nextcloud/apps/files_encryption/hooks/hooks.php

560 lines
17 KiB
PHP

<?php
/**
* ownCloud
*
* @author Sam Tuke
* @copyright 2012 Sam Tuke samtuke@owncloud.org
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
* License as published by the Free Software Foundation; either
* version 3 of the License, or any later version.
*
* This library 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 along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*/
namespace OCA\Encryption;
use OC\Files\Filesystem;
/**
* Class for hook specific logic
*/
class Hooks {
// TODO: use passphrase for encrypting private key that is separate to
// the login password
/**
* @brief Startup encryption backend upon user login
* @note This method should never be called for users using client side encryption
*/
public static function login($params) {
$l = new \OC_L10N('files_encryption');
//check if all requirements are met
if(!Helper::checkRequirements() ) {
$error_msg = $l->t("Missing requirements.");
$hint = $l->t('Please make sure that PHP 5.3.3 or newer is installed and that the OpenSSL PHP extension is enabled and configured properly. For now, the encryption app has been disabled.');
\OC_App::disable('files_encryption');
\OCP\Util::writeLog('Encryption library', $error_msg . ' ' . $hint, \OCP\Util::ERROR);
\OCP\Template::printErrorPage($error_msg, $hint);
}
$view = new \OC_FilesystemView('/');
// ensure filesystem is loaded
if(!\OC\Files\Filesystem::$loaded) {
\OC_Util::setupFS($params['uid']);
}
$util = new Util($view, $params['uid']);
// setup user, if user not ready force relogin
if (Helper::setupUser($util, $params['password']) === false) {
return false;
}
$encryptedKey = Keymanager::getPrivateKey($view, $params['uid']);
$privateKey = Crypt::decryptPrivateKey($encryptedKey, $params['password']);
if ($privateKey === false) {
\OCP\Util::writeLog('Encryption library', 'Private key for user "' . $params['uid']
. '" is not valid! Maybe the user password was changed from outside if so please change it back to gain access', \OCP\Util::ERROR);
}
$session = new \OCA\Encryption\Session($view);
$session->setPrivateKey($privateKey);
// Check if first-run file migration has already been performed
$ready = false;
if ($util->getMigrationStatus() === Util::MIGRATION_OPEN) {
$ready = $util->beginMigration();
}
// If migration not yet done
if ($ready) {
$userView = new \OC_FilesystemView('/' . $params['uid']);
// Set legacy encryption key if it exists, to support
// depreciated encryption system
if (
$userView->file_exists('encryption.key')
&& $encLegacyKey = $userView->file_get_contents('encryption.key')
) {
$plainLegacyKey = Crypt::legacyDecrypt($encLegacyKey, $params['password']);
$session->setLegacyKey($plainLegacyKey);
}
// Encrypt existing user files:
// This serves to upgrade old versions of the encryption
// app (see appinfo/spec.txt)
if (
$util->encryptAll('/' . $params['uid'] . '/' . 'files', $session->getLegacyKey(), $params['password'])
) {
\OC_Log::write(
'Encryption library', 'Encryption of existing files belonging to "' . $params['uid'] . '" completed'
, \OC_Log::INFO
);
}
// Register successful migration in DB
$util->finishMigration();
}
return true;
}
/**
* @brief setup encryption backend upon user created
* @note This method should never be called for users using client side encryption
*/
public static function postCreateUser($params) {
$view = new \OC_FilesystemView('/');
$util = new Util($view, $params['uid']);
Helper::setupUser($util, $params['password']);
}
/**
* @brief cleanup encryption backend upon user deleted
* @note This method should never be called for users using client side encryption
*/
public static function postDeleteUser($params) {
$view = new \OC_FilesystemView('/');
// cleanup public key
$publicKey = '/public-keys/' . $params['uid'] . '.public.key';
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$view->unlink($publicKey);
\OC_FileProxy::$enabled = $proxyStatus;
}
/**
* @brief If the password can't be changed within ownCloud, than update the key password in advance.
