See if user is part of Active Directory group in C# + Asp.net

Question

I need a way to see if a user is part of an active directory group from my .Net 3.5 asp.net c# application.

I am using the standard ldap authentication example off of msdn but I don't really see how to check against a group.

Thanks for any suggestions!

Answer 1

How about this

http://stackoverflow.com/questions/1032351/how-to-write-ldap-query-to-test-if-user-is-member-of-a-group

Answer 2

You could try the following code:

public bool Check_If_Member_Of_AD_Group(string username, string grouptoCheck, string domain, string ADlogin, string ADpassword)
{
    
     try {
        
        string EntryString = null;
        EntryString = "LDAP://" + domain;
        
        DirectoryEntry myDE = default(DirectoryEntry);
        
        grouptoCheck = grouptoCheck.ToLower();
        
        
        myDE = new DirectoryEntry(EntryString, ADlogin, ADpassword);
        
        DirectorySearcher myDirectorySearcher = new DirectorySearcher(myDE);
        
        myDirectorySearcher.Filter = "sAMAccountName=" + username;
        
        myDirectorySearcher.PropertiesToLoad.Add("MemberOf");
        
        SearchResult myresult = myDirectorySearcher.FindOne();
        
        int NumberOfGroups = 0;
        
        NumberOfGroups = myresult.Properties("memberOf").Count() - 1;
        
        string tempString = null;
        
        while ((NumberOfGroups >= 0)) {
            
            tempString = myresult.Properties("MemberOf").Item(NumberOfGroups);
            tempString = tempString.Substring(0, tempString.IndexOf(",", 0));
            
            tempString = tempString.Replace("CN=", "");
            
            tempString = tempString.ToLower();
            tempString = tempString.Trim();
            
            if ((grouptoCheck == tempString)) {
                
                    
                return true;
            }
            
                
            NumberOfGroups = NumberOfGroups - 1;
        }
        
            
        return false;
    }
    catch (Exception ex) {
        
        System.Diagnostics.Debugger.Break();
    }
    //HttpContext.Current.Response.Write("Error: <br><br>" & ex.ToString)
}

Answer 3

With 3.5 and System.DirectoryServices.AccountManagement this is a bit cleaner:

function List<string> GetGroupNames(string userName)
{
  var pc = new PrincipalContext(ContextType.Domain);
  var src = UserPrincipal.FindByIdentity(pc, userName).GetGroups(pc);
  var result = new List<string>();
  src.ToList().ForEach(sr => result.Add(sr.SamAccountName));
  return result;
}

Answer 4

Nick Carver's solution doesn't work for me in .NET 4.0. I get an error about an unloaded AppDomain. Instead of using that, I used this (we only have one domain). This will check groups of groups as well as direct group membership.

using System.DirectoryServices.AccountManagement;

...

using (var ctx = new PrincipalContext(ContextType.Domain, yourDomain)) {
    using (var grp = GroupPrincipal.FindByIdentity(ctx, IdentityType.Name, yourGroup)) {
        bool isInRole = grp != null && 
            grp
            .GetMembers(true)
            .Any(m => m.SamAccountName == me.Identity.Name.Replace(yourDomain + "\\", ""));
    }
}