[Opensc-devel] Understanding of ssh pkcs key provider

[Gyurgyik, M. S. <gyu...@or...>]

Hello.

First, let me say I’m new to smart cards and I haven’t been able to find much documentation on how they work. I’m looking for some education, if there is a better place to post this question, please let me know.

I can add keys provided by my smart card to ssh-agent with

$ ssh-add -s /Library/OpenSC/lib/opensc-pkcs11.so

However, if I remove the card from the reader and then reinsert it I have to re-add the keys

$ ssh-add -e /Library/OpenSC/lib/opensc-pkcs11.so
$ ssh-add -s /Library/OpenSC/lib/opensc-pkcs11.so

This happens on both OS X and RHEL7. I am assuming this expected behavior. Can someone explain (or point me to documentation) why it is necessary to remove the keys and re-add them?

Thank you,
Matthew Gyurgyik