BookStack/app/Auth/Access/LdapService.php
Dan Brown f9fa6904b9
Made LDAP auth ID attribute configurable
- Allows the field that gets stored as the "External Authentication ID"
to be configurable. Defined as LDAP_ID_ATTRIBUTE=uid in .env.
- Added test to cover usage.
- Also now auto-lowercases when searching for attributes in LDAP
response since PHP always provides them as lower case.

Closes #592.
2019-12-16 12:40:21 +00:00

326 lines
10 KiB
PHP

<?php namespace BookStack\Auth\Access;
use BookStack\Auth\User;
use BookStack\Auth\UserRepo;
use BookStack\Exceptions\LdapException;
use ErrorException;
use Illuminate\Contracts\Auth\Authenticatable;
/**
* Class LdapService
* Handles any app-specific LDAP tasks.
*/
class LdapService extends ExternalAuthService
{
protected $ldap;
protected $ldapConnection;
protected $config;
protected $userRepo;
protected $enabled;
/**
* LdapService constructor.
*/
public function __construct(Ldap $ldap, UserRepo $userRepo)
{
$this->ldap = $ldap;
$this->config = config('services.ldap');
$this->userRepo = $userRepo;
$this->enabled = config('auth.method') === 'ldap';
}
/**
* Check if groups should be synced.
* @return bool
*/
public function shouldSyncGroups()
{
return $this->enabled && $this->config['user_to_groups'] !== false;
}
/**
* Search for attributes for a specific user on the ldap.
* @throws LdapException
*/
private function getUserWithAttributes(string $userName, array $attributes): ?array
{
$ldapConnection = $this->getConnection();
$this->bindSystemUser($ldapConnection);
// Find user
$userFilter = $this->buildFilter($this->config['user_filter'], ['user' => $userName]);
$baseDn = $this->config['base_dn'];
$followReferrals = $this->config['follow_referrals'] ? 1 : 0;
$this->ldap->setOption($ldapConnection, LDAP_OPT_REFERRALS, $followReferrals);
$users = $this->ldap->searchAndGetEntries($ldapConnection, $baseDn, $userFilter, $attributes);
if ($users['count'] === 0) {
return null;
}
return $users[0];
}
/**
* Get the details of a user from LDAP using the given username.
* User found via configurable user filter.
* @throws LdapException
*/
public function getUserDetails(string $userName): ?array
{
$idAttr = $this->config['id_attribute'];
$emailAttr = $this->config['email_attribute'];
$displayNameAttr = $this->config['display_name_attribute'];
$user = $this->getUserWithAttributes($userName, ['cn', 'dn', $idAttr, $emailAttr, $displayNameAttr]);
if ($user === null) {
return null;
}
$userCn = $this->getUserResponseProperty($user, 'cn', null);
return [
'uid' => $this->getUserResponseProperty($user, $idAttr, $user['dn']),
'name' => $this->getUserResponseProperty($user, $displayNameAttr, $userCn),
'dn' => $user['dn'],
'email' => $this->getUserResponseProperty($user, $emailAttr, null),
];
}
/**
* Get a property from an LDAP user response fetch.
* Handles properties potentially being part of an array.
*/
protected function getUserResponseProperty(array $userDetails, string $propertyKey, $defaultValue)
{
$propertyKey = strtolower($propertyKey);
if (isset($userDetails[$propertyKey])) {
return (is_array($userDetails[$propertyKey]) ? $userDetails[$propertyKey][0] : $userDetails[$propertyKey]);
}
return $defaultValue;
}
/**
* Check if the given credentials are valid for the given user.
* @throws LdapException
*/
public function validateUserCredentials(Authenticatable $user, string $username, string $password): bool
{
$ldapUser = $this->getUserDetails($username);
if ($ldapUser === null) {
return false;
}
if ($ldapUser['uid'] !== $user->external_auth_id) {
return false;
}
$ldapConnection = $this->getConnection();
try {
$ldapBind = $this->ldap->bind($ldapConnection, $ldapUser['dn'], $password);
} catch (ErrorException $e) {
$ldapBind = false;
}
return $ldapBind;
}
/**
* Bind the system user to the LDAP connection using the given credentials
* otherwise anonymous access is attempted.
* @param $connection
* @throws LdapException
*/
protected function bindSystemUser($connection)
{
$ldapDn = $this->config['dn'];
$ldapPass = $this->config['pass'];
$isAnonymous = ($ldapDn === false || $ldapPass === false);
if ($isAnonymous) {
$ldapBind = $this->ldap->bind($connection);
} else {
$ldapBind = $this->ldap->bind($connection, $ldapDn, $ldapPass);
}
if (!$ldapBind) {
throw new LdapException(($isAnonymous ? trans('errors.ldap_fail_anonymous') : trans('errors.ldap_fail_authed')));
}
}
/**
* Get the connection to the LDAP server.
* Creates a new connection if one does not exist.
* @return resource
* @throws LdapException
*/
protected function getConnection()
{
if ($this->ldapConnection !== null) {
