app/Access/Saml2Service.php
<?php
namespace BookStack\Access;
use BookStack\Exceptions\JsonDebugException;
use BookStack\Exceptions\SamlException;
use BookStack\Exceptions\StoppedAuthenticationException;
use BookStack\Exceptions\UserRegistrationException;
use BookStack\Users\Models\User;
use Exception;
use OneLogin\Saml2\Auth;
use OneLogin\Saml2\Constants;
use OneLogin\Saml2\Error;
use OneLogin\Saml2\IdPMetadataParser;
use OneLogin\Saml2\ValidationError;
/**
* Class Saml2Service
* Handles any app-specific SAML tasks.
*/
class Saml2Service
{
protected array $config;
public function __construct(
protected RegistrationService $registrationService,
protected LoginService $loginService,
protected GroupSyncService $groupSyncService
) {
$this->config = config('saml2');
}
/**
* Initiate a login flow.
*
* @throws Error
*/
public function login(): array
{
$toolKit = $this->getToolkit();
$returnRoute = url('/saml2/acs');
return [
'url' => $toolKit->login($returnRoute, [], false, false, true),
'id' => $toolKit->getLastRequestID(),
];
}
/**
* Initiate a logout flow.
* Returns the SAML2 request ID, and the URL to redirect the user to.
*
* @throws Error
* @returns array{url: string, id: ?string}
*/
public function logout(User $user): array
{
$toolKit = $this->getToolkit();
$sessionIndex = session()->get('saml2_session_index');
$returnUrl = url($this->loginService->logout());
try {
$url = $toolKit->logout(
$returnUrl,
[],
$user->email,
$sessionIndex,
true,
Constants::NAMEID_EMAIL_ADDRESS
);
$id = $toolKit->getLastRequestID();
} catch (Error $error) {
if ($error->getCode() !== Error::SAML_SINGLE_LOGOUT_NOT_SUPPORTED) {
throw $error;
}
$url = $returnUrl;
$id = null;
}
return ['url' => $url, 'id' => $id];
}
/**
* Process the ACS response from the idp and return the
* matching, or new if registration active, user matched to the idp.
* Returns null if not authenticated.
*
* @throws Error
* @throws SamlException
* @throws ValidationError
* @throws JsonDebugException
* @throws UserRegistrationException
*/
public function processAcsResponse(?string $requestId, string $samlResponse): ?User
{
// The SAML2 toolkit expects the response to be within the $_POST superglobal
// so we need to manually put it back there at this point.
$_POST['SAMLResponse'] = $samlResponse;
$toolkit = $this->getToolkit();
$toolkit->processResponse($requestId);
$errors = $toolkit->getErrors();
if (!empty($errors)) {
$reason = $toolkit->getLastErrorReason();
$message = 'Invalid ACS Response; Errors: ' . implode(', ', $errors);
$message .= $reason ? "; Reason: {$reason}" : '';
throw new Error($message);
}
if (!$toolkit->isAuthenticated()) {
return null;
}
$attrs = $toolkit->getAttributes();
$id = $toolkit->getNameId();
session()->put('saml2_session_index', $toolkit->getSessionIndex());
return $this->processLoginCallback($id, $attrs);
}
/**
* Process a response for the single logout service.
*
* @throws Error
*/
public function processSlsResponse(?string $requestId): string
{
$toolkit = $this->getToolkit();
// The $retrieveParametersFromServer in the call below will mean the library will take the query
// parameters, used for the response signing, from the raw $_SERVER['QUERY_STRING']
// value so that the exact encoding format is matched when checking the signature.
// This is primarily due to ADFS encoding query params with lowercase percent encoding while
// PHP (And most other sensible providers) standardise on uppercase.
/** @var ?string $samlRedirect */
$samlRedirect = $toolkit->processSLO(true, $requestId, true, null, true);
$errors = $toolkit->getErrors();
if (!empty($errors)) {
throw new Error(
'Invalid SLS Response: ' . implode(', ', $errors)
);
}
$defaultBookStackRedirect = $this->loginService->logout();
return $samlRedirect ?? $defaultBookStackRedirect;
}
/**
* Get the metadata for this service provider.
*
* @throws Error
*/
public function metadata(): string
{
$toolKit = $this->getToolkit(true);
$settings = $toolKit->getSettings();
$metadata = $settings->getSPMetadata();
$errors = $settings->validateMetadata($metadata);
if (!empty($errors)) {
throw new Error(
'Invalid SP metadata: ' . implode(', ', $errors),
Error::METADATA_SP_INVALID
);
}
return $metadata;
}
/**
* Load the underlying Onelogin SAML2 toolkit.
*
* @throws Error
* @throws Exception
*/
protected function getToolkit(bool $spOnly = false): Auth
{
$settings = $this->config['onelogin'];
$overrides = $this->config['onelogin_overrides'] ?? [];
if ($overrides && is_string($overrides)) {
$overrides = json_decode($overrides, true);
}
$metaDataSettings = [];
if (!$spOnly && $this->config['autoload_from_metadata']) {
$metaDataSettings = IdPMetadataParser::parseRemoteXML($settings['idp']['entityId']);
}
$spSettings = $this->loadOneloginServiceProviderDetails();
$settings = array_replace_recursive($settings, $spSettings, $metaDataSettings, $overrides);
return new Auth($settings, $spOnly);
}
/**
* Load dynamic service provider options required by the onelogin toolkit.
*/
protected function loadOneloginServiceProviderDetails(): array
{
$spDetails = [
'entityId' => url('/saml2/metadata'),
'assertionConsumerService' => [
'url' => url('/saml2/acs'),
],
'singleLogoutService' => [
'url' => url('/saml2/sls'),
],
];
return [
'baseurl' => url('/saml2'),
'sp' => $spDetails,
];
}
/**
* Check if groups should be synced.
*/
protected function shouldSyncGroups(): bool
{
return $this->config['user_to_groups'] !== false;
}
/**
* Calculate the display name.
*/
protected function getUserDisplayName(array $samlAttributes, string $defaultValue): string
{
$displayNameAttr = $this->config['display_name_attributes'];
$displayName = [];
foreach ($displayNameAttr as $dnAttr) {
$dnComponent = $this->getSamlResponseAttribute($samlAttributes, $dnAttr, null);
if ($dnComponent !== null) {
$displayName[] = $dnComponent;
}
}
if (count($displayName) == 0) {
$displayName = $defaultValue;
} else {
$displayName = implode(' ', $displayName);
}
return $displayName;
}
/**
* Get the value to use as the external id saved in BookStack
* used to link the user to an existing BookStack DB user.
*/
protected function getExternalId(array $samlAttributes, string $defaultValue)
{
$userNameAttr = $this->config['external_id_attribute'];
if ($userNameAttr === null) {
return $defaultValue;
}
return $this->getSamlResponseAttribute($samlAttributes, $userNameAttr, $defaultValue);
}
/**
* Extract the details of a user from a SAML response.
*
* @return array{external_id: string, name: string, email: string, saml_id: string}
*/
protected function getUserDetails(string $samlID, $samlAttributes): array
{
$emailAttr = $this->config['email_attribute'];
$externalId = $this->getExternalId($samlAttributes, $samlID);
$defaultEmail = filter_var($samlID, FILTER_VALIDATE_EMAIL) ? $samlID : null;
$email = $this->getSamlResponseAttribute($samlAttributes, $emailAttr, $defaultEmail);
return [
'external_id' => $externalId,
'name' => $this->getUserDisplayName($samlAttributes, $externalId),
'email' => $email,
'saml_id' => $samlID,
];
}
/**
* Get the groups a user is a part of from the SAML response.
*/
public function getUserGroups(array $samlAttributes): array
{
$groupsAttr = $this->config['group_attribute'];
$userGroups = $samlAttributes[$groupsAttr] ?? null;
if (!is_array($userGroups)) {
$userGroups = [];
}
return $userGroups;
}
/**
* For an array of strings, return a default for an empty array,
* a string for an array with one element and the full array for
* more than one element.
*/
protected function simplifyValue(array $data, $defaultValue)
{
switch (count($data)) {
case 0:
$data = $defaultValue;
break;
case 1:
$data = $data[0];
break;
}
return $data;
}
/**
* Get a property from an SAML response.
* Handles properties potentially being an array.
*/
protected function getSamlResponseAttribute(array $samlAttributes, string $propertyKey, $defaultValue)
{
if (isset($samlAttributes[$propertyKey])) {
return $this->simplifyValue($samlAttributes[$propertyKey], $defaultValue);
}
return $defaultValue;
}
/**
* Process the SAML response for a user. Login the user when
* they exist, optionally registering them automatically.
*
* @throws SamlException
* @throws JsonDebugException
* @throws UserRegistrationException
* @throws StoppedAuthenticationException
*/
public function processLoginCallback(string $samlID, array $samlAttributes): User
{
$userDetails = $this->getUserDetails($samlID, $samlAttributes);
$isLoggedIn = auth()->check();
if ($this->shouldSyncGroups()) {
$userDetails['groups'] = $this->getUserGroups($samlAttributes);
}
if ($this->config['dump_user_details']) {
throw new JsonDebugException([
'id_from_idp' => $samlID,
'attrs_from_idp' => $samlAttributes,
'attrs_after_parsing' => $userDetails,
]);
}
if ($userDetails['email'] === null) {
throw new SamlException(trans('errors.saml_no_email_address'));
}
if ($isLoggedIn) {
throw new SamlException(trans('errors.saml_already_logged_in'), '/login');
}
$user = $this->registrationService->findOrRegister(
$userDetails['name'],
$userDetails['email'],
$userDetails['external_id']
);
if ($this->shouldSyncGroups()) {
$this->groupSyncService->syncUserWithFoundGroups($user, $userDetails['groups'], $this->config['remove_from_groups']);
}
$this->loginService->login($user, 'saml2');
return $user;
}
}