Don't allow previewing shared history rooms (#239)

Only `world_readable` can be considered as opting into having history publicly on the web. Anything else must not be archived until there's a dedicated state event for opting into archiving.

server/lib/matrix-utils/fetch-room-data.js

@@ -155,7 +155,6 @@ const fetchRoomData = traceFunction(async function (
     stateCanonicalAliasResDataOutcome,
     stateAvatarResDataOutcome,
     stateHistoryVisibilityResDataOutcome,
-    stateJoinRulesResDataOutcome,
     predecessorInfoOutcome,
     successorInfoOutcome,
   ] = await Promise.allSettled([
@@ -182,10 +181,6 @@ const fetchRoomData = traceFunction(async function (
         abortSignal,
       }
     ),
-    fetchEndpointAsJson(getStateEndpointForRoomIdAndEventType(roomId, 'm.room.join_rules'), {
-      accessToken: matrixAccessToken,
-      abortSignal,
-    }),
     fetchPredecessorInfo(matrixAccessToken, roomId, { abortSignal }),
     fetchSuccessorInfo(matrixAccessToken, roomId, { abortSignal }),
   ]);
@@ -220,12 +215,6 @@ const fetchRoomData = traceFunction(async function (
     historyVisibility = data?.content?.history_visibility;
   }
 
-  let joinRule;
-  if (stateJoinRulesResDataOutcome.reason === undefined) {
-    const { data } = stateJoinRulesResDataOutcome.value;
-    joinRule = data?.content?.join_rule;
-  }
-
   let roomCreationTs;
   let predecessorRoomId;
   let predecessorLastKnownEventId;
@@ -251,7 +240,6 @@ const fetchRoomData = traceFunction(async function (
     canonicalAlias,
     avatarUrl,
     historyVisibility,
-    joinRule,
     roomCreationTs,
     predecessorRoomId,
     predecessorLastKnownEventId,

server/routes/room-directory-routes.js

@@ -22,7 +22,6 @@ const matrixServerName = config.get('matrixServerName');
 assert(matrixServerName);
 const matrixAccessToken = config.get('matrixAccessToken');
 assert(matrixAccessToken);
-const stopSearchEngineIndexing = config.get('stopSearchEngineIndexing');
 
 const router = express.Router({
   caseSensitive: true,
@@ -71,7 +70,8 @@ router.get(
     }
 
     // We index the room directory unless the config says we shouldn't index anything
-    const shouldIndex = !stopSearchEngineIndexing;
+    const stopSearchEngineIndexingFromConfig = config.get('stopSearchEngineIndexing');
+    const shouldIndex = !stopSearchEngineIndexingFromConfig;
 
     const pageOptions = {
       title: `Matrix Public Archive`,

server/routes/room-routes.js

@@ -57,7 +57,6 @@ const matrixServerUrl = config.get('matrixServerUrl');
 assert(matrixServerUrl);
 const matrixAccessToken = config.get('matrixAccessToken');
 assert(matrixAccessToken);
-const stopSearchEngineIndexing = config.get('stopSearchEngineIndexing');
 
 const matrixPublicArchiveURLCreator = new MatrixPublicArchiveURLCreator(basePath);
 
@@ -828,15 +827,13 @@ router.get(
       }),
     ]);
 
-    // Only `world_readable` or `shared` rooms that are `public` are viewable in the archive
-    const allowedToViewRoom =
-      roomData.historyVisibility === 'world_readable' ||
-      (roomData.historyVisibility === 'shared' && roomData.joinRule === 'public');
+    // Only `world_readable` rooms are viewable in the archive
+    const allowedToViewRoom = roomData.historyVisibility === 'world_readable';
 
     if (!allowedToViewRoom) {
       throw new StatusError(
         403,
-        `Only \`world_readable\` or \`shared\` rooms that are \`public\` can be viewed in the archive. ${roomData.id} has m.room.history_visiblity=${roomData.historyVisibility} m.room.join_rules=${roomData.joinRule}`
+        `Only \`world_readable\` rooms can be viewed in the archive. ${roomData.id} has m.room.history_visiblity=${roomData.historyVisibility}`
       );
     }
 
@@ -891,7 +888,8 @@ router.get(
 
     // Default to no indexing (safe default)
     let shouldIndex = false;
-    if (stopSearchEngineIndexing) {
+    const stopSearchEngineIndexingFromConfig = config.get('stopSearchEngineIndexing');
+    if (stopSearchEngineIndexingFromConfig) {
       shouldIndex = false;
     } else {
       // Otherwise we only allow search engines to index `world_readable` rooms

test/e2e-tests.js

@@ -2688,15 +2688,50 @@ describe('matrix-public-archive', () => {
         assert.strictEqual(dom.document.querySelector(`meta[name="robots"]`), null);
       });
 
-      it('search engines not allowed to index `public` room', async () => {
+      it('search engines not allowed to access public room with non-`world_readable` history visibility', async () => {
         const client = await getTestClientForHs(testMatrixServerUrl1);
         const roomId = await createTestRoom(client, {
-          // The default options for the test rooms adds a
-          // `m.room.history_visiblity` state event so we override that here so
-          // it's only a public room.
-          initial_state: [],
+          // Set as `shared` since it's the next most permissive history visibility
+          // after `world_readable` but still not allowed to be accesible in the
+          // archive.
+          initial_state: [
+            {
+              type: 'm.room.history_visibility',
+              state_key: '',
+              content: {
+                history_visibility: 'shared',
+              },
+            },
+          ],
         });
 
+        try {
+          archiveUrl = matrixPublicArchiveURLCreator.archiveUrlForRoom(roomId);
+          await fetchEndpointAsText(archiveUrl);
+          assert.fail(
+            new TestError(
+              'We expect the request to fail with a 403 since the archive should not be able to view a non-world_readable room but it succeeded'
+            )
+          );
+        } catch (err) {
+          if (err instanceof TestError) {
+            throw err;
+          }
+          assert.strictEqual(
+            err.response.status,
+            403,
+            `Expected err.response.status=${err?.response?.status} to be 403 but error was: ${err.stack}`
+          );
+        }
+      });
+
+      it('Configuring `stopSearchEngineIndexing` will stop search engine indexing', async () => {
+        // Disable search engine indexing across the entire instance
+        config.set('stopSearchEngineIndexing', true);
+
+        const client = await getTestClientForHs(testMatrixServerUrl1);
+        const roomId = await createTestRoom(client);
+
         archiveUrl = matrixPublicArchiveURLCreator.archiveUrlForRoom(roomId);
         const { data: archivePageHtml } = await fetchEndpointAsText(archiveUrl);