nextcloud / server

apps/cloud_federation_api/lib/Controller/RequestHandlerController.php

Indentation +515 added lines, -515 removed lines

@@ -59,519 +59,519 @@
  */
 #[OpenAPI(scope: OpenAPI::SCOPE_FEDERATION)]
 class RequestHandlerController extends Controller {
-	public function __construct(
-		string $appName,
-		IRequest $request,
-		private LoggerInterface $logger,
-		private IUserManager $userManager,
-		private IGroupManager $groupManager,
-		private IURLGenerator $urlGenerator,
-		private ICloudFederationProviderManager $cloudFederationProviderManager,
-		private Config $config,
-		private IEventDispatcher $dispatcher,
-		private FederatedInviteMapper $federatedInviteMapper,
-		private readonly AddressHandler $addressHandler,
-		private readonly IAppConfig $appConfig,
-		private ICloudFederationFactory $factory,
-		private ICloudIdManager $cloudIdManager,
-		private readonly ISignatureManager $signatureManager,
-		private readonly OCMSignatoryManager $signatoryManager,
-		private ITimeFactory $timeFactory,
-	) {
-		parent::__construct($appName, $request);
-	}
-
-	/**
-	 * Add share
-	 *
-	 * @param string $shareWith The user who the share will be shared with
-	 * @param string $name The resource name (e.g. document.odt)
-	 * @param string|null $description Share description
-	 * @param string $providerId Resource UID on the provider side
-	 * @param string $owner Provider specific UID of the user who owns the resource
-	 * @param string|null $ownerDisplayName Display name of the user who shared the item
-	 * @param string|null $sharedBy Provider specific UID of the user who shared the resource
-	 * @param string|null $sharedByDisplayName Display name of the user who shared the resource
-	 * @param array{name: list<string>, options: array<string, mixed>} $protocol e,.g. ['name' => 'webdav', 'options' => ['username' => 'john', 'permissions' => 31]]
-	 * @param string $shareType 'group' or 'user' share
-	 * @param string $resourceType 'file', 'calendar',...
-	 *
-	 * @return JSONResponse<Http::STATUS_CREATED, CloudFederationAPIAddShare, array{}>|JSONResponse<Http::STATUS_BAD_REQUEST, CloudFederationAPIValidationError, array{}>|JSONResponse<Http::STATUS_NOT_IMPLEMENTED, CloudFederationAPIError, array{}>
-	 *
-	 * 201: The notification was successfully received. The display name of the recipient might be returned in the body
-	 * 400: Bad request due to invalid parameters, e.g. when `shareWith` is not found or required properties are missing
-	 * 501: Share type or the resource type is not supported
-	 */
-	#[PublicPage]
-	#[NoCSRFRequired]
-	#[BruteForceProtection(action: 'receiveFederatedShare')]
-	public function addShare($shareWith, $name, $description, $providerId, $owner, $ownerDisplayName, $sharedBy, $sharedByDisplayName, $protocol, $shareType, $resourceType) {
-		if (!$this->appConfig->getValueBool('core', OCMSignatoryManager::APPCONFIG_SIGN_DISABLED, lazy: true)) {
-			try {
-				// if request is signed and well signed, no exception are thrown
-				// if request is not signed and host is known for not supporting signed request, no exception are thrown
-				$signedRequest = $this->getSignedRequest();
-				$this->confirmSignedOrigin($signedRequest, 'owner', $owner);
-			} catch (IncomingRequestException $e) {
-				$this->logger->warning('incoming request exception', ['exception' => $e]);
-				return new JSONResponse(['message' => $e->getMessage(), 'validationErrors' => []], Http::STATUS_BAD_REQUEST);
-			}
-		}
-
-		// check if all required parameters are set
-		if (
-			$shareWith === null
-			|| $name === null
-			|| $providerId === null
-			|| $resourceType === null
-			|| $shareType === null
-			|| !is_array($protocol)
-			|| !isset($protocol['name'])
-			|| !isset($protocol['options'])
-			|| !is_array($protocol['options'])
-			|| !isset($protocol['options']['sharedSecret'])
-		) {
-			return new JSONResponse(
-				[
-					'message' => 'Missing arguments',
-					'validationErrors' => [],
-				],
-				Http::STATUS_BAD_REQUEST
-			);
-		}
-
-		$supportedShareTypes = $this->config->getSupportedShareTypes($resourceType);
-		if (!in_array($shareType, $supportedShareTypes)) {
-			return new JSONResponse(
-				['message' => 'Share type "' . $shareType . '" not implemented'],
-				Http::STATUS_NOT_IMPLEMENTED
-			);
-		}
-
-		$cloudId = $this->cloudIdManager->resolveCloudId($shareWith);
-		$shareWith = $cloudId->getUser();
-
-		if ($shareType === 'user') {
-			$shareWith = $this->mapUid($shareWith);
-
-			if (!$this->userManager->userExists($shareWith)) {
-				$response = new JSONResponse(
-					[
-						'message' => 'User "' . $shareWith . '" does not exists at ' . $this->urlGenerator->getBaseUrl(),
-						'validationErrors' => [],
-					],
-					Http::STATUS_BAD_REQUEST
-				);
-				$response->throttle();
-				return $response;
-			}
-		}
-
-		if ($shareType === 'group') {
-			if (!$this->groupManager->groupExists($shareWith)) {
-				$response = new JSONResponse(
-					[
-						'message' => 'Group "' . $shareWith . '" does not exists at ' . $this->urlGenerator->getBaseUrl(),
-						'validationErrors' => [],
-					],
-					Http::STATUS_BAD_REQUEST
-				);
-				$response->throttle();
-				return $response;
-			}
-		}
-
-		// if no explicit display name is given, we use the uid as display name
-		$ownerDisplayName = $ownerDisplayName === null ? $owner : $ownerDisplayName;
-		$sharedByDisplayName = $sharedByDisplayName === null ? $sharedBy : $sharedByDisplayName;
-
-		// sharedBy* parameter is optional, if nothing is set we assume that it is the same user as the owner
-		if ($sharedBy === null) {
-			$sharedBy = $owner;
