If you need to compute a hash on the Mac, the only way to do this is using the openssl command on the terminal. The problem though is that the Mac uses an older version of openssl, so the most modern has algorithm it supports is SHA1. If you need to confirm a hash using RIPEMD160, SHA256, SHA384, SHA512, SHA224 then openssl won't work for you.

The way to perform a more advanced hash is to use the GNU Privacy Guard application, also known as gpg. You can download a version of for the Mac here: http://macgpg.sourceforge.net/. Once you download the file, the install is pretty obvious -- just expand the zip and run the package.

After the install, you'll have a new app in your Applications directory called "start-gpg-agent". When you click on it, nothing really happens. But don't worry, it's working, you now have the "gpg" command available from the terminal.

To then use gpg to compute a hash on the Mac, you open a terminal window and type something like the following:

gpg --print-md sha256 FILE_NAME

where you replace FILE_NAME with the file you want to compute the hash for. Using gpg in this manner, you can compute hashes using the RIPEMD160, SHA256, SHA384, SHA512, SHA224 algorithms on your Mac.