ADR-005-v4: Authentication & Authorization Architecture (Part 1: Narrative)

Document: ADR-005-v4-authentication-authorization-part1-narrative
Version: 3.0.0
Purpose: Define comprehensive authentication and authorization strategy for human understanding
Audience: Business stakeholders, developers, security teams
Date Created: 2025-08-30
Date Modified: 2025-09-03
QA Reviewed: Pending
Status: UPDATED_FOR_STATEFULSETS
Supersedes: v2.0.0
Changes: Replaced ephemeral containers with GKE StatefulSets

Table of Contents

• 1. Document Information
• 2. Purpose of this ADR
• 3. User Story Context
• 4. Executive Summary
• 5. Visual Overview
• 6. Background & Problem
• 7. Decision
• 8. Implementation Blueprint
• 9. Testing Strategy
• 10. Security Considerations
• 11. Performance Characteristics
• 12. Operational Considerations
• 13. Migration Strategy
• 14. Consequences
• 15. References & Standards
• 16. Review & Approval
• 17. Appendix
• 18. QA Review Block

1. Document Information 🔴 REQUIRED

Field	Value
ADR Number	ADR-005
Title	Authentication & Authorization Architecture
Status	Draft
Date Created	2025-08-30
Last Modified	2025-09-03
Version	3.0.0
Decision Makers	CTO, Security Officer, Lead Architect
Stakeholders	All CODITECT teams, customers, compliance

2. Purpose of this ADR 🔴 REQUIRED

This ADR serves dual purposes:

• For Humans 👥: Understand how CODITECT secures access for users, AI agents, and services across multiple tenants
• For AI Agents 🤖: Implement JWT-based authentication with RBAC and comprehensive audit trails

3. User Story Context 🔴 REQUIRED

As a platform user,
I want secure login with proper permissions,
So that I can access only my organization's resources and persistent workspaces safely.

As an organization admin,
I want to manage user roles and permissions,
So that I can control who accesses what within my tenant.

As an AI agent,
I want authenticated API access,
So that I can perform authorized operations on behalf of users.

📋 Acceptance Criteria:

• JWT-based authentication for all actors
• Multi-tenant isolation enforced
• Role-based access control (RBAC)
• OAuth2/SSO integration support
• Complete audit trail of all auth events
• Token refresh without re-authentication
• API rate limiting per user/tenant

4. Executive Summary 🔴 REQUIRED

🏢 For Business Stakeholders

Think of CODITECT's authentication system like a sophisticated office building's security system. Every person gets a personalized key card (JWT token) that knows:

• Who they are (identity)
• Which company they work for (tenant)
• Which floors they can access (roles)
• Which rooms they can enter (permissions)

The system automatically tracks every door opened and ensures employees can never accidentally enter competitors' offices, even if they try.

Business Value:

• Zero data breaches from cross-tenant access
• 90% reduction in permission management overhead
• SOC 2 compliance out-of-the-box
• Enterprise SSO enabling 5x faster onboarding

Key Decision: Implement JWT-based multi-tenant authentication with RBAC and comprehensive auditing.

💻 For Technical Readers

Technical Summary: Stateless JWT authentication with tenant-scoped claims, Argon2 password hashing, OAuth2 SSO integration, and FoundationDB-backed session management with automatic audit logging. Seamlessly integrates with GKE StatefulSet workspaces for persistent development environments.

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5. Visual Overview 🔴 REQUIRED

5.1 Authentication Flow

5.2 JWT Token Structure

5.3 Multi-Tenant Access Control

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6. Background & Problem 🔴 REQUIRED

6.1 Business Context

Why this matters:

• Data Security: One breach can destroy customer trust forever
• Compliance: GDPR, SOC 2, HIPAA require strict access controls
• Enterprise Sales: 80% of enterprise deals require SSO
• Operational Efficiency: Manual permission management doesn't scale

User impact:

• Password fatigue from multiple systems
• Slow onboarding to new projects
• Accidental access to wrong tenant's data
• Frustration with permission requests

Cost of inaction:

