app/Access/LdapService.php
<?php
namespace BookStack\Access;
use BookStack\Exceptions\JsonDebugException;
use BookStack\Exceptions\LdapException;
use BookStack\Uploads\UserAvatars;
use BookStack\Users\Models\User;
use ErrorException;
use Illuminate\Support\Facades\Log;
/**
* Class LdapService
* Handles any app-specific LDAP tasks.
*/
class LdapService
{
/**
* @var resource|\LDAP\Connection
*/
protected $ldapConnection;
protected array $config;
protected bool $enabled;
public function __construct(
protected Ldap $ldap,
protected UserAvatars $userAvatars,
protected GroupSyncService $groupSyncService
) {
$this->config = config('services.ldap');
$this->enabled = config('auth.method') === 'ldap';
}
/**
* Check if groups should be synced.
*/
public function shouldSyncGroups(): bool
{
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);
// Clean attributes
foreach ($attributes as $index => $attribute) {
if (str_starts_with($attribute, 'BIN;')) {
$attributes[$index] = substr($attribute, strlen('BIN;'));
}
}
// 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|JsonDebugException
*/
public function getUserDetails(string $userName): ?array
{
$idAttr = $this->config['id_attribute'];
$emailAttr = $this->config['email_attribute'];
$displayNameAttr = $this->config['display_name_attribute'];
$thumbnailAttr = $this->config['thumbnail_attribute'];
$user = $this->getUserWithAttributes($userName, array_filter([
'cn', 'dn', $idAttr, $emailAttr, $displayNameAttr, $thumbnailAttr,
]));
if (is_null($user)) {
return null;
}
$userCn = $this->getUserResponseProperty($user, 'cn', null);
$formatted = [
'uid' => $this->getUserResponseProperty($user, $idAttr, $user['dn']),
'name' => $this->getUserResponseProperty($user, $displayNameAttr, $userCn),
'dn' => $user['dn'],
'email' => $this->getUserResponseProperty($user, $emailAttr, null),
'avatar' => $thumbnailAttr ? $this->getUserResponseProperty($user, $thumbnailAttr, null) : null,
];
if ($this->config['dump_user_details']) {
throw new JsonDebugException([
'details_from_ldap' => $user,
'details_bookstack_parsed' => $formatted,
]);
}
return $formatted;
}
/**
* Get a property from an LDAP user response fetch.
* Handles properties potentially being part of an array.
* If the given key is prefixed with 'BIN;', that indicator will be stripped
* from the key and any fetched values will be converted from binary to hex.
*/
protected function getUserResponseProperty(array $userDetails, string $propertyKey, $defaultValue)
{
$isBinary = str_starts_with($propertyKey, 'BIN;');
$propertyKey = strtolower($propertyKey);
$value = $defaultValue;
if ($isBinary) {
$propertyKey = substr($propertyKey, strlen('BIN;'));
}
if (isset($userDetails[$propertyKey])) {
$value = (is_array($userDetails[$propertyKey]) ? $userDetails[$propertyKey][0] : $userDetails[$propertyKey]);
if ($isBinary) {
$value = bin2hex($value);
}
}
return $value;
}
/**
* Check if the given credentials are valid for the given user.
*
* @throws LdapException
*/
public function validateUserCredentials(?array $ldapUserDetails, string $password): bool
{
if (is_null($ldapUserDetails)) {
return false;
}
$ldapConnection = $this->getConnection();
try {
$ldapBind = $this->ldap->bind($ldapConnection, $ldapUserDetails['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 resource|\LDAP\Connection $connection
*
* @throws LdapException
*/
protected function bindSystemUser($connection): void
{
$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(($isAnonymous ? trans('errors.ldap_fail_anonymous') : trans('errors.ldap_fail_authed')));
}
}
/**
* Get the connection to the LDAP server.
* Creates a new connection if one does not exist.
*
* @throws LdapException
*
* @return resource|\LDAP\Connection
*/
protected function getConnection()
{
if ($this->ldapConnection !== null) {
return $this->ldapConnection;
}
// Check LDAP extension in installed
if (!function_exists('ldap_connect') && config('app.env') !== 'testing') {
throw new LdapException(trans('errors.ldap_extension_not_installed'));
}
// Disable certificate verification.
// This option works globally and must be set before a connection is created.
if ($this->config['tls_insecure']) {
$this->ldap->setOption(null, LDAP_OPT_X_TLS_REQUIRE_CERT, LDAP_OPT_X_TLS_NEVER);
}
// Configure any user-provided CA cert files for LDAP.
