domain authentication filter

domainAuthentication.cs

#region Authentication
 
  	private List<string> getGroupNames(string userName)
		{
			using (var pc = new PrincipalContext(ContextType.Domain, _domainUri))
			{
				var identity = UserPrincipal.FindByIdentity(pc, userName);
				if (identity == null)
					return new List<string>();
 
				var src = identity.GetGroups(pc);
				var result = src.Select(sr => sr.SamAccountName).ToList();
				//var result = new List<string>();
				//src.ToList().ForEach(sr => result.Add(sr.SamAccountName));
				return result;
			}
		}
 
		private bool validateCred(string username, string password)
		{
			using (var context = new PrincipalContext(ContextType.Domain, _domainUri))
			{
				return context.ValidateCredentials(username, password);
			}
		}
 
#endregion