fix(kms): deny on an empty device allowlist in auth-simple

Author: kvinwang

dstack/kms/auth-simple/README.md

@@ -102,11 +102,11 @@ raw NitroTPM evidence by itself.
 | `allowedTcbStatuses` | No | Allowed verifier-derived TCB status strings. Defaults to `["UpToDate"]`; non-up-to-date SNP/TDX statuses remain fail-closed unless explicitly allowlisted for testing. |
 | `allowedAdvisoryIds` | No | Advisory IDs permitted in `advisoryIds`. Defaults to `[]`, which rejects any advisory. |
 | `kms.mrAggregated` | Yes | Allowed KMS early aggregate MR values (boot-mr-done). |
-| `kms.devices` | No | Allowed KMS device IDs |
-| `kms.allowAnyDevice` | No | If true, skip device ID check for KMS |
+| `kms.devices` | No | Allowed KMS device IDs. Enforced unless `kms.allowAnyDevice` is true, so an empty list denies every device. |
+| `kms.allowAnyDevice` | No | If true, skip the device ID check for KMS. Defaults to false, which enforces `kms.devices`. |
 | `apps.<appId>.composeHashes` | No | Allowed compose hashes for this app |
-| `apps.<appId>.devices` | No | Allowed device IDs for this app |
-| `apps.<appId>.allowAnyDevice` | No | If true, skip device ID check for this app |
+| `apps.<appId>.devices` | No | Allowed device IDs for this app. Enforced unless `allowAnyDevice` is true, so an empty list denies every device. |
+| `apps.<appId>.allowAnyDevice` | No | If true, skip the device ID check for this app. Defaults to false, which enforces `devices`. |
 
 For experimental AMD SEV-SNP dry-run authorization, keep the default fail-closed TCB policy unless you intentionally want the auth webhook to accept non-up-to-date verifier-derived SNP `BootInfo`. To exercise the dry-run path without enabling key release, allowlist the recomputed SNP `mrAggregated`, `osImageHash`, app/compose identity, device/chip identity, and any non-default `allowedTcbStatuses`/`allowedAdvisoryIds` values explicitly. KMS still rejects SNP before returning app keys, KMS keys, or app certificates.
 
@@ -208,7 +208,7 @@ KMS boot authorization.
 2. Every `advisoryIds` entry must be listed in `allowedAdvisoryIds` (default: none allowed)
 3. `osImageHash` must be in `osImages` array
 4. `mrAggregated` must be in the `kms.mrAggregated` early/boot-mr-done allowlist
-5. `deviceId` must be in `kms.devices` unless `allowAnyDevice` is true
+5. `deviceId` must be in `kms.devices` unless `allowAnyDevice` is true. An empty `kms.devices` with `allowAnyDevice: false` denies every device, matching `DstackApp.isAppAllowed`.
 
 ### App Boot Validation
 
@@ -217,7 +217,7 @@ KMS boot authorization.
 3. `osImageHash` must be in `osImages` array
 4. `appId` must exist in `apps` object
 5. `composeHash` must be in app's `composeHashes` array
-6. `deviceId` must be in app's `devices` (unless `allowAnyDevice` is true)
+6. `deviceId` must be in app's `devices` unless `allowAnyDevice` is true. An empty `devices` with `allowAnyDevice: false` denies every device, matching `DstackApp.isAppAllowed`.
 
