460 lines
13 KiB
PHP
460 lines
13 KiB
PHP
<?php
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/**
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* ownCloud
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*
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* @copyright (C) 2014 ownCloud, Inc.
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*
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* @author Bjoern Schiessle <schiessle@owncloud.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
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* License as published by the Free Software Foundation; either
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* version 3 of the License, or any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU AFFERO GENERAL PUBLIC LICENSE for more details.
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*
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* You should have received a copy of the GNU Affero General Public
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* License along with this library. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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namespace OCA\Files_Encryption;
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/**
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* Class to manage storage and retrieval of encryption keys
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* @note Where a method requires a view object, it's root must be '/'
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*/
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class Keymanager {
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// base dir where all the file related keys are stored
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private static $keys_base_dir = '/files_encryption/keys/';
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private static $encryption_base_dir = '/files_encryption';
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private static $public_key_dir = '/files_encryption/public_keys';
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/**
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* read key from hard disk
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*
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* @param string $path to key
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* @return string|bool either the key or false
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*/
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private static function getKey($path, $view) {
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$proxyStatus = \OC_FileProxy::$enabled;
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\OC_FileProxy::$enabled = false;
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$key = false;
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if ($view->file_exists($path)) {
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$key = $view->file_get_contents($path);
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}
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\OC_FileProxy::$enabled = $proxyStatus;
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return $key;
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}
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/**
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* write key to disk
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*
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*
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* @param string $path path to key directory
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* @param string $name key name
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* @param string $key key
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* @param \OC\Files\View $view
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* @return bool
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*/
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private static function setKey($path, $name, $key, $view) {
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$proxyStatus = \OC_FileProxy::$enabled;
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\OC_FileProxy::$enabled = false;
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self::keySetPreparation($view, $path);
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$result = $view->file_put_contents($path . '/' . $name, $key);
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\OC_FileProxy::$enabled = $proxyStatus;
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return (is_int($result) && $result > 0) ? true : false;
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}
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/**
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* retrieve the ENCRYPTED private key from a user
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*
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* @param \OC\Files\View $view
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* @param string $user
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* @return string private key or false (hopefully)
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* @note the key returned by this method must be decrypted before use
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*/
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public static function getPrivateKey(\OC\Files\View $view, $user) {
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$path = '/' . $user . '/' . 'files_encryption' . '/' . $user . '.privateKey';
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return self::getKey($path, $view);
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}
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/**
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* retrieve public key for a specified user
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* @param \OC\Files\View $view
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* @param string $userId
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* @return string public key or false
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*/
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public static function getPublicKey(\OC\Files\View $view, $userId) {
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$path = self::$public_key_dir . '/' . $userId . '.publicKey';
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return self::getKey($path, $view);
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}
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public static function getPublicKeyPath() {
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return self::$public_key_dir;
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}
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/**
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* Retrieve a user's public and private key
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* @param \OC\Files\View $view
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* @param string $userId
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* @return array keys: privateKey, publicKey
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*/
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public static function getUserKeys(\OC\Files\View $view, $userId) {
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return array(
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'publicKey' => self::getPublicKey($view, $userId),
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'privateKey' => self::getPrivateKey($view, $userId)
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);
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}
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/**
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* Retrieve public keys for given users
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* @param \OC\Files\View $view
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* @param array $userIds
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* @return array of public keys for the specified users
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*/
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public static function getPublicKeys(\OC\Files\View $view, array $userIds) {
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$keys = array();
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foreach ($userIds as $userId) {
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$keys[$userId] = self::getPublicKey($view, $userId);
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}
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return $keys;
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}
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/**
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* store file encryption key
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*
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* @param \OC\Files\View $view
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* @param \OCA\Files_Encryption\Util $util
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* @param string $path relative path of the file, including filename
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* @param string $catfile keyfile content
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* @return bool true/false
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* @note The keyfile is not encrypted here. Client code must
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* asymmetrically encrypt the keyfile before passing it to this method
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*/
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public static function setFileKey(\OC\Files\View $view, $util, $path, $catfile) {
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$path = self::getKeyPath($view, $util, $path);
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return self::setKey($path, 'fileKey', $catfile, $view);
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}
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/**
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* get path to key folder for a given file
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*
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* @param \OC\Files\View $view relative to data directory
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* @param \OCA\Files_Encryption\Util $util
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* @param string $path path to the file, relative to the users file directory
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* @return string
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*/
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public static function getKeyPath($view, $util, $path) {
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if ($view->is_dir('/' . \OCP\User::getUser() . '/' . $path)) {
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throw new Exception\EncryptionException('file was expected but directoy was given', Exception\EncryptionException::GENERIC);
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}
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list($owner, $filename) = $util->getUidAndFilename($path);
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$filename = Helper::stripPartialFileExtension($filename);
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$filePath_f = ltrim($filename, '/');
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// in case of system wide mount points the keys are stored directly in the data directory
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if ($util->isSystemWideMountPoint($filename)) {
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$keyPath = self::$keys_base_dir . $filePath_f . '/';
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} else {
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$keyPath = '/' . $owner . self::$keys_base_dir . $filePath_f . '/';
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}
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return $keyPath;
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}
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/**
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* get path to file key for a given file
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*
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* @param \OC\Files\View $view relative to data directory
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* @param \OCA\Files_Encryption\Util $util
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* @param string $path path to the file, relative to the users file directory
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* @return string
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*/
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public static function getFileKeyPath($view, $util, $path) {
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$keyDir = self::getKeyPath($view, $util, $path);
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return $keyDir . 'fileKey';
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}
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/**
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* get path to share key for a given user
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*
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* @param \OC\Files\View $view relateive to data directory
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* @param \OCA\Files_Encryption\Util $util
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* @param string $path path to file relative to the users files directoy
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* @param string $uid user for whom we want the share-key path
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* @retrun string
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*/
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public static function getShareKeyPath($view, $util, $path, $uid) {
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$keyDir = self::getKeyPath($view, $util, $path);
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return $keyDir . $uid . '.shareKey';
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}
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/**
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* delete public key from a given user
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*
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* @param \OC\Files\View $view
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* @param string $uid user
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* @return bool
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*/
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public static function deletePublicKey($view, $uid) {
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$result = false;
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if (!\OCP\User::userExists($uid)) {
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$publicKey = self::$public_key_dir . '/' . $uid . '.publicKey';
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$result = $view->unlink($publicKey);
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}
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return $result;
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}
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/**
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* check if public key for user exists
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*
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* @param \OC\Files\View $view
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* @param string $uid
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*/
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public static function publicKeyExists($view, $uid) {
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return $view->file_exists(self::$public_key_dir . '/'. $uid . '.publicKey');
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}
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/**
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* retrieve keyfile for an encrypted file
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* @param \OC\Files\View $view
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* @param \OCA\Files_Encryption\Util $util
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* @param string|false $filePath
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* @return string file key or false
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* @note The keyfile returned is asymmetrically encrypted. Decryption
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* of the keyfile must be performed by client code
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*/
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public static function getFileKey($view, $util, $filePath) {
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$path = self::getFileKeyPath($view, $util, $filePath);
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return self::getKey($path, $view);
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}
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/**
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* store private key from the user
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* @param string $key
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* @return bool
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* @note Encryption of the private key must be performed by client code
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* as no encryption takes place here
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*/
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public static function setPrivateKey($key, $user = '') {
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$user = $user === '' ? \OCP\User::getUser() : $user;
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$path = '/' . $user . '/files_encryption';
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$header = Crypt::generateHeader();
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return self::setKey($path, $user . '.privateKey', $header . $key, new \OC\Files\View());
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}
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/**
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* check if recovery key exists
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*
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* @param \OC\Files\View $view
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* @return bool
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*/
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public static function recoveryKeyExists($view) {
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$result = false;
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$recoveryKeyId = Helper::getRecoveryKeyId();
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if ($recoveryKeyId) {
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$result = ($view->file_exists(self::$public_key_dir . '/' . $recoveryKeyId . ".publicKey")
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&& $view->file_exists(self::$encryption_base_dir . '/' . $recoveryKeyId . ".privateKey"));
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}
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return $result;
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}
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public static function publicShareKeyExists($view) {
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$result = false;
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$publicShareKeyId = Helper::getPublicShareKeyId();
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if ($publicShareKeyId) {
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$result = ($view->file_exists(self::$public_key_dir . '/' . $publicShareKeyId . ".publicKey")
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&& $view->file_exists(self::$encryption_base_dir . '/' . $publicShareKeyId . ".privateKey"));
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}
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return $result;
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}
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/**
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* store public key from the user
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* @param string $key
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* @param string $user
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*
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* @return bool
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*/
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public static function setPublicKey($key, $user = '') {
