LDAP Error: The user has insufficient access rights. : LdapErr: DSID-0C09099D, comment: Error processing control, - active-directory

Question

I want to get incremental changes from Active Directory using C# and for that I am trying to build a solution as mentioned in the following article (using DirSync Control).
https://learn.microsoft.com/en-us/windows/win32/ad/polling-for-changes-using-the-dirsync-control
However, I am facing following problems:
When using following code, I am getting exception that The user has insufficient access rights. The user is part of administrators group.
What more permission needs to be given to that account? And how?
LdapConnection connection = new LdapConnection("adfs.fed.zzz.com");
connection.SessionOptions.ProtocolVersion = 3;
connection.Credential = new System.Net.NetworkCredential("adfsfed\\username", "password");
connection.AuthType = AuthType.Basic;
connection.Bind();
var filter = "(&(objectClass=*))";
var searchRequest = new SearchRequest("", filter, SearchScope.Subtree, properties);
DirSyncRequestControl dirSyncRC = new DirSyncRequestControl(null, DirectorySynchronizationOptions.None);
searchRequest.Controls.Add(dirSyncRC);
var response = connection.SendRequest(searchRequest) as SearchResponse;
If I am using below code, then I am not getting any exception but getting empty result in cookie.
String[] properties = { "objectGUID", "sAMAccountName", "displayName", "mail", "member" };
String filter = "(|(objectClass=group)(objectClass=user))";
DirectorySearcher directorySearcher = new DirectorySearcher(myLdapConnection, filter, properties);
var dSynch = new DirectorySynchronization(System.DirectoryServices.DirectorySynchronizationOptions.None);
directorySearcher.DirectorySynchronization = dSynch;
directorySearcher.SearchScope = System.DirectoryServices.SearchScope.Subtree;
var results = directorySearcher.FindAll();
var cookie = dSynch.GetDirectorySynchronizationCookie();
Considerations:
I have only one Domain Controller
I am system admin. So, I can assign appropriate permissions to the user.
Please help.

Answer 1

• Your user ID will need the "Replicating Directory Changes" permission and should be a member of ‘Domain Administrators’ group to use the DirSync LDAP control extension. But please note that it pretty much can read anything in the directory partition, regardless of standard permissions. Though they cannot change anything.
However - you may have some attributes that are sensitive in your directory. Please refer the powershell script in the below link and execute it with the user ID after giving appropriate permissions using C#. It is a dirsync code that will retrieve even attributes like ‘userAccountControl, userparameters, msexchuseraccountcontrol, pwdlastset, unicodePwd (BLANK, So no hashed domain password is returned), lockouttime, accountexpires, unixuserpassword(Its Hash is returned).
http://dloder.blogspot.com/2012/01/powershell-dirsync-sample.html

Answer 2

Based on the response given by #KartikBhiwapurkar-MT, I figured out the bug.
The error The user has insufficient access rights is completely misleading (User had already Replicating Directory Changes rights and was part of Domain Administrators group). The error was happening in System.DirectoryServices.Protocols is that I was passing out "" as first parameter (distinguishedName)
new SearchRequest("", filter, SearchScope.Subtree, properties);
but it should have been passed as
new SearchRequest("DC=adfs,DC=fed,DC=zzz,DC=com", filter, SearchScope.Subtree, properties);
I was getting empty cookie in System.DirectoryServices because of bug in latest nuget package (6.0.0). At the time of writing this answer, the bug is still open.
Reference to bug