Notes

Assume I am a Cybersecurity Architect working for an Operational Technology (OT) railway domain organization.

Your task is to generate complete systems engineering and cybersecurity architecture documentation for introducing a NEW Keycloak-based Single Sign-On (SSO) platform into an existing CyberSecurity Platform (CSP) deployed in an air-gapped OT railway environment.

The documentation shall:

follow INCOSE-style systems engineering practices,

comply with IEC 62443 cybersecurity principles,

align with OT/ICS security architecture best practices,

use formal requirement-writing methodology,

maintain traceability between operational needs, requirements, architecture, interfaces, and constraints.

ENVIRONMENT OVERVIEW

The CyberSecurity Platform (CSP) operates in:

an air-gapped OT railway infrastructure,

virtualized hypervisor-based environment,

segmented cybersecurity zones,

operationally sensitive railway systems environment.

The CSP is designed to provide:

centralized cybersecurity services,

authentication,

monitoring,

logging,

patch management,

operational visibility,

security event management.

The CSP components may also be consumed or integrated by:

external railway OT subsystems,

signaling systems,

operational applications,

maintenance applications,

monitoring systems,

future railway cybersecurity services.

The generated documentation shall therefore identify:

exported constraints,

interface constraints,

dependency constraints,

security integration constraints,

authentication integration constraints,

operational constraints applicable to consuming subsystems.

EXISTING CSP COMPONENTS

Hypervisor Infrastructure

Hosts all CSP virtual machines

Air-gapped operational environment

Active Directory Infrastructure (Windows VMs)

Primary Active Directory Server

Secondary Active Directory Server

Provides:

centralized identity management,

DNS services,

LDAP/LDAPS authentication services,

domain services.

Trellix Antivirus with ePO (Windows VM)

Endpoint protection management

rsyslog Server (Red Hat Enterprise Linux VM)

Centralized log collector

Logstash Server (Red Hat Enterprise Linux VM)

Processes collected logs

Sends processed logs to OpenSearch for storage and indexing

OpenSearch + OpenSearch Dashboard (Red Hat Enterprise Linux VM)

Security log storage

Visualization and analytics platform

File Server (Red Hat Enterprise Linux VM)

Centralized secure file storage

WSUS Server (Windows VM)

Patch management for Windows VMs

Red Hat Satellite Server (Red Hat Enterprise Linux VM)

Patch management for Linux VMs

MFA Server (Windows VM)

Time-based TOTP MFA services

Zabbix Monitoring Server (Red Hat Enterprise Linux VM)

Existing monitoring and alerting platform

NEW SYSTEM TO BE INTRODUCED

New Component:

Keycloak deployed on Red Hat Enterprise Linux VM

Keycloak shall provide:

Single Sign-On (SSO)

OpenID Connect (OIDC)

Federated Authentication

Centralized Identity Federation

Role-Based Access Control (RBAC)

JWT token issuance

Active Directory integration

LDAP/LDAPS federation

MFA integration

Centralized authentication services for CSP applications

KEYCLOAK ARCHITECTURE CONTEXT

Keycloak shall act as:

the centralized Identity Provider (IdP),

OIDC authentication authority,

federated authentication platform,

centralized authentication gateway for CSP applications,

authentication provider for future integrated OT railway subsystems.

Keycloak shall integrate with:

Active Directory (Primary and Secondary Domain Controllers),

LDAP/LDAPS services,

MFA Server,

OpenSearch Dashboard,

existing CSP web applications,

centralized logging infrastructure.

ARCHITECTURE CONSTRAINTS

Environment is fully air-gapped

No internet-based federation permitted

Internal-only identity federation allowed

Existing monitoring and logging stack already operational

Existing MFA services already operational

Existing Zabbix monitoring already operational

Existing OpenSearch infrastructure already operational

Existing rsyslog and Logstash pipeline already operational

CSP services may be consumed by external OT railway subsystems

Authentication interfaces shall support secure subsystem integration

Exported constraints shall be identified for consuming systems

COMPLIANCE REQUIREMENTS

The architecture and requirements shall comply with:

