Подключитесь к Active Directory для входа в систему (в моем продукте), используя учетную запись службы и учетные данные пользователя AD

Это функция, которую я использую для привязки к каталогу LDAP с использованием системных учетных данных, поиска предоставленного идентификатора пользователя и затем проверки предоставленных учетных данных пользователя. Для использования функции с Active Directory 'strUIDAttr' - это sAMAccountName.

protected string ldapAuthTest(string strLDAPServer, string strSuppliedUser, string strSuppliedPwd, string strSystemUID, string strSystemPwd, string strLDAPUserBase, string strUIDAttr)
{
    strSuppliedUser = strSuppliedUser.Trim();
    string strResults = "";
    string strLDAPUserHost = strLDAPServer + strLDAPUserBase;

    // Establish LDAP connection and bind with system ID
    System.DirectoryServices.DirectoryEntry dirEntry = new System.DirectoryServices.DirectoryEntry();
    dirEntry.Path = strLDAPUserHost;
    dirEntry.Username = strSystemUID;
    dirEntry.Password = strSystemPwd;

    //dirEntry.AuthenticationType = System.DirectoryServices.AuthenticationTypes.None;
    dirEntry.AuthenticationType = System.DirectoryServices.AuthenticationTypes.SecureSocketsLayer;
    try
    {
        dirEntry.RefreshCache();

        // Search directory for the user logging on
        string strLDAPFilter = "(&(" + strUIDAttr + "=" + strSuppliedUser + "))";
        System.DirectoryServices.DirectorySearcher ldapSearch = new System.DirectoryServices.DirectorySearcher(dirEntry);
        ldapSearch.ServerTimeLimit = new TimeSpan(0, 0, 30);


        ldapSearch.Filter = strLDAPFilter;
        ldapSearch.SearchScope = System.DirectoryServices.SearchScope.Subtree;

        System.DirectoryServices.SearchResultCollection searchResults = ldapSearch.FindAll();


        if (searchResults.Count == 1)
        {
        string strLogonUserBase = searchResults[0].GetDirectoryEntry().Path;
        // get rid of strLDAPServer from directory entry path
        string strLogonUserFQDN = strLogonUserBase.Replace(strLDAPServer, "");
        dirEntry.Close();

        // Attempt to bind as the user
        System.DirectoryServices.DirectoryEntry userAuthAttempt = new System.DirectoryServices.DirectoryEntry();
        userAuthAttempt.Path = strLDAPUserHost;
        userAuthAttempt.Username = strLogonUserFQDN;
        userAuthAttempt.Password = strSuppliedPwd;
        //userAuthAttempt.AuthenticationType = System.DirectoryServices.AuthenticationTypes.None;
        userAuthAttempt.AuthenticationType = System.DirectoryServices.AuthenticationTypes.SecureSocketsLayer;
        try
        {
            userAuthAttempt.RefreshCache();
            userAuthAttempt.Close();
            strResults = "<td><font color='green'>User " + UserName.Value + " has authenticated successfully.</font></td>";
        }
        catch (Exception e)
        {
            string strAuthError = e.Message;
            string strLockedOut = "A constraint violation occurred.\r\n";
            string strBadPwd = "Logon failure: unknown user name or bad password.\r\n";
            string strNSAccountLock = "The server is unwilling to process the request.\r\n";
            if (String.Compare(strAuthError, strBadPwd) == 0)
                strResults = "<td><font color='red'>Logon failure for user " + UserName.Value + " - password is invalid.</font></td></tr>"; ;
            }
            else if (String.Compare(strAuthError, strLockedOut) == 0)
            {
            strResults = "<td><font color='red'>Logon failure for user " + UserName.Value + " - account is locked out.</font></td>"; ;
            }
            else if (String.Compare(strAuthError, strNSAccountLock) == 0)
            {
            strResults = "<td><font color='red'>Logon failure for user " + UserName.Value + " - password has expired.</font></td>"; ;
            }
            else
            {
            strResults = "<td><font color='red'>Logon failure for user " + UserName.Value + " (" + strLogonUserFQDN + ") :" + strAuthError + "</font></td>"; ;
            }
        }
        }
        else if (searchResults.Count > 1)
        {
        strResults = "<td><font color='red'>Account " + UserName.Value + " was found in the directory " + searchResults.Count + " times. Please contact the Help Desk to have this issue corrected.</font></td>"; ;
        }
        else
        {
        strResults = "<td><font color='red'>Account " + UserName.Value + " was not found in the directory.</font></td>"; ;
        }
        return strResults;
    }
    catch(Exception e)
    {
        string strAuthError = e.Message;
        string strConnectFail = "The server is not operational.\r\n";
        if (String.Compare(strAuthError, strConnectFail) == 0)
        {
        strResults = "<td><font color='red'>Transient connection failure, please try again.</font></td>"; ;
        }
        else
        {
        strResults = "<td><font color='red'>Transient failure (" + strAuthError + "), please try again.</font></td>";
        }
        return strResults;
    }
}