// This option works globally and must be set before a connection is created.
if ($this->config['tls_ca_cert']) {
$this->configureTlsCaCerts($this->config['tls_ca_cert']);
}
$ldapHost = $this->parseServerString($this->config['server']);
$ldapConnection = $this->ldap->connect($ldapHost);
if ($ldapConnection === false) {
throw new LdapException(trans('errors.ldap_cannot_connect'));
}
// Set any required options
if ($this->config['version']) {
$this->ldap->setVersion($ldapConnection, $this->config['version']);
}
// Start and verify TLS if it's enabled
if ($this->config['start_tls']) {
try {
$started = $this->ldap->startTls($ldapConnection);
} catch (\Exception $exception) {
$error = $exception->getMessage() . ' :: ' . ldap_error($ldapConnection);
ldap_get_option($ldapConnection, LDAP_OPT_DIAGNOSTIC_MESSAGE, $detail);
Log::info("LDAP STARTTLS failure: {$error} {$detail}");
throw new LdapException('Could not start TLS connection. Further details in the application log.');
}
if (!$started) {
throw new LdapException('Could not start TLS connection');
}
}
$this->ldapConnection = $ldapConnection;
return $this->ldapConnection;
}
/**
* Configure TLS CA certs globally for ldap use.
* This will detect if the given path is a directory or file, and set the relevant
* LDAP TLS options appropriately otherwise throw an exception if no file/folder found.
*
* Note: When using a folder, certificates are expected to be correctly named by hash
* which can be done via the c_rehash utility.
*
* @throws LdapException
*/
protected function configureTlsCaCerts(string $caCertPath): void
{
$errMessage = "Provided path [{$caCertPath}] for LDAP TLS CA certs could not be resolved to an existing location";
$path = realpath($caCertPath);
if ($path === false) {
throw new LdapException($errMessage);
}
if (is_dir($path)) {
$this->ldap->setOption(null, LDAP_OPT_X_TLS_CACERTDIR, $path);
} else if (is_file($path)) {
$this->ldap->setOption(null, LDAP_OPT_X_TLS_CACERTFILE, $path);
} else {
throw new LdapException($errMessage);
}
}
/**
* Parse an LDAP server string and return the host suitable for a connection.
* Is flexible to formats such as 'ldap.example.com:8069' or 'ldaps://ldap.example.com'.
*/
protected function parseServerString(string $serverString): string
{
if (str_starts_with($serverString, 'ldaps://') || str_starts_with($serverString, 'ldap://')) {
return $serverString;
}
return "ldap://{$serverString}";
}
/**
* Build a filter string by injecting common variables.
* Both "${var}" and "{var}" style placeholders are supported.
* Dollar based are old format but supported for compatibility.
*/
protected function buildFilter(string $filterString, array $attrs): string
{
$newAttrs = [];
foreach ($attrs as $key => $attrText) {
$escapedText = $this->ldap->escape($attrText);
$oldVarKey = '${' . $key . '}';
$newVarKey = '{' . $key . '}';
$newAttrs[$oldVarKey] = $escapedText;
$newAttrs[$newVarKey] = $escapedText;
}
return strtr($filterString, $newAttrs);
}
/**
* Get the groups a user is a part of on ldap.
*
* @throws LdapException
* @throws JsonDebugException
*/
public function getUserGroups(string $userName): array
{
$groupsAttr = $this->config['group_attribute'];
$user = $this->getUserWithAttributes($userName, [$groupsAttr]);
if ($user === null) {
return [];
}
$userGroups = $this->groupFilter($user);
$allGroups = $this->getGroupsRecursive($userGroups, []);
if ($this->config['dump_user_groups']) {
throw new JsonDebugException([
'details_from_ldap' => $user,
'parsed_direct_user_groups' => $userGroups,
'parsed_recursive_user_groups' => $allGroups,
]);
}
return $allGroups;
}
/**
* 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
* @throws JsonDebugException
*/
public function syncGroups(User $user, string $username): void
{
$userLdapGroups = $this->getUserGroups($username);
$this->groupSyncService->syncUserWithFoundGroups($user, $userLdapGroups, $this->config['remove_from_groups']);
}
/**
* Save and attach an avatar image, if found in the ldap details, and attach
* to the given user model.
*/
public function saveAndAttachAvatar(User $user, array $ldapUserDetails): void
{
if (is_null(config('services.ldap.thumbnail_attribute')) || is_null($ldapUserDetails['avatar'])) {
return;
}
try {
$imageData = $ldapUserDetails['avatar'];
$this->userAvatars->assignToUserFromExistingData($user, $imageData, 'jpg');
} catch (\Exception $exception) {
Log::info("Failed to use avatar image from LDAP data for user id {$user->id}");
}
}
}