
  }
}

Hope this solution helps someone.
I will be glad if you tell me an even easier way.