No one, not even the Secret Service, should randomly plug in a strange USB stick

Re:No one, not even the Secret Service, should randomly plug... by megous on Monday April 08, 2019 @08:35PM (#19610546)

It's not that hard to pick some standard class, like CDC and have a userspace app that uses it just like a serial device. You can get info on which serial device to use via sysfs on Linux.

The rest is just making up a serial protocol.

No need for a special driver.

[ Parent | on HN ]

Re:No one, not even the Secret Service, should randomly plug... by cortesoft on Monday April 08, 2019 @10:43PM (#19611287)

Would this work for every operating system without requiring the user to do anything?

[ Parent | on HN ]

Re:No one, not even the Secret Service, should randomly plug... by tonyarkles on Tuesday April 09, 2019 @09:03AM (#19614129)

It was a long time ago, but I’m pretty sure CDC doesn’t auto-enumerate on Windows. Mac and Linux is fine. I think you still need a .inf for Windows, and for it to work generally, you need WHQL signing ($$, time).

The free (money-wise) approach we ended up doing was to use WinUSB and marking the device as “vendor specific”, and using libusb to talk directly to it. That was a bit awkward, but covered Windows, Linux, and OSX for us.

This was 5 years ago though. Windows 10 might directly support generic CDC devices, but Win 8.1 didn’t.

Edit: sibling mentions HID. HID does work like this, but we needed more bandwidth than HID provided. CDC was perfect for what we were doing but it didn’t auto install. Mass storage auto-installs but didn’t fit what we were doing.

[ Parent | on HN ]

Re:No one, not even the Secret Service, should randomly plug... by megous on Tuesday April 09, 2019 @08:25AM (#19613869)

Well, define "work", "every operating system", and "requiring user to do anythig".

:D Obviously you have to consider needs of your users as an engineer, when chosing any technology, for their particular problem.

[ Parent | on HN ]