# NextAuth Session Duration: 30 Days vs 4 Hours - Security Analysis

## Current Configuration

**Current Setting** (`app/api/auth/options.ts:190`):
```typescript
session: {
  strategy: "jwt",
  maxAge: 30 * 24 * 60 * 60, // 30 days (2,592,000 seconds)
}
```

**Proposed Setting**:
```typescript
session: {
  strategy: "jwt",
  maxAge: 4 * 60 * 60, // 4 hours (14,400 seconds)
}
```

---

## Security Analysis

### ✅ **Why 4 Hours is Better for Security**

1. **Reduced Attack Window**:
   - **30 days**: If session is compromised, attacker has 30 days of access
   - **4 hours**: If session is compromised, attacker has maximum 4 hours of access
   - **Risk Reduction**: 99.4% reduction in maximum exposure time

2. **Industry Best Practices**:
   - **NIST Guidelines**: Recommend session timeouts of 2-8 hours for high-security applications
   - **OWASP**: Recommends session timeouts based on risk level (typically 2-8 hours)
   - **Common Practice**: Most enterprise applications use 4-8 hour sessions

3. **Device Security**:
   - **30 days**: Device left unattended = 30 days of potential unauthorized access
   - **4 hours**: Device left unattended = maximum 4 hours of potential access
   - **Better for**: Shared devices, public computers, unattended workstations

4. **Compliance**:
   - Many security standards (ISO 27001, SOC 2) require reasonable session timeouts
   - 30 days is often considered too long for compliance
   - 4 hours aligns better with security compliance requirements

5. **Stolen Session Cookie**:
   - If session cookie is stolen (XSS, MITM), shorter duration limits damage
   - 4 hours gives attacker limited time to exploit
   - 30 days gives attacker extensive time to exploit

### ⚠️ **Considerations & Trade-offs**

1. **User Experience Impact**:
   - **30 days**: Users rarely need to re-authenticate (convenient)
   - **4 hours**: Users need to re-authenticate every 4 hours (less convenient)
   - **Impact**: Moderate - users will need to log in more frequently

2. **Token Refresh Behavior**:
   - **Good News**: Your code already handles token refresh automatically
   - **How it works**:
     - When NextAuth session expires (4 hours), JWT callback runs
     - If `accessToken` is expired, it calls `refreshAccessToken()`
     - Uses `refreshToken` to get new tokens from Keycloak
     - Session is automatically renewed (if refresh token is still valid)
   - **Result**: Users may not notice the 4-hour expiration if they're active

3. **Keycloak Refresh Token Lifetime**:
   - **Important**: Keycloak refresh tokens typically last 7-30 days
   - **What this means**:
     - NextAuth session expires after 4 hours
     - But refresh token is still valid (e.g., 7 days)
     - NextAuth automatically refreshes tokens
     - User stays logged in seamlessly (if active)
   - **Only expires if**: User is inactive for longer than refresh token lifetime

4. **Keycloak Session Alignment**:
   - **Current Issue**: Keycloak sessions typically expire in 30 minutes to a few hours
   - **With 4-hour NextAuth session**:
     - Better alignment with Keycloak session timeouts
     - Reduces session mismatch issues
     - Iframe applications will have more consistent session state

---

## How It Will Work

### Session Lifecycle with 4-Hour maxAge

```
User logs in
  ↓
NextAuth creates JWT session (expires in 4 hours)
  ↓
User is active for 2 hours
  ↓
User makes request → NextAuth checks session
  ↓
Session still valid (< 4 hours) → Continue
  ↓
User is active for 3 hours
  ↓
User makes request → NextAuth checks session
  ↓
Session still valid (< 4 hours) → Continue
  ↓
User is active for 4.5 hours (session expired)
  ↓
User makes request → NextAuth checks session
  ↓
Session expired → JWT callback runs
  ↓
Checks accessToken expiration
  ↓
If accessToken expired → Calls refreshAccessToken()
  ↓
Uses refreshToken to get new tokens from Keycloak
  ↓
If refreshToken still valid → New session created (another 4 hours)
  ↓
User continues seamlessly (no re-authentication needed)
  ↓
If refreshToken expired → User must re-authenticate
```

