To determine under which directory a given OpenSSL library stores its configuration (in file openssl.cnf) and certificate store (in directory certs), execute the command below. If there are multiple versions of OpenSSL on the machine, you may need to provide the full path to a given openssl executable.

openssl version -d

On a Debian 9 machine, for the /usr/bin/openssl executable, this command yields directory /usr/lib/ssl. /usr/lib/ssl/certs is a symbolic link to directory /etc/ssl/certs. /usr/lib/ssl/openssl.cnf is a symbolic link to file /etc/ssl/openssl.cnf. And /usr/lib/ssl/private is a symbolic link to directory /etc/ssl/private.

On a Mac OS machine with the Homebrew package manager, for the /usr/local/bin/openssl executable, this command yields directory /usr/local/etc/openssl.