PHP LDAP 将 AD 与服务器的用户帐户绑定

I have some code that uses PHP and LDAP to connect to AD:

$host = 'ldap://stack.overflow.com';
$port = 389;
$username = 'stackOverflow';
$password = 'IaMP4ssWord';
$dn = 'CN=Users, DC=STACK, DC=OVERFLOW, DC=COM';
$cond = '(&(objectcategory=user)(displayname=*))';//All users that have a displayname

if($ldap = ldap_connect($host, $port))
{
    if(ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3))
    {
        if(ldap_bind($ldap, $username, $password))
        {
            $attrs = array('displayname', 'mail');
            if($rs = ldap_search($ldap, $dn, $cond, $attrs))
            {
                $results = ldap_get_entries($ldap, $rs);
                echo "<pre>";print_r($result);echo "</pre>";//Print the results
            }
        }
        else
        { echo 'Binding failed';}
    }
    else
    { echo 'Setting options failed';}
}
else
{ echo 'Connection failed'; }

现在这段代码工作得很好.它打印出在 AD 中具有显示名称的每个用户.问题是用户名/密码绑定，我使用我自己的用户凭据绑定到服务器.

...
if(ldap_bind($ldap))
...