To elaborate on rcrow's post, if you want to convert the objectSID value to a usable string (from Active Directory) the following function will do the trick (this was borrowed from another section of the manual, just thought I'd add it here):// Returns the textual SIDfunction bin_to_str_sid($binsid) { $hex_sid = bin2hex($binsid); $rev = hexdec(substr($hex_sid, 0, 2)); $subcount = hexdec(substr($hex_sid, 2, 2)); $auth = hexdec(substr($hex_sid, 4, 12)); $result = "$rev-$auth"; for ($x=0;$x < $subcount; $x++) { $subauth[$x] = hexdec($this->little_endian(substr($hex_sid, 16 + ($x * 8), 8))); $result .= "-" . $subauth[$x]; } // Cheat by tacking on the S- return 'S-' . $result;}// Converts a little-endian hex-number to one, that 'hexdec' can convertfunction little_endian($hex) { for ($x = strlen($hex) - 2; $x >= 0; $x = $x - 2) { $result .= substr($hex, $x, 2); } return $result;}This function is not related to the ldap_get_values_len function but is still helpful if you want to convert the objectGUID binary value to a string format (converted from some vbscript provided by Richard Mueller):// This function will convert a binary value guid into a valid string.function bin_to_str_guid($object_guid) { $hex_guid = bin2hex($object_guid); $hex_guid_to_guid_str = ''; for($k = 1; $k <= 4; ++$k) { $hex_guid_to_guid_str .= substr($hex_guid, 8 - 2 * $k, 2); } $hex_guid_to_guid_str .= '-'; for($k = 1; $k <= 2; ++$k) { $hex_guid_to_guid_str .= substr($hex_guid, 12 - 2 * $k, 2); } $hex_guid_to_guid_str .= '-'; for($k = 1; $k <= 2; ++$k) { $hex_guid_to_guid_str .= substr($hex_guid, 16 - 2 * $k, 2); } $hex_guid_to_guid_str .= '-' . substr($hex_guid, 16, 4); $hex_guid_to_guid_str .= '-' . substr($hex_guid, 20); return strtoupper($hex_guid_to_guid_str);}Here's an example on how to use both:$filter="samaccountname=".$username;$fields=array("objectguid","objectsid");//establish the connection and specify the base_dn first. there are a lot of examples in the manual for this$sr=ldap_search($this->_conn,$this->_base_dn,$filter,$fields);$entries = ldap_get_entries($this->_conn, $sr);if (in_array("objectguid", $fields)) { $entries[0]["objectguid"][0]= $this->bin_to_str_guid($entries[0]["objectguid"][0]);}if (in_array("objectsid", $fields)) { $entry = ldap_first_entry($this->_conn, $sr); $objectsid_binary = ldap_get_values_len($this->_conn, $entry, "objectsid"); $entries[0]["objectsid"][0] = $this->bin_to_str_sid($objectsid_binary[0]);}Hope this helps someone!