/** * Encrypt keyfile to multiple users * @param Session $session * @param array $users list of users which should be able to access the file * @param string $filePath path of the file to be shared * @return bool */ public function setSharedFileKeyfiles(Session $session, array $users, $filePath) { // Make sure users are capable of sharing $filteredUids = $this->filterShareReadyUsers($users); // If we're attempting to share to unready users if (!empty($filteredUids['unready'])) { \OCP\Util::writeLog('Encryption library', 'Sharing to these user(s) failed as they are unready for encryption:"' . print_r($filteredUids['unready'], 1), \OCP\Util::WARN); return false; } // Get public keys for each user, ready for generating sharekeys $userPubKeys = Keymanager::getPublicKeys($this->view, $filteredUids['ready']); // Note proxy status then disable it $proxyStatus = \OC_FileProxy::$enabled; \OC_FileProxy::$enabled = false; // Get the current users's private key for decrypting existing keyfile $privateKey = $session->getPrivateKey(); try { // Decrypt keyfile $plainKeyfile = $this->decryptKeyfile($filePath, $privateKey); // Re-enc keyfile to (additional) sharekeys $multiEncKey = Crypt::multiKeyEncrypt($plainKeyfile, $userPubKeys); } catch (Exceptions\EncryptionException $e) { $msg = 'set shareFileKeyFailed (code: ' . $e->getCode() . '): ' . $e->getMessage(); \OCP\Util::writeLog('files_encryption', $msg, \OCP\Util::FATAL); return false; } catch (\Exception $e) { $msg = 'set shareFileKeyFailed (unknown error): ' . $e->getMessage(); \OCP\Util::writeLog('files_encryption', $msg, \OCP\Util::FATAL); return false; } // Save the recrypted key to it's owner's keyfiles directory // Save new sharekeys to all necessary user directory if (!Keymanager::setFileKey($this->view, $this, $filePath, $multiEncKey['data']) || !Keymanager::setShareKeys($this->view, $this, $filePath, $multiEncKey['keys'])) { \OCP\Util::writeLog('Encryption library', 'Keyfiles could not be saved for users sharing ' . $filePath, \OCP\Util::ERROR); return false; } // Return proxy to original status \OC_FileProxy::$enabled = $proxyStatus; return true; }