Microsoft is rewriting their core libraries Windows in the Rust programming language, and the more memory-safe code has already reached developers.
David “dwizzle” Weston, director of OS security for Windows, announced the arrival of Rust in the operating system core at BlueHat IL 2023 in Tel Aviv, Israel, last month.
"We're actually going to have Windows boot with Rust in the kernel in the next few weeks or months, which will be really cool," Reported. "The main goal here was to convert some of the internal data types from C++ to their Rust equivalents."
Microsoft showed interest in Rust several years ago as a way to detect and eliminate in-memory security flaws. These bugs are at the heart of about 70% of the security vulnerabilities included in the CVE list and patched by Windows developers since 2006.
Last September, an informal order was given: Microsoft Azure CTO Mark Russinovich said new software projects should use Rust, not C/C++.
Windows' transition to Rust began in 2020 with DWriteCore, the engine's Windows App SDK DWrite of Windows for analysis text, layout and performance. DWriteCore now consists of about 152.000 lines of code in Rust and about 96.000 lines of code in C++.
In addition to the supposed security improvement, performance is reported to be 5 to 15% faster by replacing OpenType Library Services.
All of these are already available to Windows developers.
The Microsoft Windows graphics device interface (Win32 GDI) is currently ported to Rust and has 36.000 lines of code. The latest version of Windows 11 it launches with the Rust build, which passes all GDI tests, but the Rust port is currently disabled behind a feature flag.
"There's actually a SysCall in the Windows kernel now that runs on Rust," Weston said.
But "the reenrollment of Windows to Rust probably isn't going to happen anytime soon," said Weston, "while we love Rust, we need a strategy that includes securing more native code."
