Issues with System.DirectoryServices.AccountManagement.FindAll after update from .net 4 to 4.5

Question

We have updated our IIS (lets say myIIS.xx1.mydomain.com) from .NET 4 to 4.5 After updating, we can't get users from one of our domains (lets say xx3.mydomain.com). From the others (lets say xx1.mydomain.com, xx2.mydomain.com, xx5.mydomain.com) we still get the users. But it worked for all domains on .NET 4

We've used to following code to test it

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.DirectoryServices.AccountManagement;
using System.DirectoryServices;
using System.Security.Principal;

namespace ADTestApp
{
    class Program
    {
        static void Main(string[] args)
        {
            bool exit = false;
            do {
                Console.WriteLine(".NET Version: " + (IsNet45OrNewer() ? "4.5" : "4"));
                Console.WriteLine("enter search query");
                string searchQuery = Console.ReadLine();
                Console.WriteLine("querying global catalog...");
                string adServer = "mydomain.com:3268";
                string adContainer = "DC=mydomain,DC=com";
                string serviceAccountUserName = "xx5\\myusername";
                string serviceAccountPW = "mypassword";
                List<string> users = new List<string>();
                PrincipalContext principalContext = new PrincipalContext(
                                                        ContextType.Domain,
                                                        adServer,
                                                        adContainer,
                                                        serviceAccountUserName,
                                                        serviceAccountPW);
                CustomUserPrincipal user = new CustomUserPrincipal(principalContext) { EmailAddress = searchQuery, Enabled = true };
                PrincipalSearcher searcher = new PrincipalSearcher() { QueryFilter = user };

                foreach (UserPrincipal p in searcher.FindAll())
                {
                    try
                    {
                        if (p.EmailAddress != null && p.Surname != null && p.GivenName != null)
                        {
                            users.Add(p.Surname + ", " + p.GivenName + " " + p.MiddleName + " - " + p.EmailAddress);
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex);
                    }
                }

                if (users.Count > 0)
                {
                    Console.WriteLine("Results:");
                    foreach (string usr in users)
                    {
                        Console.WriteLine(usr);
                    }
                }
                else
                {
                    Console.WriteLine("no results found");
                }
            } 
            while(exit == false);
        }

        public static bool IsNet45OrNewer()
        {
            // Class "ReflectionContext" exists from .NET 4.5 onwards.
            return Type.GetType("System.Reflection.ReflectionContext", false) != null;
        }
    }
}

The 'xx3.mydomain.com' (the one which doesn't work anymore) throws the following exception:

at System.DirectoryServices.AccountManagement.UserPrincipal.get_EmailAddress()

For me, it looks like as if it is an access issue. But I still have access to this domain if .NET 4 is installed on the client. I've tested it on multiple clients and servers in multiple domains, but on all clients with .NET 4.5 this specific domain doesn't work.

Help is highly appreciated. Thanks in advance for any feedback and suggestions.

Answer 1

We couldn't find out why this was not working for this specific domain. We think that it has to do with the AD setup there. We've worked around this with the following:

namespace ADTestApp
{
    class Program
    {
        static void Main(string[] args)
        {
            bool exit = false;
            do {
                Console.WriteLine(".NET Version: " + (IsNet45OrNewer() ? "4.5" : "4"));
                Console.WriteLine("enter search query");
                string searchQuery = Console.ReadLine();
                List<AdUser> adusers = Ldap1(searchQuery);
                foreach (AdUser adUser in adusers)
                {
                    Console.WriteLine(adUser.Mail + " : " + adUser.Surname + ", " + adUser.GivenName + " (" + adUser.MiddleName + ") : " + adUser.Phone + " : " + adUser.Description + " : " + adUser.Department);
                }
            } 
            while(exit == false);
        }

        public static bool IsNet45OrNewer()
        {
            // Class "ReflectionContext" exists from .NET 4.5 onwards.
            return Type.GetType("System.Reflection.ReflectionContext", false) != null;
        }

        public static List<AdUser> Ldap1(string ldapSearch)
        {
            // configuration settings!!
            var ldapServer = "GC://mydomain.com";
            //anr = ambigous name resolution, will search for firstname, lastname, email and combination of it
            //userAccountControl:1.2.840.113556.1.4.803:=2 = only use enabled users
            string ldapFilter = (string.Format("(&(anr={0})(!userAccountControl:1.2.840.113556.1.4.803:=2))", ldapSearch));
            //string ldapAttributes = "cn,department,sn,givenName,surname,middlename,description,telephoneNumber,mail,distinguishedName,userPrincipalName,sAMAccountName,lastLogonTimestamp";

