feat: use shorter channel tokens

apps/relay/src/channels.test.ts

@@ -27,7 +27,7 @@ describe("channel store", () => {
   describe("open", () => {
     test("opens a channel and returns the token", async () => {
       const channel = await channels.open();
-      expect(channel._unsafeUnwrap()).toMatch(/[a-f0-9]{8}-([a-f0-9]{4}-){3}[a-f0-9]{12}/);
+      expect(channel._unsafeUnwrap()).toMatch(/[2-9A-HJ-NP-Z]{8}/);
     });
   });
 

apps/relay/src/channels.ts

@@ -1,7 +1,7 @@
 import { Redis } from "ioredis";
 import { ResultAsync, err, ok } from "neverthrow";
-import { randomUUID } from "crypto";
 import { RelayAsyncResult, RelayError } from "./errors";
+import { generateChannelToken } from "./tokens";
 
 interface ChannelStoreOpts {
   redisUrl: string;
@@ -18,7 +18,7 @@ export class ChannelStore<T> {
   }
 
   async open(state?: T): RelayAsyncResult<string> {
-    const channelToken = randomUUID();
+    const channelToken = generateChannelToken();
     return ResultAsync.fromPromise(
       this.redis.set(channelToken, JSON.stringify(state ?? {}), "EX", this.ttl),
       (err) => new RelayError("unavailable", err as Error),

apps/relay/src/server.test.ts

@@ -74,7 +74,7 @@ describe("relay server", () => {
 
       expect(response.status).toBe(201);
       const { channelToken, url, connectUri, nonce, ...rest } = response.data;
-      expect(channelToken).toMatch(/[a-f0-9]{8}-([a-f0-9]{4}-){3}[a-f0-9]{12}/);
+      expect(channelToken).toMatch(/[2-9A-HJ-NP-Z]{8}/);
       expect(url).toMatch("https://warpcast.com/~/sign-in-with-farcaster");
       expect(url).toBe(connectUri);
       expect(rest).toStrictEqual({});
@@ -106,7 +106,7 @@ describe("relay server", () => {
       expect(params.get("expirationTime")).toBe(expirationTime);
       expect(params.get("requestId")).toBe(requestId);
       expect(params.get("redirectUrl")).toBe(redirectUrl);
-      expect(channelToken).toMatch(/[a-f0-9]{8}-([a-f0-9]{4}-){3}[a-f0-9]{12}/);
+      expect(channelToken).toMatch(/[2-9A-HJ-NP-Z]{8}/);
       expect(nonce).toBe(customNonce);
       expect(url).toBe(connectUri);
       expect(rest).toStrictEqual({});

apps/relay/src/tokens.ts

@@ -0,0 +1,16 @@
+import crypto from "crypto";
+
+const ALPHABET = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
+
+export function generateChannelToken(length = 8): string {
+  const bytes = crypto.randomBytes(length);
+  let id = "";
+  for (let i = 0; i < length; i++) {
+    const byte = bytes[i];
+    if (byte === undefined) {
+      throw new Error("Error generating channel token");
+    }
+    id += ALPHABET[byte % ALPHABET.length];
+  }
+  return id;
+}