-			$sharedByDisplayName = $ownerDisplayName;
-		}
-
-		try {
-			$provider = $this->cloudFederationProviderManager->getCloudFederationProvider($resourceType);
-			$share = $this->factory->getCloudFederationShare($shareWith, $name, $description, $providerId, $owner, $ownerDisplayName, $sharedBy, $sharedByDisplayName, '', $shareType, $resourceType);
-			$share->setProtocol($protocol);
-			$provider->shareReceived($share);
-		} catch (ProviderDoesNotExistsException|ProviderCouldNotAddShareException $e) {
-			return new JSONResponse(
-				['message' => $e->getMessage()],
-				Http::STATUS_NOT_IMPLEMENTED
-			);
-		} catch (\Exception $e) {
-			$this->logger->error($e->getMessage(), ['exception' => $e]);
-			return new JSONResponse(
-				[
-					'message' => 'Internal error at ' . $this->urlGenerator->getBaseUrl(),
-					'validationErrors' => [],
-				],
-				Http::STATUS_BAD_REQUEST
-			);
-		}
-
-		$responseData = ['recipientDisplayName' => ''];
-		if ($shareType === 'user') {
-			$user = $this->userManager->get($shareWith);
-			if ($user) {
-				$responseData = [
-					'recipientDisplayName' => $user->getDisplayName(),
-					'recipientUserId' => $user->getUID(),
-				];
-			}
-		}
-
-		return new JSONResponse($responseData, Http::STATUS_CREATED);
-	}
-
-	/**
-	 * Inform the sender that an invitation was accepted to start sharing
-	 *
-	 * Inform about an accepted invitation so the user on the sender provider's side
-	 * can initiate the OCM share creation. To protect the identity of the parties,
-	 * for shares created following an OCM invitation, the user id MAY be hashed,
-	 * and recipients implementing the OCM invitation workflow MAY refuse to process
-	 * shares coming from unknown parties.
-	 * @link https://cs3org.github.io/OCM-API/docs.html?branch=v1.1.0&repo=OCM-API&user=cs3org#/paths/~1invite-accepted/post
-	 *
-	 * @param string $recipientProvider The address of the recipent's provider
-	 * @param string $token The token used for the invitation
-	 * @param string $userID The userID of the recipient at the recipient's provider
-	 * @param string $email The email address of the recipient
-	 * @param string $name The display name of the recipient
-	 *
-	 * @return JSONResponse<Http::STATUS_OK, array{userID: string, email: string, name: string}, array{}>|JSONResponse<Http::STATUS_FORBIDDEN|Http::STATUS_BAD_REQUEST|Http::STATUS_CONFLICT, array{message: string, error: true}, array{}>
-	 *
-	 * Note: Not implementing 404 Invitation token does not exist, instead using 400
-	 * 200: Invitation accepted
-	 * 400: Invalid token
-	 * 403: Invitation token does not exist
-	 * 409: User is already known by the OCM provider
-	 */
-	#[PublicPage]
-	#[NoCSRFRequired]
-	#[BruteForceProtection(action: 'inviteAccepted')]
-	public function inviteAccepted(string $recipientProvider, string $token, string $userID, string $email, string $name): JSONResponse {
-		$this->logger->debug('Processing share invitation for ' . $userID . ' with token ' . $token . ' and email ' . $email . ' and name ' . $name);
-
-		$updated = $this->timeFactory->getTime();
-
-		if ($token === '') {
-			$response = new JSONResponse(['message' => 'Invalid or non existing token', 'error' => true], Http::STATUS_BAD_REQUEST);
-			$response->throttle();
-			return $response;
-		}
-
-		try {
-			$invitation = $this->federatedInviteMapper->findByToken($token);
-		} catch (DoesNotExistException) {
-			$response = ['message' => 'Invalid or non existing token', 'error' => true];
-			$status = Http::STATUS_BAD_REQUEST;
-			$response = new JSONResponse($response, $status);
-			$response->throttle();
-			return $response;
-		}
-
-		if ($invitation->isAccepted() === true) {
-			$response = ['message' => 'Invite already accepted', 'error' => true];
-			$status = Http::STATUS_CONFLICT;
-			return new JSONResponse($response, $status);
-		}
-
-		if ($invitation->getExpiredAt() !== null && $updated > $invitation->getExpiredAt()) {
-			$response = ['message' => 'Invitation expired', 'error' => true];
-			$status = Http::STATUS_BAD_REQUEST;
-			return new JSONResponse($response, $status);
-		}
-		$localUser = $this->userManager->get($invitation->getUserId());
-		if ($localUser === null) {
-			$response = ['message' => 'Invalid or non existing token', 'error' => true];
-			$status = Http::STATUS_BAD_REQUEST;
-			$response = new JSONResponse($response, $status);
-			$response->throttle();
-			return $response;
-		}
-
-		$sharedFromEmail = $localUser->getEMailAddress();
-		if ($sharedFromEmail === null) {
-			$response = ['message' => 'Invalid or non existing token', 'error' => true];
-			$status = Http::STATUS_BAD_REQUEST;
-			$response = new JSONResponse($response, $status);
-			$response->throttle();
-			return $response;
-		}
-		$sharedFromDisplayName = $localUser->getDisplayName();
-
-		$response = ['userID' => $localUser->getUID(), 'email' => $sharedFromEmail, 'name' => $sharedFromDisplayName];
-		$status = Http::STATUS_OK;
-
-		$invitation->setAccepted(true);
-		$invitation->setRecipientEmail($email);
-		$invitation->setRecipientName($name);
-		$invitation->setRecipientProvider($recipientProvider);
-		$invitation->setRecipientUserId($userID);
-		$invitation->setAcceptedAt($updated);
-		$invitation = $this->federatedInviteMapper->update($invitation);
-
-		$event = new FederatedInviteAcceptedEvent($invitation);
-		$this->dispatcher->dispatchTyped($event);
-
-		return new JSONResponse($response, $status);
-	}
-
-	/**
-	 * Send a notification about an existing share
-	 *
-	 * @param string $notificationType Notification type, e.g. SHARE_ACCEPTED
-	 * @param string $resourceType calendar, file, contact,...