• $4.45M average data breach cost
• 6-month sales cycles without SSO
• 20% of IT time on access management
• Failed compliance audits

6.2 Technical Context

Current state in industry:

• Simple session-based auth
• Single-tenant assumptions
• Manual permission management
• No AI agent considerations
• Poor audit trails

Limitations:

• Sessions don't scale horizontally
• Permission checks hit database
• No standard for AI auth
• Audit logs incomplete
• SSO requires custom work

Technical debt:

• Hardcoded permissions
• Mixed auth patterns
• Incomplete tenant isolation
• Missing rate limiting
• No token rotation

6.3 Constraints

Type	Constraint	Impact
⏰ Time	3-month implementation	Phased rollout required
💰 Budget	Use existing infrastructure	Leverage FoundationDB
👥 Resources	Current security team	Must be maintainable
🔧 Technical	Stateless architecture	JWT-based solution
📜 Compliance	SOC 2, GDPR requirements	Audit everything

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7. Decision 🔴 REQUIRED

7.1 Y-Statement Format

In the context of securing multi-tenant access for humans and AI agents,
facing complex permission requirements and compliance needs,
we decided for JWT-based authentication with embedded tenant claims
and neglected session-based auth and external permission services,
to achieve stateless scalability, complete audit trails, and SSO support,
accepting larger token sizes and token rotation complexity,
because horizontal scalability and compliance are critical for growth.

7.2 What We're Doing

Implementing comprehensive authentication and authorization:

1. JWT Token System

   • Stateless authentication
   • Rich claims with tenant context
   • Short-lived with refresh tokens
   • Signed with RS256

2. Multi-Actor Support

   • Human users with email/password
   • AI agents with API keys
   • Service accounts for automation
   • OAuth2/SAML for enterprise SSO

3. RBAC Implementation

   • Tenant-scoped roles
   • Fine-grained permissions
   • Dynamic permission evaluation
   • Role inheritance

4. Audit System

   • Every auth event logged
   • Immutable audit trail
   • Compliance reporting
   • Anomaly detection

7.3 Why This Approach

JWT tokens provide:

• Stateless horizontal scaling
• Complete context in each request
• Standard integration patterns
• Mobile/API friendliness

Multi-tenant claims ensure:

• Absolute tenant isolation
• Fast permission checks
• Audit trail completeness
• Simplified debugging

This approach balances:

• Security vs usability
• Performance vs features
• Compliance vs complexity
• Present needs vs future growth

7.4 Alternatives Considered 🟡 OPTIONAL

Option A: Session-Based Auth

Aspect	Details
Description	Traditional server-side sessions
✅ Pros	• Simple implementation • Instant revocation • Smaller requests
❌ Cons	• Doesn't scale horizontally • Database hit per request • Complex for APIs
Rejection Reason	Incompatible with stateless architecture

Option B: External Auth Service

Aspect	Details
Description	Dedicated auth microservice (like Auth0)
✅ Pros	• Feature-rich • Maintained by experts • Quick setup
❌ Cons	• Vendor lock-in • Additional latency • Cost at scale • Less control
Rejection Reason	Need full control for multi-tenant customization

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8. Implementation Blueprint 🔴 REQUIRED

8.1 Architecture Overview

8.2 Core Components

Authentication Service: Handles login, token generation, and validation. See Part 2 for implementation.

Token Service: Manages JWT creation, refresh, and revocation. See Part 2 for details.

RBAC Engine: Evaluates permissions based on roles and tenant context. Complete implementation in Part 2.

8.3 Configuration

All authentication configuration managed through:

• Environment variables in GKE StatefulSets
• ConfigMaps for non-sensitive settings
• Kubernetes Secrets for sensitive data
• FoundationDB for dynamic configuration

StatefulSet pods inherit authentication configuration at startup, ensuring consistent security across workspace restarts. See Part 2 for schemas.

