nextcloud/apps/encryption/lib/Recovery.php

331 lines
8.2 KiB
PHP

<?php
/**
* @copyright Copyright (c) 2016, ownCloud, Inc.
*
* @author Björn Schießle <bjoern@schiessle.org>
* @author Clark Tomlinson <fallen013@gmail.com>
* @author Lukas Reschke <lukas@statuscode.ch>
*
* @license AGPL-3.0
*
* This code is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License, version 3,
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/
namespace OCA\Encryption;
use OCA\Encryption\Crypto\Crypt;
use OCP\Encryption\Keys\IStorage;
use OCP\IConfig;
use OCP\IUser;
use OCP\IUserSession;
use OCP\PreConditionNotMetException;
use OCP\Security\ISecureRandom;
use OC\Files\View;
use OCP\Encryption\IFile;
class Recovery {
/**
* @var null|IUser
*/
protected $user;
/**
* @var Crypt
*/
protected $crypt;
/**
* @var ISecureRandom
*/
private $random;
/**
* @var KeyManager
*/
private $keyManager;
/**
* @var IConfig
*/
private $config;
/**
* @var IStorage
*/
private $keyStorage;
/**
* @var View
*/
private $view;
/**
* @var IFile
*/
private $file;
/**
* @param IUserSession $user
* @param Crypt $crypt
* @param ISecureRandom $random
* @param KeyManager $keyManager
* @param IConfig $config
* @param IStorage $keyStorage
* @param IFile $file
* @param View $view
*/
public function __construct(IUserSession $user,
Crypt $crypt,
ISecureRandom $random,
KeyManager $keyManager,
IConfig $config,
IStorage $keyStorage,
IFile $file,
View $view) {
$this->user = ($user && $user->isLoggedIn()) ? $user->getUser() : false;
$this->crypt = $crypt;
$this->random = $random;
$this->keyManager = $keyManager;
$this->config = $config;
$this->keyStorage = $keyStorage;
$this->view = $view;
$this->file = $file;
}
/**
* @param string $password
* @return bool
*/
public function enableAdminRecovery($password) {
$appConfig = $this->config;
$keyManager = $this->keyManager;
if (!$keyManager->recoveryKeyExists()) {
$keyPair = $this->crypt->createKeyPair();
if(!is_array($keyPair)) {
return false;
}
$this->keyManager->setRecoveryKey($password, $keyPair);
}
if ($keyManager->checkRecoveryPassword($password)) {
$appConfig->setAppValue('encryption', 'recoveryAdminEnabled', 1);
return true;
}
return false;
}
/**
* change recovery key id
*
* @param string $newPassword
* @param string $oldPassword
* @return bool
*/
public function changeRecoveryKeyPassword($newPassword, $oldPassword) {
$recoveryKey = $this->keyManager->getSystemPrivateKey($this->keyManager->getRecoveryKeyId());
$decryptedRecoveryKey = $this->crypt->decryptPrivateKey($recoveryKey, $oldPassword);
if($decryptedRecoveryKey === false) {
return false;
}
$encryptedRecoveryKey = $this->crypt->encryptPrivateKey($decryptedRecoveryKey, $newPassword);
$header = $this->crypt->generateHeader();
if ($encryptedRecoveryKey) {
$this->keyManager->setSystemPrivateKey($this->keyManager->getRecoveryKeyId(), $header . $encryptedRecoveryKey);
return true;
}
return false;
}
/**
* @param string $recoveryPassword
* @return bool
*/
public function disableAdminRecovery($recoveryPassword) {
$keyManager = $this->keyManager;
if ($keyManager->checkRecoveryPassword($recoveryPassword)) {
// Set recoveryAdmin as disabled
$this->config->setAppValue('encryption', 'recoveryAdminEnabled', 0);
return true;
}
return false;
}
/**
* check if recovery is enabled for user
*
* @param string $user if no user is given we check the current logged-in user
*
* @return bool
*/
public function isRecoveryEnabledForUser($user = '') {
$uid = empty($user) ? $this->user->getUID() : $user;
$recoveryMode = $this->config->getUserValue($uid,
'encryption',
'recoveryEnabled',
0);
return ($recoveryMode === '1');
}
/**
* check if recovery is key is enabled by the administrator
