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How do I sandbox CPython using OS features? (Genuine question, I've been trying to find reliable, well documented, robust patterns for doing this for years! I

by simonw 9mo ago

How do I sandbox CPython using OS features? (Genuine question, I've been trying to find reliable, well documented, robust patterns for doing this for years! I need it across macOS and Linux and ideally Windows too. Preferably without having to run anything as root.)

OutOfHere 9mo ago
Docker and other container runners allow it. https://containers.dev/ https://containers.dev/ allows it too. https://github.com/microsoft/litebox https://github.com/microsoft/litebox might somehow allow it too if a tool can be built on top of it, but there is no documentation.
- simonw 9mo ago
  Every time I use Docker as a sandbox people warn me to watch out for "container escapes". I trust Firecracker more because it was built by AWS specifically to sandbox Lambdas, but it doesn't work on macOS and is pretty fiddly to run on Linux.
  - OutOfHere 9mo ago
    I think ChatGPT can do a much better job than I can for guiding how to safely use Docker as a sandbox: /share/69875282-1e38-8012-b627-7c0a678f9365 It's not industrial-grade safety for public use, but it'll do for personal use. Other tools for it are also mentioned.
  - its-summertime 9mo ago
    Outside of VM usage, the answer seems to be (on top of containerization and selinux) writing a tight seccomp filter. Gleaned from https://github.com/containers/bubblewrap/blob/0c408e156b12ddc9097b06ce0a7bdab7085a9af2/README.md#system-security https://github.com/containers/bubblewrap/blob/0c408e156b12dd... and https://github.com/containers/bubblewrap/tree/0c408e156b12ddc9097b06ce0a7bdab7085a9af2/demos https://github.com/containers/bubblewrap/tree/0c408e156b12dd...
nickpsecurity 9mo ago
It could be difficult. My first thought would be a SELinux policy like this article attempted: https://danwalsh.livejournal.com/28545.html https://danwalsh.livejournal.com/28545.html One might have different profiles with different permissions. A network service usually wouldn't need your hone directory while a personal utility might not need networking. Also, that concept could be mixed with subprocess-style sandboxing. The two processes, main and sandboxed, might have different policies. The sandboxed one can only talk to main process over a specific channel. Nothing else. People usually also meter their CPU, RAM, etc. INTEGRITY RTOS had language-specific runtimes, esp Ada and Java, that ran directly on the microkernel. A POSIX app or Linux VM could run side by side with it. Then, some middleware for inter-process communication let them talk to each other.

by simonw 9mo ago

OutOfHere 9mo ago

Docker and other container runners allow it. https://containers.dev/ https://containers.dev/ allows it too. https://github.com/microsoft/litebox https://github.com/microsoft/litebox might somehow allow it too if a tool can be built on top of it, but there is no documentation.

simonw 9mo ago
Every time I use Docker as a sandbox people warn me to watch out for "container escapes". I trust Firecracker more because it was built by AWS specifically to sandbox Lambdas, but it doesn't work on macOS and is pretty fiddly to run on Linux.
- OutOfHere 9mo ago
  I think ChatGPT can do a much better job than I can for guiding how to safely use Docker as a sandbox: /share/69875282-1e38-8012-b627-7c0a678f9365 It's not industrial-grade safety for public use, but it'll do for personal use. Other tools for it are also mentioned.
- its-summertime 9mo ago
  Outside of VM usage, the answer seems to be (on top of containerization and selinux) writing a tight seccomp filter. Gleaned from https://github.com/containers/bubblewrap/blob/0c408e156b12ddc9097b06ce0a7bdab7085a9af2/README.md#system-security https://github.com/containers/bubblewrap/blob/0c408e156b12dd... and https://github.com/containers/bubblewrap/tree/0c408e156b12ddc9097b06ce0a7bdab7085a9af2/demos https://github.com/containers/bubblewrap/tree/0c408e156b12dd...

nickpsecurity 9mo ago

It could be difficult. My first thought would be a SELinux policy like this article attempted: https://danwalsh.livejournal.com/28545.html https://danwalsh.livejournal.com/28545.html One might have different profiles with different permissions. A network service usually wouldn't need your hone directory while a personal utility might not need networking. Also, that concept could be mixed with subprocess-style sandboxing. The two processes, main and sandboxed, might have different policies. The sandboxed one can only talk to main process over a specific channel. Nothing else. People usually also meter their CPU, RAM, etc. INTEGRITY RTOS had language-specific runtimes, esp Ada and Java, that ran directly on the microkernel. A POSIX app or Linux VM could run side by side with it. Then, some middleware for inter-process communication let them talk to each other.