On 12/12/20 4:57 PM, John-Mark Gurney wrote: > John Baldwin wrote this message on Sat, Dec 12, 2020 at 11:40 -0800: >> On 12/10/20 10:46 PM, John-Mark Gurney wrote: >>> I have not heard if OpenSSL has bother to address the breakage of >>> /dev/crypto that also recently came up, but it does appear that they >>> are no longer a good fit for FreeBSD. >> >> I think I can't disagree more. In terms of /dev/crypto, see here: >> >> https://github.com/openssl/openssl/pull/13468 > > I went back to the original PR that rewrote /dev/crypto: > https://github.com/openssl/openssl/pull/3744 > > The PR was submitted in June 2017, and they tested on FreeBSD 8.4-R, > which had support end on June 2015. Even back in 2017, it was easy > enough w/ VMs and cloud compute to spin up a modern, supported > FreeBSD box. > > Yes, it's good that it's now getting fixed, 3 years after it was broken. > > If FreeBSD is going to continue to use OpenSSL, better testing needs to > be done to figure out such breakage earliers, and how to not have them > go undetected for so long.
At some point the onus is also on FreeBSD to keep things working as well. In practice, our kernel crypto interface is pretty crappy (hopefully less crappy in 13, but there is still room for improvement). Also, when I have tested it with actual offload hardware, it doesn't really compete with native AES instructions on the CPU running in userland. KTLS does help because you can use sendfile, but /dev/crypto is not a win in my testing. I had to make additional changes to teach the engine in 1.0.2 to use AES-GCM with the extensions needed for TLS as well as wire the user buffers to avoid copies, and with that I got a hardware co-processor to break even in with AES-NI in userland in terms of both throughput and CPU usage for HTTPS. sendfile-enabled KTLS, OTOH, is able to achieve significantly higher throughput. >> Also, OpenSSL has been perfectly fine to work with in terms of >> upstreaming KTLS. kaduk@ is an OpenSSL committer and has been >> helpful with helping me find reviewers for patches when needed >> as well. >> >> In terms of OpenSSL vs other SSL libraries, I'll defer to this: >> >> https://latacora.micro.blog/2018/04/03/cryptographic-right-answers.html > > I'll note that this article is more for a developer than the maintainer > of an OS. When FreeBSD has 5 year support cycles, things are slightly > different, otherwise I agree that the article is good advice (from my > brief reading/looking over). While it's true it is tailored for a developer, I think it is still relevant in its discussion of alternative SSL library implementations. I agree with Gordon's assessment that there aren't really other viable alternatives. >>> Even as it stands, FreeBSD has committed to supporting 12 for close >>> to a year longer than OpenSSL has for 1.1.1 meaning we will be in the >>> same situation we are w/ 11 in a few years. >>> >>> Assuming 13 releases w/ OpenSSL, we'll be even in a worse situation >>> than we are now. OpenSSL 3.0.0 has no support commitment announced >>> yet, and sticking with 1.1.1 for 13 will put us even in a worse >>> situation than we are today. >>> >>> What are peoples thoughts on how to address the support mismatch between >>> FreeBSD and OpenSSL? And how to address it? >> >> I do think the support mismatch questions are still real, and I'm not >> sure what the best answer is. My guess is that the the delay of >> 3.0.0 (which I had hoped would ship in 13.0) will mean that 1.1.1's >> lifetime will get extended, but probably not enough to cover 13.x >> for 5 years. One option may be that we provide a compat openssl for >> 13.x that is 1.1.1 for things built on the head of the branch but >> actually import OpenSSL 3.0.0 into stable/13 at some point. You could >> do this with a shlib major version bump. It won't solve all problems >> if some shared library linked against 1.1.1 returns some object >> allocated by libssl that the application tries to use directly (and >> the application is linked against 3.0.0), but I'm not sure how common >> that situation will be in practice. OpenSSL isn't libc where you have >> issues with malloc/free crossing this sort of boundary. > > In the case of mixed 1.1.1 and 3.0.0, that should just be disallowed. > > Though importing 3.0.0 doesn't solve the issue if 1.1.1 has a security > problem... Because the security problem in 1.1.1 will still need to be > addressed to deal w/ all the applications that are linked against it.. If we import 3.0.0 into, say, 13.2, then when 13.0/13.1 are EOLd we are no longer having to maintain 1.1.1 in 13. If people want to keep older applications built on unsupported releases still working without recompiling, etc. they will have to manage that themselves. Currently we don't support 12.0 on the 12.x branch for example. -- John Baldwin _______________________________________________ freebsd-security@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-security To unsubscribe, send any mail to "freebsd-security-unsubscr...@freebsd.org"
