对我来说，这两个下面的工作，确保你的域名是LDAP://在开始

//"LDAP://" + domainName
private void btnValidate_Click(object sender, RoutedEventArgs e)
{
    try
    {
        DirectoryEntry de = new DirectoryEntry(txtDomainName.Text, txtUsername.Text, txtPassword.Text);
        DirectorySearcher dsearch = new DirectorySearcher(de);
        SearchResult results = null;

        results = dsearch.FindOne();

        MessageBox.Show("Validation Success.");
    }
    catch (LdapException ex)
    {
        MessageBox.Show($"Validation Failure. {ex.GetBaseException().Message}");
    }
    catch (Exception ex)
    {
        MessageBox.Show($"Validation Failure. {ex.GetBaseException().Message}");
    }
}

private void btnValidate2_Click(object sender, RoutedEventArgs e)
{
    try
    {
        LdapConnection lcon = new LdapConnection(new LdapDirectoryIdentifier((string)null, false, false));
        NetworkCredential nc = new NetworkCredential(txtUsername.Text,
                               txtPassword.Text, txtDomainName.Text);
        lcon.Credential = nc;
        lcon.AuthType = AuthType.Negotiate;
        lcon.Bind(nc);

        MessageBox.Show("Validation Success.");
    }
    catch (LdapException ex)
    {
        MessageBox.Show($"Validation Failure. {ex.GetBaseException().Message}");
    }
    catch (Exception ex)
    {
        MessageBox.Show($"Validation Failure. {ex.GetBaseException().Message}");
    }
}

这里介绍的几个解决方案缺乏区分错误用户/密码和需要更改的密码的能力。这可以通过以下方式来实现:

using System;
using System.DirectoryServices.Protocols;
using System.Net;

namespace ProtocolTest
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                LdapConnection connection = new LdapConnection("ldap.fabrikam.com");
                NetworkCredential credential = new NetworkCredential("user", "password");
                connection.Credential = credential;
                connection.Bind();
                Console.WriteLine("logged in");
            }
            catch (LdapException lexc)
            {
                String error = lexc.ServerErrorMessage;
                Console.WriteLine(lexc);
            }
            catch (Exception exc)
            {
                Console.WriteLine(exc);
            }
        }
    }
}

如果用户密码错误，或者用户不存在，error将包含

“8009030C: LdapErr: DSID-0C0904DC，注释:AcceptSecurityContext错误，数据52e, v1db1”，

如果用户密码需要修改，则包含

"8009030C: LdapErr: DSID-0C0904DC，注释:AcceptSecurityContext错误，数据773,v1db1"

lexc。ServerErrorMessage数据值是Win32错误码的十六进制表示。这些是通过调用Win32 LogonUser API调用返回的相同错误代码。下面的列表总结了一些常见的十六进制和十进制值:

525​ user not found ​(1317)
52e​ invalid credentials ​(1326)
530​ not permitted to logon at this time​ (1328)
531​ not permitted to logon at this workstation​ (1329)
532​ password expired ​(1330)
533​ account disabled ​(1331) 
701​ account expired ​(1793)
773​ user must reset password (1907)
775​ user account locked (1909)

完整的. net解决方案是使用来自系统的类。DirectoryServices名称空间。它们允许直接查询AD服务器。下面是一个可以做到这一点的小样本:

using (DirectoryEntry entry = new DirectoryEntry())
{
    entry.Username = "here goes the username you want to validate";
    entry.Password = "here goes the password";

    DirectorySearcher searcher = new DirectorySearcher(entry);

    searcher.Filter = "(objectclass=user)";

    try
    {
        searcher.FindOne();
    }
    catch (COMException ex)
    {
        if (ex.ErrorCode == -2147023570)
        {
            // Login or password is incorrect
        }
    }
}

// FindOne() didn't throw, the credentials are correct

这段代码使用提供的凭据直接连接到AD服务器。如果凭证无效，则search . findone()将抛出异常。ErrorCode是一个对应于“无效的用户名/密码”COM错误。

您不需要以AD用户的身份运行代码。事实上，我成功地使用它在AD服务器上查询信息，从域外的客户端!

使用DirectoryServices非常简单的解决方案:

using System.DirectoryServices;

//srvr = ldap server, e.g. LDAP://domain.com
//usr = user name
//pwd = user password
public bool IsAuthenticated(string srvr, string usr, string pwd)
{
    bool authenticated = false;

    try
    {
        DirectoryEntry entry = new DirectoryEntry(srvr, usr, pwd);
        object nativeObject = entry.NativeObject;
        authenticated = true;
    }
    catch (DirectoryServicesCOMException cex)
    {
        //not authenticated; reason why is in cex
    }
    catch (Exception ex)
    {
        //not authenticated due to some other exception [this is optional]
    }

    return authenticated;
}

需要NativeObject访问来检测坏的用户/密码

我们在内部网做这些

你必须使用System.DirectoryServices;

下面是代码的核心部分

using (DirectoryEntry adsEntry = new DirectoryEntry(path, strAccountId, strPassword))
{
    using (DirectorySearcher adsSearcher = new DirectorySearcher(adsEntry))
    {
        //adsSearcher.Filter = "(&(objectClass=user)(objectCategory=person))";
        adsSearcher.Filter = "(sAMAccountName=" + strAccountId + ")";

        try
        {
            SearchResult adsSearchResult = adsSearcher.FindOne();
            bSucceeded = true;

            strAuthenticatedBy = "Active Directory";
            strError = "User has been authenticated by Active Directory.";
        }
        catch (Exception ex)
        {
            // Failed to authenticate. Most likely it is caused by unknown user
            // id or bad strPassword.
            strError = ex.Message;
        }
        finally
        {
            adsEntry.Close();
        }
    }
}

如果你被。net 2.0和托管代码困住了，这里有另一种处理本地和域帐户的方法:

using System;
using System.Collections.Generic;
using System.Text;
using System.Security;
using System.Diagnostics;

static public bool Validate(string domain, string username, string password)
{
    try
    {
        Process proc = new Process();
        proc.StartInfo = new ProcessStartInfo()
        {
            FileName = "no_matter.xyz",
            CreateNoWindow = true,
            WindowStyle = ProcessWindowStyle.Hidden,
            WorkingDirectory = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData),
            UseShellExecute = false,
            RedirectStandardError = true,
            RedirectStandardOutput = true,
            RedirectStandardInput = true,
            LoadUserProfile = true,
            Domain = String.IsNullOrEmpty(domain) ? "" : domain,
            UserName = username,
            Password = Credentials.ToSecureString(password)
        };
        proc.Start();
        proc.WaitForExit();
    }
    catch (System.ComponentModel.Win32Exception ex)
    {
        switch (ex.NativeErrorCode)
        {
            case 1326: return false;
            case 2: return true;
            default: throw ex;
        }
    }
    catch (Exception ex)
    {
        throw ex;
    }

    return false;
}