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<?php
/***
* ownCloud
*
* @author Bjoern Schiessle
* @copyright 2012 Bjoern Schiessle <schiessle@owncloud.com>
*
* 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;
/**
* This class provides basic operations to read/write encryption keys from/to the filesystem
*/
class Keymanager {
# TODO: make all dependencies (including static classes) explicit, such as ocfsview objects, by adding them as method arguments (dependency injection)
/**
* @brief retrieve the ENCRYPTED private key from a user
*
* @return string private key or false
* @note the key returned by this method must be decrypted before use
*/
public static function getPrivateKey( $user, $view ) {
$view->chroot( '/' . $user . '/' . 'files_encryption' );
return $view->file_get_contents( '/' . $user.'.private.key' );
}
/**
* @brief retrieve public key for a specified user
* @return string public key or false
*/
public static function getPublicKey( $userId = NULL ) {
// If the username wasn't specified, fetch it
if ( ! $userId ) {
$userId = \OCP\User::getUser();
}
// Create new view with the right
$view = new \OC_FilesystemView( '/public-keys/' );
return $view->file_get_contents( '/' . $userId . '.public.key' );
}
/**
* @brief retrieve both keys from a user (private and public)
*
* @return string private key or false
*/
public static function getUserKeys() {
return array(
'privatekey' => self::getPrivateKey(),
'publickey' => self::getPublicKey(),
);
}
/**
* @brief retrieve a list of the public key from all users with access to the file
*
* @param string path to file
* @return array of public keys for the given file
*/
public static function getPublicKeys($path) {
$userId = \OCP\User::getUser();
$path = ltrim( $path, '/' );
$filepath = '/'.$userId.'/files/'.$path;
// Check if sharing is enabled
if ( OC_App::isEnabled( 'files_sharing' ) ) {
// // Check if file was shared with other users
// $query = \OC_DB::prepare( "SELECT uid_owner, source, target, uid_shared_with FROM `*PREFIX*sharing` WHERE ( target = ? AND uid_shared_with = ? ) OR source = ? " );
// $result = $query->execute( array ($filepath, $userId, $filepath));
// $users = array();
// if ($row = $result->fetchRow()){
// $source = $row['source'];
// $owner = $row['uid_owner'];
// $users[] = $owner;
// // get the uids of all user with access to the file
// $query = \OC_DB::prepare( "SELECT source, uid_shared_with FROM `*PREFIX*sharing` WHERE source = ?" );
// $result = $query->execute( array ($source));
// while ( ($row = $result->fetchRow()) ) {
// $users[] = $row['uid_shared_with'];
// }
// }
} else {
// check if it is a file owned by the user and not shared at all
$userview = new \OC_FilesystemView( '/'.$userId.'/files/' );
if ($userview->file_exists($path)) {
$users[] = $userId;
}
}
$view = new \OC_FilesystemView( '/public-keys/' );
$keylist = array();
$count = 0;
foreach ($users as $user) {
$keylist['key'.++$count] = $view->file_get_contents($user.'.public.key');
}
return $keylist;
}
/**
* @brief retrieve keyfile for an encrypted file
*
* @param string file name
* @return string file key or false
* @note The keyfile returned is asymmetrically encrypted. Decryption
* of the keyfile must be performed by client code
*/
public static function getFileKey( $path, $staticUserClass = 'OCP\User' ) {
$keypath = ltrim( $path, '/' );
$user = $staticUserClass::getUser();
// // update $keypath and $user if path point to a file shared by someone else
// $query = \OC_DB::prepare( "SELECT uid_owner, source, target FROM `*PREFIX*sharing` WHERE target = ? AND uid_shared_with = ?" );
//
// $result = $query->execute( array ('/'.$user.'/files/'.$keypath, $user));
//
// if ($row = $result->fetchRow()) {
//
// $keypath = $row['source'];
// $keypath_parts = explode( '/', $keypath );
// $user = $keypath_parts[1];
// $keypath = str_replace( '/' . $user . '/files/', '', $keypath );
//
// }
$view = new \OC_FilesystemView('/'.$user.'/files_encryption/keyfiles/');
return $view->file_get_contents( $keypath . '.key' );
}
/**
* @brief retrieve file encryption key
*
* @param string file name
* @return string file key or false
*/
public static function deleteFileKey( $path, $staticUserClass = 'OCP\User' ) {
$keypath = ltrim( $path, '/' );
