Question

I found several sample on Stackoverflow and over the web but any work. I’d like to check is a user is member of a specific group (or subgroup). When I try with a username who not exist in the Active Directiory, I get an Exception (normal, see the code)

Below the current code I use :

using System;
using System.DirectoryServices;
using System.Collections.Generic;

static class Program
{
    public static string GetUserContainerName(string userName)
    {
        DirectoryEntry entry = new DirectoryEntry("LDAP://xxxxxxx:389/DC=be,DC=kb,DC=int");
        DirectorySearcher mySearcher = new DirectorySearcher(entry);
        mySearcher.Filter = string.Format("(&(sAMAccountName={0}))", userName);
        mySearcher.SearchScope = SearchScope.Subtree; //Search from base down to ALL children.
        SearchResultCollection result = mySearcher.FindAll();
        if (result.Count == 0)
            throw new ApplicationException(string.Format("User '{0}' Not Found in Active Directory.", userName));
        return result[0].GetDirectoryEntry().Name.Replace("CN=", string.Empty);
    }

    public static bool IsUserMemberOfGroup(string username, string groupname)
    {
        DirectoryEntry entry = new DirectoryEntry("LDAP://xxxxxxx.be.kb.int:389/DC=be,DC=kb,DC=int");
        DirectorySearcher mySearcher = new DirectorySearcher(entry);
        mySearcher.Filter = string.Format(String.Format("(member:1.2.840.113556.1.4.1941:=(cn={0},cn=users,DC=be,DC=kb,DC=int))", username), GetUserContainerName(username));
        mySearcher.SearchScope = SearchScope.Subtree; //Search from base down to ALL children.
        SearchResultCollection result = mySearcher.FindAll();

        for (int i = 0; i < result.Count - 1; i++)
        {
            if (result[i].Path.ToUpper().Contains(string.Format("CN={0}", groupname.ToUpper())))
                return true; //Success - group found
        }
        return false;
    }

    static void Main(string[] args)
    {
        var res = IsUserMemberOfGroup("MyUSer", "MY_GROUP_TO_CHECK");
        Console.WriteLine(res.ToString());
    }
}

Answer 1

Why not use what is already in the framework.

Take a look at this: http://msdn.microsoft.com/en-us/library/fs485fwh(VS.85).aspx

WindowsIdentity identity =     WindowsIdentity.GetCurrent();
WindowsPrincipal principal = new WindowsPrincipal(identity);
principal.IsInRole("role name");