Quality & Security
Security Model
1. Security Objectives
TeamFlow must protect:
- Requirements and requirement history
- Approvals and change decisions
- Project membership
- Development tasks and QA evidence
- Defects and release decisions
- Audit records and user accounts
- Attachments
The security model must prevent:
- Unauthorized access
- Unauthorized modification
- Silent history rewriting
- Privilege escalation
- Cross-project data exposure
2. Security Principles
- Least Privilege: Users receive only minimum necessary permissions
- Deny by Default: Access is denied unless explicitly granted
- Backend Authorization: Every protected operation is validated server-side
- Separation of Duties: Critical decisions require multiple roles
- Immutable Approved Records: Cannot be edited after approval
- Append-Only Audit History: Audit logs are immutable
- Secure Defaults: Configurations start secure
- Defense in Depth: Multiple layers of security controls
- Explicit Project Scope: Authorization is scoped to specific projects
- Traceable Administrative Actions: All admin actions are audited
3. Authentication
The MVP may support:
- Built-in username/password with JWT
- Keycloak using OpenID Connect
Production Recommendation:
- OpenID Connect
- Short-lived access tokens (15 minutes)
- Refresh token rotation where supported
- Multi-factor authentication for privileged roles
- Account lockout or throttling after failed attempts
- Secure password reset with verification
4. Password Security
When built-in authentication is used:
- Passwords never stored in plain text
- Hashed using Argon2id or bcrypt with approved parameters
- Minimum password length enforced (12+ characters recommended)
- Common weak passwords prevented
- Login attempts rate-limited
- Failed attempts recorded in audit log
- Passwords never logged
5. Authorization Model
Authorization combines:
- Global role (SYSTEM_ADMIN, CTO, MANAGEMENT)
- Project membership
- Project role (BUSINESS_ANALYST, TECHNICAL_LEAD, DEVELOPER, QA_ENGINEER, etc.)
- Resource ownership where applicable
- Workflow state
- Separation-of-duty rules
Example Authorization Decision:
Can user approve requirement version?
├── Is user authenticated?
├── Is user active?
├── Is user a member of the project?
├── Does user hold required review permission?
├── Is version in correct status?
├── Has user authored the version?
└── Does policy allow self-approval?
6. Project Isolation
Critical: Every project-owned query must apply project authorization.
The system must prevent:
- Changing project IDs in URLs to view another project
- Accessing attachments from another project
- Exporting unauthorized project data
- Viewing audit records outside allowed scope
7. Requirement Immutability
Approved RequirementVersion records are protected by:
- Domain service validation
- Repository validation
- Database-level protection where practical
- API transition rules
- Audit verification
A direct update attempt returns:
409 CONFLICT
{
"code": "REQUIREMENT_VERSION_IMMUTABLE",
"message": "An approved requirement version cannot be edited."
}8. Separation of Duties
Default controls:
- Requirement author cannot provide final approval for the same version
- Developer cannot provide QA verification for own implementation
- Change requester cannot provide final approval when required
- System Administrator cannot use admin access as business approval
9. Data Protection
- All production traffic uses TLS 1.2 or higher
- Database connections use encryption
- Sensitive data at rest is encrypted where practical
- Backups are encrypted
- Secrets managed via secure configuration, not source control
10. Session Management
- Sessions expire after configured period (30 minutes recommended)
- Inactive sessions are invalidated
- Concurrent session limits enforced where configured
- Session IDs use secure random generation
- Logout invalidates session immediately
11. Input Validation and Output Encoding
- All user input is validated on backend
- SQL injection prevention via parameterized queries
- XSS prevention via proper output encoding
- CSRF tokens for state-changing operations
- File upload validation: size, type, content policy
12. Audit Logging
- All authentication events (login, logout, failed attempts)
- All authorization changes (role assignment, project membership)
- All data modifications (create, update, delete, approve)
- All sensitive operations recorded with user, timestamp, IP address
- Audit logs are immutable and append-only
- Audit logs retained per compliance requirements
13. Security Testing
- Automated scanning for common vulnerabilities (OWASP Top 10)
- Dependency vulnerability scanning
- Code review focusing on security
- Penetration testing before production release