Why does this LDAP query return an array with just a 0

Question

I'm new to LDAP and Active Directory. I'm trying to fetch the Email-ID of an authenticated user using the following code. However when I run it, all I get is an array with a 0 in it.

Here's the code

$server ='ldaps://DOMAIN'; 
$username = 'DOMAIN\UID'; 
$password = 'PASSWORD';

$base_dn = 'dc=DOMAIN';
$search_filter = 'dn=UID'; 
$attributes = ['mail']; 

$ldap = ldap_connect($server);
ldap_set_option($ldap, LDAP_OPT_REFERRALS, 0);
ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_bind($ldap, $username, $password); 
$search = ldap_search($ldap, $base_dn, $search_filter, $attributes);
$data = ldap_get_entries($ldap, $search);

foreach($data as $dataPoint)
    {
        echo $dataPoint;
        echo "<hr>";
    }

This outputs just a 0 with a horizontal line below it.

The most challenging thing here is that there is no error message whatsoever and I'm not very familiar with LDAP nor with Active Directory.

Any idea as to why this could be happening.

Answer 1

I see several things that could potentially be causing problems from the code above:

• Do you really mean to use ldaps:// ? Usually that is not what you want to do. If you want to use an encrypted connection you should use ldap_start_tls and the call should be made after ldap_connect . For the purpose of testing I would just change it to ldap:// .
• Your $base_dn variable seems to be missing part of the domain. That should not be the NETBIOS name of your domain, but rather the fully qualified domain name. So if your domain was domain.com then the base dn would be dc=domain,dc=com .
• Your search filter ( $search_filter ) is not properly formed. If you are trying to retrieve a user object from LDAP given an account name, you could use a search filter like: (sAMAccountName=UID)

To get a better idea of what may be going wrong you can use ldap_error and call it after you connect: echo "Error: ".ldap_error($ldap); . You can do this after any LDAP related call to get more information on what may have gone wrong.