Interested in using a smartcard for secure two-factor authentication on OS X? What about E-mail signing and encryption, SSH key authentication, and more? All of these applications are possible, using the built-in smartcard support in OS X and open source software. What follows is the first part of a guide to using smartcards on OS X, using software from the OpenSC Project.

A little while ago I had a problem. My phone is a Sony Ericsson K800i, with 64MB of internal storage and a slot for Memory Stick expansion storage. I was using it as an MP3 player, and so had an 8GB memory stick in there to store MP3s.

When I connected it to my Mac in USB drive mode to transfer files, it appeared in the Finder as two storage devices, one for the internal storage and one for the memory stick. When I’d finished transferring files I would click Eject on the memory stick’s device to safely remove it. Then I’d do the same on the internal storage’s device, but this would eventually fail and report an I/O error. The phone’s screen would show that the USB connection had ended, but one of the devices would still show in the Finder. If I then unplugged the USB cable the Finder would tell me that data might have been lost since I didn’t eject the storage device properly.

On Wednesday, I gave a talk at the Student Techmeetup here in Edinburgh on DS homebrew development. As promised, I’ve uploaded the slides from that talk as a PDF here, with links to a few tutorials and resources included in them, along with some notes.