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How to Get the list of all User Accounts of Windows in C#? [duplicate]

How can I get a list of users from active directory? Is there a way to pull username, firstname, lastname? I saw a similar post where this was used:
PrincipalContext ctx = new PrincipalContext(ContextType.Domain, "YOURDOMAIN");
I have never done anything with active directory so I am completely lost. Any help would be greatly appreciated!

If you are new to Active Directory, I suggest you should understand how Active Directory stores data first.
Active Directory is actually a LDAP server. Objects stored in LDAP server are stored hierarchically. It's very similar to you store your files in your file system. That's why it got the name Directory server and Active Directory
The containers and objects on Active Directory can be specified by a distinguished name. The distinguished name is like this CN=SomeName,CN=SomeDirectory,DC=yourdomain,DC=com. Like a traditional relational database, you can run query against a LDAP server. It's called LDAP query.
There are a number of ways to run a LDAP query in .NET. You can use DirectorySearcher from System.DirectoryServices or SearchRequest from System.DirectoryServices.Protocol.
For your question, since you are asking to find user principal object specifically, I think the most intuitive way is to use PrincipalSearcher from System.DirectoryServices.AccountManagement. You can easily find a lot of different examples from google. Here is a sample that is doing exactly what you are asking for.
using (var context = new PrincipalContext(ContextType.Domain, "yourdomain.com"))
{
using (var searcher = new PrincipalSearcher(new UserPrincipal(context)))
{
foreach (var result in searcher.FindAll())
{
DirectoryEntry de = result.GetUnderlyingObject() as DirectoryEntry;
Console.WriteLine("First Name: " + de.Properties["givenName"].Value);
Console.WriteLine("Last Name : " + de.Properties["sn"].Value);
Console.WriteLine("SAM account name : " + de.Properties["samAccountName"].Value);
Console.WriteLine("User principal name: " + de.Properties["userPrincipalName"].Value);
Console.WriteLine();
}
}
}
Console.ReadLine();
Note that on the AD user object, there are a number of attributes. In particular, givenName will give you the First Name and sn will give you the Last Name. About the user name. I think you meant the user logon name. Note that there are two logon names on AD user object. One is samAccountName, which is also known as pre-Windows 2000 user logon name. userPrincipalName is generally used after Windows 2000.

If you want to filter y active accounts add this to Harvey's code:
UserPrincipal userPrin = new UserPrincipal(context);
userPrin.Enabled = true;
after the first using. Then add
searcher.QueryFilter = userPrin;
before the find all. And that should get you the active ones.

PrincipalContext for browsing the AD is ridiculously slow (only use it for .ValidateCredentials, see below), use DirectoryEntry instead and .PropertiesToLoad() so you only pay for what you need.
Filters and syntax here:
https://social.technet.microsoft.com/wiki/contents/articles/5392.active-directory-ldap-syntax-filters.aspx
Attributes here:
https://learn.microsoft.com/en-us/windows/win32/adschema/attributes-all
using (var root = new DirectoryEntry($"LDAP://{Domain}"))
{
using (var searcher = new DirectorySearcher(root))
{
// looking for a specific user
searcher.Filter = $"(&(objectCategory=person)(objectClass=user)(sAMAccountName={username}))";
// I only care about what groups the user is a memberOf
searcher.PropertiesToLoad.Add("memberOf");
// FYI, non-null results means the user was found
var results = searcher.FindOne();
var properties = results?.Properties;
if (properties?.Contains("memberOf") == true)
{
// ... iterate over all the groups the user is a member of
}
}
}
Clean, simple, fast. No magic, no half-documented calls to .RefreshCache to grab the tokenGroups or to .Bind or .NativeObject in a try/catch to validate credentials.
For authenticating the user:
using (var context = new PrincipalContext(ContextType.Domain))
{
return context.ValidateCredentials(username, password);
}

Certainly the credit goes to #Harvey Kwok here, but I just wanted to add this example because in my case I wanted to get an actual List of UserPrincipals. It's probably more efficient to filter this query upfront, but in my small environment, it's just easier to pull everything and then filter as needed later from my list.
Depending on what you need, you may not need to cast to DirectoryEntry, but some properties are not available from UserPrincipal.
using (var searcher = new PrincipalSearcher(new UserPrincipal(new PrincipalContext(ContextType.Domain, Environment.UserDomainName))))
{
List<UserPrincipal> users = searcher.FindAll().Select(u => (UserPrincipal)u).ToList();
foreach(var u in users)
{
DirectoryEntry d = (DirectoryEntry)u.GetUnderlyingObject();
Console.WriteLine(d.Properties["GivenName"]?.Value?.ToString() + d.Properties["sn"]?.Value?.ToString());
}
}

