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Deploying OpenID Connect in a VPC Private Subnet with a Secure Proxy

Andrios Robert

• 1 min read

This is where precision matters. OIDC is a thin layer on top of OAuth 2.0, designed for identity verification. In a standard flow, the client talks to the OIDC provider over the internet. But in a private subnet inside your VPC, you cannot, and should not, expose direct access. The solution is a secure proxy deployment.

Why use a VPC private subnet proxy for OIDC
With a proxy running in the VPC, OIDC requests flow through a controlled ingress point. No direct traffic from the private network to the public internet. The proxy can manage TLS termination, enforce authentication policies, and integrate with internal DNS. This architecture supports compliance requirements, isolates workloads, and prevents data exfiltration.

Core deployment steps

  1. Private Subnet Design
    Place your application servers in private subnets without public IPs. Configure routing through NAT or a proxy only when required.
  2. Proxy Configuration
    Deploy the proxy in a public subnet or at the edge of your VPC. This proxy will broker communication between the private application and the OIDC provider. NGINX, Envoy, or a managed API gateway are common options.
  3. OIDC Client Setup
    Set the proxy as the OIDC callback URL. The proxy authenticates with the OIDC provider, then forwards verified tokens to the private subnet application. Ensure client IDs, secret keys, and scopes are stored securely.
  4. Security Hardening
    Use strict allow lists for outbound traffic from the proxy. Enable mutual TLS if supported by your provider. Monitor proxy logs for failed attempts and anomalies.
  5. Testing the Auth Flow
    Run end-to-end tests inside the VPC. Simulate both valid and invalid token exchanges. Verify latency impact from proxy routing.

Best practices for OIDC in private subnets

  • Keep token validation logic inside your private app.
  • Avoid storing tokens in cookies without secure, HTTP‑only flags.
  • Rotate credentials and TLS certificates on schedule.
  • Use infrastructure‑as‑code for reproducible VPC and proxy builds.

Deploying OpenID Connect inside a VPC private subnet through a proxy is not just safer—it’s predictable, repeatable, and resilient against external compromise. Done right, it becomes a locked‑down identity system operating entirely under your rules.

Ready to see a secure OIDC VPC private subnet proxy in action? Try it with hoop.dev and have it running live in minutes.