Refactor auth flow

Reimplement some node-oauth2-server methods to remove hacky code needed by our external
login workflow

server/middlewares/auth.ts

@@ -0,0 +1,76 @@
+import * as express from 'express'
+import { Socket } from 'socket.io'
+import { getAccessToken } from '@server/lib/auth/oauth-model'
+import { HttpStatusCode } from '../../shared/core-utils/miscs/http-error-codes'
+import { logger } from '../helpers/logger'
+import { handleOAuthAuthenticate } from '../lib/auth/oauth'
+
+function authenticate (req: express.Request, res: express.Response, next: express.NextFunction, authenticateInQuery = false) {
+  handleOAuthAuthenticate(req, res, authenticateInQuery)
+    .then((token: any) => {
+      res.locals.oauth = { token }
+      res.locals.authenticated = true
+
+      return next()
+    })
+    .catch(err => {
+      logger.warn('Cannot authenticate.', { err })
+
+      return res.status(err.status)
+        .json({
+          error: 'Token is invalid.',
+          code: err.name
+        })
+    })
+}
+
+function authenticateSocket (socket: Socket, next: (err?: any) => void) {
+  const accessToken = socket.handshake.query['accessToken']
+
+  logger.debug('Checking socket access token %s.', accessToken)
+
+  if (!accessToken) return next(new Error('No access token provided'))
+  if (typeof accessToken !== 'string') return next(new Error('Access token is invalid'))
+
+  getAccessToken(accessToken)
+    .then(tokenDB => {
+      const now = new Date()
+
+      if (!tokenDB || tokenDB.accessTokenExpiresAt < now || tokenDB.refreshTokenExpiresAt < now) {
+        return next(new Error('Invalid access token.'))
+      }
+
+      socket.handshake.auth.user = tokenDB.User
+
+      return next()
+    })
+    .catch(err => logger.error('Cannot get access token.', { err }))
+}
+
+function authenticatePromiseIfNeeded (req: express.Request, res: express.Response, authenticateInQuery = false) {
+  return new Promise<void>(resolve => {
+    // Already authenticated? (or tried to)
+    if (res.locals.oauth?.token.User) return resolve()
+
+    if (res.locals.authenticated === false) return res.sendStatus(HttpStatusCode.UNAUTHORIZED_401)
+
+    authenticate(req, res, () => resolve(), authenticateInQuery)
+  })
+}
+
+function optionalAuthenticate (req: express.Request, res: express.Response, next: express.NextFunction) {
+  if (req.header('authorization')) return authenticate(req, res, next)
+
+  res.locals.authenticated = false
+
+  return next()
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  authenticate,
+  authenticateSocket,
+  authenticatePromiseIfNeeded,
+  optionalAuthenticate
+}