*/
public static function preSetPassphrase($params) {
if ( ! \OC_User::canUserChangePassword($params['uid']) ) {
self::setPassphrase($params);
}
}
/**
* @brief Change a user's encryption passphrase
* @param array $params keys: uid, password
*/
public static function setPassphrase($params) {
// Only attempt to change passphrase if server-side encryption
// is in use (client-side encryption does not have access to
// the necessary keys)
if (Crypt::mode() === 'server') {
if ($params['uid'] === \OCP\User::getUser()) {
$view = new \OC_FilesystemView('/');
$session = new \OCA\Encryption\Session($view);
// Get existing decrypted private key
$privateKey = $session->getPrivateKey();
// Encrypt private key with new user pwd as passphrase
$encryptedPrivateKey = Crypt::symmetricEncryptFileContent($privateKey, $params['password']);
// Save private key
Keymanager::setPrivateKey($encryptedPrivateKey);
// NOTE: Session does not need to be updated as the
// private key has not changed, only the passphrase
// used to decrypt it has changed
} else { // admin changed the password for a different user, create new keys and reencrypt file keys
$user = $params['uid'];
$recoveryPassword = $params['recoveryPassword'];
$newUserPassword = $params['password'];
$view = new \OC_FilesystemView('/');
// make sure that the users home is mounted
\OC\Files\Filesystem::initMountPoints($user);
$keypair = Crypt::createKeypair();
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
// Save public key
$view->file_put_contents('/public-keys/' . $user . '.public.key', $keypair['publicKey']);
// Encrypt private key empty passphrase
$encryptedPrivateKey = Crypt::symmetricEncryptFileContent($keypair['privateKey'], $newUserPassword);
// Save private key
$view->file_put_contents(
'/' . $user . '/files_encryption/' . $user . '.private.key', $encryptedPrivateKey);
if ($recoveryPassword) { // if recovery key is set we can re-encrypt the key files
$util = new Util($view, $user);
$util->recoverUsersFiles($recoveryPassword);
}
\OC_FileProxy::$enabled = $proxyStatus;
}
}
}
/*
* @brief check if files can be encrypted to every user.
*/
/**
* @param $params
*/
public static function preShared($params) {
$users = array();
$view = new \OC\Files\View('/public-keys/');
switch ($params['shareType']) {
case \OCP\Share::SHARE_TYPE_USER:
$users[] = $params['shareWith'];
break;
case \OCP\Share::SHARE_TYPE_GROUP:
$users = \OC_Group::usersInGroup($params['shareWith']);
break;
}
$error = false;
foreach ($users as $user) {
if (!$view->file_exists($user . '.public.key')) {
$error = true;
break;
}
}
if ($error) // Set flag var 'run' to notify emitting
// script that hook execution failed
{
$params['run']->run = false;
}
// TODO: Make sure files_sharing provides user
// feedback on failed share
}
/**
* @brief
*/
public static function postShared($params) {
// NOTE: $params has keys:
// [itemType] => file
// itemSource -> int, filecache file ID
// [parent] =>
// [itemTarget] => /13
// shareWith -> string, uid of user being shared to
// fileTarget -> path of file being shared
// uidOwner -> owner of the original file being shared
// [shareType] => 0
// [shareWith] => test1
// [uidOwner] => admin
// [permissions] => 17
// [fileSource] => 13
// [fileTarget] => /test8
// [id] => 10
// [token] =>
// [run] => whether emitting script should continue to run
// TODO: Should other kinds of item be encrypted too?
if ($params['itemType'] === 'file' || $params['itemType'] === 'folder') {
$view = new \OC_FilesystemView('/');
$session = new \OCA\Encryption\Session($view);
$userId = \OCP\User::getUser();
$util = new Util($view, $userId);
$path = $util->fileIdToPath($params['itemSource']);
$share = $util->getParentFromShare($params['id']);
//if parent is set, then this is a re-share action
if ($share['parent'] !== null) {
// get the parent from current share
$parent = $util->getShareParent($params['parent']);
// if parent is file the it is an 1:1 share
if ($parent['item_type'] === 'file') {
// prefix path with Shared
$path = '/Shared' . $parent['file_target'];
} else {
// NOTE: parent is folder but shared was a file!
