feat(rpc): add the signed subject-context token

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-05 14:12:42 +05:30
parent 40625e98ed
commit 2257ee871e
3 changed files with 230 additions and 0 deletions
@@ -0,0 +1,107 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import type { Context } from "@wrnexus/core";
+import { exportSubjectContext, importSubjectContext } from "../src/identity.ts";
+
+const SECRET = "test-rpc-secret-at-least-32-chars-long";
+const original = { ...process.env };
+
+afterEach(() => {
+  process.env = { ...original };
+});
+
+function ctxFor(user: unknown, tenantId?: string): Context {
+  return {
+    user,
+    tenant: tenantId ? { id: tenantId } : undefined,
+    locals: {},
+  } as unknown as Context;
+}
+
+function configure(appName = "web") {
+  process.env.WRNEXUS_RPC_SECRET = SECRET;
+  process.env.WRNEXUS_APP_NAME = appName;
+}
+
+describe("subject context token", () => {
+  test("round-trips subject and tenant", async () => {
+    configure("web");
+    const token = await exportSubjectContext(ctxFor({ id: "u1" }, "acme"), "billing");
+    const imported = await importSubjectContext(token!, "billing");
+    expect(imported.subjectId).toBe("u1");
+    expect(imported.tenantId).toBe("acme");
+    expect(imported.callerApp).toBe("web");
+  });
+
+  test("carries NO roles or permissions", async () => {
+    configure();
+    const token = await exportSubjectContext(
+      ctxFor({ id: "u1", roles: ["admin"], permissions: ["*"] }),
+      "billing",
+    );
+    // Decode the payload directly: the claim set must not include privileges.
+    const payload = JSON.parse(atob(token!.split(".")[1]!.replace(/-/g, "+").replace(/_/g, "/")));
+    expect(payload.roles).toBeUndefined();
+    expect(payload.permissions).toBeUndefined();
+    expect(payload.sub).toBe("u1");
+  });
+
+  test("an anonymous context produces no token", async () => {
+    configure();
+    expect(await exportSubjectContext(ctxFor(null), "billing")).toBeUndefined();
+    expect(await exportSubjectContext(ctxFor({}), "billing")).toBeUndefined();
+  });
+
+  test("a non-string subject id is refused", async () => {
+    configure();
+    // Matches the permissions system: only a non-empty string identifies a subject.
+    for (const id of [0, "", 123, {}]) {
+      await expect(exportSubjectContext(ctxFor({ id }), "billing")).rejects.toThrow(/subject/i);
+    }
+  });
+
+  test("a token minted for one app is rejected by another", async () => {
+    configure();
+    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing");
+    await expect(importSubjectContext(token!, "reports")).rejects.toThrow();
+  });
+
+  test("an expired token is rejected", async () => {
+    configure();
+    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing", { ttlSeconds: -1 });
+    await expect(importSubjectContext(token!, "billing")).rejects.toThrow();
+  });
+
+  test("a token signed with a different secret is rejected", async () => {
+    configure();
+    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing");
+    process.env.WRNEXUS_RPC_SECRET = "a-completely-different-secret-32-chars";
+    await expect(importSubjectContext(token!, "billing")).rejects.toThrow();
+  });
+
+  test("a tampered payload is rejected", async () => {
+    configure();
+    const token = await exportSubjectContext(ctxFor({ id: "u1" }), "billing");
+    const [header, , signature] = token!.split(".");
+    const forged = btoa(JSON.stringify({ sub: "admin", aud: "billing", iss: "web" }))
+      .replace(/\+/g, "-")
+      .replace(/\//g, "_")
+      .replace(/=+$/, "");
+    await expect(
+      importSubjectContext(`${header}.${forged}.${signature}`, "billing"),
+    ).rejects.toThrow();
+  });
+
+  test("a missing secret is a setup error, not a silent pass", async () => {
+    process.env.WRNEXUS_APP_NAME = "web";
+    delete process.env.WRNEXUS_RPC_SECRET;
+    await expect(exportSubjectContext(ctxFor({ id: "u1" }), "billing")).rejects.toThrow(
+      /WRNEXUS_RPC_SECRET/,
+    );
+  });
+
+  test("a short secret is refused", async () => {
+    process.env.WRNEXUS_APP_NAME = "web";
+    process.env.WRNEXUS_RPC_SECRET = "too-short";
+    await expect(exportSubjectContext(ctxFor({ id: "u1" }), "billing")).rejects.toThrow(/32/);
+  });
+});