For those not familiar: until OpenSSL 3.4.1, if you wanted use OpenSSL and wanted to implement HTTP/3, which uses QUIC as the underlying protocol, you had to use their entire QUIC stack; you couldn't have a QUIC implementation and only use OpenSSL for the encryption parts.

QUIC, for those not familiar, is basically "what if we re-implemented TCP's functionality on top of UDP, but we could throw out all the old legacy crap". Complicated but interesting, except that if OpenSSL's implementation didn't do what you want or didn't do it well, you either had to put up with it or go use some other SSL library somewhere else. That meant that if you were using e.g. curl built against OpenSSL then curl also inherently had to use OpenSSL's QUIC implementation even if there were better ones available.

Daniel Stenberg from Curl wrote a great blog post about how bad and dumb that was if anyone is interested. https://daniel.haxx.se/blog/2026/01/17/more-http-3-focus-one...

The HAProxy people wrote a very good blog post on the state of SSL stacks: https://www.haproxy.com/blog/state-of-ssl-stacks And the Python cryptography people wrote an even more damning indictment: https://cryptography.io/en/latest/statements/state-of-openss...

Here are some juicy quotes:

> With OpenSSL 3.0, an important goal was apparently to make the library much more dynamic, with a lot of previously constant elements (e.g., algorithm identifiers, etc.) becoming dynamic and having to be looked up in a list instead of being fixed at compile-time. Since the new design allows anyone to update that list at runtime, locks were placed everywhere when accessing the list to ensure consistency.

> After everything imaginable was done, the performance of OpenSSL 3.x remains highly inferior to that of OpenSSL 1.1.1. The ratio is hard to predict, as it depends heavily on the workload, but losses from 10% to 99% were reported.

> OpenSSL 3 started the process of substantially changing its APIs — it introduced OSSL_PARAM and has been using those for all new API surfaces (including those for post-quantum cryptographic algorithms). In short, OSSL_PARAM works by passing arrays of key-value pairs to functions, instead of normal argument passing. This reduces performance, reduces compile-time verification, increases verbosity, and makes code less readable.

The software quality side of OpenSSL paradoxically probably regressed since Heartbleed: there's a rough consensus that the design of OpenSSL 3.0 was a major step backwards, not least for performance, and more than one large project (but most notably pyca/cryptography) is actively considering moving away from OpenSSL entirely as a result. Again: while security concerns might be an ancillary issue in those potential migrations, the core issue is just that OpenSSL sucks to work with now.