$user = $staticUserClass::getUser();
// update $keypath and $user if path point to a file shared by someone else
// $query = \OC_DB::prepare( "SELECT uid_owner, source, target FROM `*PREFIX*sharing` WHERE target = ? AND uid_shared_with = ?" );
//
// $result = $query->execute( array ('/'.$user.'/files/'.$keypath, $user));
//
// if ($row = $result->fetchRow()) {
//
// $keypath = $row['source'];
// $keypath_parts = explode( '/', $keypath );
// $user = $keypath_parts[1];
// $keypath = str_replace( '/' . $user . '/files/', '', $keypath );
//
// }
$view = new \OC_FilesystemView('/'.$user.'/files_encryption/keyfiles/');
return $view->unlink( $keypath . '.key' );
}
/**
* @brief store private key from the user
*
* @param string key
* @return bool true/false
*/
public static function setPrivateKey($key) {
$user = \OCP\User::getUser();
$view = new \OC_FilesystemView('/'.$user.'/files_encryption');
if (!$view->file_exists('')) $view->mkdir('');
return $view->file_put_contents($user.'.private.key', $key);
}
/**
* @brief store private keys from the user
*
* @param string privatekey
* @param string publickey
* @return bool true/false
*/
public static function setUserKeys($privatekey, $publickey) {
return (self::setPrivateKey($privatekey) && self::setPublicKey($publickey));
}
/**
* @brief store public key of the user
*
* @param string key
* @return bool true/false
*/
public static function setPublicKey($key) {
$view = new \OC_FilesystemView('/public-keys');
if (!$view->file_exists('')) $view->mkdir('');
return $view->file_put_contents(\OCP\User::getUser().'.public.key', $key);
}
/**
* @brief store file encryption key
*
* @param string $path relative path of the file, including filename
* @param string $key
* @return bool true/false
* @note The keyfile is not encrypted here. Client code must
* asymmetrically encrypt the keyfile before passing it to this method
*/
public static function setFileKey( $path, $key, $view = Null, $dbClassName = '\OC_DB') {
$targetPath = ltrim( $path, '/' );
$user = \OCP\User::getUser();
// // update $keytarget and $user if key belongs to a file shared by someone else
// $query = $dbClassName::prepare( "SELECT uid_owner, source, target FROM `*PREFIX*sharing` WHERE target = ? AND uid_shared_with = ?" );
//
// $result = $query->execute( array ( '/'.$user.'/files/'.$targetPath, $user ) );
//
// if ( $row = $result->fetchRow( ) ) {
//
// $targetPath = $row['source'];
//
// $targetPath_parts = explode( '/', $targetPath );
//
// $user = $targetPath_parts[1];
//
// $rootview = new \OC_FilesystemView( '/' );
//
// if ( ! $rootview->is_writable( $targetPath ) ) {
//
// \OC_Log::write( 'Encryption library', "File Key not updated because you don't have write access for the corresponding file", \OC_Log::ERROR );
//
// return false;
//
// }
//
// $targetPath = str_replace( '/'.$user.'/files/', '', $targetPath );
//
// //TODO: check for write permission on shared file once the new sharing API is in place
//
// }
$path_parts = pathinfo( $targetPath );
if ( !$view ) {
$view = new \OC_FilesystemView( '/' );
}
$view->chroot( '/' . $user . '/files_encryption/keyfiles' );
// If the file resides within a subdirectory, create it
if (
isset( $path_parts['dirname'] )
&& ! $view->file_exists( $path_parts['dirname'] )
) {
$view->mkdir( $path_parts['dirname'] );
}
// Save the keyfile in parallel directory
return $view->file_put_contents( '/' . $targetPath . '.key', $key );
}
/**
* @brief change password of private encryption key
*
* @param string $oldpasswd old password
* @param string $newpasswd new password
* @return bool true/false
*/
public static function changePasswd($oldpasswd, $newpasswd) {
if ( \OCP\User::checkPassword(\OCP\User::getUser(), $newpasswd) ) {
return Crypt::changekeypasscode($oldpasswd, $newpasswd);
}
return false;
}
/**
* @brief Fetch the legacy encryption key from user files
* @param string $login used to locate the legacy key
* @param string $passphrase used to decrypt the legacy key
* @return true / false
*
* if the key is left out, the default handeler will be used
*/
public function getLegacyKey() {
$user = \OCP\User::getUser();
$view = new \OC_FilesystemView( '/' . $user );
return $view->file_get_contents( 'encryption.key' );
}
}
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