// we try to rebuild the missing path
// some examples we face here
// user1 share folder1 with user2 folder1 has
// the following structure
// /folder1/subfolder1/subsubfolder1/somefile.txt
// user2 re-share subfolder2 with user3
// user3 re-share somefile.txt user4
// so our path should be
// /Shared/subfolder1/subsubfolder1/somefile.txt
// while user3 is sharing
if ($params['itemType'] === 'file') {
// get target path
$targetPath = $util->fileIdToPath($params['fileSource']);
$targetPathSplit = array_reverse(explode('/', $targetPath));
// init values
$path = '';
$sharedPart = ltrim($parent['file_target'], '/');
// rebuild path
foreach ($targetPathSplit as $pathPart) {
if ($pathPart !== $sharedPart) {
$path = '/' . $pathPart . $path;
} else {
break;
}
}
// prefix path with Shared
$path = '/Shared' . $parent['file_target'] . $path;
} else {
// prefix path with Shared
$path = '/Shared' . $parent['file_target'] . $params['fileTarget'];
}
}
}
$sharingEnabled = \OCP\Share::isEnabled();
// get the path including mount point only if not a shared folder
if (strncmp($path, '/Shared', strlen('/Shared') !== 0)) {
// get path including the the storage mount point
$path = $util->getPathWithMountPoint($params['itemSource']);
}
// if a folder was shared, get a list of all (sub-)folders
if ($params['itemType'] === 'folder') {
$allFiles = $util->getAllFiles($path);
} else {
$allFiles = array($path);
}
foreach ($allFiles as $path) {
$usersSharing = $util->getSharingUsersArray($sharingEnabled, $path);
$util->setSharedFileKeyfiles($session, $usersSharing, $path);
}
}
}
/**
* @brief
*/
public static function postUnshare($params) {
// NOTE: $params has keys:
// [itemType] => file
// [itemSource] => 13
// [shareType] => 0
// [shareWith] => test1
// [itemParent] =>
if ($params['itemType'] === 'file' || $params['itemType'] === 'folder') {
$view = new \OC_FilesystemView('/');
$userId = \OCP\User::getUser();
$util = new Util($view, $userId);
$path = $util->fileIdToPath($params['itemSource']);
// check if this is a re-share
if ($params['itemParent']) {
// get the parent from current share
$parent = $util->getShareParent($params['itemParent']);
// get target path
$targetPath = $util->fileIdToPath($params['itemSource']);
$targetPathSplit = array_reverse(explode('/', $targetPath));
// init values
$path = '';
$sharedPart = ltrim($parent['file_target'], '/');
// rebuild path
foreach ($targetPathSplit as $pathPart) {
if ($pathPart !== $sharedPart) {
$path = '/' . $pathPart . $path;
} else {
break;
}
}
// prefix path with Shared
$path = '/Shared' . $parent['file_target'] . $path;
}
// for group shares get a list of the group members
if ($params['shareType'] === \OCP\Share::SHARE_TYPE_GROUP) {
$userIds = \OC_Group::usersInGroup($params['shareWith']);
} else {
if ($params['shareType'] === \OCP\Share::SHARE_TYPE_LINK) {
$userIds = array($util->getPublicShareKeyId());
} else {
$userIds = array($params['shareWith']);
}
}
// get the path including mount point only if not a shared folder
if (strncmp($path, '/Shared', strlen('/Shared') !== 0)) {
// get path including the the storage mount point
$path = $util->getPathWithMountPoint($params['itemSource']);
}
// if we unshare a folder we need a list of all (sub-)files
if ($params['itemType'] === 'folder') {
$allFiles = $util->getAllFiles($path);
} else {
$allFiles = array($path);
}
foreach ($allFiles as $path) {
