I&#x27;m the person who is running the rav1d bounty, also involved with the Rustls project.In many (most?) situations I think Rust is effectively as fast as C, but it&#x27;s not a given. They&#x27;re close enough that depending on the situation, one can be faster than the other.If you told me I had to make a larger and more complex piece of code fast though, I&#x27;d pick Rust. Because of the rules that the Rust compiler enforces, it&#x27;s easier to have confidence in the correctness of your code and that really frees you up when you&#x27;re dealing with multi-threaded or algorithmic complexity. For example, you can be more confident about how little locking you can get away with, what the minimum amount of time is that you need to keep some memory around, or what exact state is possible and thus needs to be handled at any given time.There are some things that make rav1d performance particularly challenging. For example - unlike Rustls, which was written from the start in Rust, rav1d is largely the result of C to Rust translation. This means the code is mostly not idiomatic Rust, and the Rust compiler is generally more optimized for idiomatic Rust. How much this particular issue contributes to the performance gap I don&#x27;t know, but it&#x27;s a suspect and to the extent that it&#x27;s worth pursuing, one would probably want to figure out where being idiomatic matters most instead of blanket rewriting everything.

&gt; I don&#x27;t like the RiiR cult.For certain types of people, Rust has a way of just feeling better to use. After learning Rust I just can&#x27;t imagine choosing to use C or C++ for a future project ever again. Rust is just too good.

I stole these graphs for a branch of that thread ffmpeg started on twitter. The one where they were flaming rav1d vs dav1d performance to attack Rust generally.I don&#x27;t like the RiiR cult. I do like smart use of a safer language and think long-term it can get better than C++ with the right work.

In Rustls, TLS is implemented entirely in Rust. It uses aws-lc-rs [1] for cryptography, and aws-lc-rs uses assembly for core cryptographic routines, which are wrapped in some C code, which then exposes a Rust API which Rustls uses.It&#x27;s not practical right now to write high performance cryptographic code in a secure way (e.g. without side channels) in anything other than assembly.[1] <a href="https:&#x2F;&#x2F;github.com&#x2F;aws&#x2F;aws-lc-rs">https:&#x2F;&#x2F;github.com&#x2F;aws&#x2F;aws-lc-rs</a>

Is not rustls a mix of c++, assembly and rust ?I think it’s not a good indication of the success of the language.

I, with passion, do not agree with this. I think after embedded and other systems-programming&#x2F;bare-metal applications, PC applications with GUI is rust&#x27;s best use case.With this in mind, I&#x27;m curious: What do you feel are good use cases for Rust?

&gt; Too bad there are those who think they should use Rust to write GUIs and end-user applications, which is where Rust ergonomics breaks down fast.Disagree here, happy that those people are experimenting, and Rust is being used all the way up and down the stack. I may not prefer using Rust for web pages, but I&#x27;m super glad that some people want to -- projects like Dioxus and Tauri are really fantastic to use, and reflect well on the ecosystem as a whole.I think Rust gained from this enthusiasm, because it&#x27;s one of the languages that I think goes almost everywhere, if you pay the high upfront cost of learning. There really aren&#x27;t that many domains where you absolutely couldn&#x27;t write Rust. The fact that Swift is also chasing this quality suggests it&#x27;s valuable.

Rust was made for this kind of thing.Too bad there are those who think they should use Rust to write GUIs and end-user applications, which is where Rust ergonomics breaks down fast.

At the risk of sounding like a crustacean cult member, really hope the skeptics read this post. No hype, no drama, just slow, steady high perf incremental improvement in a crucially important area without any feet blown off.I feel bad for other&#x2F;new system languages, you get so much for the steeper learning curve with Rust (cult membership optional). And I think it’s genuinely difficult to reproduce Rust’s feature set.

