Google Online Security Blog: Open-sourcing Sandboxed API

Open-sourcing Sandboxed API

18 март 2019 г.

Posted by Christian Blichmann & Robert Swiecki, ISE Sandboxing team

memory corruption bugspath traversalsandboxingremote code executionSandbox once, use anywhereSandboxed APISandbox2Overview

The resulting API of the SAPI object is similar to the one of the original library. For example, when using zlib, the popular compression library, a code snippet like this compresses a chunk of data (error handling omitted for brevity):
void Compress(const std::string& chunk, std::string* out) { z_stream zst{}; constexpr char kZlibVersion[] = "1.2.11"; CHECK(deflateInit_(&zst, /*level=*/4, kZlibVersion, sizeof(zst)) == Z_OK);
zst.avail_in = chunk.size(); zst.next_in = reinterpret_cast<uint8_t*>(&chunk[0]); zst.avail_out = out->size(); zst.next_out = reinterpret_cast<uint8_t*>(&(*out)[0]); CHECK(deflate(&zst, Z_FINISH) != Z_STREAM_ERROR); out->resize(zst.avail_out);
deflateEnd(&zst); }
Using Sandboxed API, this becomes: void CompressSapi(const std::string& chunk, std::string* out) { sapi::Sandbox sandbox(sapi::zlib::zlib_sapi_embed_create()); CHECK(sandbox.Init().ok()); sapi::zlib::ZlibApi api(&sandbox);
sapi::v::Array<uint8_t> s_chunk(&chunk[0], chunk.size()); sapi::v::Array<uint8_t> s_out(&(*out)[0], out->size()); CHECK(sandbox.Allocate(&s_chunk).ok() && sandbox.Allocate(&s_out).ok()); sapi::v::Struct<sapi::zlib::z_stream> s_zst; constexpr char kZlibVersion[] = "1.2.11"; sapi::v::Array<char> s_version(kZlibVersion, ABSL_ARRAYSIZE(kZlibVersion)); CHECK(api.deflateInit_(s_zst.PtrBoth(), /*level=*/4, s_version.PtrBefore(), sizeof(sapi::zlib::z_stream).ValueOrDie() == Z_OK));
CHECK(sandbox.TransferToSandboxee(&s_chunk).ok()); s_zst.mutable_data()->avail_in = chunk.size(); s_zst.mutable_data()->next_in = reinterpet_cast<uint8_t*>(s_chunk.GetRemote()); s_zst.mutable_data()->avail_out = out->size(); s_zst.mutable_data()->next_out = reinterpret_cast<uint8_t*>(s_out.GetRemote()); CHECK(api.deflate(s_zst.PtrBoth(), Z_FINISH).ValueOrDie() != Z_STREAM_ERROR); CHECK(sandbox.TransferFromSandboxee(&s_out).ok()); out->resize(s_zst.data().avail_out);
CHECK(api.deflateEnd(s_zst.PtrBoth()).ok()); }Try for yourself
Bazel sudo apt-get install python-typing python-clang-7 libclang-7-dev linux-libc-dev git clone github.com/google/sandboxed-api && cd sandboxed-api bazel test //sandboxed_api/examples/stringop:main_stringopGetting Startedexamples for Sandboxed APIWhere do we go from here?

Support more operating systems - So far, only Linux is supported. We will look into bringing Sandboxed API to the Unix-like systems like the BSDs (FreeBSD, OpenBSD) and macOS. A Windows port is a bigger undertaking and will require some more groundwork to be done.

New sandboxing technologies - With things like hardware-virtualization becoming almost ubiquitous, confining code into VMs for sandboxing opens up new possibilities.

Build system - Right now, we are using Bazel to build everything, including dependencies. We acknowledge that this is not how everyone will want to use it, so CMake support is high on our priority list.

Spread the word - Use Sandboxed API to secure open source projects. If you want to get involved, this work is also eligible for the Patch Reward Program.

Get involved
We are constantly looking at improving Sandboxed API and Sandbox2 as well as adding more features: supporting more programming runtimes, different operating systems or alternative containment technologies.
Check out the Sandboxed API GitHub repository. We will be happy to consider your contributions and look forward to any suggestions to help improve and extend this code.

Няма коментари :

Публикуване на коментар

Security Blog

Open-sourcing Sandboxed API

Няма коментари :

Етикети

Archive

Feed