Connecting or Accessing Okta LDAP Interface using c# .NET Client

I have a client which uses Okta LDAP Interface facility. We have a LDAP v3 tool which connects with AD, Open LDAP other LDAP v3 supported servers.

We want to integrate Okta LDAP Interface into our tool as it is LDAPv3 Compatible. Our Code is based on .NET framework + C Sharp.

We are facing some issues/challenges while connecting with Okta LDAP Interface.

We use System.DirectoryServices by Microsoft library provided by microsoft currently. But facing issues with LDAP Interface.

For StartTLS/389

I get the error :

Unwilling to perform. LDAP Error Code 53

More: A secure connection cannot be established. To admin: This service requires TLS. LDAP

For SSL/636

Error: The server is not operational.

Links:

https://ldapwiki.com/wiki/LDAP_UNWILLING_TO_PERFORM

var oktaLDAPPath = "LDAP://dev-506668.ldap.oktapreview.com:636/ou=users,dc=dev-506668,dc=oktapreview,dc=com";
        var un = "uid=*******,dc=dev-506668,dc=oktapreview,dc=com";
        var pass = "*******";
        var filter = "((objectClass=*))";
        try
        {
            using (var userDirectoryEntry = new DirectoryEntry(oktaLDAPPath, un, pass,AuthenticationTypes.SecureSocketsLayer))
            { 
                using (var directorySearcher = new DirectorySearcher(userDirectoryEntry, filter) { PageSize = 100 })
                {
                    directorySearcher.FindOne();
                }
            }
        }
        catch (DirectoryServicesCOMException dex)
        {

        }
        catch (Exception ex)
        {

        }

Thanks

I urge Okta’s developer’s team to look into this issue. Please have a look to the Answer in the below StackOverflow link.

Solution as per StackOverflow

Connecting or Accessing Okta LDAP Interface using c# .NET Client