[...]the time to read or visit the content or sites we have linked to below the[...]…

function sid2str($sid)
{
$srl = ord($sid[0]);
$number_sub_id = ord($sid[1]);
$x = substr($sid,2,6);
$h = unpack(‘N’,”\x0\x0″.substr($x,0,2));
$l = unpack(‘N’,substr($x,2,6));
$iav = bcadd(bcmul($h[1],bcpow(2,32)),$l[1]);
for ($i=0; $i<$number_sub_id; $i++)
{
$sub_id = unpack('V', substr($sid, 8+4*$i, 4));
$sub_ids[] = $sub_id[1];
}
return sprintf('S-%d-%d-%s', $srl, $iav, implode('-',$sub_ids));
}

function get_primary_group($server, $admin, $passwd, $base, $username)
{
global $server, $admin, $passwd, $connect, $r;
$connect = ldap_connect($server);
ldap_set_option($connect, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_set_option($connect, LDAP_OPT_REFERRALS, 0);
$bind = ldap_bind($connect, $admin, $passwd) or exit('bind');

$r = ldap_search($connect, $base, "sAMAccountName=$username", array('primaryGroupID')) or exit('ldap_search');
$data = ldap_get_entries($connect, $r);
$pri_grp_rid = $data[0]['primarygroupid'][0];
print("pri_grp_rid = ${pri_grp_rid}\n");
$r = ldap_read($connect, $base, '(objectclass=*)', array('objectSid')) or exit('ldap_search');
$data = ldap_get_entries($connect, $r);
$domain_sid = $data[0]['objectsid'][0];

$domain_sid_s = sid2str($domain_sid);
print("domain_sid_s = ${domain_sid_s}\n");

$r = ldap_search($connect, $base, "objectSid=${domain_sid_s}-${pri_grp_rid}", array('cn')) or exit('ldap_search');
$data = ldap_get_entries($connect, $r);
print("cn = {$data[0]['cn'][0]}\n");
}