return $this->ldapConnection;
}
// Check LDAP extension in installed
if (!function_exists('ldap_connect') && config('app.env') !== 'testing') {
throw new LdapException(trans('errors.ldap_extension_not_installed'));
}
// Check if TLS_INSECURE is set. The handle is set to NULL due to the nature of
// the LDAP_OPT_X_TLS_REQUIRE_CERT option. It can only be set globally and not per handle.
if ($this->config['tls_insecure']) {
$this->ldap->setOption(null, LDAP_OPT_X_TLS_REQUIRE_CERT, LDAP_OPT_X_TLS_NEVER);
}
$serverDetails = $this->parseServerString($this->config['server']);
$ldapConnection = $this->ldap->connect($serverDetails['host'], $serverDetails['port']);
if ($ldapConnection === false) {
throw new LdapException(trans('errors.ldap_cannot_connect'));
}
// Set any required options
if ($this->config['version']) {
$this->ldap->setVersion($ldapConnection, $this->config['version']);
}
$this->ldapConnection = $ldapConnection;
return $this->ldapConnection;
}
/**
* Parse a LDAP server string and return the host and port for a connection.
* Is flexible to formats such as 'ldap.example.com:8069' or 'ldaps://ldap.example.com'.
*/
protected function parseServerString(string $serverString): array
{
$serverNameParts = explode(':', $serverString);
// If we have a protocol just return the full string since PHP will ignore a separate port.
if ($serverNameParts[0] === 'ldaps' || $serverNameParts[0] === 'ldap') {
return ['host' => $serverString, 'port' => 389];
}
// Otherwise, extract the port out
$hostName = $serverNameParts[0];
$ldapPort = (count($serverNameParts) > 1) ? intval($serverNameParts[1]) : 389;
return ['host' => $hostName, 'port' => $ldapPort];
}
/**
* Build a filter string by injecting common variables.
*/
protected function buildFilter(string $filterString, array $attrs): string
{
$newAttrs = [];
foreach ($attrs as $key => $attrText) {
$newKey = '${' . $key . '}';
$newAttrs[$newKey] = $this->ldap->escape($attrText);
}
return strtr($filterString, $newAttrs);
}
/**
* Get the groups a user is a part of on ldap.
* @throws LdapException
*/
public function getUserGroups(string $userName): array
{
$groupsAttr = $this->config['group_attribute'];
$user = $this->getUserWithAttributes($userName, [$groupsAttr]);
if ($user === null) {
return [];
}
$userGroups = $this->groupFilter($user);
$userGroups = $this->getGroupsRecursive($userGroups, []);
return $userGroups;
}
/**
* Get the parent groups of an array of groups.
* @throws LdapException
*/
private function getGroupsRecursive(array $groupsArray, array $checked): array
{
$groupsToAdd = [];
foreach ($groupsArray as $groupName) {
if (in_array($groupName, $checked)) {
continue;
}
$parentGroups = $this->getGroupGroups($groupName);
$groupsToAdd = array_merge($groupsToAdd, $parentGroups);
$checked[] = $groupName;
}
$groupsArray = array_unique(array_merge($groupsArray, $groupsToAdd), SORT_REGULAR);
if (empty($groupsToAdd)) {
return $groupsArray;
}
return $this->getGroupsRecursive($groupsArray, $checked);
}
/**
* Get the parent groups of a single group.
* @throws LdapException
*/
private function getGroupGroups(string $groupName): array
{
$ldapConnection = $this->getConnection();
$this->bindSystemUser($ldapConnection);
$followReferrals = $this->config['follow_referrals'] ? 1 : 0;
$this->ldap->setOption($ldapConnection, LDAP_OPT_REFERRALS, $followReferrals);
$baseDn = $this->config['base_dn'];
$groupsAttr = strtolower($this->config['group_attribute']);
$groupFilter = 'CN=' . $this->ldap->escape($groupName);
$groups = $this->ldap->searchAndGetEntries($ldapConnection, $baseDn, $groupFilter, [$groupsAttr]);
if ($groups['count'] === 0) {
return [];
}
return $this->groupFilter($groups[0]);
}
/**
* Filter out LDAP CN and DN language in a ldap search return.
* Gets the base CN (common name) of the string.
*/
protected function groupFilter(array $userGroupSearchResponse): array
{
$groupsAttr = strtolower($this->config['group_attribute']);
$ldapGroups = [];
$count = 0;
if (isset($userGroupSearchResponse[$groupsAttr]['count'])) {
$count = (int)$userGroupSearchResponse[$groupsAttr]['count'];
}
for ($i = 0; $i < $count; $i++) {
$dnComponents = $this->ldap->explodeDn($userGroupSearchResponse[$groupsAttr][$i], 1);
if (!in_array($dnComponents[0], $ldapGroups)) {
$ldapGroups[] = $dnComponents[0];
}
}
return $ldapGroups;
}
/**
* Sync the LDAP groups to the user roles for the current user.
* @throws LdapException
*/
public function syncGroups(User $user, string $username)
{
$userLdapGroups = $this->getUserGroups($username);
$this->syncWithGroups($user, $userLdapGroups);
}
}