feat: add support for jwks-rsa (#1)

src/__test__/authorize.test.ts

@@ -3,12 +3,12 @@ import { io } from 'socket.io-client'
 
 import { fixtureStart, fixtureStop } from './fixture'
 
-describe('authorize', () => {
+describe('authorize - with secret as string in options', () => {
   let token: string = ''
 
-  beforeEach((done) => {
+  beforeEach(async (done) => {
     jest.setTimeout(15_000)
-    fixtureStart(async () => {
+    await fixtureStart(async () => {
       const response = await axios.post('http://localhost:9000/login')
       token = response.data.token
       done()
@@ -67,3 +67,37 @@ describe('authorize', () => {
     })
   })
 })
+
+const secretCallback = async (): Promise<string> => {
+  return 'somesecret'
+}
+
+describe('authorize - with secret as callback in options', () => {
+  let token: string = ''
+
+  beforeEach(async (done) => {
+    jest.setTimeout(15_000)
+    await fixtureStart(
+      async () => {
+        const response = await axios.post('http://localhost:9000/login')
+        token = response.data.token
+        done()
+      },
+      { secret: secretCallback }
+    )
+  })
+
+  afterEach((done) => {
+    fixtureStop(done)
+  })
+
+  it('should connect the user', (done) => {
+    const socket = io('http://localhost:9000', {
+      extraHeaders: { Authorization: `Bearer ${token}` }
+    })
+    socket.on('connect', () => {
+      socket.close()
+      done()
+    })
+  })
+})

src/__test__/fixture/index.ts

@@ -5,7 +5,7 @@ import { Server as HttpsServer } from 'https'
 import { Server as SocketIoServer } from 'socket.io'
 import enableDestroy from 'server-destroy'
 
-import { authorize } from '../../index'
+import { authorize, AuthorizeOptions } from '../../index'
 
 interface Socket {
   io: null | SocketIoServer
@@ -21,16 +21,26 @@ const socket: Socket = {
 
 let server: HttpServer | null = null
 
-export const fixtureStart = (done: any): void => {
-  const options = { secret: 'aaafoo super sercret' }
+export const fixtureStart = async (
+  done: any,
+  options: AuthorizeOptions = { secret: 'aaafoo super sercret' }
+): Promise<void> => {
   const app = express()
   app.use(express.json())
+  let keySecret = 'secret'
+  if (typeof options.secret === 'string') {
+    keySecret = options.secret
+  } else {
+    keySecret = await options.secret(() => {})
+  }
   app.post('/login', (_req, res) => {
     const profile = {
       email: 'john@doe.com',
       id: 123
     }
-    const token = jwt.sign(profile, options.secret, { expiresIn: 60 * 60 * 5 })
+    const token = jwt.sign(profile, keySecret, {
+      expiresIn: 60 * 60 * 5
+    })
     return res.json({ token })
   })
   server = app.listen(9000, done)

src/authorize.ts

@@ -21,15 +21,17 @@ type SocketIOMiddleware = (
   next: (err?: ExtendedError) => void
 ) => void
 
-interface AuthorizeOptions {
-  secret: string
+type SecretCallback = (decodedToken: null | { [key: string]: any } | string) => Promise<string>
+
+export interface AuthorizeOptions {
+  secret: string | SecretCallback
   algorithms?: Algorithm[]
 }
 
 export const authorize = (options: AuthorizeOptions): SocketIOMiddleware => {
   const { secret, algorithms = ['HS256'] } = options
-  return (socket, next) => {
-    let token: string | null = null
+  return async (socket, next) => {
+    let encodedToken: string | null = null
     const authorizationHeader = socket.request.headers.authorization
     if (authorizationHeader != null) {
       const tokenSplitted = authorizationHeader.split(' ')
@@ -40,9 +42,9 @@ export const authorize = (options: AuthorizeOptions): SocketIOMiddleware => {
           })
         )
       }
-      token = tokenSplitted[1]
+      encodedToken = tokenSplitted[1]
     }
-    if (token == null) {
+    if (encodedToken == null) {
       return next(
         new UnauthorizedError('credentials_required', {
           message: 'no token provided'
@@ -50,10 +52,17 @@ export const authorize = (options: AuthorizeOptions): SocketIOMiddleware => {
       )
     }
     // Store encoded JWT
-    socket.encodedToken = token
-    let payload: any
+    socket.encodedToken = encodedToken
+    let keySecret: string | null = null
+    let decodedToken: any
+    if (typeof secret === 'string') {
+      keySecret = secret
+    } else {
+      decodedToken = jwt.decode(encodedToken, { complete: true })
+      keySecret = await secret(decodedToken)
+    }
     try {
-      payload = jwt.verify(token, secret, { algorithms })
+      decodedToken = jwt.verify(encodedToken, keySecret, { algorithms })
     } catch {
       return next(
         new UnauthorizedError('invalid_token', {
@@ -62,7 +71,7 @@ export const authorize = (options: AuthorizeOptions): SocketIOMiddleware => {
       )
     }
     // Store decoded JWT
-    socket.decodedToken = payload
+    socket.decodedToken = decodedToken
     return next()
   }
 }