 ## Hot Reload
 

dstack/kms/auth-simple/index.test.ts

@@ -421,4 +421,76 @@ describe('auth-simple', () => {
       expect(json.isAllowed).toBe(true);
     });
   });
+
+  // `DstackApp.isAppAllowed` denies when `!allowAnyDevice && !allowedDeviceIds[id]`,
+  // so an empty allowlist denies every device. auth-simple must agree: an
+  // operator who writes `allowAnyDevice: false` has asked for a restriction,
+  // and an empty list is the most restrictive one, not the absence of one.
+  describe('device restriction parity with DstackApp.sol', () => {
+    const OS_IMAGE = '0x1fbb0cf9cc6cfbf23d6b779776fabad2c5403d643badb9e5e238615e4960a78a';
+
+    // The on-chain rule, transcribed from DstackApp.sol:209.
+    const onChainAllows = (allowAnyDevice: boolean, devices: string[], deviceId: string) =>
+      allowAnyDevice || devices.map((d) => d.toLowerCase()).includes(deviceId.toLowerCase());
+
+    const appDecision = async (allowAnyDevice: boolean, devices: string[]) => {
+      writeTestConfig({
+        gatewayAppId: '0xgateway',
+        osImages: [OS_IMAGE],
+        apps: {
+          '0xapp123': { composeHashes: ['0xcompose456'], devices, allowAnyDevice }
+        }
+      });
+      const res = await app.fetch(new Request('http://localhost/bootAuth/app', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(baseBootInfo)
+      }));
+      return (await res.json()).isAllowed;
+    };
+
+    const kmsDecision = async (allowAnyDevice: boolean, devices: string[]) => {
+      writeTestConfig({
+        gatewayAppId: '0xgateway',
+        osImages: [OS_IMAGE],
+        kms: { mrAggregated: ['0xabc123'], devices, allowAnyDevice }
+      });
+      const res = await app.fetch(new Request('http://localhost/bootAuth/kms', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(baseBootInfo)
+      }));
+      return (await res.json()).isAllowed;
+    };
+
+    it('denies an app when the device restriction is on and the list is empty', async () => {
+      expect(await appDecision(false, [])).toBe(false);
+    });
+
+    it('denies the KMS when the device restriction is on and the list is empty', async () => {
+      expect(await kmsDecision(false, [])).toBe(false);
+    });
+
+    it('matches the on-chain decision for every allowAnyDevice/devices pairing', async () => {
+      const cases: Array<[boolean, string[]]> = [
+        [false, []],
+        [false, ['0xdevice999']],
+        [false, ['0xotherdevice']],
+        [true, []],
+        [true, ['0xotherdevice']]
+      ];
+
+      for (const [allowAnyDevice, devices] of cases) {
+        const expected = onChainAllows(allowAnyDevice, devices, baseBootInfo.deviceId);
+        expect(
+          await appDecision(allowAnyDevice, devices),
+          `app: allowAnyDevice=${allowAnyDevice} devices=${JSON.stringify(devices)}`
+        ).toBe(expected);
+        expect(
+          await kmsDecision(allowAnyDevice, devices),
+          `kms: allowAnyDevice=${allowAnyDevice} devices=${JSON.stringify(devices)}`
+        ).toBe(expected);
+      }
+    });
+  });
 });

dstack/kms/auth-simple/index.ts

@@ -28,6 +28,9 @@ const BootResponseSchema = z.object({
 });
 
 // config schema
+// `allowAnyDevice: false` means the device allowlist is enforced, and an empty
+// allowlist therefore denies every device — the same rule as
+// `DstackApp.isAppAllowed`. Opting out of the restriction is `allowAnyDevice: true`.
 const AppConfigSchema = z.object({
   composeHashes: z.array(z.string()).default([]),
   devices: z.array(z.string()).default([]),
@@ -149,7 +152,7 @@ class ConfigBackend {
     // check device ID
     if (!config.kms.allowAnyDevice) {
       const allowedDevices = config.kms.devices.map(normalizeHex);
-      if (allowedDevices.length > 0 && !allowedDevices.includes(deviceId)) {
+      if (!allowedDevices.includes(deviceId)) {
         return {
           isAllowed: false,
           reason: 'KMS is not allowed to boot on this device',
@@ -195,7 +198,7 @@ class ConfigBackend {
     // check device ID
     if (!appConfig.allowAnyDevice) {
       const allowedDevices = appConfig.devices.map(normalizeHex);
-      if (allowedDevices.length > 0 && !allowedDevices.includes(deviceId)) {
+      if (!allowedDevices.includes(deviceId)) {
         return {
           isAllowed: false,
           reason: 'app is not allowed to boot on this device',