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 o

Answer 1

This seems much simpler:

public bool IsInRole(string groupname)
{
    var myIdentity = WindowsIdentity.GetCurrent();
    if (myIdentity == null) return false;

    var myPrincipal = new WindowsPrincipal(myIdentity);
    var result = myPrincipal.IsInRole(groupname);

    return result;
}

Answer 2

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

public 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;
}