Subject: Re: detect linkage against openssl or gcrypt

Re: detect linkage against openssl or gcrypt

From: Daniel Stenberg <>
Date: Mon, 29 Jul 2013 16:05:02 +0200 (CEST)

On Mon, 29 Jul 2013, Peter Stuge wrote:

>> Is it? How would you build your makefile / build scripts with pkg-config
>> to figure this out?
> Run:
> pkg-config --print-requires libssh2
> pkg-config --print-requires-private libssh2
> If the output is empty then that is a libssh2 bug.

"pkg-config --print-requires libssh2" is completely blank for me on Debian,
but so is "pkg-config --print-requires libcurl" as well, and both are listed
with pkg-config --list-all... In fact, I couldn't find any package showing
something in --print-requires on my Debian box when I tried a bunch of others
as well.

Clearly not a very reliable method up until now at least!

>> But I could also imagine a run-time API so that an application can
>> figure this out on its own...
> It can't be runtime, or applications must depend on every single crypto lib
> supported by libssh2, in order to have all symbols available.

I didn't claim they would be used for the same thing (even though a truly
agnostic application may want to try). I can think of cases where detecting
the underlying crypto lib at run-time can be useful or at least helpful.

Received on 2013-07-29