If you want to do this well, as other commenters pointed out, your entire C library interface is going to have to change to accept bounded arrays instead of pointers and lengths as separate arguments, or worse, just pointers and implicit lengths by looking for the NUL character. But then you've given up the ability to directly call into existing code; everything is at best using a little translation layer to check bounds before/after passing buffers to outside functions. So the advantage of staying in the language is minimal (note that you've given up on "C strings" entirely), and if you're going to have all of this, you might as well use a language with compile-time checks (types, etc.) that you're doing all of this right.

Rust and Go are not your only choices here. C++ with aggressive use of modern features and aggressive non-use of everything inherited from C is also a fine choice, but enforcing that discipline is hard, and the compiler won't help you a lot. Honestly, a dynamic language like Python or Ruby is also a fine choice in many cases, although NTP might be too latency-sensitive for that to work. (But it might not be! Premature optimization and all that.)