This report contains more details about the results discussed in the blog post:<a href="https:&#x2F;&#x2F;rustls.dev&#x2F;perf&#x2F;2024-11-28-threading&#x2F;" rel="nofollow">https:&#x2F;&#x2F;rustls.dev&#x2F;perf&#x2F;2024-11-28-threading&#x2F;</a>

I wish they included details on how they ran these benchmarks, like they did last year [1].I&#x27;d like to take a look and try to understand why there&#x27;s such a big difference in handshake performance. I wouldn&#x27;t expect single threaded handshake performance to vary so much between stacks... it should be mostly limited by crypto operations. Last time, they did say something about having a cpu optimization for handshaking that the other stack might not have, but this is on a different platform and they didn&#x27;t mention that.I&#x27;d also be interested in seeing what it looks like with OpenSSL 1.1.1, given the recent article from HAProxy about difficulties with OpenSSL 3 [2][1] <a href="https:&#x2F;&#x2F;www.memorysafety.org&#x2F;blog&#x2F;rustls-performance-outperforms&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.memorysafety.org&#x2F;blog&#x2F;rustls-performance-outperf...</a>[2] <a href="https:&#x2F;&#x2F;www.haproxy.com&#x2F;blog&#x2F;state-of-ssl-stacks" rel="nofollow">https:&#x2F;&#x2F;www.haproxy.com&#x2F;blog&#x2F;state-of-ssl-stacks</a>

I&#x27;m not a Rust guy and I probably won&#x27;t be any time soon, but Rustls is such an exciting project in my eyes. Projects like BoringSSL are cool and noble in their intentions, but having something that&#x27;s not just a hygienic codebase but an implicitly safer one feels deeply satisfying. I&#x27;m eagerly looking forward to this finding its way into production use cases.

I should probably help with that whole OpenSSL compat. thing. Is there guidance somewhere or should I just find something interesting to implement and send over a PR ?

Rustls has two C APIs.The first is C bindings for the native Rustls API. This should work great for anyone who wants to use Rustls from C, but it means writing to the Rustls API.The second is C bindings that provide OpenSSL compatibility. This only supports a subset of the OpenSSL API (enough for Nginx but not yet HAProxy, for example), so not everything that uses OpenSSL will work with the Rustls OpenSSL compatibility layer yet. We are actively improving the amount of OpenSSL API surface that we support.

The default cryptographic back-end for Rustls, aws-lc-rs, is FIPS compliant and integrated in a FIPS-compliant way so it&#x27;s easy to get FIPS compliance with Rustls.

Would love to see compliance and accreditation coming through for native rusttls, like FIPS. That&#x27;ll unlock a large potential market, which can in turn unlock other markets.You can get FIPS by using some of the third party back-end integration via aws-lc-rs.

Also in referent news: &quot;The State of TLS Stacks&quot; by HAProxy devs <a href="https:&#x2F;&#x2F;www.haproxy.com&#x2F;blog&#x2F;state-of-ssl-stacks" rel="nofollow">https:&#x2F;&#x2F;www.haproxy.com&#x2F;blog&#x2F;state-of-ssl-stacks</a> <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=43912164">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=43912164</a>TLDR OpenSSL days seem to be coming to an end, but Rustls C bindings add not production ready yet.

I think it is worth optimizing, there&#x27;s a noticable, but small, dip in handshakes per second going from 1 to 2 threads.If I were to optimize it, and the cycling rate is fixed and long, I would have the global storage be behind a simple Mutex, and be something like (Expiration, oldval, newval), on use, check a threadlocal copy, use it if it&#x27;s not expired, otherwise lock the global, if the global is not expired, copy it to thread local. If the global is expired, generate a new one, saving the old value so that the previous generation tickets are still valid.You can use a simple Mutex, because contention is limited to the expiration window. You could generate a new ticket secret outside the lock to reduce the time spent while locked, at the expense of generating a ticket secret that&#x27;s immediately discarded for each thread except the winning thread. Not a huge difference either way, unless you cycle tickets very frequently, or run a very large number of threads.

AIUI epoch GC doesn&#x27;t require Arc&#x27;s atomic increment&#x2F;decrement operations which can be slower than naive loads (<a href="https:&#x2F;&#x2F;codeberg.org&#x2F;nyanpasu64&#x2F;cachebash" rel="nofollow">https:&#x2F;&#x2F;codeberg.org&#x2F;nyanpasu64&#x2F;cachebash</a>), but at this point we&#x27;re getting into nano-optimization territory.

