[Pkg-openssl-devel] Bug#754513: RFP: libressl -- SSL library, forked from OpenSSL

[Colin Watson]

On Mon, Oct 16, 2017 at 10:00:50PM +0200, Sebastian Andrzej Siewior wrote:
> On 2017-10-16 17:29:09 [+0100], Colin Watson wrote:
> > While there does exist a skeletal compatibility layer linked from the
> > upstream wiki [1], the OpenSSL developers explicitly don't want to
> > maintain this properly [2], and the OpenSSH developers say that it is
> > "unversioned, incomplete, barely documented, and seems to be
> > unmaintained" [3].  Kurt Roeckx proposed a patch to add a compatibility
> > shim [4], and a number of other projects have done something similar,
> > but the OpenSSH developers have explicitly said that they do not want to
> > take that approach [5].
> It has never been explained what it is that upstream wants. I get the
> impression, that they want a compat/shim layer and things have to work
>   https://lists.mindrot.org/pipermail/openssh-unix-dev/2016-November/035456.html
>   https://lists.mindrot.org/pipermail/openssh-unix-dev/2016-November/035497.html

Ingo replied to me privately (but giving me permission to use the
information any way I saw fit) with this:

  Here is one example of a posting where it is explained
  in a comment:
  
    https://plus.google.com/u/0/+IngoSchwarze/posts/WQ9ouupTVgx
  
  In other words, an officially maintained library that *uses* the
  OpenSSL-1.0 API (i.e. links against existing existing libcrypto
  lbraries) and that *exports* the OpenSSL-1.1 API for application
  programs to link against, such that application programs using the
  OpenSSL-1.1 API can run on systems providing an OpenSSL-1.0 library.

> I didn't even figure out if they want to alter their code or not.

  https://lists.mindrot.org/pipermail/openssh-unix-dev/2017-October/036370.html

> > It's not currently clear to me whether anyone has explicitly talked with
> > the OpenSSL developers about this problem from the point of view of the
> > OpenSSH developers, rather than just as users trying to get OpenSSH to
> > compile against the new version.
> 
> Kurt is aware of the situation, he is part of upstream. It might be that
> OpenSSH is playing hard to get.

I don't see any benefit in conducting a discussion in which we assume
bad faith.  There are different opinions on what makes for a good API
transition, and pressures coming from different choices upstream
(remembering that Debian's immediate upstream for OpenSSH is OpenSSH
Portable, which itself has OpenBSD as an upstream) and from available
development and review time, but simplifying that as "playing hard to
get" isn't particularly helpful.

> > At the moment I can see the following somewhat realistic paths forward:
> > 
> >  * Accept an upstream bundling of LibreSSL (still hypothetical, but
> >    plausible).  I'm sure this would also not be the security team's
> >    favourite outcome, although presumably only a subset of LibreSSL CVEs
> >    would apply to OpenSSH, and it wouldn't be making it available as a
> >    general-purpose library.
> 
> 4.13. Convenience copies of code

I helped to draft that section, so I'm aware of what it says.  Note that
it's a "should", and that it's not currently in the list of release
standards for packages in buster
(https://release.debian.org/buster/rc_policy.txt).  According to our
current policy standards, it would certainly be a bug to have an
embedded copy, it might well make various people cross with me, but it's
something we're allowed to trade off against other considerations if
they're sufficiently compelling.

We could, for example, reasonably embed LibreSSL for a while and then
switch to an externally-packaged library if it looks like API stability
will be good enough for our needs.

-- 
Colin Watson                                       [cjwatson at debian.org]