<?php
/**
* ldaplib.php - LDAP functions & data library
*
* Library file of miscellaneous general-purpose LDAP functions and
* data structures, useful for both ldap authentication (or ldap based
* authentication like CAS) and enrolment plugins.
*
* @author Iñaki Arenaza
* @package core
* @subpackage lib
* @copyright 1999 onwards Martin Dougiamas http://dougiamas.com
* @copyright 2010 onwards Iñaki Arenaza
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
// rootDSE is defined as the root of the directory data tree on a directory server.
if (!defined('ROOTDSE')) {
define ('ROOTDSE', '');
}
// Default page size when using LDAP paged results
if (!defined('LDAP_DEFAULT_PAGESIZE')) {
define('LDAP_DEFAULT_PAGESIZE', 250);
}
/**
* Returns predefined user types
*
* @return array of predefined user types
*/
function ldap_supported_usertypes() {
$types = array();
$types['edir'] = 'Novell Edirectory';
$types['rfc2307'] = 'posixAccount (rfc2307)';
$types['rfc2307bis'] = 'posixAccount (rfc2307bis)';
$types['samba'] = 'sambaSamAccount (v.3.0.7)';
$types['ad'] = 'MS ActiveDirectory';
$types['default'] = get_string('default');
return $types;
}
/**
* Initializes needed variables for ldap-module
*
* Uses names defined in ldap_supported_usertypes.
* $default is first defined as:
* $default['pseudoname'] = array(
* 'typename1' => 'value',
* 'typename2' => 'value'
* ....
* );
*
* @return array of default values
*/
function ldap_getdefaults() {
// All the values have to be written in lowercase, even if the
// standard LDAP attributes are mixed-case
$default['objectclass'] = array(
'edir' => 'user',
'rfc2307' => 'posixaccount',
'rfc2307bis' => 'posixaccount',
'samba' => 'sambasamaccount',
'ad' => 'user',
'default' => '*'
);
$default['user_attribute'] = array(
'edir' => 'cn',
'rfc2307' => 'uid',
'rfc2307bis' => 'uid',
'samba' => 'uid',
'ad' => 'cn',
'default' => 'cn'
);
$default['memberattribute'] = array(
'edir' => 'member',
'rfc2307' => 'member',
'rfc2307bis' => 'member',
'samba' => 'member',
'ad' => 'member',
'default' => 'member'
);
$default['memberattribute_isdn'] = array(
'edir' => '1',
'rfc2307' => '0',
'rfc2307bis' => '1',
'samba' => '0', // is this right?
'ad' => '1',
'default' => '0'
);
$default['expireattr'] = array (
'edir' => 'passwordexpirationtime',
'rfc2307' => 'shadowexpire',
'rfc2307bis' => 'shadowexpire',
'samba' => '', // No support yet
'ad' => 'pwdlastset',
'default' => ''
);
return $default;
}
/**
* Checks if user belongs to specific group(s) or is in a subtree.
*
* Returns true if user belongs to a group in grupdns string OR if the
* DN of the user is in a subtree of the DN provided as "group"
*
* @param mixed $ldapconnection A valid LDAP connection.
* @param string $userid LDAP user id (dn/cn/uid/...) to test membership for.
* @param array $group_dns arrary of group dn
* @param string $member_attrib the name of the membership attribute.
* @return boolean
*
*/
function ldap_isgroupmember($ldapconnection, $userid, $group_dns, $member_attrib) {
if (empty($ldapconnection) || empty($userid) || empty($group_dns) || empty($member_attrib)) {
return false;
}
$result = false;
foreach ($group_dns as $group) {
$group = trim($group);
if (empty($group)) {
continue;
}
// Check cheaply if the user's DN sits in a subtree of the
// "group" DN provided. Granted, this isn't a proper LDAP
// group, but it's a popular usage.
if (stripos(strrev(strtolower($userid)), strrev(strtolower($group))) === 0) {
$result = true;
break;
}
$search = ldap_read($ldapconnection, $group,
'('.$member_attrib.'='.ldap_filter_addslashes($userid).')',
array($member_attrib));
if (!empty($search) && ldap_count_entries($ldapconnection, $search)) {
$info = ldap_get_entries_moodle($ldapconnection, $search);
if (count($info) > 0 ) {
// User is member of group
$result = true;
break;
}
}
}
return $result;
}
/**
* Tries connect to specified ldap servers. Returns a valid LDAP
* connection or false.