// check if the user still has access to the file, otherwise delete share key
$sharingUsers = $util->getSharingUsersArray(true, $path);
// Unshare every user who no longer has access to the file
$delUsers = array_diff($userIds, $sharingUsers);
// delete share key
Keymanager::delShareKey($view, $delUsers, $path);
}
}
}
/**
* @brief after a file is renamed, rename its keyfile and share-keys also fix the file size and fix also the sharing
* @param array with oldpath and newpath
*
* This function is connected to the rename signal of OC_Filesystem and adjust the name and location
* of the stored versions along the actual file
*/
public static function postRename($params) {
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$view = new \OC_FilesystemView('/');
$session = new \OCA\Encryption\Session($view);
$userId = \OCP\User::getUser();
$util = new Util($view, $userId);
// Format paths to be relative to user files dir
$oldKeyfilePath = \OC\Files\Filesystem::normalizePath(
$userId . '/' . 'files_encryption' . '/' . 'keyfiles' . '/' . $params['oldpath']);
$newKeyfilePath = \OC\Files\Filesystem::normalizePath(
$userId . '/' . 'files_encryption' . '/' . 'keyfiles' . '/' . $params['newpath']);
// add key ext if this is not an folder
if (!$view->is_dir($oldKeyfilePath)) {
$oldKeyfilePath .= '.key';
$newKeyfilePath .= '.key';
// handle share-keys
$localKeyPath = $view->getLocalFile($userId . '/files_encryption/share-keys/' . $params['oldpath']);
$matches = glob(preg_quote($localKeyPath) . '*.shareKey');
foreach ($matches as $src) {
$dst = \OC\Files\Filesystem::normalizePath(str_replace($params['oldpath'], $params['newpath'], $src));
// create destination folder if not exists
if (!file_exists(dirname($dst))) {
mkdir(dirname($dst), 0750, true);
}
rename($src, $dst);
}
} else {
// handle share-keys folders
$oldShareKeyfilePath = \OC\Files\Filesystem::normalizePath(
$userId . '/' . 'files_encryption' . '/' . 'share-keys' . '/' . $params['oldpath']);
$newShareKeyfilePath = \OC\Files\Filesystem::normalizePath(
$userId . '/' . 'files_encryption' . '/' . 'share-keys' . '/' . $params['newpath']);
// create destination folder if not exists
if (!$view->file_exists(dirname($newShareKeyfilePath))) {
$view->mkdir(dirname($newShareKeyfilePath), 0750, true);
}
$view->rename($oldShareKeyfilePath, $newShareKeyfilePath);
}
// Rename keyfile so it isn't orphaned
if ($view->file_exists($oldKeyfilePath)) {
// create destination folder if not exists
if (!$view->file_exists(dirname($newKeyfilePath))) {
$view->mkdir(dirname($newKeyfilePath), 0750, true);
}
$view->rename($oldKeyfilePath, $newKeyfilePath);
}
// build the path to the file
$newPath = '/' . $userId . '/files' . $params['newpath'];
$newPathRelative = $params['newpath'];
if ($util->fixFileSize($newPath)) {
// get sharing app state
$sharingEnabled = \OCP\Share::isEnabled();
// get users
$usersSharing = $util->getSharingUsersArray($sharingEnabled, $newPathRelative);
// update sharing-keys
$util->setSharedFileKeyfiles($session, $usersSharing, $newPathRelative);
}
\OC_FileProxy::$enabled = $proxyStatus;
}
/**
* set migration status back to '0' so that all new files get encrypted
* if the app gets enabled again
* @param array $params contains the app ID
*/
public static function preDisable($params) {
if ($params['app'] === 'files_encryption') {
$query = \OC_DB::prepare('UPDATE `*PREFIX*encryption` SET `migration_status`=0');
$query->execute();
}
}
}