We had a customer question the other day about configuring FTP Client Certificate Authentication in FTP 7.0 and in FTP 7.5. It had been a while since the last time that I had configured those settings on an FTP server, so I thought that it would be great to re-familiarize myself with that feature. To my initial dismay, it was a little more difficult than I had remembered, because there are a lot of parts to be configured.
A few years ago I wrote a blog that was titled "FTP 7.5 Service Extensibility References", in which I discussed the extensibility APIs that we added in FTP 7.5. Over the next couple of years I followed that initial blog with a series of walkthroughs on IIS.net and several related blog posts. Here are just a few examples: