# NaviDocs Multi-Tenancy Auth System - Executive Summary

## Overview

This document provides a high-level summary of the comprehensive multi-tenancy authentication and authorization system designed for NaviDocs. For detailed technical specifications, refer to the companion documents.

---

## Problem Statement

NaviDocs currently lacks:
- User authentication (registration, login, password reset)
- Multi-tenancy support (agencies managing multiple entities)
- Granular access control (specific users accessing specific boats/entities)
- Role-based permissions (view, edit, admin, etc.)
- Cross-vertical compatibility (works for boats, aircraft, marinas, etc.)

**Business Requirement:** An agency with multiple boats needs to grant different users access to different boats with varying permission levels.

---

## Solution Overview

**Recommended Approach:** JWT-based authentication + RBAC with entity-level permissions

### Core Components:

1. **Authentication System**
   - User registration with email verification
   - Login with email/password
   - JWT access tokens (15min expiry)
   - Refresh tokens (7 days expiry, revocable)
   - Password reset flow
   - Account management (suspend, delete)

2. **Authorization System**
   - 3-tier permission model: Organization → Entity → Resource
   - 4 permission levels: Viewer, Editor, Manager, Admin
   - Granular entity-level access control
   - Permission inheritance and hierarchy

3. **Multi-Tenancy Model**
   - Organizations contain multiple entities (boats, aircraft, etc.)
   - Users are members of organizations with roles
   - Users have explicit permissions on specific entities
   - Vertical-agnostic design (same logic for all entity types)

4. **Security Features**
   - bcrypt password hashing (cost factor 12)
   - JWT signature verification
   - Rate limiting on auth endpoints
   - Audit logging for all security events
   - Session management and revocation
   - CSRF and XSS protection

---

## Permission Model

### Organization Roles (Broad Access):
- **Admin:** Full control over organization, all entities, and users
- **Manager:** Manage all entities, grant entity permissions
- **Member:** Access only explicitly granted entities
- **Viewer:** Read-only access to all entities

### Entity Permissions (Granular Access):
- **Admin:** Full control (view, edit, create, delete, share, manage permissions)
- **Manager:** Management (view, edit, create, delete, share)
- **Editor:** Content editing (view, edit, create)
- **Viewer:** Read-only (view)

### Resolution Order:
1. Org admin/manager → automatic access
2. Entity-level permission → overrides member/viewer status
3. Document shares → fallback for specific documents

---

## Example Use Case

**Scenario:** Coastal Marine Services (organization) has 3 boats

**Users:**
- Alice: Organization Admin
- Bob: Organization Manager
- Carol: Organization Member
- Dave: Organization Viewer

**Access Control:**

| User  | Org Role | Boat 1     | Boat 2    | Boat 3    |
|-------|----------|------------|-----------|-----------|
| Alice | Admin    | Admin (org)| Admin (org)| Admin (org)|
| Bob   | Manager  | Manager (org)| Manager (org)| Manager (org)|
| Carol | Member   | Editor (explicit)| No Access | Viewer (explicit)|
| Dave  | Viewer   | Viewer (org)| Viewer (org)| Viewer (org)|

**Result:**
- Alice can fully manage all 3 boats
- Bob can manage all 3 boats but cannot modify org settings
- Carol can only edit Boat 1 and view Boat 3 (no access to Boat 2)
- Dave can view all boats but cannot make changes

---

## Database Changes

### New Tables (4):
1. **entity_permissions:** Granular entity-level access control
2. **refresh_tokens:** Secure session management
3. **password_reset_tokens:** Password recovery
4. **audit_log:** Security event tracking

### Modified Tables (1):
- **users:** Add email_verified, status, suspension fields

### Total Impact:
- 4 new tables
- 5 new indexes
- 1 table modification (backward compatible)
- Migration script provided with rollback support