8.4 API Endpoints

Endpoint	Method	Purpose
/auth/login	POST	User authentication
/auth/refresh	POST	Token refresh
/auth/logout	POST	Token revocation
/auth/sso/{provider}	GET	SSO initiation
/auth/api-key	POST	Generate API key

8.5 Logging Requirements

All auth events must be logged with:

• Actor identification
• Action performed
• Resource accessed
• Result (success/failure)
• Client information

Detailed logging patterns in Part 2.

8.6 Error Handling

Authentication errors must:

• Never leak sensitive information
• Use consistent error codes
• Include correlation IDs
• Trigger appropriate alerts

See Part 2 for implementation.

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9. Testing Strategy 🔴 REQUIRED

9.1 Test Scenarios

1. Authentication Tests

   • Valid login flow
   • Invalid credentials
   • Account lockout
   • Password reset
   • SSO integration

2. Authorization Tests

   • Role-based access
   • Permission inheritance
   • Cross-tenant isolation
   • API rate limiting
   • Token expiration

3. Security Tests

   • Token tampering
   • Replay attacks
   • Privilege escalation
   • Session hijacking
   • Brute force protection

9.2 Performance Tests

Test	Target	Method
Login throughput	1000/sec	Load test
Token validation	<5ms	Benchmark
Permission check	<10ms	Profile
SSO round-trip	<2sec	E2E test

9.3 Test Coverage Requirements

Component	Unit	Integration	E2E
Auth Service	≥90%	≥80%	≥70%
Token Service	≥95%	≥85%	≥70%
RBAC Engine	≥95%	≥90%	≥80%
Audit Logger	≥85%	≥80%	≥60%

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10. Security Considerations 🔴 REQUIRED

10.1 Token Security

Protection measures:

• RS256 signing (asymmetric)
• Short expiration (15 minutes)
• Secure refresh tokens
• Token binding to IP
• Automatic rotation

Storage requirements:

• Never store in localStorage
• HttpOnly, Secure cookies
• SameSite protection
• Encrypted at rest

10.2 Password Security

Requirements:

• Argon2id hashing
• Minimum complexity rules
• Breach database checking
• Regular rotation reminders
• No password reuse

10.3 Threat Model

Threat	Likelihood	Impact	Mitigation
Token theft	Medium	High	Short expiration, binding
Brute force	High	Medium	Rate limiting, captcha
Privilege escalation	Low	Critical	Audit, permission validation
Cross-tenant access	Low	Critical	Tenant validation layer

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11. Performance Characteristics 🔴 REQUIRED

11.1 Expected Metrics

Operation	Target	Actual	Notes
Login	<200ms	TBD	Including password check
Token generation	<50ms	TBD	JWT creation
Token validation	<5ms	TBD	Signature verification
Permission check	<10ms	TBD	RBAC evaluation
Audit write	<20ms	TBD	Async to FDB

11.2 Scalability

Horizontal scaling:

• Stateless auth service
• JWT validation at edge
• Distributed cache for revocation
• Read replicas for permissions

Bottlenecks:

• Password hashing (CPU)
• SSO provider latency
• Audit write throughput
• Token size in headers

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12. Operational Considerations 🔴 REQUIRED

12.1 Monitoring

Metric	Alert Threshold	Action
Failed logins	>100/min	Check for attack
Token errors	>1%	Review JWT config
SSO failures	>5%	Check provider
Audit lag	>5sec	Scale writers

12.2 Maintenance

Regular tasks:

• Rotate signing keys quarterly
• Review unused permissions
• Archive old audit logs
• Update OAuth2 providers
• Check password breaches

12.3 Emergency Procedures

Token compromise:

1. Revoke all tokens for user
2. Force password reset
3. Review audit logs
4. Notify security team

System compromise:

1. Rotate all signing keys
2. Invalidate all sessions
3. Force global re-auth
4. Full security audit

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13. Migration Strategy 🔴 REQUIRED

13.1 Phase 1: Foundation (Month 1)

• Deploy auth service
• Implement JWT generation
• Setup token validation
• Create audit pipeline

13.2 Phase 2: Migration (Month 2)

• Migrate existing users
• Convert permissions
• Enable SSO providers
• Update all services

