feat: Require admin to transfer/assign reserved usernames

We're getting a number of users claiming fnames for obvious/well-known
names that they don't actually represent or belong to.

Require these names to be transferred by an admin.

src/reserved.ts

@@ -0,0 +1,110 @@
+// Usernames that we want only admins to be able to assign to an FID, in order
+// to prevent abuse and obvious username squatting.
+const RESERVED_USERNAMES = new Set([
+  'adidas',
+  'amazon',
+  'apple',
+  'arbitrum',
+  'barackobama',
+  'bbc',
+  'billgates',
+  'binance',
+  'bitcoin',
+  'blockchain',
+  'bmw',
+  'cia',
+  'cloud',
+  'cnn',
+  'coinbase',
+  'consensys',
+  'context',
+  'crypto',
+  'data',
+  'dell',
+  'disney',
+  'drake',
+  'elonmusk',
+  'ethereum',
+  'f1',
+  'facebook',
+  'fashion',
+  'fbi',
+  'fifa',
+  'finance',
+  'fitness',
+  'food',
+  'fwb',
+  'fwbdao',
+  'gallery',
+  'games',
+  'ge',
+  'gem',
+  'gm',
+  'gnosis',
+  'gnosissafe',
+  'google',
+  'health',
+  'hp',
+  'hyperverse',
+  'ibm',
+  'intel',
+  'invest',
+  'jpmorgan',
+  'kraken',
+  'kucoin',
+  'lebronjames',
+  'lionelmessi',
+  'luxury',
+  'messi',
+  'metamask',
+  'microsoft',
+  'midjourney',
+  'mirror',
+  'ml',
+  'money',
+  'nasa',
+  'nba',
+  'netflix',
+  'news',
+  'nfl',
+  'nike',
+  'nounsdao',
+  'obsidian',
+  'openai',
+  'opensea',
+  'optimism',
+  'oracle',
+  'ourzora',
+  'pga',
+  'poap',
+  'polygon',
+  'privacy',
+  'rainbow',
+  'rarible',
+  'ronaldo',
+  'samsung',
+  'sony',
+  'starknet',
+  'stripe',
+  'sudoswap',
+  'superrare',
+  'sushiswap',
+  'syndicate',
+  'tesla',
+  'tezos',
+  'travel',
+  'twitter',
+  'uber',
+  'un',
+  'uniswap',
+  'urbit',
+  'viamirror',
+  'vitalik',
+  'youtube',
+  'zora',
+  'zoraco',
+]);
+
+export function reservedUsername(username: string) {
+  return RESERVED_USERNAMES.has(username);
+}

src/transfers.ts

@@ -1,6 +1,7 @@
 import { Kysely, Selectable } from 'kysely';
 import { Database, TransfersTable } from './db.js';
 import { ADMIN_KEYS, generateSignature, signer, verifySignature } from './signature.js';
+import { reservedUsername } from './reserved.js';
 import { bytesToHex, currentTimestamp, hexToBytes } from './util.js';
 import { bytesCompare, validations } from '@farcaster/hub-nodejs';
 import { log } from './log.js';
@@ -30,6 +31,7 @@ export type TransferHistoryFilter = {
 
 type ErrorCode =
   | 'USERNAME_TAKEN'
+  | 'USERNAME_RESERVED'
   | 'TOO_MANY_NAMES'
   | 'UNAUTHORIZED'
   | 'USERNAME_NOT_FOUND'
@@ -100,10 +102,13 @@ async function getAndValidateVerifierAddress(req: TransferRequest, idContract: I
 export async function validateTransfer(req: TransferRequest, db: Kysely<Database>, idContract: IdRegistry) {
   const verifierAddress = await getAndValidateVerifierAddress(req, idContract);
   if (!verifierAddress) {
-    // Only admin transfers are allowed until we finish migrating
     throw new ValidationError('UNAUTHORIZED');
   }
 
+  if (reservedUsername(req.username) && !ADMIN_KEYS[req.userFid]) {
+    throw new ValidationError('USERNAME_RESERVED');
+  }
+
   if (!verifySignature(req.username, req.timestamp, req.owner, req.userSignature, verifierAddress)) {
     log.error(`Invalid signature for req ${JSON.stringify(req)}`);
     throw new ValidationError('INVALID_SIGNATURE');

tests/transfers.test.ts

@@ -33,6 +33,16 @@ describe('transfers', () => {
       await expect(createTestTransfer(db, { username: 'test3', to: 4 })).rejects.toThrow('USERNAME_TAKEN');
     });
 
+    test('cannot register a reserved name with a non-admin account', async () => {
+      await expect(createTestTransfer(db, { username: 'apple', to: 123, userFid: 123 })).rejects.toThrow(
+        'USERNAME_RESERVED'
+      );
+    });
+
+    test('can register a reserved name with an admin account', async () => {
+      expect(await createTestTransfer(db, { username: 'apple', to: 123 }));
+    });
+
     test('same fid cannot register twice', async () => {
       await expect(createTestTransfer(db, { username: 'test1234', to: 2 })).rejects.toThrow('TOO_MANY_NAMES');
     });