Normalise pre-signed URLs pasted into editors #368

classes/hook_callbacks.php

@@ -0,0 +1,49 @@
+<?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/>.
+
+namespace tool_objectfs;
+
+use tool_objectfs\local\store\object_file_system;
+
+/**
+ * Hook callbacks for tool_objectfs.
+ *
+ * @package   tool_objectfs
+ * @author    Benjamin Walker (benjaminwalker@catalyst-au.net)
+ * @copyright 2026 Catalyst IT Australia
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class hook_callbacks {
+    /**
+     * Rewrites embedded pre-signed URLs back to pluginfiles before editor content is persisted
+     *
+     * @param \core_files\hook\before_editor_content_saved $hook
+     */
+    public static function before_editor_content_saved(\core_files\hook\before_editor_content_saved $hook): void {
+        global $CFG;
+
+        if (during_initial_install() || isset($CFG->upgraderunning)) {
+            return;
+        }
+
+        $fs = get_file_storage()->get_file_system();
+        if (!($fs instanceof object_file_system)) {
+            return;
+        }
+
+        $hook->set_text($fs->normalise_presigned_urls($hook->get_text()));
+    }
+}

classes/local/store/object_file_system.php

@@ -53,6 +53,9 @@
  * [Description object_file_system]
  */
 abstract class object_file_system extends \file_system_filedir {
+    /** @var string Origin for pre-signed urls. */
+    public const PLUGINFILE_ORIGIN_SEGMENT_PREFIX = 'objectfs-origin=';
+
     /**
      * @var mixed
      */
@@ -887,6 +890,30 @@ public function redirect_to_presigned_url($contenthash, $headers = []) {
         }
     }
 
+    /**
+     * Convert pre-signed URLs inside text back to pluginfiles.
+     *
+     * @param string $text The content that may contain URLs in need of rewriting.
+     * @return string The processed text.
+     */
+    public function normalise_presigned_urls(string $text): string {
+        if (!$this->presigned_url_configured()) {
+            return $text;
+        }
+
+        $re = sprintf(
+            '!https?://[^\s<>"\']*?\#%s([^\s<>"\']+\w)!',
+            preg_quote(self::PLUGINFILE_ORIGIN_SEGMENT_PREFIX)
+        );
+
+        // The origin URL should only have minimal RFC 3986 encoding on anchors.
+        // These characters should be rare and even desirable to keep encoded in pluginfile links.
+        return preg_replace_callback(
+            $re,
+            fn($matches) => (new \moodle_url($matches[1]))->out(),
+            $text
+        );
+    }
 
     /**
      * Return if the file system supports presigned_urls.

classes/local/store/signed_url.php

@@ -45,5 +45,19 @@ class signed_url {
     public function __construct($url, $expiresat) {
         $this->url = $url;
         $this->expiresat = $expiresat;
+        $this->embed_origin_url();
+    }
+
+    /**
+     * Embed origin URL to pre-signed URL.
+     */
+    public function embed_origin_url(): void {
+        global $ME;
+
+        if (!empty($ME)) {
+            $this->url->set_anchor(object_file_system::PLUGINFILE_ORIGIN_SEGMENT_PREFIX . $ME);
+        } else if (!CLI_SCRIPT && !PHPUNIT_TEST) {
+            debugging(OBJECTFS_PLUGIN_NAME . ': Missing origin for pre-signed url.', DEBUG_DEVELOPER);
+        }
     }
 }

db/hooks.php

@@ -0,0 +1,34 @@
+<?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/>.
+
+/**
+ * Hook callbacks for tool_objectfs.
+ *
+ * @package   tool_objectfs
+ * @author    Benjamin Walker (benjaminwalker@catalyst-au.net)
+ * @copyright 2026 Catalyst IT Australia
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+$callbacks = [
+    [
+        'hook' => \core_files\hook\before_editor_content_saved::class,
+        'callback' => '\tool_objectfs\hook_callbacks::before_editor_content_saved',
+        'priority' => 0,
+    ],
+];

