Separate Zapier, web, API, and leaf access planes with NATS authz

Zapier is one ingress. Direct web, customer API, and S2S leaf nodes are their own services. Every hop to an internal subject must pass verae.access.authz.check (default deny by plane).

packages/verae-access-authz/src/client.js

@@ -0,0 +1,38 @@
+/** Call verae.access.authz.check then the internal subject. Fail closed. */
+import { SUBJECTS } from './subjects.js';
+
+export async function authorizeThenRequest(nc, sc, { plane, subject, principal, payload, timeout = 2000 }) {
+  const kind = payload?.kind;
+  const checkMsg = await nc.request(
+    SUBJECTS.AUTHZ_CHECK,
+    sc.encode(JSON.stringify({ plane, subject, principal, kind, payload })),
+    { timeout },
+  );
+  const decision = JSON.parse(sc.decode(checkMsg.data) || '{}');
+  if (!decision.allow) {
+    const err = new Error(decision.reason || 'denied');
+    err.decision = decision;
+    throw err;
+  }
+  const internal = decision.subject;
+  const body = { ...payload, plane, principal, traceId: payload?.traceId };
+  const m = await nc.request(internal, sc.encode(JSON.stringify(body)), { timeout });
+  return { decision, body: JSON.parse(sc.decode(m.data) || '{}') };
+}
+
+export async function authorizeThenPublish(nc, sc, { plane, subject, principal, payload, timeout = 2000 }) {
+  const kind = payload?.kind;
+  const checkMsg = await nc.request(
+    SUBJECTS.AUTHZ_CHECK,
+    sc.encode(JSON.stringify({ plane, subject, principal, kind, payload })),
+    { timeout },
+  );
+  const decision = JSON.parse(sc.decode(checkMsg.data) || '{}');
+  if (!decision.allow) {
+    const err = new Error(decision.reason || 'denied');
+    err.decision = decision;
+    throw err;
+  }
+  nc.publish(decision.subject, sc.encode(JSON.stringify({ ...payload, plane, principal })));
+  return { decision };
+}