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Enabled multiple SSL backends

From: Daniel Stenberg <>
Date: Mon, 28 Aug 2017 23:22:51 +0200 (CEST)

Hi friends!

As of minutes ago, libcurl has the ability to change SSL backend dynamically
at run-time - if built with the support enabled. That means that the choice
does no longer only have to happen at build-time.

curl_global_sslset() is the new function for selecting which SSL backend to
use. See

There's also a new example showing it in use:

To build with multiple backends, just specify all you want on the configure
line. Ie "--with-ssl --with-gnutls" builds with both OpenSSL *and* GnuTLS.

Tell configure which backend to use by default when built to use several, with

This is of course a rather huge change to a lot of TLS code so of course
there's a risk that some things broke in this process even if Johannes has
done a wonderful work on this and I've done my best in reviewing it. Please
be extra alert for SSL related quirks in the nearest future.

Finally, all credits for the heavy lifting here should go to Johannes
Schindelin! Thanks!


Received on 2017-08-28