firebase-verifier middleware for expressjs

When you don't want to install firebase-admin-sdk just to verify id token and/or app check token.

Install

1npm install firebase-verifier

Configs

Obtains project_id and project_no from Google Cloud Console

Usage

1import express from "express";
2import {
3  authVerifier,
4  appCheckVerifier,
5  firebaseVerifier,
6} from "firebase-verifier";
7
8const project_id = "<project_id>";
9const project_no = "<project_no>";
10
11const app = express();
12
13// Verify Id token
14app.use(authVerifier(project_id));
15app.get("/", (req, res) => {
16  console.log(res.locals.user);
17  /* Output
18    {
19      "sub": "kxljssoieeJKLe",
20      "email": "chientrm@gmail.com",
21      ...
22    }
23  */
24});
25
26...
27
28// Verify App Check token
29app.use(appCheckVerifier(project_no));
30app.get("/", (req, res) => {
31  console.log(res.locals.device);
32  /* Output
33    {
34      ...
35    }
36  */
37});
38
39...
40
41// Verify both Id token and App Check token
42app.use(firebaseVerifier({ project_id, project_no }));
43app.get("/", (req, res) => {
44  console.log(res.locals.user);
45  console.log(res.locals.device);
46});
47
48app.listen(3000);

Check verification

If any of the verifiers failed, res.locals.user, res.locals.device are null and res.locals.error contains the error.