-	 * @param string|null $providerId ID of the share
-	 * @param array<string, mixed>|null $notification The actual payload of the notification
-	 *
-	 * @return JSONResponse<Http::STATUS_CREATED, array<string, mixed>, array{}>|JSONResponse<Http::STATUS_BAD_REQUEST, CloudFederationAPIValidationError, array{}>|JSONResponse<Http::STATUS_FORBIDDEN|Http::STATUS_NOT_IMPLEMENTED, CloudFederationAPIError, array{}>
-	 *
-	 * 201: The notification was successfully received
-	 * 400: Bad request due to invalid parameters, e.g. when `type` is invalid or missing
-	 * 403: Getting resource is not allowed
-	 * 501: The resource type is not supported
-	 */
-	#[NoCSRFRequired]
-	#[PublicPage]
-	#[BruteForceProtection(action: 'receiveFederatedShareNotification')]
-	public function receiveNotification($notificationType, $resourceType, $providerId, ?array $notification) {
-		// check if all required parameters are set
-		if (
-			$notificationType === null
-			|| $resourceType === null
-			|| $providerId === null
-			|| !is_array($notification)
-		) {
-			return new JSONResponse(
-				[
-					'message' => 'Missing arguments',
-					'validationErrors' => [],
-				],
-				Http::STATUS_BAD_REQUEST
-			);
-		}
-
-		if (!$this->appConfig->getValueBool('core', OCMSignatoryManager::APPCONFIG_SIGN_DISABLED, lazy: true)) {
-			try {
-				// if request is signed and well signed, no exception are thrown
-				// if request is not signed and host is known for not supporting signed request, no exception are thrown
-				$signedRequest = $this->getSignedRequest();
-				$this->confirmNotificationIdentity($signedRequest, $resourceType, $notification);
-			} catch (IncomingRequestException $e) {
-				$this->logger->warning('incoming request exception', ['exception' => $e]);
-				return new JSONResponse(['message' => $e->getMessage(), 'validationErrors' => []], Http::STATUS_BAD_REQUEST);
-			}
-		}
-
-		try {
-			$provider = $this->cloudFederationProviderManager->getCloudFederationProvider($resourceType);
-			$result = $provider->notificationReceived($notificationType, $providerId, $notification);
-		} catch (ProviderDoesNotExistsException $e) {
-			return new JSONResponse(
-				[
-					'message' => $e->getMessage(),
-					'validationErrors' => [],
-				],
-				Http::STATUS_BAD_REQUEST
-			);
-		} catch (ShareNotFound $e) {
-			$response = new JSONResponse(
-				[
-					'message' => $e->getMessage(),
-					'validationErrors' => [],
-				],
-				Http::STATUS_BAD_REQUEST
-			);
-			$response->throttle();
-			return $response;
-		} catch (ActionNotSupportedException $e) {
-			return new JSONResponse(
-				['message' => $e->getMessage()],
-				Http::STATUS_NOT_IMPLEMENTED
-			);
-		} catch (BadRequestException $e) {
-			return new JSONResponse($e->getReturnMessage(), Http::STATUS_BAD_REQUEST);
-		} catch (AuthenticationFailedException $e) {
-			$response = new JSONResponse(['message' => 'RESOURCE_NOT_FOUND'], Http::STATUS_FORBIDDEN);
-			$response->throttle();
-			return $response;
-		} catch (\Exception $e) {
-			$this->logger->warning('incoming notification exception', ['exception' => $e]);
-			return new JSONResponse(
-				[
-					'message' => 'Internal error at ' . $this->urlGenerator->getBaseUrl(),
-					'validationErrors' => [],
-				],
-				Http::STATUS_BAD_REQUEST
-			);
-		}
-
-		return new JSONResponse($result, Http::STATUS_CREATED);
-	}
-
-	/**
-	 * map login name to internal LDAP UID if a LDAP backend is in use
-	 *
-	 * @param string $uid
-	 * @return string mixed
-	 */
-	private function mapUid($uid) {
-		// FIXME this should be a method in the user management instead
-		$this->logger->debug('shareWith before, ' . $uid, ['app' => $this->appName]);
-		Util::emitHook(
-			'\OCA\Files_Sharing\API\Server2Server',
-			'preLoginNameUsedAsUserName',
-			['uid' => &$uid]
-		);
-		$this->logger->debug('shareWith after, ' . $uid, ['app' => $this->appName]);
-
-		return $uid;
-	}
-
-
-	/**
-	 * returns signed request if available.
