[openssl-users] Architecture-specific headers

[Michael Wojcik]

> From: openssl-users [mailto:openssl-users-bounces at openssl.org] On Behalf
> Of Kim Gräsman
> Sent: Tuesday, October 18, 2016 07:04
> 
> On Tue, Oct 18, 2016 at 2:21 PM, Michael Wojcik
> <Michael.Wojcik at microfocus.com> wrote:
> >
> > So, in short: You do in fact have to publish and maintain one architecture-
> specific header.
> 
> Thanks, I was afraid so. We're compiling for 6 different targets, so
> this will turn into an exciting problem :-)

I don't know what your build system looks like, but it wasn't a terribly difficult problem for us. Don't you already have platform-specific headers? You have platform-specific libraries...

I deal with 11 platforms for OpenSSL currently - most of which have multiple flavors (bitness and threadedness; fortunately at the moment we're not doing both debug and release builds as well). Not that big a deal to build all of them and harvest opensslconf.h alongside the shared objects / DLLs.

> Any chance that OpenSSL 1.1 is different in this regard?

I don't see how it could be. Other OpenSSL headers need to know information about the configuration used to build OpenSSL, and the attributes of the platform such as endianness. Some of the settings in opensslconf.h are necessary for correctness; others greatly affect performance. There are also convenience settings like the default OPENSSLDIR. That information is required at compile time and has to come from somewhere.

Michael Wojcik 
Distinguished Engineer, Micro Focus