feat(admission): add group VPN exceptions

packages/auth/src/index.ts

@@ -115,6 +115,24 @@ export function resolveEffectiveGroup<T>(explicitGroup: T | null, defaultGroup:
   return explicitGroup ?? defaultGroup;
 }
 
+export function isGameNetworkAllowed(
+  classification: "unknown" | "clear" | "vpn" | "proxy" | "hosting" | "tor",
+  anonymizedNetworksAllowed: boolean,
+) {
+  return anonymizedNetworksAllowed || !["vpn", "proxy", "tor"].includes(classification);
+}
+
+export function gameAdmissionDenialReason(
+  group: { accessEnabled: boolean; anonymizedNetworksAllowed: boolean } | null,
+  classification: "unknown" | "clear" | "vpn" | "proxy" | "hosting" | "tor",
+) {
+  if (!group?.accessEnabled) return "group_access_disabled" as const;
+  if (!isGameNetworkAllowed(classification, group.anonymizedNetworksAllowed)) {
+    return "anonymized_network_disallowed" as const;
+  }
+  return null;
+}
+
 export function verifyHashedToken(providedToken: string, expectedHash: string) {
   const provided = Buffer.from(hashToken(providedToken), "utf8");
   const expected = Buffer.from(expectedHash, "utf8");

packages/auth/test/group-access.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { resolveEffectiveGroup } from "../src/index";
+import { gameAdmissionDenialReason, isGameNetworkAllowed, resolveEffectiveGroup } from "../src/index";
 
 describe("group-based admission", () => {
   const everyone = { name: "everyone", accessEnabled: false };
@@ -17,4 +17,26 @@ describe("group-based admission", () => {
     const limited = { name: "limited", accessEnabled: false };
     expect(resolveEffectiveGroup(limited, enabledDefault)?.accessEnabled).toBe(false);
   });
+
+  it("denies confirmed anonymized game networks unless the effective group allows them", () => {
+    for (const classification of ["vpn", "proxy", "tor"] as const) {
+      expect(isGameNetworkAllowed(classification, false)).toBe(false);
+      expect(isGameNetworkAllowed(classification, true)).toBe(true);
+    }
+  });
+
+  it("does not apply the group exception policy to clear, hosting, or unavailable intelligence", () => {
+    for (const classification of ["clear", "hosting", "unknown"] as const) {
+      expect(isGameNetworkAllowed(classification, false)).toBe(true);
+    }
+  });
+
+  it("prioritizes disabled group access before the network exception policy", () => {
+    expect(gameAdmissionDenialReason({ accessEnabled: false, anonymizedNetworksAllowed: false }, "vpn"))
+      .toBe("group_access_disabled");
+    expect(gameAdmissionDenialReason({ accessEnabled: true, anonymizedNetworksAllowed: false }, "vpn"))
+      .toBe("anonymized_network_disallowed");
+    expect(gameAdmissionDenialReason({ accessEnabled: true, anonymizedNetworksAllowed: true }, "vpn"))
+      .toBeNull();
+  });
 });