Include the System.DirectoryServices.dll, then use the code below:
DirectoryEntry directoryEntry = new DirectoryEntry("WinNT://" + Environment.MachineName);
string userNames="Users: ";
foreach (DirectoryEntry child in directoryEntry.Children)
{
if (child.SchemaClassName == "User")
{
userNames += child.Name + Environment.NewLine ;
}
}
MessageBox.Show(userNames);

Trying to test LDAP-based authentication from forumsys?

I've not done any LDAP-based authentication before and also I've not worked with any LDAP server before. So I need a free online LDAP server to play with, I've found this https://www.forumsys.com/tutorials/integration-how-to/ldap/online-ldap-test-server/
However my code is not working (or the info there has become invalid, I'm not sure), the result of authen is always false, here is my code:
path = "ldap.forumsys.com:389/dc=example,dc=com";
using (var pc = new PrincipalContext(ContextType.Domain, null, path))
{
//this always returns false
var ok = pc.ValidateCredentials("read-only-admin", "password");
}
Could you make it work on your side? Or at least please assert that the info there is invalid, in that case if possible please give me some other info (from other free LDAP servers for testing).

I don't think the server is Active Directory. You can refer to this question for how to connect to a LDAP server in C#.
Second Edit:
Checked with MS people. They also suggest LdapConnection.
https://github.com/dotnet/corefx/issues/31809
Edit:
I can use DirectoryEntry to bind to the server. I am not sure why PrincipalContext does not work, but you can try this way.
Here is a sample code for validating user and password.
Tested on .Net Core 2.1, with System.DirectoryServices package 4.5.0.
using System;
using System.DirectoryServices;
namespace LDAPTest
{
class Program
{
static void Main(string[] args)
{
string ldapServer = "LDAP://ldap.forumsys.com:389/dc=example,dc=com";
string userName = "cn=read-only-admin,dc=example,dc=com";
string password = "password";
var directoryEntry = new DirectoryEntry(ldapServer, userName, password, AuthenticationTypes.ServerBind);
// Bind to server with admin. Real life should use a service user.
object obj = directoryEntry.NativeObject;
if (obj == null)
{
Console.WriteLine("Bind with admin failed!.");
Environment.Exit(1);
}
else
{
Console.WriteLine("Bind with admin succeeded!");
}
// Search for the user first.
DirectorySearcher searcher = new DirectorySearcher(directoryEntry);
searcher.Filter = "(uid=riemann)";
searcher.PropertiesToLoad.Add("*");
SearchResult rc = searcher.FindOne();
// First we should handle user not found.
// To simplify, skip it and try to bind to the user.
DirectoryEntry validator = new DirectoryEntry(ldapServer, "uid=riemann,dc=example,dc=com", password, AuthenticationTypes.ServerBind);
if (validator.NativeObject.Equals(null))
{
Console.WriteLine("Cannot bind to user!");
}
else
{
Console.WriteLine("Bind with user succeeded!");
}
}
}
}
Reference:
https://www.c-sharpcorner.com/forums/ldap-authentication2

I figure it out too, and having no LDAP knowledge I´ve come up with this.
The problem in your solution may be first, you are using "ldap://" instead of "LDAP://", since it was something I came into when coding this. But I use System.DirectoryServices library.
I tested against this magnificent free to test LDAP server
var path = "LDAP://ldap.forumsys.com:389/dc=example,dc=com";
var user = $#"uid={username},dc=example,dc=com";
var pass = "password";
var directoryEntry = new DirectoryEntry(path, user, pass, AuthenticationTypes.None);
var searcher = new DirectorySearcher(directoryEntry);
searcher.PropertiesToLoad.Add("*");
var searchResult = searcher.FindOne();
I don´t understand exactly what all of this lines does, however, and lookign for a solution I found some recommendations.
on the path the "LDAP://" string should be on block mayus.
in the user, sometimes you need to use "cn=username-admin" for validating admins, be sure to also set Authentication type to ServerBind.