---

## API Endpoints

### Authentication (8 endpoints):
```
POST   /api/auth/register           - Create account
POST   /api/auth/login              - Authenticate
POST   /api/auth/logout             - Revoke session
POST   /api/auth/refresh            - Renew access token
POST   /api/auth/forgot-password    - Request reset
POST   /api/auth/reset-password     - Complete reset
GET    /api/auth/verify-email/:token - Verify email
GET    /api/auth/me                 - Get current user
```

### Organizations (8 endpoints):
```
GET    /api/organizations           - List user's orgs
POST   /api/organizations           - Create org
GET    /api/organizations/:id       - Get org details
PATCH  /api/organizations/:id       - Update org
DELETE /api/organizations/:id       - Delete org
GET    /api/organizations/:id/members - List members
POST   /api/organizations/:id/members - Add member
DELETE /api/organizations/:id/members/:userId - Remove member
```

### Entity Permissions (4 endpoints):
```
GET    /api/entities/:id/permissions - List entity access
POST   /api/entities/:id/permissions - Grant access
PATCH  /api/entities/:id/permissions/:userId - Update level
DELETE /api/entities/:id/permissions/:userId - Revoke access
```

### Total: 20+ new endpoints

---

## Implementation Roadmap

### Phase 1: Foundation (Week 1)
- Database schema migration
- Authentication service (register, login, refresh)
- Authentication routes
- Enhanced auth middleware
- Audit logging

**Deliverables:** 5 PRs

### Phase 2: Authorization (Week 2)
- Authorization service (permission resolution)
- Permission middleware
- Apply auth to existing routes
- Entity permission management

**Deliverables:** 4 PRs

### Phase 3: User & Org Management (Week 3)
- User management endpoints
- Organization CRUD
- Member management
- Email verification & password reset

**Deliverables:** 3 PRs

### Phase 4: Security Hardening (Week 4)
- Rate limiting enhancements
- Brute force protection
- Password strength validation
- Cross-vertical testing

**Deliverables:** 2 PRs

### Phase 5: Documentation & Deployment (Week 5)
- API documentation (OpenAPI/Swagger)
- Migration scripts
- Deployment guide
- Rollback procedures

**Deliverables:** 2 PRs

**Total Timeline:** 5 weeks, 16 PRs

---

## Module Boundaries

### Service Layer (Business Logic):
```
services/
├── auth.js              - AuthService (registration, login, tokens)
├── authorization.js     - AuthorizationService (permission checks)
├── audit.js             - AuditService (security event logging)
├── users.js             - UserService (profile management)
└── organizations.js     - OrganizationService (multi-tenancy)
```

### Route Layer (API Endpoints):
```
routes/
├── auth.js              - Authentication endpoints
├── users.js             - User management endpoints
├── organizations.js     - Organization management endpoints
├── entities.js          - Entity CRUD (updated with auth)
└── documents.js         - Document CRUD (updated with auth)
```

### Middleware Layer (Cross-Cutting Concerns):
```
middleware/
├── auth.js              - JWT validation, user loading
└── permissions.js       - Permission enforcement
```

**Clear Separation:** Routes call Services, Services call Database, Middleware intercepts requests

---

## Performance Optimizations

1. **LRU Cache:** In-memory cache for permission checks
   - 10,000 entry capacity
   - 5 minute TTL
   - 80-90% cache hit rate expected
   - Reduces permission check from 50ms to <5ms

2. **Database Indexes:** Strategic indexes on:
   - entity_permissions(user_id, entity_id)
   - refresh_tokens(user_id, expires_at)
   - audit_log(user_id, event_type, created_at)

3. **Prepared Statements:** All queries use prepared statements (SQLite default)

4. **Stateless JWT:** No database lookup on every request (only on permission checks)

**Expected Performance:**
- Login: <100ms
- Permission check (cached): <5ms
- Permission check (uncached): <50ms
- Token refresh: <50ms

---

## Security Considerations

### Implemented:
- Password hashing (bcrypt, cost=12)
- JWT signature verification
- Token expiry enforcement
- Refresh token rotation
- Rate limiting (5 req/15min for auth endpoints)
- Audit logging (all auth events)
- Account suspension capability
- HTTPS required (production)
- CORS policy enforcement

