Microsoft released SSL diagnostics utility. I just found it mention in an article called Troubleshooting SSL in IIS. However, it has one drawback: it comes as installable MSI package.
If you don’t want to install anything on your server, just run a one-time scan of it, I created a ZIP package with just the executable files – you can just copy this to the server and run it. It contains both 32 and 64 bit versions in one archive.