Get parent OU of user in Active Directory using C#

Question

I want to check, if a a user is in a specific parent OU.

How can I do that?

Check below code for a clear desciption of what I am looking for.

using System.DirectoryServices.AccountManagement;

public bool IsUserInOU(string samAccountName, string OUName){

    using (var context = new PrincipalContext(ContextType.Domain))
        {
            using (var user = UserPrincipal.FindByIdentity(context, IdentityType.SamAccountName, samAccountName))
            {                    
                //Check if the user is in the OU specified in OUName
                //Something like:
                //return user.IsInOU(OUName);
            }
         }
}

public void TestIt_1(){
  //The parent OU of this user is "AwesomeOU"
  string samAccountName = "Joe";
  string OUName = "AwesomeOU";
  bool expected = true;
  bool actual = IsUserInOU(samAccountName, OUName);
  Assert.AreEqual(expected, actual);
}

public void TestIt_2(){
  //The parent OU of this user is "WhateverOU"
  string samAccountName = "Mike";
  string OUName = "AwesomeOU";
  bool expected = false;
  bool actual = IsUserInOU(samAccountName, OUName);
  Assert.AreEqual(expected, actual);
}

The Domain:

• National OU
  • Awesome OU
    • Joe
  • Whatever OU
    • Mike

Solution 1 after empi's answer

With the information given by empi, I wrote the below method to extract the first OU in the DistinguishedName. Having done that, the rest is a breeze.

public static string GetOUForUser(string samAccountName)
    {
        using (var context = new PrincipalContext(ContextType.Domain))
        {
            using (var user = UserPrincipal.FindByIdentity(context, IdentityType.SamAccountName, samAccountName))
            {
                //System.Console.WriteLine(user.DistinguishedName);
                int startIndex = user.DistinguishedName.IndexOf("OU=", 1) + 3; //+3 for  length of "OU="
                int endIndex = user.DistinguishedName.IndexOf(",", startIndex);
                var group = user.DistinguishedName.Substring((startIndex), (endIndex - startIndex));
                return group;
            }
        }
    }

Solution 2 after JPBlanc's answer

public static string GetOUForUser(string samAccountName)
    {
        using (var context = new PrincipalContext(ContextType.Domain))
        {
            using (var user = UserPrincipal.FindByIdentity(context, IdentityType.SamAccountName, samAccountName))
            {
                using (DirectoryEntry deUser = user.GetUnderlyingObject() as DirectoryEntry)
                {
                    using (DirectoryEntry deUserContainer = deUser.Parent)
                    {
                        return deUserContainer.Properties["Name"].Value.ToString();
                    }
                }
            }
        }
    }

Answer 1

Ok @Empi solution is working, but UserPrincipal is built on DirectoryEntry objects that provides a parent or container properties that just give you the object you are looking for, without using string way.

/* Retreiving a principal context
 */
PrincipalContext domainContext = new PrincipalContext(ContextType.Domain, "WM2008R2ENT:389", "dc=dom,dc=fr", "dom\\jpb", "MyPwd");

/* Retreive a user
 */
UserPrincipal user = UserPrincipal.FindByIdentity(domainContext, "user1");

/* Retreive the container
 */
DirectoryEntry deUser = user.GetUnderlyingObject() as DirectoryEntry;
DirectoryEntry deUserContainer = deUser.Parent;
Console.WriteLine (deUserContainer.Properties["distinguishedName"].Value);

Answer 2

This information is in UserPrincipal.DistinguishedName. You should check if DistinguishedName ends with "," + ou distinguished name (case insensitive). However, you must know the distingushed name of ou you're checking.

For example, if dn is: CN=Jeff Smith,OU=Sales,DC=Fabrikam,DC=COM, then it says that user is in OU=Sales,DC=Fabrikam,DC=COM ou.