tests/object_file_system_test.php

@@ -18,6 +18,7 @@
 
 use coding_exception;
 use tool_objectfs\local\store\object_file_system;
+use tool_objectfs\local\store\signed_url;
 use tool_objectfs\local\manager;
 use tool_objectfs\local\tag\tag_manager;
 use tool_objectfs\tests\test_client;
@@ -1269,4 +1270,122 @@ public function test_is_file_stored_externally_by_hash(): void {
         $result = $reflection->invokeArgs($this->filesystem, [$contenthash]);
         $this->assertFalse($result);
     }
+
+    /**
+     * Data provider for test_normalise_presigned_urls
+     *
+     * @return array
+     */
+    public static function normalise_presigned_urls_provider(): array {
+        return [
+            'default' => [[]],
+            's3 style presignedurl' => [[
+                'presignedurl' => 'https://bucket.s3.ap-southeast-2.amazonaws.com/bucketkeyprefix/?param1=val1&param2=val2',
+            ]],
+            'presignedurl uses http' => [[
+                'presignedurl' => 'https://presigned.url/x?param1=val1&param2=val2',
+            ]],
+            'presignedurl already has fragment' => [[
+                'presignedurl' => 'https://presigned.url/x?param1=val1#already-fragment',
+            ]],
+            'invalid presignedurl missing protocol' => [[
+                'presignedurl' => 'presigned.url/x?param1=val1',
+                'replace' => false,
+            ]],
+            'invalid presignedurl containing space' => [[
+                'presignedurl' => 'https://presigned.url/x?param1=val 1',
+                'replace' => false,
+            ]],
+            'url with embdedded image' => [[
+                'text' => '<img src="%s">',
+            ]],
+            'url in markdown style text' => [[
+                'text' => '[link](%s)',
+            ]],
+            'multiple embedded urls' => [[
+                'text' => 'One: https://example.org/unrelated.pdf Two: %s Three: https://example.org/other.pdf',
+            ]],
+            'multiple embedded urls without space' => [[
+                'text' => '<a href="https://example.org/">%s</a>',
+            ]],
+            'pluginfile with space' => [[
+                'pluginfiles' => ['/pluginfile.php/3854/tool_objectfs/content/1/test file.pdf'],
+            ]],
+            'pluginfile with trailing )' => [[
+                'pluginfiles' => ['/pluginfile.php/3854/tool_objectfs/content/1/test-file(1)'],
+            ]],
+            'pluginfile with trailing /' => [[
+                'pluginfiles' => ['/pluginfile.php/3854/tool_objectfs/content/1/test-file/'],
+            ]],
+            'pluginfile with encoded chars' => [[
+                'pluginfiles' => ['/pluginfile.php/1/tool_objectfs/settings/0/%F0%9F%98%80.txt'],
+            ]],
+            'multiple pluginfiles' => [[
+                'text' => 'One: %s Two: %s',
+                'pluginfiles' => [
+                    '/pluginfile.php/3854/tool_objectfs/content/1/test.pdf',
+                    '/pluginfile.php/7316/tool_objectfs/content/2/red.pdf',
+                ],
+            ]],
+            'multiple pluginfiles with no space' => [[
+                'text' => '<a href="%s">%s</a>',
+                'pluginfiles' => [
+                    '/pluginfile.php/3854/tool_objectfs/content/1/test.pdf',
+                    '/pluginfile.php/3854/tool_objectfs/content/1/test.pdf',
+                ],
+            ]],
+        ];
+    }
+
+    /**
+     * Test rewriting pre-signed URLs to pluginfiles.
+     *
+     * @dataProvider normalise_presigned_urls_provider
+     * @covers ::normalise_presigned_urls
+     *
+     * @param array $config
+     */
+    public function test_normalise_presigned_urls(array $config): void {
+        global $ME;
+
+        $presignedurl = $config['presignedurl'] ?? 'https://presigned.url/x?param1=val1&param2=val2';
+        $text = $config['text'] ?? 'File %s link';
+        $pluginfiles = $config['pluginfiles'] ?? ['/pluginfile.php/3854/tool_objectfs/content/1/test-file.pdf'];
+        $replace = $config['replace'] ?? true;
+
+        // The normalisation logic can be tested with a limited test client.
+        $filesystem = $this->getMockBuilder(test_file_system::class)
+            ->onlyMethods(['presigned_url_configured'])
+            ->getMock();
+        $filesystem->method('presigned_url_configured')->willReturn(true);
+
+        $anchorprop = (new \ReflectionClass(\moodle_url::class))->getProperty('anchor');
+        $prefix = object_file_system::PLUGINFILE_ORIGIN_SEGMENT_PREFIX;
+
+        $embeddedurls = [];
+        $expectedurls = [];
+        foreach ($pluginfiles as $pluginfile) {
+            $ME = $pluginfile;
+            $fullurl = (new signed_url(new \moodle_url($presignedurl), DAYSECS))->url;
+
+            // Verify that origin is added as an anchor when creating signed urls.
+            $anchor = $anchorprop->getValue($fullurl);
+            $this->assertEquals($prefix . $pluginfile, $anchor);
+
+            // Moodle url automatically encodes the fragment as RFC 3986, which we should keep for the link.
+            $fragment = (string)parse_url($fullurl->out(), PHP_URL_FRAGMENT);
+            $fullpluginfile = new \moodle_url(substr($fragment, strlen($prefix)));
+
+            // Manually build the embedded text from the provider so we can test poorly copied HTML text.
+            $embeddedurl = $presignedurl . '#' . $fragment;
+            $embeddedurls[] = $embeddedurl;
+            $expectedurls[] = $replace ? $fullpluginfile->out() : $embeddedurl;
+        }
+
+        // Verify that embedded pre-signed urls are converted back to the original pluginfiles.
+        $this->assertEquals(
+            sprintf($text, ...$expectedurls),
+            $filesystem->normalise_presigned_urls(sprintf($text, ...$embeddedurls))
+        );
+    }
 }

version.php

@@ -25,8 +25,8 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2026041008;      // The current plugin version (Date: YYYYMMDDXX).
-$plugin->release   = 2026041008;      // Same as version.
+$plugin->version   = 2026041009;      // The current plugin version (Date: YYYYMMDDXX).
+$plugin->release   = 2026041009;      // Same as version.
 $plugin->requires  = 2024042200;      // Requires 4.4.
 $plugin->component = "tool_objectfs";
 $plugin->maturity  = MATURITY_STABLE;