It's somewhat(?) common for GPL projects to add an exemption to the license to allow it to be linked to openssl. See e.g. https://people.gnome.org/~markmc/openssl-and-the-gpl.html

In other cases, there's the "system library" argument (the GPL contains language that if a library the program links to is a "system library" the GPL "virality" doesn't extend there).

And in yet other cases, people just ignore it.

If you want to play it safe, just use GnuTLS, or Mozilla NSS.