We tried this when we were benchmarking and it was not significantly better than the Arc&lt;RwLock&lt;_&gt;&gt; that we&#x27;re using now.

You might like <a href="https:&#x2F;&#x2F;docs.rs&#x2F;arc-swap&#x2F;latest&#x2F;arc_swap&#x2F;" rel="nofollow">https:&#x2F;&#x2F;docs.rs&#x2F;arc-swap&#x2F;latest&#x2F;arc_swap&#x2F;</a>

I wonder if replacing the encryption key every 6 hours would be a good use case for a crossbeam-epoch, though this may be premature optimization, and that library requires writing unsafe code as far as I can tell.

That was rls, but I can see what you mean from the name of the package once I looked at it again.<a href="https:&#x2F;&#x2F;github.com&#x2F;rust-lang&#x2F;rls">https:&#x2F;&#x2F;github.com&#x2F;rust-lang&#x2F;rls</a>

That name is confusing. Reading the headline, I first thought it was about the deprecated language server and was very confused.

Did you file an issue or ask in the rustls Discord channel? We&#x27;re happy to help.

The irony is that due to CA stores (and how verification is handled) it&#x27;s usually a tad more ficklish to replace TLS clients than TLS servers.Was there no way to provide a custom CA store (that only included your self signed one)?

Wow this is fast.However I tried rustls with redis for my axum application, for some reason it was not working, even though my self signed ca certificate was updated in my system&#x27;s local CA store.After a lot of try I gave up then thought about trying native tls, and it worked in first go.

Yes the core thing everybody actually wants is the constant time cryptographic primitives, and it&#x27;s not at all practical to attempt those in a high level programming language like C or Rust, they&#x27;re always raw machine code, or - which is less awful to work with - assembler. So yeah it&#x27;s roughly the same code in all of the projects you mentioned - the correct machine code for a high quality ChaCha20 implementation on x86-64 is the same if the rest of your TLS implementation is C (OpenSSL) or Rust (rustls) or like, hand written Perl (please tell me nobody did this)Although of course the Rust compiler has no way to inspect this ChaCha20 primitive and check it is memory safe, we can &quot;vouch&quot; for it, and these primitives have been eyeballed by a huge number of people since they&#x27;re so widely used so it feels as reasonable as the claim that ChaCha20 itself works, which has been considered by plenty of cryptanalysis experts from government and industry.Pretty much everything else is Rust, so the bit-twiddling inside a DER implementation to parse certificates is Rust, the TLS handshake implementation is Rust, and so on.

Rustls uses aws-lc-rs for cryptography, which, roughly speaking, is based on the cryptography from BoringSSL, which is a heavily modified fork of OpenSSL from a long time ago. I&#x27;m not sure how similar OpenSSL and aws-lc-rs cryptography implementations are today (maybe someone else knows?), but it&#x27;s probably not accurate in a useful way to say that aws-lc-rs just uses cryptography from OpenSSL.In any case, OpenSSL does a whole bunch of things, and one of those is providing low-level cryptographic routines. When people talk about issues with OpenSSL, they&#x27;re usually not (in my experience) talking about issues with its low-level cryptographic routines. They&#x27;re talking about things like the TLS implementation and API.Rustls has its own Rust code for the TLS protocol and certificate parsing&#x2F;validation, which doesn&#x27;t come, directly or by lineage, from OpenSSL or any OpenSSL derivatives.

Out of curiosity, rustls uses aws-lc-rs which in turn uses aws-lc, which is in turn &quot;based on code from the Google BoringSSL project and the OpenSSL project.&quot;You&#x27;re trying to get rid of OpenSSL, but you&#x27;re actually relying on OpenSSL code. Sounds a bit iffy imo. Can somebody provide a bit more depth here?Or is it just the OpenSSL TLS API that is hopelessly confusing and bug inducing? I can imagine that the crypto primitives in OpenSSL are very solid.

Rustls Server-Side Performance