ADR-0005: Authentication and Access Management Model¶

Status¶

Accepted

Context¶

As the HomeOps Platform introduces a self-hosted server environment and adopts explicit trust boundaries, controlling who can access which resources becomes a central concern. Authentication and access management apply not only to user-facing services, but also to administrative access, inter-service communication, and access to sensitive data.

At this stage of the platform’s evolution, the goal is to define a clear and consistent access model that aligns with the platform’s modular architecture and security baseline. The model must be simple enough to manage on limited hardware while still supporting realistic access control practices.

This decision focuses on defining access principles and responsibility boundaries, rather than selecting specific authentication technologies or identity providers.

Decision¶

The HomeOps Platform will adopt a role-based and context-aware authentication and access management model.

Access to system resources will be governed by clearly defined roles and scopes. Different types of access, such as administrative access, service-to-service communication, and user interaction, will be treated as distinct concerns and managed separately.

Authentication and authorization mechanisms will be introduced incrementally, with access defaults set to deny unless explicitly permitted.

Rationale¶

Defining an explicit authentication and access model provides the following benefits:

Reduces implicit trust between users, services, and system components
Supports the principle of least privilege across the platform
Aligns access control with the platform’s modular structure
Improves clarity when reasoning about security boundaries
Allows access management to evolve independently of implementation details

By separating access concerns conceptually, the platform avoids tightly coupling identity management to specific technologies or deployment choices.

Access Categories¶

The platform distinguishes between the following access categories:

Administrative Access
Used for system maintenance, configuration, and operational tasks. This access is restricted to trusted administrators and is limited to management interfaces and tooling.
Service Access
Used by backend services to communicate with other services or data stores. Access is scoped narrowly and granted only where required for functionality.
User Access
Used by client applications and end users to interact with platform services. This access is mediated through backend APIs and does not provide direct access to infrastructure or data storage.
Emergency (Break-Glass) Access
A highly restricted form of administrative access reserved for exceptional recovery scenarios, such as loss or compromise of standard administrative credentials.
This access is not intended for routine use and is kept isolated from normal operational workflows.

Each category is subject to different authentication requirements and authorization rules.

Consequences¶

Positive¶

Clear separation of access responsibilities
Reduced risk of privilege escalation
Improved ability to reason about access paths
Strong foundation for future authentication and authorization decisions
The inclusion of a break-glass access model ensures that the platform can be recovered from critical access failures without relying on implicit trust or ad-hoc privilege escalation.

Negative¶

Additional design and configuration effort
Increased complexity compared to implicit trust models
Access policies must be maintained as the platform evolves

These trade-offs are considered acceptable given the platform’s emphasis on security clarity and realistic system design.

ADR-0001: Decision to introduce a self-hosted server environment
ADR-0003: Baseline security hardening for self-hosted server
ADR-0004: Network segmentation and trust boundaries
Future decisions regarding authentication mechanisms and identity providers
Future decisions regarding secrets management and credential rotation