After a couple of months of using my Nitrokey Pro successfully, it seems to have stopped working, and now gives a ‘card error’ when used from GPG (for example, with
gpg2 --card-status). It looks to me like a hardware problem, as the symptoms are the same when I use the NItrokey on two different machines.
What can I do to debug the problem?
$ sudo gpg2 --card-status
[sudo] password for philip:
gpg: detected reader `Nitrokey Nitrokey Pro (0000392B0000000000000000) 00 00'
gpg: pcsc_connect failed: proto mismatch (0x8010000f)
gpg: apdu_send_simple(0) failed: general error
Please insert the card and hit return or enter 'c' to cancel: c
gpg: selecting openpgp failed: general error
gpg: OpenPGP card not available: general error
I can sometimes get it working by rebooting and plugging the key into a different USB port, but not deterministically.