no_std support

[roblabla]

With alloc now stable since 1.36 (released last month) it'd be nice to have this crate support no_std (perhaps behind a feature gate to keep compatibility with rust 1.31). My end-goal is to have the RSA crate working in no_std environments.

[dignifiedquire]

I agree, this would be great, I don't have any experience in turning things no_std compatible though, so happy to get some help with this.

[roblabla]

Awesome, I'll get to work on this then.