This seems ill-advised. The protocol as documented is trivially exploitable by reflection attacks. The cat next door said one meow, and now every cat in the neighborhood is wailing in response.
There is a rustls side project called Graviola that's building a fast crypto provider in Rust+ASM. It's taken an interesting approach: starting with an assembly library that's been formally proven correct, and then programmatically translating that into Rust with inline assembly that's easy to build with Rust tooling.