Current Path : C:/xampp/htdocs/moodle/repository/nextcloud/classes/ |
Current File : C:/xampp/htdocs/moodle/repository/nextcloud/classes/access_controlled_link_manager.php |
<?php // This file is part of Moodle - http://moodle.org/ // // Moodle is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // Moodle 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 General Public License for more details. // // You should have received a copy of the GNU General Public License // along with Moodle. If not, see <http://www.gnu.org/licenses/>. /** * Manages the creation and usage of access controlled links. * * @package repository_nextcloud * @copyright 2017 Nina Herrmann (Learnweb, University of Münster) * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ namespace repository_nextcloud; use context; use \core\oauth2\api; use \core\notification; use repository_exception; defined('MOODLE_INTERNAL') || die(); require_once($CFG->libdir . '/webdavlib.php'); /** * Manages the creation and usage of access controlled links. * * @package repository_nextcloud * @copyright 2017 Nina Herrmann (Learnweb, University of Münster) * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ class access_controlled_link_manager{ /** * OCS client that uses the Open Collaboration Services REST API. * @var ocs_client */ protected $ocsclient; /** * ocsclient of the systemaccount. * @var ocs_client */ protected $systemocsclient; /** * Client to manage oauth2 features from the systemaccount. * @var \core\oauth2\client */ protected $systemoauthclient; /** * Client to manage webdav request from the systemaccount.. * @var \webdav_client */ protected $systemwebdavclient; /** * Issuer from the oauthclient. * @var \core\oauth2\issuer */ protected $issuer; /** * Name of the related repository. * @var string */ protected $repositoryname; /** * Access_controlled_link_manager constructor. * @param ocs_client $ocsclient * @param \core\oauth2\client $systemoauthclient * @param ocs_client $systemocsclient * @param \core\oauth2\issuer $issuer * @param string $repositoryname * @throws configuration_exception */ public function __construct($ocsclient, $systemoauthclient, $systemocsclient, $issuer, $repositoryname) { $this->ocsclient = $ocsclient; $this->systemoauthclient = $systemoauthclient; $this->systemocsclient = $systemocsclient; $this->repositoryname = $repositoryname; $this->issuer = $issuer; $this->systemwebdavclient = $this->create_system_dav(); } /** * Deletes the share of the systemaccount and a user. In case the share could not be deleted a notification is * displayed. * @param int $shareid Remote ID of the share to be deleted. */ public function delete_share_dataowner_sysaccount($shareid) { $shareid = (int) $shareid; $deleteshareparams = [ 'share_id' => $shareid ]; $deleteshareresponse = $this->ocsclient->call('delete_share', $deleteshareparams); $xml = simplexml_load_string($deleteshareresponse); if (empty($xml->meta->statuscode) || $xml->meta->statuscode != 100 ) { notification::warning('You just shared a file with a access controlled link. However, the share between you and the systemaccount could not be deleted and is still present in your instance.'); } } /** * Creates a share between a user and the system account. If $username is set the sharing direction is system account -> user, * otherwise user -> system account. * @param string $path Remote path of the file that will be shared * @param string $username optional when set the file is shared with the corresponding user otherwise with * the systemaccount. * @param bool $maywrite if false, only(!) read access is granted. * @return array statuscode, shareid, and filetarget * @throws request_exception */ public function create_share_user_sysaccount($path, $username = null, $maywrite = false) { $result = array(); if ($username != null) { $shareusername = $username; } else { $systemaccount = \core\oauth2\api::get_system_account($this->issuer); $shareusername = $systemaccount->get('username'); } $permissions = ocs_client::SHARE_PERMISSION_READ; if ($maywrite) { // Add more privileges (write, reshare) if allowed for the given user. $permissions |= ocs_client::SHARE_PERMISSION_ALL; } $createshareparams = [ 'path' => $path, 'shareType' => ocs_client::SHARE_TYPE_USER, 'publicUpload' => false, 'shareWith' => $shareusername, 'permissions' => $permissions, ]; // File is now shared with the system account. if ($username === null) { $createshareresponse = $this->ocsclient->call('create_share', $createshareparams); } else { $createshareresponse = $this->systemocsclient->call('create_share', $createshareparams); } $xml = simplexml_load_string($createshareresponse); $statuscode = (int)$xml->meta->statuscode; if ($statuscode != 100 && $statuscode != 403) { $details = get_string('filenotaccessed', 'repository_nextcloud'); throw new request_exception(get_string('request_exception', 'repository_nextcloud', array('instance' => $this->repositoryname, 'errormessage' => $details))); } $result['shareid'] = (int)$xml->data->id; $result['statuscode'] = $statuscode; $result['filetarget'] = (string)$xml->data[0]->file_target; return $result; } /** Copy or moves a file to a new path. * @param string $srcpath source path * @param string $dstpath * @param string $operation move or copy * @param \webdav_client $webdavclient needed when moving files. * @return String Http-status of the request * @throws configuration_exception * @throws \coding_exception * @throws \moodle_exception * @throws \repository_nextcloud\request_exception */ public function transfer_file_to_path($srcpath, $dstpath, $operation, $webdavclient = null) { $this->systemwebdavclient->open(); $webdavendpoint = issuer_management::parse_endpoint_url('webdav', $this->issuer); $srcpath = ltrim($srcpath, '/'); $sourcepath = $webdavendpoint['path'] . $srcpath; $dstpath = ltrim($dstpath, '/'); $destinationpath = $webdavendpoint['path'] . $dstpath . '/' . $srcpath; if ($operation === 'copy') { $result = $this->systemwebdavclient->copy_file($sourcepath, $destinationpath, true); } else if ($operation === 'move') { $result = $webdavclient->move($sourcepath, $destinationpath, false); if ($result == 412) { // A file with that name already exists at that target. Find a unique location! $increment = 0; // Will be appended to/inserted into the filename. // Define the pattern that is used to insert the increment to the filename. if (substr_count($srcpath, '.') === 0) { // No file extension; append increment to the (sprintf-escaped) name. $namepattern = str_replace('%', '%%', $destinationpath) . ' (%s)'; } else { // Append the increment to the second-to-last component, which is presumably the one before the extension. // Again, the original path is sprintf-escaped. $components = explode('.', str_replace('%', '%%', $destinationpath)); $components[count($components) - 2] .= ' (%s)'; $namepattern = implode('.', $components); } } while ($result == 412) { $increment++; $destinationpath = sprintf($namepattern, $increment); $result = $webdavclient->move($sourcepath, $destinationpath, false); } } $this->systemwebdavclient->close(); if (!($result == 201 || $result == 412)) { $details = get_string('contactadminwith', 'repository_nextcloud', 'A webdav request to ' . $operation . ' a file failed.'); throw new request_exception(array('instance' => $this->repositoryname, 'errormessage' => $details)); } return $result; } /** * Creates a unique folder path for the access controlled link. * @param context $context * @param string $component * @param string $filearea * @param string $itemid * @return string $result full generated path. * @throws request_exception If the folder path cannot be created. */ public function create_folder_path_access_controlled_links($context, $component, $filearea, $itemid) { global $CFG, $SITE; // The fullpath to store the file is generated from the context. $contextlist = array_reverse($context->get_parent_contexts(true)); $fullpath = ''; $allfolders = []; foreach ($contextlist as $ctx) { // Prepare human readable context folders names, making sure they are still unique within the site. $prevlang = force_current_language($CFG->lang); $foldername = $ctx->get_context_name(); force_current_language($prevlang); if ($ctx->contextlevel === CONTEXT_SYSTEM) { // Append the site short name to the root folder. $foldername .= ' ('.$SITE->shortname.')'; // Append the relevant object id. } else if ($ctx->instanceid) { $foldername .= ' (id '.$ctx->instanceid.')'; } else { // This does not really happen but just in case. $foldername .= ' (ctx '.$ctx->id.')'; } $foldername = clean_param($foldername, PARAM_FILE); $allfolders[] = $foldername; } $allfolders[] = clean_param($component, PARAM_FILE); $allfolders[] = clean_param($filearea, PARAM_FILE); $allfolders[] = clean_param($itemid, PARAM_FILE); // Extracts the end of the webdavendpoint. $parsedwebdavurl = issuer_management::parse_endpoint_url('webdav', $this->issuer); $webdavprefix = $parsedwebdavurl['path']; $this->systemwebdavclient->open(); // Checks whether folder exist and creates non-existent folders. foreach ($allfolders as $foldername) { $fullpath .= '/' . $foldername; $isdir = $this->systemwebdavclient->is_dir($webdavprefix . $fullpath); // Folder already exist, continue. if ($isdir === true) { continue; } $response = $this->systemwebdavclient->mkcol($webdavprefix . $fullpath); if ($response != 201) { $this->systemwebdavclient->close(); $details = get_string('contactadminwith', 'repository_nextcloud', get_string('pathnotcreated', 'repository_nextcloud', $fullpath)); throw new request_exception(array('instance' => $this->repositoryname, 'errormessage' => $details)); } } $this->systemwebdavclient->close(); return $fullpath; } /** Creates a new webdav_client for the system account. * @return \webdav_client * @throws configuration_exception */ public function create_system_dav() { $webdavendpoint = issuer_management::parse_endpoint_url('webdav', $this->issuer); // Selects the necessary information (port, type, server) from the path to build the webdavclient. $server = $webdavendpoint['host']; if ($webdavendpoint['scheme'] === 'https') { $webdavtype = 'ssl://'; $webdavport = 443; } else if ($webdavendpoint['scheme'] === 'http') { $webdavtype = ''; $webdavport = 80; } // Override default port, if a specific one is set. if (isset($webdavendpoint['port'])) { $webdavport = $webdavendpoint['port']; } // Authentication method is `bearer` for OAuth 2. Pass oauth client from which WebDAV obtains the token when needed. $dav = new \webdav_client($server, '', '', 'bearer', $webdavtype, $this->systemoauthclient->get_accesstoken()->token, $webdavendpoint['path']); $dav->port = $webdavport; $dav->debug = false; return $dav; } /** Creates a folder to store access controlled links. * @param string $controlledlinkfoldername * @param \webdav_client $webdavclient * @throws \coding_exception * @throws configuration_exception * @throws request_exception */ public function create_storage_folder($controlledlinkfoldername, $webdavclient) { $parsedwebdavurl = issuer_management::parse_endpoint_url('webdav', $this->issuer); $webdavprefix = $parsedwebdavurl['path']; // Checks whether folder exist and creates non-existent folders. $webdavclient->open(); $isdir = $webdavclient->is_dir($webdavprefix . $controlledlinkfoldername); // Folder already exist, continue. if (!