It seems as if read-only-admin is not a valid user. Try replacing:
var ok = pc.ValidateCredentials("read-only-admin", "password");
with
var ok = pc.ValidateCredentials("tesla", "password");
If that does not work, the other other issue would be on the LDAP's server side.
A good option regardless is to set up an Amazon Web Services EC2 server (it is free) and load Windows Server onto it. This gives you your own server and you learn how to set up an LDAP server (which is pretty easy).

LDAP not finding user when user on a different domain

Firstly, I am new to AD / LDAP etc so this might be something obvious (I do hope so?!) and apologise if my terminology is not right, please correct me.
We have two domains, BUSINESS (being a Global Group) and AUTH (being a Domain Local Group) with one way trust between them (AUTH trusts BUSINESS).
The following code works on MachineA sitting on BUSINESS domain when string LDAPServer = "BUSINESS".
But when run on MachineB sitting on AUTH domain with string LDAPServer = "AUTH", it shows the message 2f. User Not Found as the user returned in Step 2 is NULL. If I change string LDAPServer = "BUSINESS" then an exception is thrown in Step 1 that the domain controller cannot be found.
As a note the fact that LDAPServiceAccount can be a BUSINESS user shows that AUTH can see BUSINESS. If I change this to LDAPServiceAccount = "BUSINESS\\NotRealName" then Step 1 throws an exception with invalid credentials. This suggests it has resolved the BUSINESS domain user to authenticate the call? If I change LDAPServiceAccount = "AUTH\\ValidAccount" I get the same issue of User == NULL and so 2f. User Not Found.
namespace ConsoleApplication1
{
using System;
using System.DirectoryServices.AccountManagement;
class Program
{
static void Main(string[] args)
{
// Who are we looking for?
string userName = "BUSINESS\\User.Name";
// Where are we looking?
string LDAPServer = "AUTH";
string LDAPServiceAccount = "BUSINESS\\InternalServiceAccountName";
string LDAPServiceAccountPassword = "CorrespondingPassword";
Console.WriteLine("1. Connecting to: " + LDAPServer);
using (PrincipalContext adPrincipalContext = new PrincipalContext(ContextType.Domain, LDAPServer, LDAPServiceAccount, LDAPServiceAccountPassword))
{
Console.WriteLine("2. Finding: " + userName);
using (UserPrincipal user = UserPrincipal.FindByIdentity(adPrincipalContext, userName))
{
if (user == null)
{
Console.WriteLine("2f. User Not Found!");
Console.ReadKey();
return;
}
Console.WriteLine("3. Getting groups...");
using (var groups = user.GetGroups())
{
Console.WriteLine("4. The groups are:");
foreach (Principal group in groups)
{
Console.WriteLine("\t{0}", group.Name);
}
}
}
}
Console.WriteLine("END.");
}
}
}
I am wondering if this is an issue between the two AD Servers where the AUTH is not checking with BUSINESS but checking if the user exists on its configuration? Do I need to setup my LDAPServiceAccount user to have any special permissions? Any pointers would be much appreciated!

I guess you need to check pre-conditions while communicating with the AD server
(1) Your machine should be on the same domain to which you are communicating.
(2) Username and Password which you passed in query should exist on that AD server.
(3) In case you are updating records, then the credential you have passed to the server should have Admin rights.
Please check these points once.
Hope this helps you.

How to check if Windows user account name exists in domain?

What is the simplest and most efficient way in C# to check if a Windows user account name exists? This is in a domain environment.
Input: user name in [domain]/[user] format (e.g. "mycompany\bob")
Output: True if the user name exists, false if not.
I did find this article but the examples there are related to authenticating and manipulating user accounts, and they assume you already have a user distinguished name, whereas I am starting with the user account name.
I'm sure I can figure this out using AD, but before I do so I was wondering if there is a simple higher level API that does what I need.
* UPDATE *
There are probably many ways to do this, Russ posted one that could work but I couldn't figure out how to tweak it to work in my environment. I did find a different approach, using the WinNT provider that did the job for me:
public static bool UserInDomain(string username, string domain)
{
string path = String.Format("WinNT://{0}/{1},user", domain, username);
try
{
DirectoryEntry.Exists(path);
return true;
}
catch (Exception)
{
// For WinNT provider DirectoryEntry.Exists throws an exception
// instead of returning false so we need to trap it.
return false;
}
}
P.S.
For those who aren't familiar with the API used above: you need to add a reference to System.DirectoryServices to use it.
The link I found that helped me with this: How Can I Get User Information Using ADSI
The examples use ADSI but can be applied to .NET DirectoryServices as well. They also demonstrate other properties of the user object that may be useful.