-	 * throw an exception:
-	 * - if request is signed, but wrongly signed
-	 * - if request is not signed but instance is configured to only accept signed ocm request
-	 *
-	 * @return IIncomingSignedRequest|null null if remote does not (and never did) support signed request
-	 * @throws IncomingRequestException
-	 */
-	private function getSignedRequest(): ?IIncomingSignedRequest {
-		try {
-			$signedRequest = $this->signatureManager->getIncomingSignedRequest($this->signatoryManager);
-			$this->logger->debug('signed request available', ['signedRequest' => $signedRequest]);
-			return $signedRequest;
-		} catch (SignatureNotFoundException|SignatoryNotFoundException $e) {
-			$this->logger->debug('remote does not support signed request', ['exception' => $e]);
-			// remote does not support signed request.
-			// currently we still accept unsigned request until lazy appconfig
-			// core.enforce_signed_ocm_request is set to true (default: false)
-			if ($this->appConfig->getValueBool('core', OCMSignatoryManager::APPCONFIG_SIGN_ENFORCED, lazy: true)) {
-				$this->logger->notice('ignored unsigned request', ['exception' => $e]);
-				throw new IncomingRequestException('Unsigned request');
-			}
-		} catch (SignatureException $e) {
-			$this->logger->warning('wrongly signed request', ['exception' => $e]);
-			throw new IncomingRequestException('Invalid signature');
-		}
-		return null;
-	}
-
-
-	/**
-	 * confirm that the value related to $key entry from the payload is in format userid@hostname
-	 * and compare hostname with the origin of the signed request.
-	 *
-	 * If request is not signed, we still verify that the hostname from the extracted value does,
-	 * actually, not support signed request
-	 *
-	 * @param IIncomingSignedRequest|null $signedRequest
-	 * @param string $key entry from data available in data
-	 * @param string $value value itself used in case request is not signed
-	 *
-	 * @throws IncomingRequestException
-	 */
-	private function confirmSignedOrigin(?IIncomingSignedRequest $signedRequest, string $key, string $value): void {
-		if ($signedRequest === null) {
-			$instance = $this->getHostFromFederationId($value);
-			try {
-				$this->signatureManager->getSignatory($instance);
-				throw new IncomingRequestException('instance is supposed to sign its request');
-			} catch (SignatoryNotFoundException) {
-				return;
-			}
-		}
-
-		$body = json_decode($signedRequest->getBody(), true) ?? [];
-		$entry = trim($body[$key] ?? '', '@');
-		if ($this->getHostFromFederationId($entry) !== $signedRequest->getOrigin()) {
-			throw new IncomingRequestException('share initiation (' . $signedRequest->getOrigin() . ') from different instance (' . $entry . ') [key=' . $key . ']');
-		}
-	}
-
-	/**
-	 *  confirm identity of the remote instance on notification, based on the share token.
-	 *
-	 *  If request is not signed, we still verify that the hostname from the extracted value does,
-	 *  actually, not support signed request
-	 *
-	 * @param IIncomingSignedRequest|null $signedRequest
-	 * @param string $resourceType
-	 *
-	 * @throws IncomingRequestException
-	 * @throws BadRequestException
-	 */
-	private function confirmNotificationIdentity(
-		?IIncomingSignedRequest $signedRequest,
-		string $resourceType,
-		array $notification,
-	): void {
-		$sharedSecret = $notification['sharedSecret'] ?? '';
-		if ($sharedSecret === '') {
-			throw new BadRequestException(['sharedSecret']);
-		}
-
-		try {
-			$provider = $this->cloudFederationProviderManager->getCloudFederationProvider($resourceType);
-			if ($provider instanceof ISignedCloudFederationProvider) {
-				$identity = $provider->getFederationIdFromSharedSecret($sharedSecret, $notification);
-			} else {
-				$this->logger->debug('cloud federation provider {provider} does not implements ISignedCloudFederationProvider', ['provider' => $provider::class]);
-				return;
-			}
-		} catch (\Exception $e) {
-			throw new IncomingRequestException($e->getMessage(), previous: $e);
-		}
-
-		$this->confirmNotificationEntry($signedRequest, $identity);
-	}
-
-
-	/**
-	 * @param IIncomingSignedRequest|null $signedRequest
-	 * @param string $entry
-	 *
-	 * @return void
-	 * @throws IncomingRequestException
-	 */
-	private function confirmNotificationEntry(?IIncomingSignedRequest $signedRequest, string $entry): void {
-		$instance = $this->getHostFromFederationId($entry);
-		if ($signedRequest === null) {
-			try {
-				$this->signatureManager->getSignatory($instance);
-				throw new IncomingRequestException('instance is supposed to sign its request');
-			} catch (SignatoryNotFoundException) {
-				return;
-			}
-		} elseif ($instance !== $signedRequest->getOrigin()) {
-			throw new IncomingRequestException('remote instance ' . $instance . ' not linked to origin ' . $signedRequest->getOrigin());
-		}
-	}
-
-	/**
-	 * @param string $entry
-	 * @return string
-	 * @throws IncomingRequestException
-	 */
-	private function getHostFromFederationId(string $entry): string {
-		if (!str_contains($entry, '@')) {
-			throw new IncomingRequestException('entry ' . $entry . ' does not contain @');
-		}
-		$rightPart = substr($entry, strrpos($entry, '@') + 1);
-
-		// in case the full scheme is sent; getting rid of it
-		$rightPart = $this->addressHandler->removeProtocolFromUrl($rightPart);
-		try {
-			return $this->signatureManager->extractIdentityFromUri('https://' . $rightPart);
-		} catch (IdentityNotFoundException) {
-			throw new IncomingRequestException('invalid host within federation id: ' . $entry);
-		}
-	}
+    public function __construct(
+        string $appName,
+        IRequest $request,
+        private LoggerInterface $logger,
+        private IUserManager $userManager,
+        private IGroupManager $groupManager,
+        private IURLGenerator $urlGenerator,
+        private ICloudFederationProviderManager $cloudFederationProviderManager,
+        private Config $config,
+        private IEventDispatcher $dispatcher,
+        private FederatedInviteMapper $federatedInviteMapper,
+        private readonly AddressHandler $addressHandler,