### Future Enhancements:
- Two-factor authentication (TOTP)
- Email service integration (SendGrid/SES)
- Social login (Google, Microsoft)
- Passwordless auth (WebAuthn)
- Anomaly detection (ML-based)

---

## Testing Strategy

### Unit Tests:
- Target: >90% code coverage
- All service methods tested
- All middleware tested
- Edge cases and error conditions

### Integration Tests:
- End-to-end auth flows
- Multi-user scenarios
- Cross-vertical compatibility
- Permission resolution accuracy

### Security Tests:
- SQL injection attempts
- JWT tampering
- Brute force simulation
- CSRF attacks
- Rate limit enforcement

### Performance Tests:
- 1000 concurrent logins
- 10,000 permission checks/sec
- Database query benchmarks
- Cache hit rate measurement

---

## Migration Strategy

### Step 1: Backup
```bash
cp db/navidocs.db db/navidocs.db.backup
```

### Step 2: Run Migration
```bash
npm run migrate:up -- 003_auth_tables
```

### Step 3: Seed Default Data
```javascript
// Create default admin user
// Create personal organizations for existing users
// Grant entity permissions to existing owners
```

### Step 4: Verify
```bash
npm run migrate:verify
```

### Rollback (if needed):
```bash
npm run migrate:down -- 003_auth_tables
```

**Zero Downtime:** Migration can run on live system (new tables don't affect existing routes)

---

## Deployment Checklist

### Pre-Deployment:
- [ ] All tests passing (unit, integration, security)
- [ ] Code review completed for all PRs
- [ ] Database backup created
- [ ] Migration script tested on staging
- [ ] Environment variables configured (.env)
- [ ] JWT_SECRET rotated (production)
- [ ] Rate limits configured
- [ ] Audit log retention policy set

### Deployment:
- [ ] Deploy database migration
- [ ] Deploy backend code
- [ ] Deploy frontend updates
- [ ] Smoke test critical flows
- [ ] Monitor error logs
- [ ] Monitor performance metrics

### Post-Deployment:
- [ ] Verify auth endpoints working
- [ ] Verify permission checks enforced
- [ ] Verify audit logs recording
- [ ] Send user communication (new login required)
- [ ] Monitor for issues (24h)

---

## Comparison of Approaches

### Approach 1: JWT + RBAC (RECOMMENDED) ✅
**Pros:**
- Stateless (horizontal scaling)
- Industry standard
- Minimal database changes
- Clear permission model
- Easy to understand and maintain

**Cons:**
- Cannot revoke JWTs before expiry (mitigated by refresh tokens)
- Permission cache can be stale (5min max)

### Approach 2: Session + ABAC
**Pros:**
- Instant revocation
- Very flexible policies
- Can add complex rules (time, location, etc.)

**Cons:**
- Requires Redis
- More complex to implement
- Harder to debug
- Overkill for current needs
- Not stateless (harder to scale)

### Approach 3: OAuth2 + External IDP
**Pros:**
- Offload auth complexity
- Enterprise features (SSO, MFA)
- Compliance built-in

**Cons:**
- Vendor lock-in
- Monthly cost
- External dependency
- Still need to build authorization layer

**Decision:** Approach 1 provides best balance of simplicity, scalability, and security for NaviDocs' requirements.

---

## Success Criteria

The system is considered complete when:

1. ✅ User can register and login with email/password
2. ✅ User receives JWT access token + refresh token
3. ✅ Access token expires and can be refreshed
4. ✅ User can reset forgotten password
5. ✅ User can verify email address
6. ✅ Organization admin can invite users
7. ✅ Organization admin can grant entity access
8. ✅ Permission levels work correctly (viewer, editor, manager, admin)
9. ✅ Unauthorized access returns 403
10. ✅ All security events logged
11. ✅ System works identically across all verticals
12. ✅ Migration completes without data loss
13. ✅ All tests pass (>90% coverage)
14. ✅ API documentation complete
15. ✅ Performance benchmarks met (<50ms permission checks)

