MDL-36754 core_files: Add a token version of pluginfile

files/classes/privacy/provider.php

@@ -27,6 +27,8 @@
 defined('MOODLE_INTERNAL') || die();
 
 use core_privacy\local\metadata\collection;
+use core_privacy\local\request\contextlist;
+use core_privacy\local\request\approved_contextlist;
 
 /**
  * Data provider class.
@@ -41,7 +43,10 @@
  */
 class provider implements
     \core_privacy\local\metadata\provider,
-    \core_privacy\local\request\subsystem\plugin_provider {
+    \core_privacy\local\request\subsystem\plugin_provider,
+
+    // We store a userkey for token-based file access.
+    \core_privacy\local\request\subsystem\provider {
 
     /**
      * Returns metadata.
@@ -65,7 +70,95 @@ public static function get_metadata(collection $collection) : collection {
             'timemodified' => 'privacy:metadata:files:timemodified',
         ], 'privacy:metadata:files');
 
+        $collection->add_subsystem_link('core_userkey', [], 'privacy:metadata:core_userkey');
+
         return $collection;
     }
 
+    /**
+     * Get the list of contexts that contain user information for the specified user.
+     *
+     * This is currently just the user context.
+     *
+     * @param int $userid The user to search.
+     * @return contextlist $contextlist The contextlist containing the list of contexts used in this plugin.
+     */
+    public static function get_contexts_for_userid(int $userid) : contextlist {
+        $sql = "SELECT ctx.id
+                  FROM {user_private_key} k
+                  JOIN {user} u ON k.userid = u.id
+                  JOIN {context} ctx ON ctx.instanceid = u.id AND ctx.contextlevel = :contextlevel
+                 WHERE k.userid = :userid AND k.script = :script";
+        $params = [
+            'userid' => $userid,
+            'contextlevel' => CONTEXT_USER,
+            'script' => 'core_files',
+        ];
+        $contextlist = new contextlist();
+        $contextlist->add_from_sql($sql, $params);
+
+        return $contextlist;
+    }
+
+    /**
+     * Export all user data for the specified user, in the specified contexts.
+     *
+     * @param approved_contextlist $contextlist The approved contexts to export information for.
+     */
+    public static function export_user_data(approved_contextlist $contextlist) {
+        // If the user has data, then only the CONTEXT_USER should be present so get the first context.
+        $contexts = $contextlist->get_contexts();
+        if (count($contexts) == 0) {
+            return;
+        }
+
+        // Sanity check that context is at the user context level, then get the userid.
+        $context = reset($contexts);
+        if ($context->contextlevel !== CONTEXT_USER) {
+            return;
+        }
+
+        // Export associated userkeys.
+        $subcontext = [
+            get_string('files'),
+        ];
+        \core_userkey\privacy\provider::export_userkeys($context, $subcontext, 'core_files');
+    }
+
+    /**
+     * Delete all use data which matches the specified deletion_criteria.
+     *
+     * @param context $context A user context.
+     */
+    public static function delete_data_for_all_users_in_context(\context $context) {
+        // Sanity check that context is at the user context level, then get the userid.
+        if ($context->contextlevel !== CONTEXT_USER) {
+            return;
+        }
+
+        // Delete all the userkeys.
+        \core_userkey\privacy\provider::delete_userkeys('core_files', $context->instanceid);
+    }
+
+    /**
+     * Delete all user data for the specified user, in the specified contexts.
+     *
+     * @param approved_contextlist $contextlist The approved contexts and user information to delete information for.
+     */
+    public static function delete_data_for_user(approved_contextlist $contextlist) {
+        // If the user has data, then only the user context should be present so get the first context.
+        $contexts = $contextlist->get_contexts();
+        if (count($contexts) == 0) {
+            return;
+        }
+
+        // Sanity check that context is at the user context level, then get the userid.
+        $context = reset($contexts);
+        if ($context->contextlevel !== CONTEXT_USER) {
+            return;
+        }
+
+        // Delete all the userkeys for core_files..
+        \core_userkey\privacy\provider::delete_userkeys('core_files', $context->instanceid);
+    }
 }

lang/en/files.php

@@ -37,3 +37,4 @@
 $string['privacy:metadata:files:timecreated'] = 'The time when the file was created';
 $string['privacy:metadata:files:timemodified'] = 'The time when the file was last modified';
 $string['privacy:metadata:files:userid'] = 'The user who created the file';
+$string['privacy:metadata:core_userkey'] = 'A private token is generated and stored. This token can be used to access Moodle files without requiring you to log in.';

lib/moodlelib.php

@@ -3112,9 +3112,10 @@ function validate_user_key($keyvalue, $script, $instance) {
  * @uses PARAM_ALPHANUM
  * @param string $script unique script identifier
  * @param int $instance optional instance id
+ * @param string $keyvalue The key. If not supplied, this will be fetched from the current session.
  * @return int Instance ID
  */
-function require_user_key_login($script, $instance=null) {
+function require_user_key_login($script, $instance = null, $keyvalue = null) {
     global $DB;
 
     if (!NO_MOODLE_COOKIES) {
@@ -3124,7 +3125,9 @@ function require_user_key_login($script, $instance=null) {
     // Extra safety.
     \core\session\manager::write_close();
 
-    $keyvalue = required_param('key', PARAM_ALPHANUM);
+    if (null === $keyvalue) {
+        $keyvalue = required_param('key', PARAM_ALPHANUM);
+    }
 
     $key = validate_user_key($keyvalue, $script, $instance);
 

pluginfile.php

@@ -25,12 +25,16 @@
  */
 
 // Disable moodle specific debug messages and any errors in output.
-define('NO_DEBUG_DISPLAY', true);
+if (!defined('NO_DEBUG_DISPLAY')) {
+    define('NO_DEBUG_DISPLAY', true);
+}
 
 require_once('config.php');
 require_once('lib/filelib.php');
 
-$relativepath = get_file_argument();
+if (empty($relativepath)) {
+    $relativepath = get_file_argument();
+}
 $forcedownload = optional_param('forcedownload', 0, PARAM_BOOL);
 $preview = optional_param('preview', null, PARAM_ALPHANUM);
 // Offline means download the file from the repository and serve it, even if it was an external link.

tokenpluginfile.php

@@ -0,0 +1,44 @@
+<?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/>.
+
+/**
+ * Entry point for token-based access to pluginfile.php.
+ *
+ * @package    core
+ * @copyright  2018 Andrew Nicols <[email protected]>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+// Disable the use of sessions/cookies - we recreate $USER for every call.
+define('NO_MOODLE_COOKIES', true);
+
+// Disable debugging for this script.
+// It is typically used to display images.
+define('NO_DEBUG_DISPLAY', true);
+
+require_once('config.php');
+
+$relativepath = get_file_argument();
+$token = optional_param('token', '', PARAM_ALPHANUM);
+if (0 == strpos($relativepath, '/token/')) {
+    $relativepath = ltrim($relativepath, '/');
+    $pathparts = explode('/', $relativepath, 2);
+    $token = $pathparts[0];
+    $relativepath = "/{$pathparts[1]}";
+}
+
+require_user_key_login('core_files', null, $token);
+require_once('pluginfile.php');