+        private readonly IAppConfig $appConfig,
+        private ICloudFederationFactory $factory,
+        private ICloudIdManager $cloudIdManager,
+        private readonly ISignatureManager $signatureManager,
+        private readonly OCMSignatoryManager $signatoryManager,
+        private ITimeFactory $timeFactory,
+    ) {
+        parent::__construct($appName, $request);
+    }
+
+    /**
+     * Add share
+     *
+     * @param string $shareWith The user who the share will be shared with
+     * @param string $name The resource name (e.g. document.odt)
+     * @param string|null $description Share description
+     * @param string $providerId Resource UID on the provider side
+     * @param string $owner Provider specific UID of the user who owns the resource
+     * @param string|null $ownerDisplayName Display name of the user who shared the item
+     * @param string|null $sharedBy Provider specific UID of the user who shared the resource
+     * @param string|null $sharedByDisplayName Display name of the user who shared the resource
+     * @param array{name: list<string>, options: array<string, mixed>} $protocol e,.g. ['name' => 'webdav', 'options' => ['username' => 'john', 'permissions' => 31]]
+     * @param string $shareType 'group' or 'user' share
+     * @param string $resourceType 'file', 'calendar',...
+     *
+     * @return JSONResponse<Http::STATUS_CREATED, CloudFederationAPIAddShare, array{}>|JSONResponse<Http::STATUS_BAD_REQUEST, CloudFederationAPIValidationError, array{}>|JSONResponse<Http::STATUS_NOT_IMPLEMENTED, CloudFederationAPIError, array{}>
+     *
+     * 201: The notification was successfully received. The display name of the recipient might be returned in the body
+     * 400: Bad request due to invalid parameters, e.g. when `shareWith` is not found or required properties are missing
+     * 501: Share type or the resource type is not supported
+     */
+    #[PublicPage]
+    #[NoCSRFRequired]
+    #[BruteForceProtection(action: 'receiveFederatedShare')]
+    public function addShare($shareWith, $name, $description, $providerId, $owner, $ownerDisplayName, $sharedBy, $sharedByDisplayName, $protocol, $shareType, $resourceType) {
+        if (!$this->appConfig->getValueBool('core', OCMSignatoryManager::APPCONFIG_SIGN_DISABLED, lazy: true)) {
+            try {
+                // if request is signed and well signed, no exception are thrown
+                // if request is not signed and host is known for not supporting signed request, no exception are thrown
+                $signedRequest = $this->getSignedRequest();
+                $this->confirmSignedOrigin($signedRequest, 'owner', $owner);
+            } catch (IncomingRequestException $e) {
+                $this->logger->warning('incoming request exception', ['exception' => $e]);
+                return new JSONResponse(['message' => $e->getMessage(), 'validationErrors' => []], Http::STATUS_BAD_REQUEST);
+            }
+        }
+
+        // check if all required parameters are set
+        if (
+            $shareWith === null
+            || $name === null
+            || $providerId === null
+            || $resourceType === null
+            || $shareType === null
+            || !is_array($protocol)
+            || !isset($protocol['name'])
+            || !isset($protocol['options'])
+            || !is_array($protocol['options'])
+            || !isset($protocol['options']['sharedSecret'])
+        ) {
+            return new JSONResponse(
+                [
+                    'message' => 'Missing arguments',
+                    'validationErrors' => [],
+                ],
+                Http::STATUS_BAD_REQUEST
+            );
+        }
+
+        $supportedShareTypes = $this->config->getSupportedShareTypes($resourceType);
+        if (!in_array($shareType, $supportedShareTypes)) {
+            return new JSONResponse(
+                ['message' => 'Share type "' . $shareType . '" not implemented'],
+                Http::STATUS_NOT_IMPLEMENTED
+            );
+        }
+
+        $cloudId = $this->cloudIdManager->resolveCloudId($shareWith);
+        $shareWith = $cloudId->getUser();
+
+        if ($shareType === 'user') {
+            $shareWith = $this->mapUid($shareWith);
+
+            if (!$this->userManager->userExists($shareWith)) {
+                $response = new JSONResponse(
+                    [
+                        'message' => 'User "' . $shareWith . '" does not exists at ' . $this->urlGenerator->getBaseUrl(),
+                        'validationErrors' => [],
+                    ],
+                    Http::STATUS_BAD_REQUEST
+                );
+                $response->throttle();
+                return $response;
+            }
+        }
+
+        if ($shareType === 'group') {
+            if (!$this->groupManager->groupExists($shareWith)) {
+                $response = new JSONResponse(
+                    [
+                        'message' => 'Group "' . $shareWith . '" does not exists at ' . $this->urlGenerator->getBaseUrl(),
+                        'validationErrors' => [],
+                    ],
+                    Http::STATUS_BAD_REQUEST
+                );
+                $response->throttle();
+                return $response;
+            }
+        }
+
+        // if no explicit display name is given, we use the uid as display name
+        $ownerDisplayName = $ownerDisplayName === null ? $owner : $ownerDisplayName;
+        $sharedByDisplayName = $sharedByDisplayName === null ? $sharedBy : $sharedByDisplayName;
+
+        // sharedBy* parameter is optional, if nothing is set we assume that it is the same user as the owner
+        if ($sharedBy === null) {
+            $sharedBy = $owner;
+            $sharedByDisplayName = $ownerDisplayName;
+        }
+
+        try {
+            $provider = $this->cloudFederationProviderManager->getCloudFederationProvider($resourceType);
+            $share = $this->factory->getCloudFederationShare($shareWith, $name, $description, $providerId, $owner, $ownerDisplayName, $sharedBy, $sharedByDisplayName, '', $shareType, $resourceType);
