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).
Related
I am developing a web application that authenticate the user against an Active Directory Server. Now if I run my code from the development PC under the domain of that AD server, my code is running smoothly. We need to run the code from a totally different network using VPN and here the development PC is not into that AD. I am getting following error while trying to access the AD server.
The specified domain either does not exist or could not be contacted.
My VPN is working fine. I could access remote desktops using this VPN. I know a little tweak is required to solve the problem but could not find it. I went through following links but could not find any solution.
Domain Authentication from .NET Client over VPN
How do I get the Current User identity for a VPN user in a Windows forms app?
Following is my settings in web.config
<appSettings>
<add key="LDAPPath" value="LDAP://DC=MYSERVER,DC=COM" />
<add key="ADGroupName" value="Analyst"/>
</appSettings>
and here is my code
public class LdapAuthentication
{
private string _path;
private string _filterAttribute;
public LdapAuthentication()
{
_path = System.Configuration.ConfigurationManager.AppSettings["LDAPPath"].ToString();
}
public bool IsAuthenticated(string username, string pwd)
{
try
{
DirectoryEntry entry = new DirectoryEntry(_path, username, pwd);
entry.Path = _path;
entry.Username = username;
entry.Password = pwd;
// Bind to the native AdsObject to force authentication.
object obj = entry.NativeObject;
DirectorySearcher search = new DirectorySearcher(entry);
search.Filter = "(SAMAccountName=" + username + ")";
search.PropertiesToLoad.Add("cn");
SearchResult result = search.FindOne();
if (null == result)
{
return false;
}
// Update the new path to the user in the directory.
_path = result.Path;
_filterAttribute = (string)result.Properties["cn"][0];
}
catch (Exception ex)
{
throw new Exception("Error authenticating user. " + ex.Message);
}
return true;
}
}
Any help would be appreciated. Thank you.
I had a similar, though simpler problem. I had success in using the following code:
private bool DoLogin(string userName, string password)
{
using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, "DomainName.com")) {
bool isValid = pc.ValidateCredentials(userName, password);
if (isValid) {
// authenticated
...
return true;
}
else {
// invalid credentials
...
return false;
}
}
}
Using the ".com" at the end of the domain name was important to get it working for me. Without it I got the same symptoms you describe.
I've just been grappling with this for a couple of hours. No problems when on the network, lots of problems when connecting via VPN. It seems that when you are connecting over a VPN, the 'connection string' for DirectoryEntry has to be a lot more precise. I finally got it to work with an LDAP address/connection string like this:
LDAP://ip_of_primary_domain_controller/fully qualified path of the container object where the binding user is located
So for example something like this worked for me:
DirectoryEntry directoryEntry = new DirectoryEntry(
"LDAP://192.168.0.20/OU=Service Accounts,OU=Admin Accounts,DC=myserver,DC=com",
"username#myserver.com", "password");
... where "username#myserver.com" is located in OU=Service Accounts,OU=Admin Accounts,DC=myserver,DC=com. If you use SysInternals ADExplorer (or similar) to search for your username, it will tell you the correct fully qualified path for the container.
See here for a long answer about exactly whats should be in the 'connection string': https://serverfault.com/a/130556
We use sharepoint, and in SP we have a people picker which searches on samaccountname but also on name. On dev it works fine, but on prod it returns sometimes duplicated results.
I wonder if there is an easy application there which I can make queries against the AD and see the results. (Maybe the duplicated users are really in different domains in one ad forest or something.
I found this, but it doesnt have a working example in c#
http://msdn.microsoft.com/en-us/library/ms973834.aspx
I've got two snippets for this :
using System.DirectoryServices.AccountManagement;
using System.DirectoryServices;
// Authentication
using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, sDn))
{
// validate the credentials
bIsValid = pc.ValidateCredentials(sUsr, sPassword);
}
//List users
DirectorySearcher adsSearcher = new DirectorySearcher();
adsSearcher.Filter = string.Format(Parameters.ActiveDirectoryFilter, "*");
try
{
foreach (SearchResult sr in adsSearcher.FindAll())
{
string sUsrName = sr.GetDirectoryEntry().Properties["UserPrincipalName"].Value as string;
Console.WriteLine(string.Format("User : {0}", sUsrName));
}
}
Of course, it needs two references (System.DirectoryServices and System.DirectoryServices.AccountManagement).
I'm attempting to query AD in an ASP.Net (4.0) application that is running on Windows Server 2008 R2 (IIS7 installed). (It also fails when running as a 2.0 application as well)
This is nothing new for me, as I've done this many times before. I wrote a small ASP.Net program that runs fine on my own machine (Windows XP with IIS6), but fails when run on the 2008 box.
(The result is that you see a list of groups the user is a member of in a textbox)
(on button_click)
var userName = txtUserName.Text;
if (userName.Trim().Length == 0)
{
txtResults.Text = "-- MISSING USER NAME --";
return;
}
var entry = new DirectoryEntry("LDAP://blah.blah/DC=blah,DC=blah",
"cn=acct, dc=blah, dc=blah",
"pass");
var search = new DirectorySearcher(entry);
search.Filter = "(SAMAccountName=" + userName + ")";
search.PropertiesToLoad.Add("memberOf");
var groupsList = new StringBuilder();
var result = search.FindOne();
if (result != null)
{
int groupCount = result.Properties["memberOf"].Count;
for (int counter = 0; counter < groupCount; counter++)
{
groupsList.Append((string)result.Properties["memberOf"][counter]);
groupsList.Append("\r\n");
}
}
txtResults.Text = groupsList.ToString();
When I run this code I get the following error on search.FindOne():
System.DirectoryServices.DirectoryServicesCOMException (0x8007203B): A local error has occurred.
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()
at WebApplication1._Default.btnSearch_Click(Object sender, EventArgs e)
We've done a lot of research with this and twiddled every IIS7 setting we can think of, but no go so far. Any clues?
Change the username parameter from "cn=xxx, dc=yyy, dc=zzz" to "Domain\Username"
You can also change the IIS Application Pool to run a domain account with the query priveleges you are searching for.
I have a few other comments as well:
Make sure the first entry for the DirectoryEntry constructor includes the container for the users as well. This should help the DirectorySearcher to work more reliably.
I believe the second parameter in the DirectoryEntry constructor should be the user name, not the AD query path.
You should set the AuthenticationType property as well. With Server 2008, by default, this needs to be set to AuthenticationTypes.Secure | AuthenticationTypes.ServerBind | AuthenticationTypes.Sealing. I'd guess that 2008R2 has a simliar requirement.
I see that the question is rather old, but after struggling with this I thought to mention that it is indeed possible to use the LDAP-style of the username (in opposite to the DNS style). This works well for me:
string connString = "LDAP://MyDomain/CN=blah,DC=blah,DC=blah";
string username = "CN=MyAdmin,CN=Users,CN=blah,DC=blah,DC=blah";
string password = "myLittleSecret";
DirectoryEntry root = new DirectoryEntry(
connString,
username,
password,
AuthenticationTypes.None);
Where MyAdmin is a member in the Administrators role.
One little thing that took me a while to find is the AuthenticationTypes.None parameter that is needed if you do not want to communicate over SSL. Surely, you want to do this in production, but for development purposes it may be OK to skip the encryption.
Environment: Windows 7
I was also getting this exception when tried to query the active directory:
SearchResult result = srch.FindOne();
To resolve this, just put the above code inside Security.RunWithElevatedPrivileges().
Final Solution:
SPSecurity.RunWithElevatedPrivileges(delegate()
{
result = srch.FindOne();
});
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;
}
}
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)