fix(web): verify deletions against the signer and read crypto state afresh

web/src/core-bridge/worker/channelDataKeys.ts

@@ -37,13 +37,29 @@ export function attachDataKeys(session: ChannelSession, resource: SavedResource)
   };
 }
 type DataKeys = { state: CryptoState; keys: Record<string, string> };
-const pendingKeys = new Map<string, Promise<DataKeys>>();
-/** 同一空间同时发起的读取合并成一次请求 */
-export function readDataKeys(resource: SavedResource, session: ChannelSession): Promise<DataKeys> {
-  let task = pendingKeys.get(resource.id);
-  if (!task) { task = loadDataKeys(resource, session).finally(() => pendingKeys.delete(resource.id)); pendingKeys.set(resource.id, task); }
+const runningKeys = new Map<string, Promise<DataKeys>>();
+const queuedKeys = new Map<string, Promise<DataKeys>>();
+function startKeys(resource: SavedResource, session: ChannelSession): Promise<DataKeys> {
+  const task: Promise<DataKeys> = loadDataKeys(resource, session).finally(() => { if (runningKeys.get(resource.id) === task) runningKeys.delete(resource.id); });
+  runningKeys.set(resource.id, task);
   return task;
 }
+/**
+ * 读取空间的加密状态。fresh(默认)表示调用方刚发现本地缺对象或事件签名,需要一份比现在更新的结果:
+ * 已有请求在途时不能直接借用它(它可能在新对象登记之前就发出了),而是排在它后面再请求一次,同时到达的调用合并成这一次。
+ * 不要求最新(首次打开)的调用可以直接借用在途请求。
+ */
+export function readDataKeys(resource: SavedResource, session: ChannelSession, fresh = true): Promise<DataKeys> {
+  const running = runningKeys.get(resource.id);
+  if (!running) return startKeys(resource, session);
+  if (!fresh) return running;
+  let next = queuedKeys.get(resource.id);
+  if (!next) {
+    next = running.catch(() => undefined).then(() => { queuedKeys.delete(resource.id); return startKeys(resource, session); });
+    queuedKeys.set(resource.id, next);
+  }
+  return next;
+}
 /** 内存里的结果满足 enough 就复用,不满足再请求 */
 async function cachedKeys(resource: SavedResource, session: ChannelSession, enough: (data: DataKeys) => boolean): Promise<DataKeys> {
   const have = loaded.get(resource.id);
@@ -222,18 +238,20 @@ export async function verifyObjectDeletion(resource: SavedResource, session: Cha
   const eventId = fromBase64Url(deleted.eventId, 16); const manifestHash = fromBase64Url(object.event.manifestHash, 32);
   const signature = fromBase64Url(deleted.signature, 64); const certificate = fromBase64Url(deleted.deviceCertificateSignature, 64);
   if (!spaceId || !itemBytes || !eventId || !manifestHash || !signature || !certificate) return false;
+  // 撤回别人的消息时(空间主),删除事件由撤回者签名,不是作者;旧记录没有 signerAccount,按作者处理
+  const signer = deleted.signerAccount || object.authorAccount;
   const rootJwk = JSON.parse(deleted.signerRootPublicKey) as JsonWebKey;
   const deviceJwk = JSON.parse(deleted.signerDevicePublicKey) as JsonWebKey;
   const root = await importSigningPublicKey(rootJwk);
   const { unlockedAccount } = await import('./account'); const local = unlockedAccount();
-  if (object.authorAccount === local.username && local.profile.keys.signing
+  if (signer === local.username && local.profile.keys.signing
       && (rootJwk.x !== local.profile.keys.signing.publicKey.x || rootJwk.y !== local.profile.keys.signing.publicKey.y)) return false;
-  await pinSigningRoot(object.authorAccount, rootJwk);
-  if (!await verifyDeviceCertificate(object.authorAccount, deleted.signerDeviceId, deviceJwk, certificate, root)) return false;
+  await pinSigningRoot(signer, rootJwk);
+  if (!await verifyDeviceCertificate(signer, deleted.signerDeviceId, deviceJwk, certificate, root)) return false;
   const domain = object.domain;
   const expectedKind = domain === 'chat' ? 'chat.delete' : 'file.delete';
   if (deleted.kind !== expectedKind) return false;
-  const payload = contentEventPayload({ spaceId, channelId: object.channelId, username: object.authorAccount,
+  const payload = contentEventPayload({ spaceId, channelId: object.channelId, username: signer,
     deviceId: deleted.signerDeviceId, eventId, eventKind: expectedKind, domain, epoch: object.epoch,
     itemId: itemBytes, frameCount: object.event.frameCount, manifestHash });
   const deviceKey = await importSigningPublicKey(deviceJwk);

web/src/core-bridge/worker/channelEvents.ts

@@ -110,7 +110,8 @@ export async function applyChannelRecord(resource: SavedResource, session: Chann
         break;
       }
       case 'removed':
-        if (event.reason === 'deleted' && !await verifyObjectDeletion(resource, session, event.itemId)) {
+        // 验签过程中的异常(例如签名公钥与已固定的不一致)按「拒绝这条记录」处理,不能让整条连接断开重连
+        if (event.reason === 'deleted' && !await verifyObjectDeletion(resource, session, event.itemId).catch(() => false)) {
           showRejected(resource.id, { type: 'rejected', itemId: event.itemId, seq: event.seq, reason: 'auth_failed' });
           break;
         }
@@ -145,7 +146,7 @@ export async function syncChannel(resource: SavedResource, session: ChannelSessi
   clearFileCatalog(resource.id);
   readers.set(resource.id, session.createItemReader());
   // 密钥与第一页日志互不依赖,同时发出,首次打开少等一个往返
-  const keys = resource.mode === 'enc' ? readDataKeys(resource, session) : undefined;
+  const keys = resource.mode === 'enc' ? readDataKeys(resource, session, false) : undefined;
   keys?.catch(() => undefined);
   let from = 0;
   for (let first = true; ; first = false) {