IEC 62443 principles

OT cybersecurity segmentation concepts

Zones and conduits methodology

Least privilege access principles

Defense-in-depth architecture

Secure authentication and auditability requirements

SECURITY REQUIREMENTS

The architecture shall enforce:

TLS 1.2 or higher

LDAPS authentication

MFA enforcement

RBAC authorization

Signed JWT tokens

Centralized authentication logging

Segmented authentication zones

Fail-secure authentication behavior

Audit logging

Secure inter-zone communications

EXPORTED CONSTRAINT REQUIREMENTS

The documentation shall identify exported constraints applicable to external subsystem integrations, including:

supported authentication protocols,

supported TLS versions,

token formats and signing constraints,

identity federation constraints,

RBAC integration constraints,

session timeout constraints,

network segmentation requirements,

conduit security requirements,

logging and audit requirements,

subsystem trust boundary requirements,

interface rate limitations if applicable,

operational availability constraints,

maintenance window constraints,

certificate trust requirements,

dependency constraints on AD, MFA, and logging infrastructure.

The exported constraints shall clearly identify:

assumptions,

dependencies,

limitations,

mandatory security requirements for consuming systems.

DOCUMENTATION TO GENERATE

Generate the following engineering artifacts:

SyOCD (System Operational Concept Description)Include:

operational purpose,

railway OT operational context,

Keycloak authentication workflows,

subsystem integration workflows,

user roles,

maintenance workflows,

operational constraints,

exported operational constraints,

security considerations.

SyRB (System Requirements Baseline)Include:

approved baseline requirements,

Keycloak authentication requirements,

subsystem integration requirements,

exported constraint requirements,

security requirements,

audit requirements,

availability requirements.

SyRS (System Requirements Specification)Include:

formal “shall” statements,

Keycloak OIDC requirements,

authentication requirements,

MFA requirements,

RBAC requirements,

JWT token requirements,

LDAP/LDAPS federation requirements,

logging requirements,

subsystem integration requirements,

exported constraint requirements,

performance requirements,

IEC 62443 aligned security requirements.

SyAD (System Architecture Document)Include:

high-level Keycloak architecture,

trust boundaries,

authentication architecture,

network segmentation,

IEC 62443 zones and conduits,

security architecture,

logging integration,

identity federation architecture,

subsystem integration architecture,

exported security constraints.

SyID (System Interface Description)Include:

interface definitions,

protocols,

ports,

LDAPS interfaces,

OIDC interfaces,

MFA interfaces,

logging interfaces,

subsystem interfaces,

trust boundaries,

exported interface constraints.

Data Flow Diagram (DFD)Include:

Keycloak authentication flow,

LDAP validation flow,

MFA validation flow,

JWT token issuance flow,

centralized logging flow,

Logstash to OpenSearch flow,

subsystem authentication flow,

administrative access flow.

High-Level Design (HLD)Include:

major architecture components,

Keycloak placement within CSP,

subsystem integration architecture,

security zones,

authentication zones,

OT segmentation concepts,

logging architecture,

monitoring integration,

trust boundaries,

exported architectural constraints.

Low-Level Design (LLD)Include:

Keycloak VM specifications,

network interfaces,

port definitions,

TLS requirements,

OIDC configuration,

JWT signing configuration,

LDAP/LDAPS configuration,

RBAC mappings,

logging configuration,

subsystem integration configuration,

backup requirements,

monitoring requirements,

fail-secure behavior,

exported technical constraints.

ENGINEERING REQUIREMENTS

Use:

formal systems engineering terminology,

cybersecurity architecture terminology,

OT security terminology,

IEC 62443 aligned concepts,

INCOSE-style requirement writing,

measurable/testable “shall” statements.

Clearly distinguish:

Existing Systems,

New Systems,

Trust Boundaries,

Security Zones,

Authentication Zones,

Supporting Services,

Interfaces and Conduits,

Exported Constraints,

External Dependencies.

OUTPUT STYLE

Provide:

professional engineering documentation style,

structured sections,

engineering tables,

ASCII architecture diagrams,

ASCII data flow diagrams,

cybersecurity-focused architecture language,

OT railway operational considerations,

IEC 62443 aligned segmentation concepts.