[PATCH 0 of 1] Upstream: fix warning when building with BoringSSL

[Alessandro Ghedini]

Hey Maxim,

On Wed, Sep 28, 2016 at 07:40:13PM +0300, Maxim Dounin wrote:
> Hello!
> 
> On Wed, Sep 28, 2016 at 05:28:48PM +0100, Alessandro Ghedini wrote:
> 
> > On Wed, Sep 28, 2016 at 07:00:00PM +0300, Maxim Dounin wrote:
> > > Hello!
> > > 
> > > On Wed, Sep 28, 2016 at 03:37:48PM +0100, Alessandro Ghedini wrote:
> > > 
> > > > On Wed, Sep 28, 2016 at 05:19:02PM +0300, Maxim Dounin wrote:
> > > > > Hello!
> > > > > 
> > > > > On Wed, Sep 28, 2016 at 03:10:46PM +0100, Alessandro Ghedini wrote:
> > > > > 
> > > > > > Hello,
> > > > > > 
> > > > > > I don't now what your current plans for supporting BoringSSL are, but its
> > > > > > API has been fairly stable for a while and this is the only change required
> > > > > > to make NGINX build with it again (the other issue with error definitions was
> > > > > > fixed in BoringSSL itself).
> > > > > > 
> > > > > > I don't think BoringSSL is going to change the API back, so NGINX migh want
> > > > > > to fix this if support for BoringSSL is desired (again, don't know your
> > > > > > opinion on this).
> > > > > > 
> > > > > > Please have a look and let me know what you think.
> > > > > 
> > > > > Quoting 
> > > > > http://mailman.nginx.org/pipermail/nginx-devel/2016-August/008680.html:
> > > > > 
> > > > > : Ok, this looks like the real reason for the patch.  This looks 
> > > > > : like an API change in BoringSSL, and should be threated 
> > > > > : accordingly.
> > > > > 
> > > > > : Given the number of various API changes BoringSSL introduces here 
> > > > > : and there - we probably don't want to follow, at least till some 
> > > > > : version is actually released.
> > > > 
> > > > Ok, thanks, I missed that. TBH I don't think the BoringSSL team intends to
> > > > release "proper" versions like OpenSSL does, so what you propose to wait for
> > > > might not actually ever happen.
> > > 
> > > Sure, and I'm fine with it.
> > > 
> > > > I understand your concern of wanting to target a fixed release, but as I
> > > > mentioned (and Piotr as well) BoringSSL's API seems to have been fairly stable
> > > > for a while (except for fixes like the one for the problem mentioned in the
> > > > patch you linked, which was worked around in BoringSSL itself), and AFAIK there
> > > > aren't other similar compatibility problems left except for this build warning
> > > > (but maybe Piotr could prove me wrong on that), so it might make sense to start
> > > > looking at supporting BoringSSL again.
> > > 
> > > Last time I looked into BoringSSL code due to ticket #993 several 
> > > months ago (https://trac.nginx.org/nginx/ticket/993), and my 
> > > impression wasn't that positive.
> > 
> > Ah, BoringSSL actually supports the new SSL_CTX_set1_curves_list() API that
> > NGINX already uses, but it doesn't seem to define SSL_CTRL_SET_CURVES_LIST
> > (yet) so the other API is picked. I'll make a patch for BoringSSL to fix this.
> 
> I'm afraid you are wrong here,
> 
> $ grep -r SSL_CTX_set1_curves_list boringssl/ | wc -l
>        0
> 
> Instead, BoringSSL introduced its own API to work with curves.

BoringSSL now provides SSL_CTX_set1_curves_list() as well:
https://github.com/google/boringssl/commit/5fd1807d95f75895ae99e336ac21b422f3cc6bd3

Both me and Piotr verified that it works with NGINX.

David Benjamin also suggested to modify my NGINX patch to always cast to
(const char *) the argument of SSL_set_tlsext_host_name(), even when using
OpenSSL since it uses macros and force-cast the argument back to (char *):
https://github.com/openssl/openssl/blob/master/include/openssl/ssl.h#L1231

This way there would be no need for the #ifdef, which makes the whole thing
nicer. I'll send an updated patch in a bit so you can pick the one you like
the most if you decide to add BoringSSL compatibility.

Cheers