bynd-zero-trus-acce-mode

name	bynd-zero-trus-acce-mode
description	Implementing Google's BeyondCorp zero trust access model to eliminate implicit trust from the network perimeter, enforce identity-aware access controls using IAP, Access Context Manager, and Chrome Enterprise Premium for VPN-less secure application access.
domain	cybersecurity
subdomain	zero-trust-architecture
tags	["beyondcorp","zero-trust","google-cloud","iap","identity-aware-proxy","ztna","access-context-manager"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["PR.AA-01","PR.AA-05","PR.IR-01","GV.PO-01"]

Implementing BeyondCorp Zero Trust Access Model

When to Use

• When replacing traditional VPN infrastructure with identity-based application access
• When migrating to Google Cloud and requiring zero trust access for internal applications
• When implementing device trust verification as a prerequisite for resource access
• When needing context-aware access policies based on user identity, device posture, and location
• When securing access for remote and hybrid workforce without network-level trust

Do not use when applications require raw network-level access (e.g., UDP-based protocols not supported by IAP), for consumer-facing public applications, or when the organization lacks an identity provider with MFA capabilities.

Prerequisites

• Google Cloud organization with Cloud Identity or Google Workspace
• Identity-Aware Proxy (IAP) API enabled on the GCP project
• Chrome Enterprise Premium license for endpoint verification
• Applications deployed behind a Google Cloud Load Balancer or on App Engine/Cloud Run
• Endpoint Verification extension deployed on all corporate devices
• Access Context Manager API enabled

Workflow

Step 1: Configure Access Context Manager with Access Levels

Define access levels that represent trust tiers based on device and user attributes.

# Enable required APIs
gcloud services enable iap.googleapis.com
gcloud services enable accesscontextmanager.googleapis.com
gcloud services enable beyondcorp.googleapis.com

# Create an access policy (organization level)
gcloud access-context-manager policies create \
  --organization=ORG_ID \
  --title="BeyondCorp Enterprise Policy"

# Create a basic access level for corporate managed devices
cat > corporate-device-level.yaml << 'EOF'
- devicePolicy:
    allowedEncryptionStatuses:
      - ENCRYPTED
    osConstraints:
      - osType: DESKTOP_CHROME_OS
        minimumVersion: "13816.0.0"
      - osType: DESKTOP_WINDOWS
        minimumVersion: "10.0.19045"
      - osType: DESKTOP_MAC
        minimumVersion: "13.0.0"
    requireScreenlock: true
    requireAdminApproval: true
  regions:
    - US
    - GB
    - DE
EOF

gcloud access-context-manager levels create corporate-managed \
  --policy=POLICY_ID \
  --title= \
  --basic-level-spec=corporate-device-level.yaml


gcloud access-context-manager levels create high-trust \
  --policy=POLICY_ID \
  --title= \
  --custom-level-spec=high-trust-cel.yaml