*
* @param string $host_url
* @param integer $ldap_version either 2 (LDAPv2) or 3 (LDAPv3).
* @param string $user_type the configured user type for this connection.
* @param string $bind_dn the binding user dn. If an emtpy string, anonymous binding is used.
* @param string $bind_pw the password for the binding user. Ignored for anonymous bindings.
* @param boolean $opt_deref whether to set LDAP_OPT_DEREF on this connection or not.
* @param string &$debuginfo the debugging information in case the connection fails.
* @param boolean $start_tls whether to use LDAP with TLS (not to be confused with LDAP+SSL)
* @return mixed connection result or false.
*/
function ldap_connect_moodle($host_url, $ldap_version, $user_type, $bind_dn, $bind_pw, $opt_deref, &$debuginfo, $start_tls=false) {
if (empty($host_url) || empty($ldap_version) || empty($user_type)) {
$debuginfo = 'No LDAP Host URL, Version or User Type specified in your LDAP settings';
return false;
}
$debuginfo = '';
$urls = explode(';', $host_url);
foreach ($urls as $server) {
$server = trim($server);
if (empty($server)) {
continue;
}
$connresult = ldap_connect($server); // ldap_connect returns ALWAYS true
if (!empty($ldap_version)) {
ldap_set_option($connresult, LDAP_OPT_PROTOCOL_VERSION, $ldap_version);
}
// Fix MDL-10921
if ($user_type === 'ad') {
ldap_set_option($connresult, LDAP_OPT_REFERRALS, 0);
}
if (!empty($opt_deref)) {
ldap_set_option($connresult, LDAP_OPT_DEREF, $opt_deref);
}
if ($start_tls && (!ldap_start_tls($connresult))) {
$debuginfo .= "Server: '$server', Connection: '$connresult', STARTTLS failed.\n";
continue;
}
if (!empty($bind_dn)) {
$bindresult = @ldap_bind($connresult, $bind_dn, $bind_pw);
} else {
// Bind anonymously
$bindresult = @ldap_bind($connresult);
}
if ($bindresult) {
return $connresult;
}
$debuginfo .= "Server: '$server', Connection: '$connresult', Bind result: '$bindresult'\n";
}
// If any of servers were alive we have already returned connection.
return false;
}
/**
* Search specified contexts for username and return the user dn like:
* cn=username,ou=suborg,o=org
*
* @param mixed $ldapconnection a valid LDAP connection.
* @param mixed $username username (external LDAP encoding, no db slashes).
* @param array $contexts contexts to look for the user.
* @param string $objectclass objectlass of the user (in LDAP filter syntax).
* @param string $search_attrib the attribute use to look for the user.
* @param boolean $search_sub whether to search subcontexts or not.
* @return mixed the user dn (external LDAP encoding, no db slashes) or false
*
*/
function ldap_find_userdn($ldapconnection, $username, $contexts, $objectclass, $search_attrib, $search_sub) {
if (empty($ldapconnection) || empty($username) || empty($contexts) || empty($objectclass) || empty($search_attrib)) {
return false;
}
// Default return value
$ldap_user_dn = false;
// Get all contexts and look for first matching user
foreach ($contexts as $context) {
$context = trim($context);
if (empty($context)) {
continue;
}
if ($search_sub) {
if (!$ldap_result = @ldap_search($ldapconnection, $context,
'(&'.$objectclass.'('.$search_attrib.'='.ldap_filter_addslashes($username).'))',
array($search_attrib))) {
break; // Not found in this context.
}
} else {
$ldap_result = ldap_list($ldapconnection, $context,
'(&'.$objectclass.'('.$search_attrib.'='.ldap_filter_addslashes($username).'))',
array($search_attrib));
}
$entry = ldap_first_entry($ldapconnection, $ldap_result);
if ($entry) {
$ldap_user_dn = ldap_get_dn($ldapconnection, $entry);
break;
}
}
return $ldap_user_dn;
}
/**
* Returns values like ldap_get_entries but is binary compatible and
* returns all attributes as array.
*
* @param mixed $ldapconnection A valid LDAP connection
* @param mixed $searchresult A search result from ldap_search, ldap_list, etc.