13.3 Phase 3: Deprecation (Month 3)

• Remove old auth code
• Archive legacy data
• Update documentation
• Security audit

13.4 Rollback Plan

If issues arise:

1. Keep old auth running
2. Dual auth period
3. Gradual migration
4. Quick rollback switch

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14. Consequences 🔴 REQUIRED

14.1 Positive Outcomes

✅ Security improvements:

• Zero cross-tenant breaches
• Complete audit trail
• Faster incident response
• Reduced attack surface

✅ Business benefits:

• Enterprise SSO capability
• SOC 2 compliance ready
• 90% faster onboarding
• Reduced support tickets

✅ Technical advantages:

• Horizontal scalability
• Stateless architecture
• Standard JWT integration
• API-first design

14.2 Negative Impacts

⚠️ Increased complexity:

• Token rotation logic
• Key management overhead
• Debugging JWT issues
• Larger request headers

⚠️ Operational overhead:

• Key rotation process
• Token size monitoring
• Audit log management
• SSO provider updates

⚠️ Migration effort:

• User data conversion
• Service updates required
• Client library changes
• Testing overhead

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15. References & Standards 🔴 REQUIRED

15.1 Related ADRs

• ADR-003-v4: Multi-tenant architecture
• ADR-008-v4: Monitoring auth events
• ADR-011-v4: Audit requirements
• LOGGING-STANDARD-v4: Logging patterns

15.2 External Standards

• OAuth 2.0: Authorization framework
• OpenID Connect: Identity layer
• JWT RFC 7519: Token standard
• OWASP Auth: Security guidelines

15.3 Best Practices

• NIST 800-63B: Authentication guidelines
• SANS Password Policy: Password standards
• Zero Trust Architecture: Security model

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16. Review & Approval 🔴 REQUIRED

Approval Signatures

Role	Name	Date	Signature
CTO	_______	_______	___________
Security Officer	_______	_______	___________
Lead Architect	_______	_______	___________
Compliance Manager	_______	_______	___________

Review History

Version	Date	Reviewer	Status	Comments
1.0.0	2025-08-30	Initial	DRAFT	Original version
2.0.0	2025-09-01	SESSION4	DRAFT	Complete rewrite to v4.2

Approval Workflow

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17. Appendix

17.1 Glossary

Term	Definition
JWT	JSON Web Token - Self-contained token with claims
RBAC	Role-Based Access Control - Permission model
SSO	Single Sign-On - One login for multiple systems
OAuth2	Authorization framework for delegated access
SAML	Security Assertion Markup Language for SSO
MFA	Multi-Factor Authentication - Multiple proofs
Argon2	Password hashing algorithm winner of PHC
Claims	Statements about an entity in JWT
Tenant	Isolated customer organization
IdP	Identity Provider for SSO

17.2 Permission Model Example

Organization: ACME Corp (tenant_id: 123)
├── Admin Role
│   ├── user:*
│   ├── project:*
│   └── billing:*
├── Developer Role
│   ├── project:read
│   ├── project:write
│   └── code:*
└── Viewer Role
    ├── project:read
    └── dashboard:read

17.3 Token Example

{
  "header": {
    "alg": "RS256",
    "typ": "JWT"
  },
  "payload": {
    "sub": "user-123",
    "user_id": "550e8400-e29b-41d4-a716-446655440000",
    "tenant_id": "660e8400-e29b-41d4-a716-446655440001",
    "email": "user@example.com",
    "roles": ["developer"],
    "permissions": ["project:read", "project:write"],
    "actor_type": "human",
    "exp": 1693526400,
    "iat": 1693522800,
    "iss": "coditect.com"
  }
}

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18. QA Review Block

Status: AWAITING INDEPENDENT QA REVIEW

This section will be completed by an independent QA reviewer (not the author) according to ADR-QA-REVIEW-GUIDE-v4.2.

Document ready for review as of: 2025-09-01
Version ready for review: 2.0.0

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Next: See Part 2: Technical Implementation for complete implementation details.