*
* @return bool
*/
public function isRecoveryKeyEnabled() {
$enabled = $this->config->getAppValue('encryption', 'recoveryAdminEnabled', 0);
return ($enabled === '1');
}
/**
* @param string $value
* @return bool
*/
public function setRecoveryForUser($value) {
try {
$this->config->setUserValue($this->user->getUID(),
'encryption',
'recoveryEnabled',
$value);
if ($value === '1') {
$this->addRecoveryKeys('/' . $this->user->getUID() . '/files/');
} else {
$this->removeRecoveryKeys('/' . $this->user->getUID() . '/files/');
}
return true;
} catch (PreConditionNotMetException $e) {
return false;
}
}
/**
* add recovery key to all encrypted files
* @param string $path
*/
private function addRecoveryKeys($path) {
$dirContent = $this->view->getDirectoryContent($path);
foreach ($dirContent as $item) {
$filePath = $item->getPath();
if ($item['type'] === 'dir') {
$this->addRecoveryKeys($filePath . '/');
} else {
$fileKey = $this->keyManager->getFileKey($filePath, $this->user->getUID());
if (!empty($fileKey)) {
$accessList = $this->file->getAccessList($filePath);
$publicKeys = array();
foreach ($accessList['users'] as $uid) {
$publicKeys[$uid] = $this->keyManager->getPublicKey($uid);
}
$publicKeys = $this->keyManager->addSystemKeys($accessList, $publicKeys, $this->user->getUID());
$encryptedKeyfiles = $this->crypt->multiKeyEncrypt($fileKey, $publicKeys);
$this->keyManager->setAllFileKeys($filePath, $encryptedKeyfiles);
}
}
}
}
/**
* remove recovery key to all encrypted files
* @param string $path
*/
private function removeRecoveryKeys($path) {
$dirContent = $this->view->getDirectoryContent($path);
foreach ($dirContent as $item) {
$filePath = $item->getPath();
if ($item['type'] === 'dir') {
$this->removeRecoveryKeys($filePath . '/');
} else {
$this->keyManager->deleteShareKey($filePath, $this->keyManager->getRecoveryKeyId());
}
}
}
/**
* recover users files with the recovery key
*
* @param string $recoveryPassword
* @param string $user
*/
public function recoverUsersFiles($recoveryPassword, $user) {
$encryptedKey = $this->keyManager->getSystemPrivateKey($this->keyManager->getRecoveryKeyId());
$privateKey = $this->crypt->decryptPrivateKey($encryptedKey, $recoveryPassword);
if($privateKey !== false) {
$this->recoverAllFiles('/' . $user . '/files/', $privateKey, $user);
}
}
/**
* recover users files
*
* @param string $path
* @param string $privateKey
* @param string $uid
*/
private function recoverAllFiles($path, $privateKey, $uid) {
$dirContent = $this->view->getDirectoryContent($path);
foreach ($dirContent as $item) {
// Get relative path from encryption/keyfiles
$filePath = $item->getPath();
if ($this->view->is_dir($filePath)) {
$this->recoverAllFiles($filePath . '/', $privateKey, $uid);
} else {
$this->recoverFile($filePath, $privateKey, $uid);
}
}
}
/**
* recover file
*
* @param string $path
* @param string $privateKey
* @param string $uid
*/
private function recoverFile($path, $privateKey, $uid) {
$encryptedFileKey = $this->keyManager->getEncryptedFileKey($path);
$shareKey = $this->keyManager->getShareKey($path, $this->keyManager->getRecoveryKeyId());
if ($encryptedFileKey && $shareKey && $privateKey) {
$fileKey = $this->crypt->multiKeyDecrypt($encryptedFileKey,
$shareKey,
$privateKey);
}
if (!empty($fileKey)) {
$accessList = $this->file->getAccessList($path);
$publicKeys = array();
foreach ($accessList['users'] as $user) {
$publicKeys[$user] = $this->keyManager->getPublicKey($user);
}
$publicKeys = $this->keyManager->addSystemKeys($accessList, $publicKeys, $uid);
$encryptedKeyfiles = $this->crypt->multiKeyEncrypt($fileKey, $publicKeys);
$this->keyManager->setAllFileKeys($path, $encryptedKeyfiles);
}
}
}