A cryptographically secure bootloader for RISC-V in Rust

Re:A cryptographically secure bootloader for RISC-V in Rust by bri3d on Tuesday August 06, 2024 @01:52PM (#41173333)

The layers don't really matter. Any side-effect or implementation detail (especially in a language with an optimizing compiler) is not a good protection against side channel attacks.

Where Rust (and most languages with a robust type system) can help prevent side channel issues is via typing - all cryptographic operations in a given library can be implemented with (for example), a TimingSafeU32 type that only implements constant-time operations (comparison, multiplication, addition, etc). This massively reduces the opportunity for mistakes. Traits make implementing this type of system much easier and more elegant.

`rust-timing-shield` and `subtle` are both a good example here, as well as really everything in https://github.com/dalek-cryptography .

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Re:A cryptographically secure bootloader for RISC-V in Rust by throwawaymaths on Wednesday August 07, 2024 @11:13AM (#41182268)

I'd be more worried about early exits from loops in an iterator, e.g. if you had a .any() derived function, or short-circuiting logic in boolean operators with a lazily evaluated second parameter. A type system won't protect you from that.

Or maybe an early return and having an expensive destructor called as it goes out of phase with RAII

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