🚨 Current JWT Problem
Issue: When users logout, your JWT tokens remain valid until they naturally expire. This creates a security vulnerability where:
- Stolen tokens can still access APIs after logout
- Users can't truly "logout" from all devices
- Long-lived tokens increase security risks
- No way to revoke access immediately
✅ OAuth2 Solution Overview
Two-Token System:
- Access Token: Short-lived (15-30 minutes), used for API calls
- Refresh Token: Long-lived (7 days), stored securely, used to get new access tokens
📊 Current vs OAuth2 Comparison
| Aspect | Current JWT Approach | OAuth2 Approach |
|---|---|---|
| Token Lifetime | Long-lived (hours/days) | Access: 15-30 mins, Refresh: 7 days |
| Logout Behavior | Token stays valid | Refresh token deleted, access expires soon |
| Security Risk | High (long exposure window) | Low (short exposure window) |
| Token Renewal | Manual re-login required | Automatic background refresh |
| Revocation | Not possible | Immediate via database |
🔄 Complete OAuth2 Flow Diagram
Initial Login Process
1
User Sends Login Credentials
POST /login with email/password
↓
2
Server Validates & Generates Tokens
Creates Access Token (15min) + Refresh Token (7 days)
↓
3
Store & Send Tokens
Refresh token → Database + HttpOnly Cookie
Access token → JSON response
Access token → JSON response
↓
4
Client Stores Access Token
Frontend saves access token in memory/localStorage
API Request & Auto-Refresh Process
5
API Request with Access Token
Authorization: Bearer {access_token}
↓
6
Token Expired? (After 15-30 mins)
Server returns 401 with TOKEN_EXPIRED code
↓
7
Frontend Auto-Refresh
POST /refresh (refresh token sent via cookie)
↓
8
New Access Token Generated
Server validates refresh token & returns new access token
↓
9
Retry Original Request
Frontend automatically retries API call with new token
Secure Logout Process
10
User Clicks Logout
POST /logout request
↓
11
Server Invalidates Refresh Token
Deletes refresh token from database
↓
12
Clear Client Storage
Remove access token from frontend + clear cookies
🔑 Key Security Benefits
- Short Attack Window: Access tokens expire in 15-30 minutes
- True Logout: Refresh token deletion prevents future access
- Automatic Renewal: Users don't need to re-login frequently
- HttpOnly Cookies: Refresh tokens protected from XSS attacks
- Database Control: Can revoke access immediately
💾 Storage Strategy
Frontend (Client):
- Access Token → localStorage or memory (15-30 min lifetime)
- Refresh Token → HttpOnly Cookie (not accessible via JavaScript)
Backend (Server):
- Refresh Tokens → Database (with expiration dates)
- User Sessions → Redis (for production scale)
🛠️ Implementation Summary
Node.js Requirements:
- jsonwebtoken: For creating and verifying JWT tokens
- Database: MongoDB/PostgreSQL to store refresh tokens
- Redis: Optional, for production session management
- Express middleware: For token validation
🎯 Result: Perfect Security Balance
This OAuth2 approach gives you:
- ✅ Immediate logout (refresh token revocation)
- ✅ Short-lived access tokens (minimal exposure)
- ✅ Seamless user experience (auto-refresh)
- ✅ Scalable architecture (database-controlled)
- ✅ Industry standard security practices