Gateway: make device approval scope checks atomic

src/gateway/net.test.ts

@@ -223,6 +223,13 @@ describe("resolveClientIp", () => {
       trustedProxies: ["127.0.0.1", "::1"],
       expected: undefined,
     },
+    {
+      name: "fails closed when all non-loopback X-Forwarded-For hops are trusted proxies",
+      remoteAddr: "10.0.0.50",
+      forwardedFor: "10.0.0.2, 10.0.0.1",
+      trustedProxies: ["10.0.0.0/8"],
+      expected: undefined,
+    },
     {
       name: "fails closed when trusted proxy omits forwarding headers",
       remoteAddr: "127.0.0.1",

src/gateway/server-methods/devices.ts

@@ -1,6 +1,5 @@
 import {
   approveDevicePairing,
-  getPendingDevicePairing,
   getPairedDevice,
   listDevicePairing,
   removePairedDevice,
@@ -94,31 +93,20 @@ export const deviceHandlers: GatewayRequestHandlers = {
       return;
     }
     const { requestId } = params as { requestId: string };
-    const pending = await getPendingDevicePairing(requestId);
-    if (!pending) {
+    const callerScopes = Array.isArray(client?.connect?.scopes) ? client.connect.scopes : [];
+    const approved = await approveDevicePairing(requestId, { callerScopes });
+    if (!approved) {
       respond(false, undefined, errorShape(ErrorCodes.INVALID_REQUEST, "unknown requestId"));
       return;
     }
-    const callerScopes = Array.isArray(client?.connect?.scopes) ? client.connect.scopes : [];
-    const requestedScopes = normalizeDeviceAuthScopes(pending.scopes);
-    const missingScope = resolveMissingRequestedScope({
-      role: pending.role,
-      requestedScopes,
-      callerScopes,
-    });
-    if (missingScope) {
+    if (approved.status === "forbidden") {
       respond(
         false,
         undefined,
-        errorShape(ErrorCodes.INVALID_REQUEST, `missing scope: ${missingScope}`),
+        errorShape(ErrorCodes.INVALID_REQUEST, `missing scope: ${approved.missingScope}`),
       );
       return;
     }
-    const approved = await approveDevicePairing(requestId);
-    if (!approved) {
-      respond(false, undefined, errorShape(ErrorCodes.INVALID_REQUEST, "unknown requestId"));
-      return;
-    }
     context.logGateway.info(
       `device pairing approved device=${approved.device.deviceId} role=${approved.device.role ?? "unknown"}`,
     );

src/infra/device-pairing.ts

@@ -71,6 +71,11 @@ export type DevicePairingList = {
   paired: PairedDevice[];
 };
 
+export type ApproveDevicePairingResult =
+  | { status: "approved"; requestId: string; device: PairedDevice }
+  | { status: "forbidden"; missingScope: string }
+  | null;
+
 type DevicePairingStateFile = {
   pendingById: Record<string, DevicePairingPendingRequest>;
   pairedByDeviceId: Record<string, PairedDevice>;
@@ -237,6 +242,25 @@ function scopesWithinApprovedDeviceBaseline(params: {
   });
 }
 
+function resolveMissingRequestedScope(params: {
+  role: string;
+  requestedScopes: readonly string[];
+  callerScopes: readonly string[];
+}): string | null {
+  for (const scope of params.requestedScopes) {
+    if (
+      !roleScopesAllow({
+        role: params.role,
+        requestedScopes: [scope],
+        allowedScopes: params.callerScopes,
+      })
+    ) {
+      return scope;
+    }
+  }
+  return null;
+}
+
 export async function listDevicePairing(baseDir?: string): Promise<DevicePairingList> {
   const state = await loadState(baseDir);
   const pending = Object.values(state.pendingById).toSorted((a, b) => b.ts - a.ts);
@@ -312,14 +336,25 @@ export async function requestDevicePairing(
 
 export async function approveDevicePairing(
   requestId: string,
+  options?: { callerScopes?: readonly string[] },
   baseDir?: string,
-): Promise<{ requestId: string; device: PairedDevice } | null> {
+): Promise<ApproveDevicePairingResult> {
   return await withLock(async () => {
     const state = await loadState(baseDir);
     const pending = state.pendingById[requestId];
     if (!pending) {
       return null;
     }
+    if (pending.role && options?.callerScopes) {
+      const missingScope = resolveMissingRequestedScope({
+        role: pending.role,
+        requestedScopes: normalizeDeviceAuthScopes(pending.scopes),
+        callerScopes: options.callerScopes,
+      });
+      if (missingScope) {
+        return { status: "forbidden", missingScope };
+      }
+    }
     const now = Date.now();
     const existing = state.pairedByDeviceId[pending.deviceId];
     const roles = mergeRoles(existing?.roles, existing?.role, pending.roles, pending.role);
@@ -372,7 +407,7 @@ export async function approveDevicePairing(
     delete state.pendingById[requestId];
     state.pairedByDeviceId[device.deviceId] = device;
     await persistState(state, baseDir);
-    return { requestId, device };
+    return { status: "approved", requestId, device };
   });
 }