+            $share->setProtocol($protocol);
+            $provider->shareReceived($share);
+        } catch (ProviderDoesNotExistsException|ProviderCouldNotAddShareException $e) {
+            return new JSONResponse(
+                ['message' => $e->getMessage()],
+                Http::STATUS_NOT_IMPLEMENTED
+            );
+        } catch (\Exception $e) {
+            $this->logger->error($e->getMessage(), ['exception' => $e]);
+            return new JSONResponse(
+                [
+                    'message' => 'Internal error at ' . $this->urlGenerator->getBaseUrl(),
+                    'validationErrors' => [],
+                ],
+                Http::STATUS_BAD_REQUEST
+            );
+        }
+
+        $responseData = ['recipientDisplayName' => ''];
+        if ($shareType === 'user') {
+            $user = $this->userManager->get($shareWith);
+            if ($user) {
+                $responseData = [
+                    'recipientDisplayName' => $user->getDisplayName(),
+                    'recipientUserId' => $user->getUID(),
+                ];
+            }
+        }
+
+        return new JSONResponse($responseData, Http::STATUS_CREATED);
+    }
+
+    /**
+     * Inform the sender that an invitation was accepted to start sharing
+     *
+     * Inform about an accepted invitation so the user on the sender provider's side
+     * can initiate the OCM share creation. To protect the identity of the parties,
+     * for shares created following an OCM invitation, the user id MAY be hashed,
+     * and recipients implementing the OCM invitation workflow MAY refuse to process
+     * shares coming from unknown parties.
+     * @link https://cs3org.github.io/OCM-API/docs.html?branch=v1.1.0&repo=OCM-API&user=cs3org#/paths/~1invite-accepted/post
+     *
+     * @param string $recipientProvider The address of the recipent's provider
+     * @param string $token The token used for the invitation
+     * @param string $userID The userID of the recipient at the recipient's provider
+     * @param string $email The email address of the recipient
+     * @param string $name The display name of the recipient
+     *
+     * @return JSONResponse<Http::STATUS_OK, array{userID: string, email: string, name: string}, array{}>|JSONResponse<Http::STATUS_FORBIDDEN|Http::STATUS_BAD_REQUEST|Http::STATUS_CONFLICT, array{message: string, error: true}, array{}>
+     *
+     * Note: Not implementing 404 Invitation token does not exist, instead using 400
+     * 200: Invitation accepted
+     * 400: Invalid token
+     * 403: Invitation token does not exist
+     * 409: User is already known by the OCM provider
+     */
+    #[PublicPage]
+    #[NoCSRFRequired]
+    #[BruteForceProtection(action: 'inviteAccepted')]
+    public function inviteAccepted(string $recipientProvider, string $token, string $userID, string $email, string $name): JSONResponse {
+        $this->logger->debug('Processing share invitation for ' . $userID . ' with token ' . $token . ' and email ' . $email . ' and name ' . $name);
+
+        $updated = $this->timeFactory->getTime();
+
+        if ($token === '') {
+            $response = new JSONResponse(['message' => 'Invalid or non existing token', 'error' => true], Http::STATUS_BAD_REQUEST);
+            $response->throttle();
+            return $response;
+        }
+
+        try {
+            $invitation = $this->federatedInviteMapper->findByToken($token);
+        } catch (DoesNotExistException) {
+            $response = ['message' => 'Invalid or non existing token', 'error' => true];
+            $status = Http::STATUS_BAD_REQUEST;
+            $response = new JSONResponse($response, $status);
+            $response->throttle();
+            return $response;
+        }
+
+        if ($invitation->isAccepted() === true) {
+            $response = ['message' => 'Invite already accepted', 'error' => true];
+            $status = Http::STATUS_CONFLICT;
+            return new JSONResponse($response, $status);
+        }
+
+        if ($invitation->getExpiredAt() !== null && $updated > $invitation->getExpiredAt()) {
+            $response = ['message' => 'Invitation expired', 'error' => true];
+            $status = Http::STATUS_BAD_REQUEST;
+            return new JSONResponse($response, $status);
+        }
+        $localUser = $this->userManager->get($invitation->getUserId());
+        if ($localUser === null) {
+            $response = ['message' => 'Invalid or non existing token', 'error' => true];
+            $status = Http::STATUS_BAD_REQUEST;
+            $response = new JSONResponse($response, $status);
+            $response->throttle();
+            return $response;
+        }
+
+        $sharedFromEmail = $localUser->getEMailAddress();
+        if ($sharedFromEmail === null) {
+            $response = ['message' => 'Invalid or non existing token', 'error' => true];
+            $status = Http::STATUS_BAD_REQUEST;
+            $response = new JSONResponse($response, $status);
+            $response->throttle();
+            return $response;
+        }
+        $sharedFromDisplayName = $localUser->getDisplayName();
+
+        $response = ['userID' => $localUser->getUID(), 'email' => $sharedFromEmail, 'name' => $sharedFromDisplayName];
+        $status = Http::STATUS_OK;
+
+        $invitation->setAccepted(true);
+        $invitation->setRecipientEmail($email);
+        $invitation->setRecipientName($name);
+        $invitation->setRecipientProvider($recipientProvider);
+        $invitation->setRecipientUserId($userID);
+        $invitation->setAcceptedAt($updated);
+        $invitation = $this->federatedInviteMapper->update($invitation);
+
+        $event = new FederatedInviteAcceptedEvent($invitation);
+        $this->dispatcher->dispatchTyped($event);
+
+        return new JSONResponse($response, $status);
+    }
+
+    /**
+     * Send a notification about an existing share
+     *
+     * @param string $notificationType Notification type, e.g. SHARE_ACCEPTED
+     * @param string $resourceType calendar, file, contact,...
