I was trying to compile the program "ircII" on LEAP 42.1, and got these errors in the make process:

cannot find -lcrypto
cannot find -lssl
collect2: error: ld returned 1 exit status
Makefile:350: recipe for target 'mksiginc' failed
make: *** [mksiginc] Error 1
I learned that in addition to the pattern "devel_basis" which I had already installed, I needed to install the package "libopenssl-devel". That fixed the error message and compiling was successful. I'm leaving this here for anybody else who has the same problem.

The hint which led me to realizing this was running the command "zypper search libopenssl*" which showed that the -devel package was not installed.