'PACE' is extremely card specific protocol and has not to be ostensibly
present in the common part of OpenSC:
* currently in OpenSC there is no card driver that supports or uses this protocol;
* amazing content of the common 'sc_perform_pace' -- beside the verbose logs
the only substantial action is to call the card/reader specific handler.
According to the current sources and the pull request 83
this 'common' procedure is called by the card driver or
card specific tool/operation.
* currently the 'PACE' can be thouroghly tested only by one person (Frank Morgner),
and only using the OpenSSL patched with the PACE specific patch.
So, at least a dedicated configuration option could be introduced when comiting PACE to the common part.
* common 'sc_perfom_pace' has the same role as the 'initialize-SM' handler of the existing SM framework
and can be implemented as card specific SM, as the others cards do.
This confirmed by Frank Morgner, the author of PACE commits and nPA card driver, himself.
(https://github.com/OpenSC/OpenSC/pull/83)
In VERIFY, allow the user to enter the PIN unteractively if it was not given
on the command line, and if the card reader does not support PIN input.
If it was not given on the command line and the card reader supports PIN input,
then the bahaviour is unchanged: enter PIN via card reader.