nextcloud/apps/files_encryption/hooks/hooks.php

434 lines
13 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;
/**
* 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 ) {
// Manually initialise Filesystem{} singleton with correct
// fake root path, in order to avoid fatal webdav errors
// NOTE: disabled because this give errors on webdav!
//\OC\Files\Filesystem::init( $params['uid'], '/' . 'files' . '/' );
$view = new \OC_FilesystemView( '/' );
$util = new Util( $view, $params['uid'] );
// Check files_encryption infrastructure is ready for action
if ( ! $util->ready() ) {
\OC_Log::write( 'Encryption library', 'User account "' . $params['uid'] . '" is not ready for encryption; configuration started', \OC_Log::DEBUG );
if(!$util->setupServerSide( $params['password'] )) {
return false;
}
}
\OC_FileProxy::$enabled = false;
$encryptedKey = Keymanager::getPrivateKey( $view, $params['uid'] );
\OC_FileProxy::$enabled = true;
$privateKey = Crypt::symmetricDecryptFileContent( $encryptedKey, $params['password'] );
$session = new Session( $view );
$session->setPrivateKey( $privateKey, $params['uid'] );
// Check if first-run file migration has already been performed
$migrationCompleted = $util->getMigrationStatus();
// If migration not yet done
if ( ! $migrationCompleted ) {
$view1 = new \OC_FilesystemView( '/' . $params['uid'] );
// Set legacy encryption key if it exists, to support
// depreciated encryption system
if (
$view1->file_exists( 'encryption.key' )
&& $encLegacyKey = $view1->file_get_contents( 'encryption.key' )
) {
$plainLegacyKey = Crypt::legacyDecrypt( $encLegacyKey, $params['password'] );
$session->setLegacyKey( $plainLegacyKey );
}
\OC_FileProxy::$enabled = false;
$publicKey = Keymanager::getPublicKey( $view, $params['uid'] );
\OC_FileProxy::$enabled = false;
// Encrypt existing user files:
// This serves to upgrade old versions of the encryption
// app (see appinfo/spec.txt)
if (
$util->encryptAll( $publicKey, '/' . $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->setMigrationStatus( 1 );
}
return true;
}
/**
* @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' ) {
$view = new \OC_FilesystemView( '/' );
$session = new Session($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
}
}
/**
* @brief update the encryption key of the file uploaded by the client
*/
public static function updateKeyfile( $params ) {
if ( Crypt::mode() == 'client' ) {
if ( isset( $params['properties']['key'] ) ) {
$view = new \OC_FilesystemView( '/' );
$userId = \OCP\User::getUser();
Keymanager::setFileKey( $view, $params['path'], $userId, $params['properties']['key'] );
} else {
\OC_Log::write(
'Encryption library', "Client side encryption is enabled but the client doesn't provide a encryption key for the file!"
, \OC_Log::ERROR
);
}
}
}
/**
* @brief
*/
public static function postShared($params) {
// NOTE: $params has keys:
// [itemType] => file
// itemSource -> int, filecache file ID
// [parent] =>
// [itemTarget] => /13
// shareWith -> string, uid of user being shared to
// fileTarget -> path of file being shared
// uidOwner -> owner of the original file being shared
// [shareType] => 0
// [shareWith] => test1
// [uidOwner] => admin
// [permissions] => 17
// [fileSource] => 13
// [fileTarget] => /test8
// [id] => 10
// [token] =>
// TODO: Should other kinds of item be encrypted too?
if ($params['itemType'] === 'file' || $params['itemType'] === 'folder') {
$view = new \OC_FilesystemView('/');
$session = new Session($view);
$userId = \OCP\User::getUser();
$util = new Util($view, $userId);
$path = $util->fileIdToPath($params['itemSource']);
//if parent is set, then this is a re-share action
if($params['parent']) {
// 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 {
// 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'];
}
}
}
$sharingEnabled = \OCP\Share::isEnabled();
// if a folder was shared, get a list if all (sub-)folders
if ($params['itemType'] === 'folder') {
$allFiles = $util->getAllFiles($path);
} else {
$allFiles = array($path);
}
foreach ($allFiles as $path) {
$usersSharing = $util->getSharingUsersArray($sharingEnabled, $path);
$failed = array();
// Attempt to set shareKey
if (!$util->setSharedFileKeyfiles($session, $usersSharing, $path)) {
$failed[] = $path;
}
}
// If no attempts to set keyfiles failed
if (empty($failed)) {
return true;
} else {
return false;
}
}
}
/**
* @brief
*/
public static function postUnshare( $params ) {
// NOTE: $params has keys:
// [itemType] => file
// [itemSource] => 13
// [shareType] => 0
// [shareWith] => test1
if ( $params['itemType'] === 'file' || $params['itemType'] === 'folder' ) {
$view = new \OC_FilesystemView( '/' );
$session = new Session($view);
$userId = \OCP\User::getUser();
$util = new Util( $view, $userId );
$path = $util->fileIdToPath( $params['itemSource'] );
// for group shares get a list of the group members
if ($params['shareType'] == \OCP\Share::SHARE_TYPE_GROUP) {
$userIds = \OC_Group::usersInGroup($params['shareWith']);
} else {
$userIds = array($params['shareWith']);
}
// 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
//TODO: does not work properly atm
$delUsers = array_diff($userIds, $sharingUsers);
if ( ! Keymanager::delShareKey( $view, $delUsers, $path ) ) {
$failed[] = $path;
}
}
// If no attempts to set keyfiles failed
if ( empty( $failed ) ) {
return true;
} else {
return false;
}
}
}
/**
* @brief
*/
public static function postUnshareAll( $params ) {
// NOTE: It appears that this is never called for files, so
// we may not need to implement it
}
/**
* @brief after a file is renamed, rename its keyfile and share-keys also fix the file size and fix also the sharing
* @param array with oldpath and newpath
*
* This function is connected to the rename signal of OC_Filesystem and adjust the name and location
* of the stored versions along the actual file
*/
public static function postRename($params) {
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$view = new \OC_FilesystemView('/');
$session = new Session($view);
$userId = \OCP\User::getUser();
$util = new Util( $view, $userId );
// Format paths to be relative to user files dir
$oldKeyfilePath = $userId . '/' . 'files_encryption' . '/' . 'keyfiles' . '/' . $params['oldpath'];
$newKeyfilePath = $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) {
$dst = str_replace($params['oldpath'], $params['newpath'], $src);
rename($src, $dst);
}
} else {
// handle share-keys folders
$oldShareKeyfilePath = $userId . '/' . 'files_encryption' . '/' . 'share-keys' . '/' . $params['oldpath'];
$newShareKeyfilePath = $userId . '/' . 'files_encryption' . '/' . 'share-keys' . '/' . $params['newpath'];
$view->rename($oldShareKeyfilePath, $newShareKeyfilePath);
}
// Rename keyfile so it isn't orphaned
if($view->file_exists($oldKeyfilePath)) {
$view->rename($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;
}
}