The System.DirectoryServices namespace in the article is exactly what you need and intended for this purpose. If I recall correctly, it is a wrapper around the Active Directory Server Interfaces COM interfaces
EDIT:
Something like the following should do it (it could probably do with some checking and handling). It will use the domain of the current security context to find a domain controller, but this could easily be amended to pass in a named server.
public bool UserInDomain(string username, string domain)
{
string LDAPString = string.Empty;
string[] domainComponents = domain.Split('.');
StringBuilder builder = new StringBuilder();
for (int i = 0; i < domainComponents.Length; i++)
{
builder.AppendFormat(",dc={0}", domainComponents[i]);
}
if (builder.Length > 0)
LDAPString = builder.ToString(1, builder.Length - 1);
DirectoryEntry entry = new DirectoryEntry("LDAP://" + LDAPString);
DirectorySearcher searcher = new DirectorySearcher(entry);
searcher.Filter = "sAMAccountName=" + username;
SearchResult result = searcher.FindOne();
return result != null;
}
and tested with the following
Console.WriteLine(UserInDomain("username","MyDomain.com").ToString());

Found a simple way to do this if you're on a high enough framework version:
using System.DirectoryServices.AccountManagement;
bool UserExists(string userName, string domain) {
using (var pc = new PrincipalContext(ContextType.Domain, domain))
using (var p = Principal.FindByIdentity(pc, IdentityType.SamAccountName, userName)) {
return p != null;
}
}

Error 0x80005000 and DirectoryServices

I'm trying to run a simple LDAP query using directory services in .Net.
DirectoryEntry directoryEntry = new DirectoryEntry("LDAP://someserver.contoso.com/DC=contoso,DC=com");
directoryEntry.AuthenticationType = AuthenticationTypes.Secure;
DirectorySearcher directorySearcher = new DirectorySearcher(directoryEntry);
directorySearcher.Filter = string.Format("(&(objectClass=user)(objectCategory=user) (sAMAccountName={0}))", username);
var result = directorySearcher.FindOne();
var resultDirectoryEntry = result.GetDirectoryEntry();
return resultDirectoryEntry.Properties["msRTCSIP-PrimaryUserAddress"].Value.ToString();
And I'm getting the following exception:
System.Runtime.InteropServices.COMException (0x80005000): Unknown error (0x80005000)
at System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail)
at System.DirectoryServices.DirectoryEntry.Bind()
at System.DirectoryServices.DirectoryEntry.get_AdsObject()
at System.DirectoryServices.DirectorySearcher.FindAll(Boolean findMoreThanOne)
at System.DirectoryServices.DirectorySearcher.FindOne()
As a snippet in a Console app, this works. But when I run it as part of a WCF service (run under the same credentials), it throws the above exception.
Any suggestions?
Thanks

I had the same again and again and nothing seemed to help.
Changing the path from ldap:// to LDAP:// did the trick.

It's a permission problem.
When you run the console app, that app runs with your credentials, e.g. as "you".
The WCF service runs where? In IIS? Most likely, it runs under a separate account, which is not permissioned to query Active Directory.
You can either try to get the WCF impersonation thingie working, so that your own credentials get passed on, or you can specify a username/password on creating your DirectoryEntry:
DirectoryEntry directoryEntry =
new DirectoryEntry("LDAP://someserver.contoso.com/DC=contoso,DC=com",
userName, password);
OK, so it might not be the credentials after all (that's usually the case in over 80% of the cases I see).
What about changing your code a little bit?
DirectorySearcher directorySearcher = new DirectorySearcher(directoryEntry);
directorySearcher.Filter = string.Format("(&(objectClass=user)(objectCategory=user) (sAMAccountName={0}))", username);
directorySearcher.PropertiesToLoad.Add("msRTCSIP-PrimaryUserAddress");
var result = directorySearcher.FindOne();
if(result != null)
{
if(result.Properties["msRTCSIP-PrimaryUserAddress"] != null)
{
var resultValue = result.Properties["msRTCSIP-PrimaryUserAddress"][0];
}
}
My idea is: why not tell the DirectorySearcher right off the bat what attribute you're interested in? Then you don't need to do another extra step to get the full DirectoryEntry from the search result (should be faster), and since you told the directory searcher to find that property, it's certainly going to be loaded in the search result - so unless it's null (no value set), then you should be able to retrieve it easily.
Marc