### When User Must Re-authenticate

**User must re-authenticate if**:
1. **Inactive for longer than refresh token lifetime** (typically 7-30 days)
2. **Refresh token is revoked** (logout, admin action, security event)
3. **Keycloak session is invalidated** (logout from another application)

**User does NOT need to re-authenticate if**:
1. **Active within refresh token lifetime** (automatic token refresh)
2. **Session expires but refresh token is valid** (automatic renewal)

---

## Recommendations

### ✅ **Recommendation: Implement 4-Hour Session**

**Reasons**:
1. ✅ **Significantly better security** (99.4% reduction in exposure window)
2. ✅ **Aligns with industry best practices** (NIST, OWASP)
3. ✅ **Better compliance** (meets security standards)
4. ✅ **Better alignment with Keycloak sessions**
5. ✅ **Minimal UX impact** (automatic token refresh handles renewal)
6. ✅ **Code already supports it** (token refresh mechanism exists)

### ⚠️ **Important Considerations**

1. **Verify Keycloak Refresh Token Lifetime**:
   - Check Keycloak configuration for refresh token lifetime
   - Ensure it's longer than 4 hours (typically 7-30 days)
   - If shorter, users will need to re-authenticate frequently

2. **Monitor User Experience**:
   - Track how often users need to re-authenticate
   - If too frequent, consider increasing to 6-8 hours
   - Balance security with usability

3. **Consider Activity-Based Extension**:
   - Current implementation: Fixed 4-hour expiration
   - Alternative: Extend session on activity (sliding window)
   - Requires additional implementation (activity tracking)

4. **Keycloak Session Configuration**:
   - Consider aligning Keycloak SSO session timeout with NextAuth
   - Or ensure Keycloak session is longer than NextAuth session
   - Prevents session mismatch issues

### 📋 **Implementation Checklist**

Before implementing:

- [ ] Verify Keycloak refresh token lifetime (should be > 4 hours)
- [ ] Test token refresh flow with 4-hour session
- [ ] Monitor user re-authentication frequency
- [ ] Consider user feedback on session duration
- [ ] Document the change for users (if needed)
- [ ] Update security documentation

---

## Comparison Table

| Aspect | 30 Days | 4 Hours | Winner |
|--------|---------|---------|--------|
| **Security** | Low (long exposure window) | High (short exposure window) | ✅ 4 Hours |
| **User Convenience** | High (rare re-authentication) | Medium (automatic refresh) | ✅ 30 Days |
| **Compliance** | Poor (too long) | Good (meets standards) | ✅ 4 Hours |
| **Risk Reduction** | Low | High (99.4% reduction) | ✅ 4 Hours |
| **Keycloak Alignment** | Poor (mismatch) | Good (better alignment) | ✅ 4 Hours |
| **Token Refresh** | Works | Works (same mechanism) | ✅ Tie |

---

## Conclusion

**Recommendation: Change to 4 hours**

**Why**:
- Significantly better security posture
- Aligns with industry best practices
- Better compliance with security standards
- Minimal UX impact (automatic token refresh)
- Better alignment with Keycloak session timeouts
- Code already supports it

**Implementation**:
- Simple change: `maxAge: 4 * 60 * 60`
- No code changes needed (token refresh already works)
- Monitor user experience and adjust if needed

**Alternative Consideration**:
- If 4 hours is too aggressive, consider 6-8 hours as a middle ground
- Still provides significant security improvement over 30 days
- Better user experience than 4 hours

---

## Final Verdict

**✅ Yes, change to 4 hours** - This is a good security practice that:
- Significantly reduces security risk
- Aligns with industry standards
- Has minimal UX impact (automatic refresh)
- Works with existing code
- Better aligns with Keycloak sessions

The only trade-off is slightly more frequent re-authentication for inactive users, but this is a reasonable security trade-off.