            PropertyInfo[] classProperties = typeof(AdUser).GetProperties(BindingFlags.Public);

            // return a list of users (might be an empty list)
            List<AdUser> dt = new List<AdUser>();

            // initiate searcher
            DirectoryEntry de = new DirectoryEntry(ldapServer);
            DirectorySearcher deSearch = new DirectorySearcher(de);
            try
            {
                // adjust search attributes
                deSearch.Filter = ldapFilter;
                deSearch.SearchScope = SearchScope.Subtree;
                deSearch.SizeLimit = 100;
                deSearch.ServerTimeLimit = new TimeSpan(30);

                // define attributes to be returned by a search
                foreach (PropertyInfo s in classProperties)
                {
                    deSearch.PropertiesToLoad.Add(s.Name.ToLower());
                }
                // do search
                SearchResultCollection results = deSearch.FindAll();
                // analyze data
                foreach (SearchResult result in results)
                {
                    var u = new AdUser();
                    var p = result.Properties;
                    if (p.PropertyNames != null)
                    {
                        foreach (string key in p.PropertyNames)
                        {
                            foreach (var values in p[key])
                            {
                                switch (key.ToLower())
                                {
                                    case "adspath": // always returned
                                        u.AdsPath = values.ToString();
                                        break;
                                    case "cn":
                                        u.CN = values.ToString();
                                        break;
                                    case "sn":
                                        u.Surname = values.ToString();
                                        u.SN = values.ToString();
                                        break;
                                    case "givenname":
                                        u.GivenName = values.ToString();
                                        break;
                                    case "surname":
                                        u.Surname = values.ToString();
                                        break;
                                    case "middlename":
                                        u.MiddleName = values.ToString();
                                        break;
                                    case "department":
                                        u.Department = values.ToString();
                                        break;
                                    case "description":
                                        u.Description = values.ToString();
                                        break;
                                    case "mail":
                                        u.Mail = values.ToString();
                                        break;
                                    case "distinguishedname":
                                        u.DistinguishedName = values.ToString();
                                        int idx = u.DistinguishedName.IndexOf("DC=");
                                        string x = u.DistinguishedName.Substring(idx + 3);
                                        idx = x.IndexOf(",");
                                        u.Domain = (idx > 0) ? x.Substring(0, idx) : x;
                                        break;
                                    case "telephonenumber":
                                        u.Phone = values.ToString();
                                        break;
                                    case "userprincipalname":
                                        u.UserPrincipalName = values.ToString();
                                        break;
                                    case "samaccountname":
                                        u.Account = values.ToString();
                                        break;
                                    default:
                                        // log entry??
                                        break;
                                } // end switch
                            } // foreach values
                        } // foreach key
                    }
                    dt.Add(u);
                }
                de.Close();
            }
            catch (Exception ex) { throw ex; }
            finally
            {
                deSearch.Dispose();
                de.Dispose();
            }
            return dt;
        }
    }
    public class AdUser
    {
        public string AdsPath { get; set; }
        public string CN { get; set; }
        public string GivenName { get; set; }
        public string Surname { get; set; }
        public string MiddleName { get; set; }
        public string Description { get; set; }
        public string SN { get; set; }
        public string DN { get; set; }
        public string Mail { get; set; }
        public string Phone { get; set; }
        public string Department { get; set; }
        public string DistinguishedName { get; set; }
        public string UserPrincipalName { get; set; }
        public string Account { get; set; }
        public string Domain { get; set; }
    }
}