[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 04:14
> 
> Everything seems to work pretty well, but one thing is worrying -- the
> opensslconf.h header comes out different between the two builds.
> 
> I'm assuming this only affects implementation details in OpenSSL and
> not the public API? I don't have to publish and maintain
> architecture-specific headers, do I?

opensslconf.h is generated from the configuration settings and platform characteristics, and applications must be compiled using the opensslconf.h that corresponds to the build they link to (or one that's equivalent).

Sometimes you can get away with using the wrong opensslconf.h, but this can cause hard-to-find errors. One project I know of went for several years using the wrong opensslconf.h, and it was only discovered when a different project used some other OpenSSL features and got incorrect results on some platforms.

So, in short: You do in fact have to publish and maintain one architecture-specific header.

Michael Wojcik 
Distinguished Engineer, Micro Focus