ASP.Net Core : get members of Active Directory group - asp.net

Question

I'm wondering how I could get a list of members of an AD group.
Checking if an entered password of a user is correct works perfectly fine. For this I'm using Novell's Ldap.NetStandard:
private bool IsUserValid(string userName,string userPassword)
{
try{
using (var connection = new LdapConnection { SecureSocketLayer = false })
{
connection.Connect("test.local", LdapConnection.DEFAULT_PORT);
connection.Bind(userDn, userPassword);
if (connection.Bound)
{
return true;
}
}
}
catch (LdapException ex)
{
Console.WriteLine(ex.Massage);
}
return false;
}
What I want now is something like this:
bool isUserInGroup("testUser","testGroup");
The problem is I can't get my method working:
public bool IsUserMemberOfGroup(string userName,string groupName)
{
var ldapConn = GetConnection();
var searchBase = "";
var filter = $"(&(objectClass=group)(cn={groupName}))";
var search = ldapConn.Search(searchBase, LdapConnection.SCOPE_BASE, filter, null, false);
while (search.hasMore())
{
var nextEntry = search.next();
if (nextEntry.DN == userName)
return true;
}
return false;
}
What ever I'm doing, I'm not getting back any value from my Ldap.Search()...

Answer 1

Now there is an implementation of System.DirectoryServices.AccountManagement for .NET Core 2. It is available via nuget.
With this package you are able to things like that:
using (var principalContext = new PrincipalContext(ContextType.Domain, "YOUR AD DOMAIN"))
{
var domainUsers = new List<string>();
var userPrinciple = new UserPrincipal(principalContext);
// Performe search for Domain users
using (var searchResult = new PrincipalSearcher(userPrinciple))
{
foreach (var domainUser in searchResult.FindAll())
{
if (domainUser.DisplayName != null)
{
domainUsers.Add(domainUser.DisplayName);
}
}
}
}
This performs a search for the user in your domain.Nearly the same is possible for searching your group. The way I used to search my AD (description in my question) is now obsolet:
Checking if an entered password of a user is correct works perfectly
fine. For this I'm using Novell's Ldap.NetStandard:

Answer 2

How about:
HttpContext.User.IsInRole("nameOfYourAdGroup");
(namespace System.Security.Claims)