---

## Risk Assessment

| Risk | Probability | Impact | Mitigation |
|------|-------------|--------|------------|
| Password data breach | Low | Critical | bcrypt hashing, never log passwords |
| JWT token theft | Medium | High | Short expiry, refresh rotation, HTTPS |
| Permission bypass | Low | Critical | Comprehensive testing, code review |
| Database migration failure | Low | High | Rollback script, backup, staging test |
| Performance degradation | Medium | Medium | LRU cache, indexes, load testing |
| User lockout | Medium | Medium | Admin override, backup codes (future) |
| Audit log growth | High | Low | Retention policy, archival strategy |

**Overall Risk Level:** LOW (with mitigations in place)

---

## Cost Analysis

### Development Cost:
- 5 weeks × 1 developer = **5 developer-weeks**
- Assumes mid-level backend engineer

### Infrastructure Cost:
- SQLite (free, no additional cost)
- JWT (free, no external service)
- Email service (future): ~$10-50/month (SendGrid)
- No additional cloud costs (runs on existing server)

### Maintenance Cost:
- Minimal (well-architected, well-tested)
- Estimated 1-2 hours/month for security updates

**Total First Year Cost:** Development time only (no recurring costs until email service added)

---

## Future Roadmap

### Short Term (3-6 months):
- Email service integration
- Two-factor authentication
- Social login (Google, Microsoft)
- Mobile app support (OAuth2 PKCE)

### Medium Term (6-12 months):
- SSO integration (SAML, OIDC)
- API key management
- Webhook security
- Advanced audit analytics

### Long Term (12+ months):
- ML-based anomaly detection
- Passwordless authentication (WebAuthn)
- Zero-trust architecture
- Multi-region token replication
- Blockchain-based audit trail (if needed for compliance)

---

## Key Takeaways

1. **Vertical Agnostic:** One system handles boats, aircraft, marinas, condos - any entity type
2. **Scalable:** Stateless JWT design supports horizontal scaling to 10,000+ users
3. **Secure:** Industry-standard practices (bcrypt, JWT, audit logging)
4. **Granular:** 3-tier permission model provides flexibility without complexity
5. **Testable:** Modular design with clear boundaries enables comprehensive testing
6. **Maintainable:** Well-documented, follows established patterns
7. **Migration-Friendly:** Designed for eventual PostgreSQL migration
8. **Compliance-Ready:** Audit logging supports GDPR, SOC2 requirements

---

## Documentation Index

1. **DESIGN_AUTH_MULTITENANCY.md** - Full technical design (50 pages)
   - 3 architectural approaches analyzed
   - Detailed database schema
   - Authentication & authorization flows
   - Security considerations
   - Performance optimizations

2. **IMPLEMENTATION_TASKS.md** - Task breakdown (40 pages)
   - 16 PRs with acceptance criteria
   - Code interfaces and contracts
   - Testing requirements
   - File structure

3. **ARCHITECTURE_DIAGRAM.md** - Visual diagrams (this document)
   - System architecture
   - Authentication flow
   - Authorization resolution
   - Permission hierarchy
   - Multi-tenancy model

4. **AUTH_SYSTEM_SUMMARY.md** - Executive summary (this document)
   - Problem statement
   - Solution overview
   - Implementation roadmap
   - Success criteria

**Start Here:** This summary document
**For Developers:** IMPLEMENTATION_TASKS.md
**For Architects:** DESIGN_AUTH_MULTITENANCY.md
**For Visual Learners:** ARCHITECTURE_DIAGRAM.md

---

## Approval Sign-Off

| Role | Name | Date | Signature |
|------|------|------|-----------|
| Product Owner | | | |
| Tech Lead | | | |
| Security Lead | | | |
| Database Admin | | | |

**Status:** ⏳ Awaiting Review

---

**Document Version:** 1.0
**Last Updated:** 2025-10-21
**Next Review:** After Phase 1 completion
**Contact:** Tech Lead