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$user = $user === '' ? \OCP\User::getUser() : $user;
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return self::setKey(self::$public_key_dir, $user . '.publicKey', $key, new \OC\Files\View('/'));
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}
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/**
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* write private system key (recovery and public share key) to disk
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*
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* @param string $key encrypted key
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* @param string $keyName name of the key
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* @return boolean
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*/
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public static function setPrivateSystemKey($key, $keyName) {
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$keyName = $keyName . '.privateKey';
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$header = Crypt::generateHeader();
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return self::setKey(self::$encryption_base_dir, $keyName,$header . $key, new \OC\Files\View());
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}
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/**
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* read private system key (recovery and public share key) from disk
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*
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* @param string $keyName name of the key
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* @return string|boolean private system key or false
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*/
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public static function getPrivateSystemKey($keyName) {
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$path = $keyName . '.privateKey';
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return self::getKey($path, new \OC\Files\View(self::$encryption_base_dir));
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}
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/**
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* store multiple share keys for a single file
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* @param \OC\Files\View $view
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* @param \OCA\Files_Encryption\Util $util
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* @param string $path
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* @param array $shareKeys
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* @return bool
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*/
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public static function setShareKeys($view, $util, $path, array $shareKeys) {
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// in case of system wide mount points the keys are stored directly in the data directory
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$basePath = Keymanager::getKeyPath($view, $util, $path);
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self::keySetPreparation($view, $basePath);
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$result = true;
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foreach ($shareKeys as $userId => $shareKey) {
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if (!self::setKey($basePath, $userId . '.shareKey', $shareKey, $view)) {
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// If any of the keys are not set, flag false
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$result = false;
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}
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}
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// Returns false if any of the keys weren't set
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return $result;
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}
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/**
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* retrieve shareKey for an encrypted file
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* @param \OC\Files\View $view
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* @param string $userId
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* @param \OCA\Files_Encryption\Util $util
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* @param string $filePath
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* @return string file key or false
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* @note The sharekey returned is encrypted. Decryption
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* of the keyfile must be performed by client code
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*/
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public static function getShareKey($view, $userId, $util, $filePath) {
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$path = self::getShareKeyPath($view, $util, $filePath, $userId);
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return self::getKey($path, $view);
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}
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/**
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* Delete a single user's shareKey for a single file
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*
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* @param \OC\Files\View $view relative to data/
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* @param array $userIds list of users we want to remove
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* @param string $keyPath
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* @param string $owner the owner of the file
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* @param string $ownerPath the owners name of the file for which we want to remove the users relative to data/user/files
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*/
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public static function delShareKey($view, $userIds, $keysPath, $owner, $ownerPath) {
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$key = array_search($owner, $userIds, true);
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if ($key !== false && $view->file_exists('/' . $owner . '/files/' . $ownerPath)) {
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unset($userIds[$key]);
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}
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self::recursiveDelShareKeys($keysPath, $userIds, $view);
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}
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/**
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* recursively delete share keys from given users
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*
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* @param string $dir directory
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* @param array $userIds user ids for which the share keys should be deleted
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* @param \OC\Files\View $view view relative to data/
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*/
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private static function recursiveDelShareKeys($dir, $userIds, $view) {
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$dirContent = $view->opendir($dir);
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if (is_resource($dirContent)) {
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while (($file = readdir($dirContent)) !== false) {
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if (!\OC\Files\Filesystem::isIgnoredDir($file)) {
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if ($view->is_dir($dir . '/' . $file)) {
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self::recursiveDelShareKeys($dir . '/' . $file, $userIds, $view);
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} else {
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foreach ($userIds as $userId) {
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if ($userId . '.shareKey' === $file) {
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\OCP\Util::writeLog('files_encryption', 'recursiveDelShareKey: delete share key: ' . $file, \OCP\Util::DEBUG);
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$view->unlink($dir . '/' . $file);
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}
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}
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}
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}
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}
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closedir($dirContent);
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}
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}
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/**
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* Make preparations to vars and filesystem for saving a keyfile
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*
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* @param \OC\Files\View $view
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* @param string $path relatvie to the views root
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* @param string $basePath
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*/
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protected static function keySetPreparation($view, $path) {
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// If the file resides within a subdirectory, create it
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if (!$view->file_exists($path)) {
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$sub_dirs = explode('/', $path);
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$dir = '';
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foreach ($sub_dirs as $sub_dir) {
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$dir .= '/' . $sub_dir;
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if (!$view->is_dir($dir)) {
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$view->mkdir($dir);
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}
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}
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}
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}
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}
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