owncloud / core

	 * @return \OCP\Files\Folder|null

	 */

	public function getUserFolder($userId = null) {

		if ($userId === null) {

			$user = $this->getUserSession()->getUser();

			if (!$user) {

				return null;

			}

			$userId = $user->getUID();

		}

		$root = $this->getRootFolder();

		return $root->getUserFolder($userId);

	}

	 * @return \OCP\ICertificateManager | null if $uid is null and no user is logged in

	 */

	public function getCertificateManager($userId = '') {

		if ($userId === '') {

			$userSession = $this->getUserSession();

			$user = $userSession->getUser();

			if ($user === null) {

				return null;

			}

			$userId = $user->getUID();

		}

		return new CertificateManager($userId, new View(), $this->getConfig());

	}