LinkedIn authentication with passport.js

package.json

@@ -20,9 +20,11 @@
     "cors": "^2.8.5",
     "dotenv": "^16.3.1",
     "express": "^4.18.2",
+    "express-session": "^1.17.3",
     "jsonwebtoken": "^9.0.1",
     "passport": "^0.6.0",
     "passport-jwt": "^4.0.1",
+    "passport-linkedin-oauth2": "^2.0.0",
     "pg": "^8.10.0",
     "reflect-metadata": "^0.1.13",
     "ts-node": "^10.9.1",
@@ -34,11 +36,13 @@
     "@types/cookie-parser": "^1.4.3",
     "@types/cors": "^2.8.13",
     "@types/express": "^4.17.17",
+    "@types/express-session": "^1.17.10",
     "@types/jest": "^29.5.3",
     "@types/jsonwebtoken": "^9.0.2",
     "@types/node": "^20.1.4",
     "@types/passport": "^1.0.12",
     "@types/passport-jwt": "^3.0.9",
+    "@types/passport-linkedin-oauth2": "^1.5.5",
     "@types/pg": "^8.10.1",
     "@types/prettier": "^2.7.2",
     "@types/supertest": "^2.0.12",

src/app.ts

@@ -11,13 +11,16 @@ import categoryRouter from './routes/category/category.route'
 import passport from 'passport'
 import './configs/passport'
 import cookieParser from 'cookie-parser'
-
+import session from 'express-session'
+import { SESSION_SECRET } from './configs/envConfig'
 const app = express()
 
 app.use(cookieParser())
 app.use(bodyParser.json())
 app.use(cors())
+app.use(session({ secret: SESSION_SECRET }))
 app.use(passport.initialize())
+app.use(passport.session())
 
 app.get('/', (req, res) => {
   res.send('ScholarX Backend')

src/configs/envConfig.ts

@@ -9,3 +9,6 @@ export const DB_PASSWORD = process.env.DB_PASSWORD
 export const DB_PORT = process.env.DB_PORT
 export const SERVER_PORT = process.env.SERVER_PORT ?? 3000
 export const JWT_SECRET = process.env.JWT_SECRET ?? ''
+export const LINKEDIN_KEY = process.env.LINKEDIN_KEY ?? ''
+export const LINKEDIN_SECRET = process.env.LINKEDIN_SECRET ?? ''
+export const SESSION_SECRET = process.env.SESSION_SECRET ?? ''

src/configs/passport.ts

@@ -2,8 +2,10 @@ import passport from 'passport'
 import { Strategy as JwtStrategy } from 'passport-jwt'
 import { dataSource } from './dbConfig'
 import Profile from '../entities/profile.entity'
-import { JWT_SECRET } from './envConfig'
+import { JWT_SECRET, LINKEDIN_KEY, LINKEDIN_SECRET } from './envConfig'
 import type { Request } from 'express'
+import { Strategy as LinkedInStrategy } from 'passport-linkedin-oauth2'
+import type { LinkedInUser } from '../types'
 
 const cookieExtractor = (req: Request): string => {
   let token = null
@@ -37,4 +39,26 @@ passport.use(
   })
 )
 
+passport.use(
+  new LinkedInStrategy(
+    {
+      clientID: LINKEDIN_KEY,
+      clientSecret: LINKEDIN_SECRET,
+      callbackURL: 'http://localhost:3000/api/auth/linkedin/callback',
+      scope: ['r_emailaddress', 'r_liteprofile']
+    },
+    (accessToken, refreshToken, profile, done) => {
+      done(null, profile)
+    }
+  )
+)
+
+passport.serializeUser((user, done) => {
+  done(null, user)
+})
+
+passport.deserializeUser((user: LinkedInUser, done) => {
+  done(null, user)
+})
+
 export default passport

src/routes/auth/auth.route.ts

@@ -1,10 +1,21 @@
 import express from 'express'
 import { register, login, logout } from '../../controllers/auth.controller'
+import passport from 'passport'
 
 const authRouter = express.Router()
 
 authRouter.post('/register', register)
 authRouter.post('/login', login)
 authRouter.get('/logout', logout)
-
+authRouter.get(
+  '/linkedin',
+  passport.authenticate('linkedin', { state: 'SOME STATE' })
+)
+authRouter.get(
+  '/linkedin/callback',
+  passport.authenticate('linkedin', {
+    successRedirect: '/',
+    failureRedirect: '/'
+  })
+)
 export default authRouter

src/types.ts

@@ -22,3 +22,14 @@ export interface ApiResponse<T> {
   message?: string
   data?: T | null
 }
+
+export interface LinkedInUser {
+  id: string
+  displayName: string
+  name: {
+    familyName: string
+    givenName: string
+  }
+  emails: [{ value: string }]
+  photos: [{ value: string }]
+}