nextcloud/apps/files_encryption/hooks/hooks.php

264 lines
7.2 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
\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 );
return $util->setupServerSide( $params['password'] );
}
\OC_FileProxy::$enabled = false;
$encryptedKey = Keymanager::getPrivateKey( $view, $params['uid'] );
\OC_FileProxy::$enabled = true;
$privateKey = Crypt::symmetricDecryptFileContent( $encryptedKey, $params['password'] );
$session = new Session();
$session->setPrivateKey( $privateKey, $params['uid'] );
$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'] . '" started at login'
, \OC_Log::INFO
);
}
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' ) {
$session = new Session();
// 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
);
error_log( "Client side encryption is enabled but the client doesn't provide an encryption key for the file!" );
}
}
}
/**
* @brief
*/
public static function postShared( $params ) {
// NOTE: $params is an array with these keys:
// itemSource -> int, filecache file ID
// shareWith -> string, uid of user being shared to
// fileTarget -> path of file being shared
// uidOwner -> owner of the original file being shared
$view = new \OC_FilesystemView( '/' );
$userId = \OCP\User::getUser();
$util = new Util( $view, $userId );
$session = new Session();
$shares = \OCP\Share::getUsersSharingFile( $params['fileTarget'], 1 );
$userIds = array();
foreach ( $shares as $share ) {
$util = new Util( $view, $share['userId'] );
// Check that the user is encryption capable
if ( $util->ready() ) {
// Construct array of just UIDs for Keymanager{}
$userIds[] = $share['userId'];
} else {
// Log warning; we can't do necessary setup here
// because we don't have the user passphrase
// TODO: Provide user feedback indicating that
// sharing failed
\OC_Log::write( 'Encryption library', 'File cannot be shared: user "'.$share['userId'].'" is not setup for encryption', \OC_Log::WARN );
}
}
$userPubKeys = Keymanager::getPublicKeys( $view, $userIds );
\OC_FileProxy::$enabled = false;
// get the keyfile
$encKeyfile = Keymanager::getFileKey( $view, $userId, $params['fileTarget'] );
$privateKey = $session->getPrivateKey();
// decrypt the keyfile
$plainKeyfile = Crypt::keyDecrypt( $encKeyfile, $privateKey );
// re-enc keyfile to sharekeys
$shareKeys = Crypt::multiKeyEncrypt( $plainKeyfile, $userPubKeys );
// save sharekeys
if ( ! Keymanager::setShareKeys( $view, $params['fileTarget'], $shareKeys['keys'] ) ) {
trigger_error( "SET Share keys failed" );
}
// Delete existing keyfile
// Do this last to ensure file is recoverable in case of error
// Keymanager::deleteFileKey( $view, $userId, $params['fileTarget'] );
\OC_FileProxy::$enabled = true;
return true;
}
/**
* @brief
*/
public static function preUnshare( $params ) {
// Delete existing catfile
// Generate new catfile and env keys
// Save env keys to user folders
}
/**
* @brief
*/
public static function preUnshareAll( $params ) {
trigger_error( "preUnshareAll" );
}
}