Guidewire Install Auth

Guidewire Install & Auth

Overview

Authenticate a backend service to a Guidewire Cloud tenant using OAuth2 client credentials and operate the auth layer in production. This is not a hello-world walkthrough; it is the auth code your service runs at 3am when a token expires mid-batch, when a tenant admin rotates a scope, when a private CA renews a cert, and when on-call needs to swap a leaked secret without dropping in-flight requests.

The four production failures this skill prevents:

1. Token expiry storms — every request races to refresh, the Hub rate-limits the auth endpoint, the integration cascades to red.
2. Scope drift — a GCC admin removes a scope, every cached token starts returning 403, retrying does not help.
3. PKIX path building failed — JVM cannot validate the tenant's TLS chain because the private CA is not in the trust store; common when carriers front Cloud API with their own DLP appliance.
4. Secret rotation downtime — the active client secret is rotated and the old secret stops working before the new one is loaded; in-flight token refreshes fail until restart.

Prerequisites

• JDK 17 (Guidewire Cloud release 202503 and later)
• A registered Service Application in Guidewire Cloud Console (GCC) with Cloud API roles assigned per least privilege
• Network egress from your runtime to *.guidewire.net (runtime APIs) and gcc.guidewire.com (console only)
• A secret store the runtime can read at startup and on rotation signal (AWS Secrets Manager, GCP Secret Manager, HashiCorp Vault, or Kubernetes Secret with CSI driver)
• For private-CA tenants: the carrier's CA chain in PEM form

Instructions

Build the auth layer in this order. Each section solves one production failure mode; do not skip steps because the failure shows up in production, not in dev.

1. Implement the token-cache pattern below — proactive refresh, single-flight gate, JWT-based expiry.
2. Wire secret rotation to your secret store; do not commit secrets or bake them into images.
3. For private-CA tenants, install the trust store at the JVM/init-container layer.
4. Validate scope hardening on every refresh so drift fails fast, not on the next business call.

Token-cache pattern (production)

Tokens are short-lived, typically one hour. Reactive refresh on 401 is wrong: it doubles latency on the failing request and creates a thundering herd when many requests notice expiry simultaneously. Cache the token in-process and refresh proactively at 80% of TTL, behind a single-flight gate so concurrent refreshers serialize.

import jwt from "jsonwebtoken";

type Cached = { value: string; expiresAt: number };
let cached: Cached | null = null;
let inflight: Promise<string> | null = null;

export async function getToken(): Promise<string> {
  if (cached && Date.now() < cached.expiresAt - 60_000) return cached.value;
  if (inflight) return inflight;

  inflight = (async () => {
    const res = await fetch(process.env.GW_AUTH_URL!, {
      method: "POST",
      headers: { "Content-Type": "application/x-www-form-urlencoded" },
      body: new URLSearchParams({
        grant_type: "client_credentials",
        client_id: process.env.GW_CLIENT_ID!,
        client_secret: process.env.GW_CLIENT_SECRET!,
        scope: process.env.GW_SCOPES!,
      }),
    });
    if (!res.ok) throw new Error(`auth ${res.status}: ${await res.text()}`);
    const { access_token } = await res.json();
    const { exp } = jwt.decode(access_token) as { exp: number };
    // exp is seconds since epoch; multiply by 1000 for JS ms. Refresh at 80% of remaining TTL.
    const expMs = exp * 1000;
    cached = { value: access_token, expiresAt: expMs - 0.2 * (expMs - Date.now()) };
    return access_token;
  })().finally(() => { inflight = null; });

  return inflight;
}

The exp - 20% early-refresh window absorbs clock skew and prevents the cliff at TTL boundary. The inflight single-flight gate makes a high-rps service issue one refresh per cache-miss, not one per concurrent request — without it, a 1000-rps service produces 1000 simultaneous Hub calls and trips 429 rate-limiting on the auth endpoint.

Secret rotation without downtime

Rotation breaks if the runtime reads the secret only at startup, or if the plaintext lives somewhere reviewable (committed .env, container image layer, unencrypted Kubernetes Secret). Three patterns work, in order of operational simplicity:

SOPS + age (recommended for VM/container deployments). Encrypt secrets.prod.sops.yaml with one or more age public keys, commit the encrypted file to git, decrypt in-process at startup and on SIGHUP. The repo holds an auditable history of who rotated what and when; only holders of the age private key can read plaintext. Bootstrap a repo with the same conventions used across this organization:

sops-init                                    # idempotent; writes .sops.yaml + .env.sops + scripts/sops-env
sops secrets.prod.sops.yaml   # interactive edit; ciphertext re-written on save
eval "$(sops -d secrets.prod.sops.yaml | sed -nE 's/^([A-Za-z_][A-Za-z0-9_]*)=(.*)$/export \1=\2/p')"

The anchored sed regex is non-negotiable: a naive sed 's/^/export /' turns blank lines and comments into bare export calls, and bare export dumps every exported variable to stdout — every secret leaks if anything captures that stdout (cron mail, an SSH session running this).

Cloud-native projection (managed Kubernetes / cloud VMs). Mount the secret as a file from the secret store via Vault Agent, the Secrets Store CSI driver, or AWS Secrets and Configuration Provider. The orchestrator handles restart-on-rotation and the runtime re-reads the file on each token refresh.

Dual-secret env-var window (manual rotation, last resort). Configure the runtime with both GW_CLIENT_SECRET_PRIMARY and GW_CLIENT_SECRET_SECONDARY. On invalid_client from the primary, fall back to the secondary; on success, schedule the swap. Close the window when monitoring confirms 24h of zero primary failures.

Private-CA trust store setup (PKIX)

When a carrier fronts Cloud API with a DLP appliance or proxy that re-signs TLS with a private CA, the JVM rejects the chain. Symptom: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException.

Fix at the JVM level, not the application level:

keytool -importcert \
  -alias guidewire-tenant-ca \
  -file ./tenant-ca.pem \
  -keystore "$JAVA_HOME/lib/security/cacerts" \
  -storepass changeit -noprompt

For Kubernetes deployments, bake the CA into a sidecar that runs keytool against a shared cacerts volume, or use JAVA_OPTS=-Djavax.net.ssl.trustStore=/etc/ssl/cacerts.jks. Do not disable validation with -Dcom.sun.net.ssl.checkRevocation=false or trust-all SSL contexts; the OWASP A02 audit will find that too.