Harden backup and download token flows

src/handlers/attachments.ts

@@ -439,17 +439,16 @@ export async function handlePublicDownloadAttachment(
   }
 
   const path = getAttachmentObjectKey(cipherId, attachmentId);
-  const object = await getBlobObject(env, path);
-
-  if (!object) {
-    return errorResponse('Attachment file not found', 404);
-  }
-
   const firstUse = await storage.consumeAttachmentDownloadToken(claims.jti, claims.exp);
   if (!firstUse) {
     return errorResponse('Invalid or expired token', 401);
   }
 
+  const object = await getBlobObject(env, path);
+  if (!object) {
+    return errorResponse('Attachment file not found', 404);
+  }
+
   return new Response(object.body, {
     headers: {
       'Content-Type': sanitizeDownloadContentType(object.contentType),

src/handlers/backup.ts

@@ -1062,12 +1062,21 @@ export async function handleDownloadAdminRemoteBackup(request: Request, env: Env
 export async function handleInspectAdminRemoteBackup(request: Request, env: Env, actorUser: User): Promise<Response> {
   if (!isAdmin(actorUser)) return errorResponse('Forbidden', 403);
 
+  let body: { destinationId?: string; path?: string; masterPasswordHash?: string };
+  try {
+    body = await request.json<{ destinationId?: string; path?: string; masterPasswordHash?: string }>();
+  } catch {
+    return errorResponse('Remote backup integrity payload is invalid', 400);
+  }
+
+  const verificationError = await requireBackupUserVerification(actorUser, String(body.masterPasswordHash || ''), env);
+  if (verificationError) return verificationError;
+
   const storage = new StorageService(env.DB);
   try {
     const settings = await loadBackupSettings(storage, env, 'UTC');
-    const url = new URL(request.url);
-    const path = ensureRemoteRestoreCandidate(url.searchParams.get('path') || '');
-    const destination = requireBackupDestination(settings, url.searchParams.get('destinationId') || null);
+    const path = ensureRemoteRestoreCandidate(String(body.path || ''));
+    const destination = requireBackupDestination(settings, body.destinationId || null);
     const remoteFile = await downloadRemoteBackupFile(destination, path);
     const integrity = await inspectBackupArchiveFileNameChecksum(remoteFile.bytes, remoteFile.fileName || path);
     return jsonResponse({

src/handlers/sends-public.ts

@@ -300,17 +300,17 @@ export async function handleDownloadSendFile(
     return errorResponse(SEND_INACCESSIBLE_MSG, 404);
   }
 
+  const firstUse = await storage.consumeAttachmentDownloadToken(`send:${claims.jti}`, claims.exp);
+  if (!firstUse) {
+    return errorResponse('Invalid or expired token', 401);
+  }
+
   const object = await getBlobObject(env, getSendFileObjectKey(sendId, fileId));
   if (!object) {
     return errorResponse('Send file not found', 404);
   }
   const fileName = typeof data.fileName === 'string' ? data.fileName : fileId;
 
-  const firstUse = await storage.consumeAttachmentDownloadToken(`send:${claims.jti}`, claims.exp);
-  if (!firstUse) {
-    return errorResponse('Invalid or expired token', 401);
-  }
-
   return new Response(object.body, {
     headers: {
       'Content-Type': sanitizeDownloadContentType(object.contentType),