Add implementation for setting to disable Github extensions (#12838)

docs/get-started/configuration.md

@@ -490,6 +490,11 @@ their corresponding top-level category object in your `settings.json` file.
   - **Default:** `false`
   - **Requires restart:** Yes
 
+- **`security.blockGitExtensions`** (boolean):
+  - **Description:** Blocks installing and loading extensions from Git.
+  - **Default:** `false`
+  - **Requires restart:** Yes
+
 - **`security.folderTrust.enabled`** (boolean):
   - **Description:** Setting to track whether Folder trust is enabled.
   - **Default:** `false`

packages/cli/src/config/extension-manager.ts

@@ -128,6 +128,15 @@ export class ExtensionManager extends ExtensionLoader {
     installMetadata: ExtensionInstallMetadata,
     previousExtensionConfig?: ExtensionConfig,
   ): Promise<GeminiCLIExtension> {
+    if (
+      (installMetadata.type === 'git' ||
+        installMetadata.type === 'github-release') &&
+      this.settings.security?.blockGitExtensions
+    ) {
+      throw new Error(
+        'Installing extensions from remote sources is disallowed by your current settings.',
+      );
+    }
     const isUpdate = !!previousExtensionConfig;
     let newExtensionConfig: ExtensionConfig | null = null;
     let localSourcePath: string | undefined;
@@ -449,6 +458,13 @@ export class ExtensionManager extends ExtensionLoader {
 
     const installMetadata = loadInstallMetadata(extensionDir);
     let effectiveExtensionPath = extensionDir;
+    if (
+      (installMetadata?.type === 'git' ||
+        installMetadata?.type === 'github-release') &&
+      this.settings.security?.blockGitExtensions
+    ) {
+      return null;
+    }
 
     if (installMetadata?.type === 'link') {
       effectiveExtensionPath = installMetadata.source;

packages/cli/src/config/extension.test.ts

@@ -594,6 +594,34 @@ describe('extension tests', () => {
       consoleSpy.mockRestore();
     });
 
+    it('should not load github extensions if blockGitExtensions is set', async () => {
+      createExtension({
+        extensionsDir: userExtensionsDir,
+        name: 'my-ext',
+        version: '1.0.0',
+        installMetadata: {
+          type: 'git',
+          source: 'http://somehost.com/foo/bar',
+        },
+      });
+
+      const blockGitExtensionsSetting = {
+        security: {
+          blockGitExtensions: true,
+        },
+      };
+      extensionManager = new ExtensionManager({
+        workspaceDir: tempWorkspaceDir,
+        requestConsent: mockRequestConsent,
+        requestSetting: mockPromptForSettings,
+        settings: blockGitExtensionsSetting,
+      });
+      const extensions = await extensionManager.loadExtensions();
+      const extension = extensions.find((e) => e.name === 'my-ext');
+
+      expect(extension).toBeUndefined();
+    });
+
     describe('id generation', () => {
       it('should generate id from source for non-github git urls', async () => {
         createExtension({
@@ -876,6 +904,30 @@ describe('extension tests', () => {
       fs.rmSync(targetExtDir, { recursive: true, force: true });
     });
 
+    it('should not install a github extension if blockGitExtensions is set', async () => {
+      const gitUrl = 'https://somehost.com/somerepo.git';
+      const blockGitExtensionsSetting = {
+        security: {
+          blockGitExtensions: true,
+        },
+      };
+      extensionManager = new ExtensionManager({
+        workspaceDir: tempWorkspaceDir,
+        requestConsent: mockRequestConsent,
+        requestSetting: mockPromptForSettings,
+        settings: blockGitExtensionsSetting,
+      });
+      await extensionManager.loadExtensions();
+      await expect(
+        extensionManager.installOrUpdateExtension({
+          source: gitUrl,
+          type: 'git',
+        }),
+      ).rejects.toThrow(
+        'Installing extensions from remote sources is disallowed by your current settings.',
+      );
+    });
+
     it('should prompt for trust if workspace is not trusted', async () => {
       vi.mocked(isWorkspaceTrusted).mockReturnValue({
         isTrusted: false,

packages/cli/src/config/settingsSchema.ts

@@ -1102,6 +1102,15 @@ const SETTINGS_SCHEMA = {
         description: 'Disable YOLO mode, even if enabled by a flag.',
         showInDialog: true,
       },
+      blockGitExtensions: {
+        type: 'boolean',
+        label: 'Blocks extensions from Git',
+        category: 'Security',
+        requiresRestart: true,
+        default: false,
+        description: 'Blocks installing and loading extensions from Git.',
+        showInDialog: true,
+      },
       folderTrust: {
         type: 'object',
         label: 'Folder Trust',

schemas/settings.schema.json

@@ -997,6 +997,13 @@
           "default": false,
           "type": "boolean"
         },
+        "blockGitExtensions": {
+          "title": "Blocks extensions from Git",
+          "description": "Blocks installing and loading extensions from Git.",
+          "markdownDescription": "Blocks installing and loading extensions from Git.\n\n- Category: `Security`\n- Requires restart: `yes`\n- Default: `false`",
+          "default": false,
+          "type": "boolean"
+        },
         "folderTrust": {
           "title": "Folder Trust",
           "description": "Settings for folder trust.",