There isn't need for any other programs. Tunnelblick includes easy-rsa (an offshoot of the OpenVPN project), which will generate all the PKI (Public Key Infrastructure) that's needed.
To start easy-rsa, launch Tunnelblick, triple-click the Tunnelblick icon in the menu/status bar to open the "VPN Details…" window, then click on the "Utilities" tab at the top of the window. Click the "Open easy-rsa in Termal" button to open a Terminal window already cd-ed to a copy of easy-rsa.