Zero Trust Architecture

Implement "never trust, always verify" security model.

When to Use This Skill

Use this skill when:

• Replacing traditional perimeter-based VPN access models
• Implementing BeyondCorp-style access to internal applications
• Securing multi-cloud or hybrid-cloud environments
• Enforcing identity-based access for every service interaction
• Meeting compliance requirements for continuous verification and least privilege
• Adopting micro-segmentation for Kubernetes or cloud workloads

Prerequisites

• Identity provider (IdP) supporting OIDC/SAML (Okta, Azure AD, Google Workspace)
• Service mesh or proxy infrastructure (Istio, Envoy, Cloudflare Access)
• Device management/MDM solution for device posture checks
• Kubernetes cluster for workload-level examples
• Understanding of mTLS, RBAC, and network policies

Core Principles

zero_trust_principles:
  verify_explicitly:
    description: "Authenticate and authorize every access request"
    controls:
      - Strong multi-factor authentication
      - Identity-aware proxy for all applications
      - Service-to-service mTLS
      - API token validation on every request

  least_privilege:
    description: "Grant minimum access needed for the task"
    controls:
      - Just-in-time (JIT) access provisioning
      - Time-bounded access grants
      - Role-based access with fine-grained permissions
      - Regular access reviews and certification

  assume_breach:
    description: "Design systems expecting compromise has occurred"
    controls:
      - Micro-segmentation between all services
      - End-to-end encryption (data in transit and at rest)
      - Continuous monitoring and anomaly detection
      - Blast radius containment

BeyondCorp Implementation

Cloudflare Access Configuration

# Create an Access application for an internal service
curl -X POST "https://api.cloudflare.com/client/v4/accounts/${ACCOUNT_ID}/access/apps" \
  -H "Authorization: Bearer ${CF_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Internal Dashboard",
    "domain": "dashboard.internal.example.com",
    "type": "self_hosted",
    "session_duration": "12h",
    "auto_redirect_to_identity": true,
    "allowed_idps": ["google-workspace-idp-id"]
  }'

# Create an Access policy
curl -X POST "https://api.cloudflare.com/client/v4/accounts/${ACCOUNT_ID}/access/apps/${APP_ID}/policies" \
  -H "Authorization: Bearer ${CF_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Engineering team access",
    "decision": "allow",
    "include": [
      { "group": { "id": "engineering-group-id" } }
    ],
    "require": [
      { "login_method": { "id": "google-workspace-idp-id" } }
    ],
    "exclude": [
      { "geo": { "country_code": "KP" } }
    ]
  }'

# Create a device posture rule
curl -X POST "https://api.cloudflare.com/client/v4/accounts/${ACCOUNT_ID}/devices/posture" \
  -H "Authorization: Bearer ${CF_TOKEN}" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Require disk encryption",
    "type": "disk_encryption",
    "match": { "platform": "linux" },
    "schedule": "1h",
    "input": { "requireAll": true }
  }'

Cloudflare Access Terraform

resource "cloudflare_access_application" "dashboard" {
  account_id       = var.cloudflare_account_id
  name             = "Internal Dashboard"
  domain           = "dashboard.internal.example.com"
  type             = "self_hosted"
  session_duration = "12h"

  auto_redirect_to_identity = true
}

resource "cloudflare_access_policy" "engineering" {
  account_id     = var.cloudflare_account_id
  application_id = cloudflare_access_application.dashboard.id
  name           = "Engineering team"
  precedence     = 1
  decision       = "allow"

  include {
    group = [cloudflare_access_group.engineering.id]
  }

  require {
    login_method = [var.google_idp_id]
  }
}

resource "cloudflare_access_group" "engineering" {
  account_id = var.cloudflare_account_id
  name       = "Engineering"

  include {
    email_domain = ["example.com"]
  }

  require {
    group = ["engineering@example.com"]
  }
}

Identity-Aware Proxy with OAuth2 Proxy

# oauth2-proxy deployment for protecting internal services
apiVersion: apps/v1
kind: Deployment
metadata:
  name: oauth2-proxy
  namespace: auth
spec:
  replicas: 2
  selector:
    matchLabels:
      app: oauth2-proxy
  template:
    metadata:
      labels:
        app: oauth2-proxy

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