+     * @param string|null $providerId ID of the share
+     * @param array<string, mixed>|null $notification The actual payload of the notification
+     *
+     * @return JSONResponse<Http::STATUS_CREATED, array<string, mixed>, array{}>|JSONResponse<Http::STATUS_BAD_REQUEST, CloudFederationAPIValidationError, array{}>|JSONResponse<Http::STATUS_FORBIDDEN|Http::STATUS_NOT_IMPLEMENTED, CloudFederationAPIError, array{}>
+     *
+     * 201: The notification was successfully received
+     * 400: Bad request due to invalid parameters, e.g. when `type` is invalid or missing
+     * 403: Getting resource is not allowed
+     * 501: The resource type is not supported
+     */
+    #[NoCSRFRequired]
+    #[PublicPage]
+    #[BruteForceProtection(action: 'receiveFederatedShareNotification')]
+    public function receiveNotification($notificationType, $resourceType, $providerId, ?array $notification) {
+        // check if all required parameters are set
+        if (
+            $notificationType === null
+            || $resourceType === null
+            || $providerId === null
+            || !is_array($notification)
+        ) {
+            return new JSONResponse(
+                [
+                    'message' => 'Missing arguments',
+                    'validationErrors' => [],
+                ],
+                Http::STATUS_BAD_REQUEST
+            );
+        }
+
+        if (!$this->appConfig->getValueBool('core', OCMSignatoryManager::APPCONFIG_SIGN_DISABLED, lazy: true)) {
+            try {
+                // if request is signed and well signed, no exception are thrown
+                // if request is not signed and host is known for not supporting signed request, no exception are thrown
+                $signedRequest = $this->getSignedRequest();
+                $this->confirmNotificationIdentity($signedRequest, $resourceType, $notification);
+            } catch (IncomingRequestException $e) {
+                $this->logger->warning('incoming request exception', ['exception' => $e]);
+                return new JSONResponse(['message' => $e->getMessage(), 'validationErrors' => []], Http::STATUS_BAD_REQUEST);
+            }
+        }
+
+        try {
+            $provider = $this->cloudFederationProviderManager->getCloudFederationProvider($resourceType);
+            $result = $provider->notificationReceived($notificationType, $providerId, $notification);
+        } catch (ProviderDoesNotExistsException $e) {
+            return new JSONResponse(
+                [
+                    'message' => $e->getMessage(),
+                    'validationErrors' => [],
+                ],
+                Http::STATUS_BAD_REQUEST
+            );
+        } catch (ShareNotFound $e) {
+            $response = new JSONResponse(
+                [
+                    'message' => $e->getMessage(),
+                    'validationErrors' => [],
+                ],
+                Http::STATUS_BAD_REQUEST
+            );
+            $response->throttle();
+            return $response;
+        } catch (ActionNotSupportedException $e) {
+            return new JSONResponse(
+                ['message' => $e->getMessage()],
+                Http::STATUS_NOT_IMPLEMENTED
+            );
+        } catch (BadRequestException $e) {
+            return new JSONResponse($e->getReturnMessage(), Http::STATUS_BAD_REQUEST);
+        } catch (AuthenticationFailedException $e) {
+            $response = new JSONResponse(['message' => 'RESOURCE_NOT_FOUND'], Http::STATUS_FORBIDDEN);
+            $response->throttle();
+            return $response;
+        } catch (\Exception $e) {
+            $this->logger->warning('incoming notification exception', ['exception' => $e]);
+            return new JSONResponse(
+                [
+                    'message' => 'Internal error at ' . $this->urlGenerator->getBaseUrl(),
+                    'validationErrors' => [],
+                ],
+                Http::STATUS_BAD_REQUEST
+            );
+        }
+
+        return new JSONResponse($result, Http::STATUS_CREATED);
+    }
+
+    /**
+     * map login name to internal LDAP UID if a LDAP backend is in use
+     *
+     * @param string $uid
+     * @return string mixed
+     */
+    private function mapUid($uid) {
+        // FIXME this should be a method in the user management instead
+        $this->logger->debug('shareWith before, ' . $uid, ['app' => $this->appName]);
+        Util::emitHook(
+            '\OCA\Files_Sharing\API\Server2Server',
+            'preLoginNameUsedAsUserName',
+            ['uid' => &$uid]
+        );
+        $this->logger->debug('shareWith after, ' . $uid, ['app' => $this->appName]);
+
+        return $uid;
+    }
+
+
+    /**
+     * returns signed request if available.