* @return array ldap-entries with lower-cased attributes as indexes
*/
function ldap_get_entries_moodle($ldapconnection, $searchresult) {
if (empty($ldapconnection) || empty($searchresult)) {
return array();
}
$i = 0;
$result = array();
$entry = ldap_first_entry($ldapconnection, $searchresult);
if (!$entry) {
return array();
}
do {
$attributes = array_change_key_case(ldap_get_attributes($ldapconnection, $entry), CASE_LOWER);
for ($j = 0; $j < $attributes['count']; $j++) {
$values = ldap_get_values_len($ldapconnection, $entry, $attributes[$j]);
if (is_array($values)) {
$result[$i][$attributes[$j]] = $values;
} else {
$result[$i][$attributes[$j]] = array($values);
}
}
$i++;
} while ($entry = ldap_next_entry($ldapconnection, $entry));
return ($result);
}
/**
* Quote control characters in texts used in LDAP filters - see RFC 4515/2254
*
* @param string filter string to quote
* @return string the filter string quoted
*/
function ldap_filter_addslashes($text) {
$text = str_replace('\\', '\\5c', $text);
$text = str_replace(array('*', '(', ')', "\0"),
array('\\2a', '\\28', '\\29', '\\00'), $text);
return $text;
}
if(!defined('LDAP_DN_SPECIAL_CHARS')) {
define('LDAP_DN_SPECIAL_CHARS', 0);
}
if(!defined('LDAP_DN_SPECIAL_CHARS_QUOTED_NUM')) {
define('LDAP_DN_SPECIAL_CHARS_QUOTED_NUM', 1);
}
if(!defined('LDAP_DN_SPECIAL_CHARS_QUOTED_ALPHA')) {
define('LDAP_DN_SPECIAL_CHARS_QUOTED_ALPHA', 2);
}
/**
* The order of the special characters in these arrays _IS IMPORTANT_.
* Make sure '\\5C' (and '\\') are the first elements of the arrays.
* Otherwise we'll double replace '\' with '\5C' which is Bad(tm)
*/
function ldap_get_dn_special_chars() {
return array (
LDAP_DN_SPECIAL_CHARS => array('\\', ' ', '"', '#', '+', ',', ';', '<', '=', '>', "\0"),
LDAP_DN_SPECIAL_CHARS_QUOTED_NUM => array('\\5c','\\20','\\22','\\23','\\2b','\\2c','\\3b','\\3c','\\3d','\\3e','\\00'),
LDAP_DN_SPECIAL_CHARS_QUOTED_ALPHA => array('\\\\','\\ ', '\\"', '\\#', '\\+', '\\,', '\\;', '\\<', '\\>', '\\=', '\\00'),
);
}
/**
* Quote control characters in distinguished names used in LDAP - See RFC 4514/2253
*
* @param string The text to quote
* @return string The text quoted
*/
function ldap_addslashes($text) {
$special_dn_chars = ldap_get_dn_special_chars();
$text = str_replace ($special_dn_chars[LDAP_DN_SPECIAL_CHARS],
$special_dn_chars[LDAP_DN_SPECIAL_CHARS_QUOTED_NUM],
$text);
return $text;
}
/**
* Unquote control characters in distinguished names used in LDAP - See RFC 4514/2253
*
* @param string The text quoted
* @return string The text unquoted
*/
function ldap_stripslashes($text) {
$special_dn_chars = ldap_get_dn_special_chars();
// First unquote the simply backslashed special characters. If we
// do it the other way, we remove too many slashes.
$text = str_replace($special_dn_chars[LDAP_DN_SPECIAL_CHARS_QUOTED_ALPHA],
$special_dn_chars[LDAP_DN_SPECIAL_CHARS],
$text);
// Next unquote the 'numerically' quoted characters. We don't use
// LDAP_DN_SPECIAL_CHARS_QUOTED_NUM because the standard allows us
// to quote any character with this encoding, not just the special
// ones.
$text = preg_replace('/\\\([0-9A-Fa-f]{2})/e', "chr(hexdec('\\1'))", $text);
return $text;
}
/**
* Check if PHP supports LDAP paged results and we can use them (we have to use LDAP
* version 3, otherwise the server doesn't use them).
*
* @param ldapversion integer The LDAP protocol version we use.
*
* @return boolean true is paged results can be used, false otherwise.
*/
function ldap_paged_results_supported($ldapversion) {
if (((int)$ldapversion === 3) &&
function_exists('ldap_control_paged_result') &&
function_exists('ldap_control_paged_result_response')) {
return true;
}
return false;
}