Hello everyone, On Mon, Oct 16, 2017 at 5:18 PM, Ingo Schwarze <schwarze@xxxxxxx> wrote: > Hi Colin, > > Colin Watson wrote on Mon, Oct 16, 2017 at 10:26:03AM +0100: >> <snip> >> I realise that this is not the OpenSSH team's >> problem as such, and that as a LibreSSL developer you may well not be >> super-sympathetic to this argument; but nevertheless, I don't think this >> is a viable option right now for us as a distributor. > > I completely understand that you are in a difficult situation and > that you like none of the options you have: > > (1) package LibreSSL > (2) bundle LibreSSL > (3) keep the existing OpenSSL-1.0 package (still supported upstream) > > Until somebody sufficiently qualified maintains a compat library, > *and* LibreSSL gains 1.1-compatible interfaces *and* OpenSSH switches > over (three large items lacking volunteers, which consequently seem > very unlikely to be completed by the end of the year), these three > are the only options i can see. Let's restate these in numbered bullet points: (a) somebody sufficiently qualified maintains a compat library (b) LibreSSL gains 1.1-compatible interfaces (c) OpenSSH switches over I'm not sure point (b) is necessary. The goal of the shim is to emulate the OpenSSL 1.1 interface by encapsulating OpenSSL 1.0 / LibreSSL code, so no change is needed in the upstream library (that would make the change really impossible IMHO). So the problem goes down to 2 point: (a) and (c). >From my experience, (a) is not that problematic. The goal is not to add any cryptographic code in the shim. Doing that would be both quite dangerous and not very productive since downstream users are not using theses (new) features anyway. The goal for now is to use the OpenSSL 1.1 API, not OpenSSL 1.1 itself. Good news: the shim code is quite neutral (w.r.t. security) and often very simple. If you really give a look to the Fedora patch [1] (and I encourage everyone who's serious about porting OpenSSL to OpensSSL 1.1 to do so, without judging the quelity of the patch itself), you'll see that the shim itself is less than 550 lines long. Most of the patch deals with changing the OpenSSH code to match the new API (some of the functions used in this patch are older and are already present in OpenSSL 1.0 and LibreSSL). At a first glance, this shim code seems to be mostly extracted from the OpenSSL 1.1 code and is trivial in many cases. There are parts that require some attention (again, w.r.t. security) but even those are quite simple (most of these if not all are related to memory management). In any case it does not require the mastery of the crypto code in OpenSSL. Thus I would say that the real problematic point is point (c): is the OpenSSL team comfortable with changing the OpenSSH code to support this API? Changing openssh-portable but not openssh means the two versions are likely to diverge at some point, so the wise among us would call for a global change (i.e. make openssh compatible with the OpenSSL 1.1 API and port the changes to openssh-portable). As I understood it, this would be problematic because openssh does not target OpenSSL at all, so that would introduce a number of changes that are not needed into the code base. The change is not as urgent as it may seem: OpenSSL 1.0.2 is to be supported for another 14 monthes so unless distributions want to phase it out earlier, there is still time to do it (I do understand that some distributions are phasing out OpenSSL 1.0). > Yours, > Ingo BR, -- Emmanuel Deloget [1] http://pkgs.fedoraproject.org/cgit/rpms/openssh.git/tree/openssh-7.3p1-openssl-1.1.0.patch _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