+     * throw an exception:
+     * - if request is signed, but wrongly signed
+     * - if request is not signed but instance is configured to only accept signed ocm request
+     *
+     * @return IIncomingSignedRequest|null null if remote does not (and never did) support signed request
+     * @throws IncomingRequestException
+     */
+    private function getSignedRequest(): ?IIncomingSignedRequest {
+        try {
+            $signedRequest = $this->signatureManager->getIncomingSignedRequest($this->signatoryManager);
+            $this->logger->debug('signed request available', ['signedRequest' => $signedRequest]);
+            return $signedRequest;
+        } catch (SignatureNotFoundException|SignatoryNotFoundException $e) {
+            $this->logger->debug('remote does not support signed request', ['exception' => $e]);
+            // remote does not support signed request.
+            // currently we still accept unsigned request until lazy appconfig
+            // core.enforce_signed_ocm_request is set to true (default: false)
+            if ($this->appConfig->getValueBool('core', OCMSignatoryManager::APPCONFIG_SIGN_ENFORCED, lazy: true)) {
+                $this->logger->notice('ignored unsigned request', ['exception' => $e]);
+                throw new IncomingRequestException('Unsigned request');
+            }
+        } catch (SignatureException $e) {
+            $this->logger->warning('wrongly signed request', ['exception' => $e]);
+            throw new IncomingRequestException('Invalid signature');
+        }
+        return null;
+    }
+
+
+    /**
+     * confirm that the value related to $key entry from the payload is in format userid@hostname
+     * and compare hostname with the origin of the signed request.
+     *
+     * If request is not signed, we still verify that the hostname from the extracted value does,
+     * actually, not support signed request
+     *
+     * @param IIncomingSignedRequest|null $signedRequest
+     * @param string $key entry from data available in data
+     * @param string $value value itself used in case request is not signed
+     *
+     * @throws IncomingRequestException
+     */
+    private function confirmSignedOrigin(?IIncomingSignedRequest $signedRequest, string $key, string $value): void {
+        if ($signedRequest === null) {
+            $instance = $this->getHostFromFederationId($value);
+            try {
+                $this->signatureManager->getSignatory($instance);
+                throw new IncomingRequestException('instance is supposed to sign its request');
+            } catch (SignatoryNotFoundException) {
+                return;
+            }
+        }
+
+        $body = json_decode($signedRequest->getBody(), true) ?? [];
+        $entry = trim($body[$key] ?? '', '@');
+        if ($this->getHostFromFederationId($entry) !== $signedRequest->getOrigin()) {
+            throw new IncomingRequestException('share initiation (' . $signedRequest->getOrigin() . ') from different instance (' . $entry . ') [key=' . $key . ']');
+        }
+    }
+
+    /**
+     *  confirm identity of the remote instance on notification, based on the share token.
+     *
+     *  If request is not signed, we still verify that the hostname from the extracted value does,
+     *  actually, not support signed request
+     *
+     * @param IIncomingSignedRequest|null $signedRequest
+     * @param string $resourceType
+     *
+     * @throws IncomingRequestException
+     * @throws BadRequestException
+     */
+    private function confirmNotificationIdentity(
+        ?IIncomingSignedRequest $signedRequest,
+        string $resourceType,
+        array $notification,
+    ): void {
+        $sharedSecret = $notification['sharedSecret'] ?? '';
+        if ($sharedSecret === '') {
+            throw new BadRequestException(['sharedSecret']);
+        }
+
+        try {
+            $provider = $this->cloudFederationProviderManager->getCloudFederationProvider($resourceType);
+            if ($provider instanceof ISignedCloudFederationProvider) {
+                $identity = $provider->getFederationIdFromSharedSecret($sharedSecret, $notification);
+            } else {
+                $this->logger->debug('cloud federation provider {provider} does not implements ISignedCloudFederationProvider', ['provider' => $provider::class]);
+                return;
+            }
+        } catch (\Exception $e) {
+            throw new IncomingRequestException($e->getMessage(), previous: $e);
+        }
+
+        $this->confirmNotificationEntry($signedRequest, $identity);
+    }
+
+
+    /**
+     * @param IIncomingSignedRequest|null $signedRequest
+     * @param string $entry
+     *
+     * @return void
+     * @throws IncomingRequestException
+     */
+    private function confirmNotificationEntry(?IIncomingSignedRequest $signedRequest, string $entry): void {
+        $instance = $this->getHostFromFederationId($entry);
+        if ($signedRequest === null) {
+            try {
+                $this->signatureManager->getSignatory($instance);
+                throw new IncomingRequestException('instance is supposed to sign its request');
+            } catch (SignatoryNotFoundException) {
+                return;
+            }
+        } elseif ($instance !== $signedRequest->getOrigin()) {
+            throw new IncomingRequestException('remote instance ' . $instance . ' not linked to origin ' . $signedRequest->getOrigin());
+        }
+    }
+
+    /**
+     * @param string $entry
+     * @return string
+     * @throws IncomingRequestException
+     */
+    private function getHostFromFederationId(string $entry): string {
+        if (!str_contains($entry, '@')) {
+            throw new IncomingRequestException('entry ' . $entry . ' does not contain @');
+        }
+        $rightPart = substr($entry, strrpos($entry, '@') + 1);
+
+        // in case the full scheme is sent; getting rid of it
+        $rightPart = $this->addressHandler->removeProtocolFromUrl($rightPart);
+        try {
+            return $this->signatureManager->extractIdentityFromUri('https://' . $rightPart);
+        } catch (IdentityNotFoundException) {
+            throw new IncomingRequestException('invalid host within federation id: ' . $entry);
+        }
+    }
 }