信頼できない JavaScript コードの実行

重要:これは JavaScript と TypeScript コードの実行についてのみ説明します。そうは言っても、この記述は、他のコードを他の言語で実行する方向にもなるかもしれません。

ユーザーがアプリケーション内でコードを実行できるようにすると、カスタマイズと機能の世界が開かれますが、プラットフォームが重大なセキュリティ脅威にさらされることにもなります。

それがuserコードであることを考えると、サーバーの停止 (無限ループの可能性があります) から機密情報の窃取まで、あらゆることが予想されます。

ユーザーの信頼の獲得: ユーザーが信頼できる場合でも、他の悪意のある人からコピーしたコードを実行する可能性があります。
環境を保護する: サーバーを停止するコードは絶対に避けてください。 (true) {} ながら考える

クロスサイト スクリプティング (XSS)。
サービス拒否 (DoS) 攻撃。
データの引き出し。適切な保護策がなければ、これらの脅威はアプリケーションの整合性とパフォーマンスを損なう可能性があります。

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2 番目の引数は関数本体です。

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function evaluate() { const { code, input } = JSON.parse(Host.inputString()); const func = eval(code); const result = func(input).toString(); Host.outputString(result); } module.exports = { evaluate };

You'll have to compile the above code first using Extism, which will output a Wasm file that can be run in an environment that has Wasm-runtime (browser or node.js).

const message = { input: '1,2,3,4,5', code: ` const sum = (str) => str .split(',') .reduce((acc, curr) => acc + parseInt(curr), 0); module.exports = sum; `, }; // continue running the wasm file

Docker

We're now moving to the server-side, Docker is a great option to run code in an isolation from the host machine. (Beware of container escape)

You can use dockerode to run the code in a container.

import Docker from 'dockerode'; const docker = new Docker(); const code = `console.log("hello world")`; const container = await docker.createContainer({ Image: 'node:lts', Cmd: ['node', '-e', code], User: 'node', WorkingDir: '/app', AttachStdout: true, AttachStderr: true, OpenStdin: false, AttachStdin: false, Tty: true, NetworkDisabled: true, HostConfig: { AutoRemove: true, ReadonlyPaths: ['/'], ReadonlyRootfs: true, CapDrop: ['ALL'], Memory: 8 * 1024 * 1024, SecurityOpt: ['no-new-privileges'], }, });

Keep in mind that you need to make sure the server has docker installed and running. I'd recommend having a separate server dedicated only to this that acts as a pure-function server.

Moreover, you might benefit from taking a look at sysbox, a VM-like container runtime that provides a more secure environment. Sysbox is worth it, especially if the main app is running in a container, which means that you'll be running Docker in Docker.

This was the method of choice at January but soon enough, the language capabilities mandated more than passing the code through the container shell. Besides, for some reason, the server memory spikes frequently; we run the code inside self-removable containers on every 1s debounced keystroke. (You can do better!)

Other options

• Web Containers
• MicroVM (Firecraker)
• Deno subhosting
• Wasmer
• ShadowRealms

Safest option

I'm particularly fond of Firecracker, but it’s a bit of work to set up, so if you cannot afford the time yet, you want to be on the safe side, do a combination of static analysis and time-boxing execution. You can use esprima to parse the code and check for any malicious act.

How to run TypeScript code?

Well, same story with one (could be optional) extra step: Transpile the code to JavaScript before running it. Simply put, you can use esbuild or typescript compiler, then continue with the above methods.

async function build(userCode: string) { const result = await esbuild.build({ stdin: { contents: `${userCode}`, loader: 'ts', resolveDir: __dirname, }, inject: [ // In case you want to inject some code ], platform: 'node', write: false, treeShaking: false, sourcemap: false, minify: false, drop: ['debugger', 'console'], keepNames: true, format: 'cjs', bundle: true, target: 'es2022', plugins: [ nodeExternalsPlugin(), // make all the non-native modules external ], }); return result.outputFiles![0].text; }

Notes:

• Rust-based bundlers usually offer a web assembly version, which means you can transpile the code in the browser. Esbuild does have a web assembly version.
• Don't include user specified imports into the bundle unless you've allow-listed them.

Additionally, you can avoid transpiling altogether by running the code usingDenoorBunin a docker container since they support TypeScript out of the box.

Conclusion

Running user code is a double-edged sword. It can provide a lot of functionality and customization to your platform, but it also exposes you to significant security risks. It’s essential to understand the risks and take appropriate measures to mitigate them and remember that the more isolated the environment, the safer it is.

References

• January instant compilation
• Running untrusted JavaScript in Node.js
• How do languages support executing untrusted user code at runtime?
• Safely Evaluating JavaScript with Context Data

以上が信頼できない JavaScript コードの実行の詳細内容です。詳細については、PHP 中国語 Web サイトの他の関連記事を参照してください。