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?? Surely Rust would have helped against heartbleed? I mean, some servers were leaking private keys because they sent random segments of memory back to clients.

gsnedders 9y ago
The problem is they implementing their own memory management on top of the standard primitives; they never sent unallocated memory to the client.
- the8472 9y ago
  rust can also help you make custom memory management safer, e.g. there are several arena crates which hand out allocations with lifetimes, which means the arenas won't be freed before all references went out of scope. And there also is no pointer arithmetic into the arena, you only interact with individual allocations. I don't know if it would have prevented heartbleed, but it enables 3rd-party allocators to provide the same safety guarantees as the rust standard lib does. Something that cannot be said about C because there are no safety guarantees in C in the first place.
  - klodolph 9y ago
    There are some safety guarantees in C, it's just that Rust has more. Rust doesn't guarantee total safety, just like C doesn't mean no safety.
Manishearth 9y ago
It's ... debatable. Heartbleed implemented their own memory management system (and had a bug in their use of it). This is pretty unusual even in C. It's extremely unusual in Rust, but who's to say that a similar implementation in Rust would come across the same challenges and implement their own memory management too? And write the same bug? Ultimately this kind of system would be unsafe code anyway, so Rust won't help you there. The question is if a Rust programmer would design such a thing (it's very non-Rust-y). The answer is probably "no". However, the same can be said about C programmers and the heartbleed code, so you have a bit of a no-true-scotsman vibe happening here. So, yes, heartbleed could have happened in Rust too. I do feel it's less likely (Rust more strongly forces you to compartmentalize unsafe abstractions), but all of that is really debatable.
- youdontknowtho 9y ago
  Yeah, the openssl codebase was pretty crazy due to cross platform support over multiple decades...I guess it grew organically and turned into a enough of a mess that the OpenBSD team started the libressl project. There are some pretty good youtube videos about the work that they did.
- petters 9y ago
  Thank you for the clarification.

gsnedders 9y ago

The problem is they implementing their own memory management on top of the standard primitives; they never sent unallocated memory to the client.

the8472 9y ago
rust can also help you make custom memory management safer, e.g. there are several arena crates which hand out allocations with lifetimes, which means the arenas won't be freed before all references went out of scope. And there also is no pointer arithmetic into the arena, you only interact with individual allocations. I don't know if it would have prevented heartbleed, but it enables 3rd-party allocators to provide the same safety guarantees as the rust standard lib does. Something that cannot be said about C because there are no safety guarantees in C in the first place.
- klodolph 9y ago
  There are some safety guarantees in C, it's just that Rust has more. Rust doesn't guarantee total safety, just like C doesn't mean no safety.

Manishearth 9y ago

It's ... debatable. Heartbleed implemented their own memory management system (and had a bug in their use of it). This is pretty unusual even in C. It's extremely unusual in Rust, but who's to say that a similar implementation in Rust would come across the same challenges and implement their own memory management too? And write the same bug? Ultimately this kind of system would be unsafe code anyway, so Rust won't help you there. The question is if a Rust programmer would design such a thing (it's very non-Rust-y). The answer is probably "no". However, the same can be said about C programmers and the heartbleed code, so you have a bit of a no-true-scotsman vibe happening here. So, yes, heartbleed could have happened in Rust too. I do feel it's less likely (Rust more strongly forces you to compartmentalize unsafe abstractions), but all of that is really debatable.

youdontknowtho 9y ago
Yeah, the openssl codebase was pretty crazy due to cross platform support over multiple decades...I guess it grew organically and turned into a enough of a mess that the OpenBSD team started the libressl project. There are some pretty good youtube videos about the work that they did.
petters 9y ago
Thank you for the clarification.