[Gambas-bugtracker] Bug #1733: gb.openssl Expose Key Derivation Functions

[bugtracker at gambaswiki.org]

http://gambaswiki.org/bugtracker/edit?object=BUG.1733&from=L21haW4-

Comment #1 by Tobias BOEGE:

May I ask, since you appear to know what you're doing, if you want to
implement this yourself? The gb.openssl component is written in "Gambas C",
which is C plastered with interpreter-specific macros, which I can help
you through (either on the mailing list or on IRC).

Otherwise can you be more specific about which interface you want exposed?
I see that an orderly set of EVP_KDF_* functions comes with OpenSSL 3.0 [1].
That is basically how Cipher and Digest are implemented, so I like the idea
of a parametric "KeyDerivation" or so class.

However, I'm reluctant to add this because as soon as gb.openssl fails to
build on the grandfather of Debian oldstable, I get more tickets. And finding
out what will work and what won't isn't always easy, not to mention that I
don't have time for any of this at the moment.

The goal would be to make an interface that looks normal with 3.0 but is
backwards-compatible, not only with Gambas but also with OpenSSL. I don't
know if we do this in Gambas, but maybe the component can just throw a
runtime error if some new part of it is used with too old OpenSSL, Benoît?

[1] https://www.openssl.org/docs/manmaster/man3/EVP_KDF.html