Linger.Ldap.ActiveDirectory 1.4.0

Linger.Ldap.ActiveDirectory

An Active Directory focused LDAP client implementation based on System.DirectoryServices.

Features

• Active Directory user authentication and validation
• Async user lookup and search APIs
• OU-scoped search support via searchBase
• Optional Attributes projection to limit returned fields
• LDAPS support via LdapConfig.Security
• Configurable SearchFilter for FindUserAsync and GetUsersAsync
• Cross-provider advanced query via ILdap.SearchUsersByFilterAsync
• Optional domain controller auto-discovery when LdapConfig.Url is empty
• Convenience constructor overloads (new Ldap() / new Ldap(logger)) for auto-filling defaults (especially SearchBase)

Supported Frameworks

• .NET 10.0
• .NET 9.0
• .NET 8.0
• .NET Standard 2.0

Installation

dotnet add package Linger.Ldap.ActiveDirectory

Quick Start

using Linger.Ldap.ActiveDirectory;
using Linger.Ldap.Contracts;

var config = new LdapConfig
{
    Url = "example.com",
    Domain = "example",
    SearchBase = "DC=example,DC=com",
    SearchFilter = "(&(objectClass=user)(sAMAccountName={0}))",
    Security = true,
    Credentials = new LdapCredentials
    {
        BindDn = "serviceAccount",
        BindCredentials = "SecurePassword123!"
    },
    Attributes =
    [
        "displayName",
        "sAMAccountName",
        "mail",
        "department",
        "memberOf"
    ]
};

var ldap = new Ldap(config);

Convenience Creation with Auto Defaults

var ldap = new Ldap();

// With custom logger
var ldapWithLogger = new Ldap(logger);

When SearchBase is empty, the convenience constructor overloads infer it from Domain (for example, example.com → DC=example,DC=com) and then fall back to the current domain distinguished name.

Usage

Validate User Credentials

var (isValid, userInfo) = await ldap.ValidateUserAsync("alice", "Password123!");

if (isValid && userInfo is not null)
{
    Console.WriteLine($"DisplayName: {userInfo.DisplayName}");
    Console.WriteLine($"Email: {userInfo.Email}");
}

Find a Single User

var user = await ldap.FindUserAsync("alice");

if (user is not null)
{
    Console.WriteLine($"SamAccountName: {user.SamAccountName}");
    Console.WriteLine($"DN: {user.Dn}");
}

Search Users

var users = await ldap.GetUsersAsync("alice");

foreach (var item in users)
{
    Console.WriteLine($"{item.DisplayName} ({item.Email})");
}

Search in a Specific OU with Custom Bind Credentials

var customCreds = new LdapCredentials
{
    BindDn = "readonly.user",
    BindCredentials = "ReadonlyPassword123!"
};

var usersInOu = await ldap.GetUsersAsync(
    "alice",
    ldapCredentials: customCreds,
    searchBase: "OU=Sales,DC=example,DC=com");

Advanced Filter Search (Cross-Provider)

ILdap ldapContract = ldap;

var users = await ldapContract.SearchUsersByFilterAsync(
    "(&(objectClass=person)(department=IT)(mail=*))",
    searchBase: "DC=example,DC=com");

Active Directory Specific: Get DirectoryEntry

using var entry = ldap.GetEntryByUsername("alice");
var nativeObject = entry.NativeObject;
var properties = entry.Properties;

Notes

• This implementation is intended for Windows environments using System.DirectoryServices.
• In .NET 5+, the implementation is marked with [SupportedOSPlatform("windows")].
• When Security = true, the client uses LDAPS (LDAPS://) and secure bind options.
• SearchFilter is used by both FindUserAsync and GetUsersAsync; using {0} placeholder is recommended.
• SearchUsersByFilterAsync provides provider-agnostic advanced raw-filter queries.
• If SearchFilter format is invalid, the implementation falls back to a default user filter.
• Input value in user search is escaped before building LDAP filter to reduce malformed/injection risk.
• Bind username normalization supports existing domain\\user, UPN (user@domain), and full DN forms.
• If LdapConfig.Url is empty, Active Directory provider attempts domain controller auto-discovery.
• Convenience constructor overloads can auto-fill missing Domain and SearchBase defaults.

Key User Properties (AdUserInfo)

• DisplayName, SamAccountName, Upn, Dn
• Email, TelephoneNumber, Mobile, Department, Title
• Company, Manager, WhenCreated, Status, PwdLastSet
• MemberOf, ProfilePath, HomeDirectory, ExtensionAttribute1

Dependencies

• System.DirectoryServices
• System.DirectoryServices.AccountManagement
• Linger.Ldap.Contracts

Related Packages

• Linger.Ldap.Contracts: core LDAP interfaces and data models
• Linger.Ldap.Novell: cross-platform LDAP implementation based on Novell library