In the context of Ektron, this issue is resolved by installing the "IIS6 Metabase compatibility" feature in Windows:
Check 'Windows features' or 'Role Services' for IIS6 Metabase
compatibility, add if missing:
Ref: https://portal.ektron.com/KB/1088/

On IIS hosted sites, try recycling the app pool. It fixed my issue.
Thanks

I had the same error - in my case it was extra slash in path argument that made the difference.
BAD:
DirectoryEntry directoryEntry =
new DirectoryEntry("LDAP://someserver.contoso.com/DC=contoso,DC=com/",
userName, password);
GOOD:
DirectoryEntry directoryEntry =
new DirectoryEntry("LDAP://someserver.contoso.com/DC=contoso,DC=com",
userName, password);

I had this error as well and for me it was an OU with a forward slash in the name: "File/Folder Access Groups".
This forum thread pointed me in the right direction. In the end, calling .Replace("/","\\/") on each path value before use solved the problem for me.

Just FYI, I had the same error and was using the correct credentials but my LDAP url was wrong :(
I got the exact same error message and code

Just had that problem in a production system in the company where I live... A webpage that made a LDAP bind stopped working after an IP changed.
The solution...
... I installed Basic Authentication to perform the troubleshooting indicated here: https://support.microsoft.com/en-us/kb/329986
And after that, things just started to work. Even after I re-disabled Basic Authentication in the page I was testing, all other pages started working again with Windows Authentication.
Regards,
Acácio

I encounter this error when I'm querying an entry of another domain of the forrest and this entry have some custom attribut of the other domain.
To solve this error, I only need to specify the server in the url LDAP :
Path with error = LDAP://CN=MyObj,DC=DOMAIN,DC=COM
Path without error : LDAP://domain.com:389/CN=MyObj,DC=Domain,DC=COM

This Error can occur if the physical machine has run out of memory.
In my case i was hosting a site on IIS trying to access the AD, but the server had run out of memory.

I had to change my code from this:
DirectoryEntry entry = new DirectoryEntry(path, ldapUser, ldapPassword);
DirectorySearcher searcher = new DirectorySearcher();
searcher.SearchRoot = entry;
searcher.SearchScope = SearchScope.Subtree;
To this:
DirectoryEntry entry = new DirectoryEntry(path, ldapUser, ldapPassword);
DirectorySearcher searcher = new DirectorySearcher();
searcher.SearchScope = SearchScope.OneLevel;
SearchResult searchResult = searcher.FindOne();

The same error occurs if in DirectoryEntry.Patch is nothing after the symbols "LDAP//:". It is necessary to check the directoryEntry.Path before directorySearcher.FindOne(). Unless explicitly specified domain, and do not need to "LDAP://".
private void GetUser(string userName, string domainName)
{
DirectoryEntry dirEntry = new DirectoryEntry();
if (domainName.Length > 0)
{
dirEntry.Path = "LDAP://" + domainName;
}
DirectorySearcher dirSearcher = new DirectorySearcher(dirEntry);
dirSearcher.SearchScope = SearchScope.Subtree;
dirSearcher.Filter = string.Format("(&(objectClass=user)(|(cn={0})(sn={0}*)(givenName={0})(sAMAccountName={0}*)))", userName);
var searchResults = dirSearcher.FindAll();
//var searchResults = dirSearcher.FindOne();
if (searchResults.Count == 0)
{
MessageBox.Show("User not found");
}
else
{
foreach (SearchResult sr in searchResults)
{
var de = sr.GetDirectoryEntry();
string user = de.Properties["SAMAccountName"][0].ToString();
MessageBox.Show(user);
}
}
}

Spent a day on my similar issue, but all these answers didn't help.
Turned out in my case, I didn't enable Windows Authentication in IIS setting...

In my case, the problem was that I was trying to reference a DirectoryEntry's property value, even though that DirectoryEntry did not have that property at all.
If you for example, have:
var myGroup = new DirectoryEntry("LDAP://CN=mygroup,OU=mydomain....", myUsername, myPassword);
var groupManager = myGroup.Properties["managedBy"].Value.ToString();
If myGroup has no managedBy attribute set in the AD, this will result in Unknown error (0x80005000)