$isdir) { $responsecreateshare = $webdavclient->mkcol($webdavprefix . $controlledlinkfoldername); if ($responsecreateshare != 201) { $webdavclient->close(); throw new request_exception(array('instance' => $this->repositoryname, 'errormessage' => get_string('contactadminwith', 'repository_nextcloud', 'The folder to store files in the user account could not be created.'))); } } $webdavclient->close(); } /** Gets all shares from a path (the path is file specific) and extracts the share of a specific user. In case * multiple shares exist the first one is taken. Multiple shares can only appear when shares are created outside * of this plugin, therefore this case is not handled. * @param string $path * @param string $username * @return \SimpleXMLElement * @throws \moodle_exception */ public function get_shares_from_path($path, $username) { $ocsparams = [ 'path' => $path, 'reshares' => true ]; $getsharesresponse = $this->systemocsclient->call('get_shares', $ocsparams); $xml = simplexml_load_string($getsharesresponse); $validelement = array(); foreach ($fileid = $xml->data->element as $element) { if ($element->share_with == $username) { $validelement = $element; break; } } if (empty($validelement)) { throw new request_exception(array('instance' => $this->repositoryname, 'errormessage' => get_string('filenotaccessed', 'repository_nextcloud'))); } return $validelement->id; } /** This method can only be used if the response is from a newly created share. In this case there is more information * in the response. For a reference refer to * https://docs.nextcloud.com/server/13/developer_manual/core/ocs-share-api.html#get-information-about-a-known-share. * @param int $shareid * @param string $username * @return mixed the id of the share * @throws \coding_exception * @throws \repository_nextcloud\request_exception */ public function get_share_information_from_shareid($shareid, $username) { $ocsparams = [ 'share_id' => (int) $shareid ]; $shareinformation = $this->ocsclient->call('get_information_of_share', $ocsparams); $xml = simplexml_load_string($shareinformation); foreach ($fileid = $xml->data->element as $element) { if ($element->share_with == $username) { $validelement = $element; break; } } if (empty($validelement)) { throw new request_exception(array('instance' => $this->repositoryname, 'errormessage' => get_string('filenotaccessed', 'repository_nextcloud'))); } return (string) $validelement->file_target; } /** * Find a file that has previously been shared with the system account. * @param string $path Path to file in user context. * @return array shareid: ID of share, filetarget: path to file in sys account. * @throws request_exception If the share cannot be resolved. */ public function find_share_in_sysaccount($path) { $systemaccount = \core\oauth2\api::get_system_account($this->issuer); $systemaccountuser = $systemaccount->get('username'); // Find out share ID from user files. $ocsparams = [ 'path' => $path, 'reshares' => true ]; $getsharesresponse = $this->ocsclient->call('get_shares', $ocsparams); $xml = simplexml_load_string($getsharesresponse); $validelement = array(); foreach ($fileid = $xml->data->element as $element) { if ($element->share_with == $systemaccountuser) { $validelement = $element; break; } } if (empty($validelement)) { throw new request_exception(array('instance' => $this->repositoryname, 'errormessage' => get_string('filenotaccessed', 'repository_nextcloud'))); } $shareid = (int) $validelement->id; // Use share id to find file name in system account's context. $ocsparams = [ 'share_id' => $shareid ]; $shareinformation = $this->systemocsclient->call('get_information_of_share', $ocsparams); $xml = simplexml_load_string($shareinformation); foreach ($fileid = $xml->data->element as $element) { if ($element->share_with == $systemaccountuser) { $validfile = $element; break; } } if (empty($validfile)) { throw new request_exception(array('instance' => $this->repositoryname, 'errormessage' => get_string('filenotaccessed', 'repository_nextcloud'))); } return [ 'shareid' => $shareid, 'filetarget' => (string) $validfile->file_target ]; } /** * Download a file from the system account for the purpose of offline usage. * @param string $srcpath Name of a file owned by the system account * @param string $targetpath Temporary filename in Moodle * @throws repository_exception The download was unsuccessful, maybe the file does not exist. */ public function download_for_offline_usage(string $srcpath, string $targetpath): void { $this->systemwebdavclient->open(); $webdavendpoint = issuer_management::parse_endpoint_url('webdav', $this->issuer); $srcpath = ltrim($srcpath, '/'); $sourcepath = $webdavendpoint['path'] . $srcpath; // Write file into temp location. if (!$this->systemwebdavclient->get_file($sourcepath, $targetpath)) { $this->systemwebdavclient->close(); throw new repository_exception('cannotdownload', 'repository'); } $this->systemwebdavclient->close(); } }