Accessing the private DOs of the smartcard

[Sven Radde]

Hello GnuPG users,

Is there a convenient way to access the data objects of the OpenPGP 
smartcard? The best thing I know is to use "gpg --card-edit" to get at 
the PIN-protected DOs, which is cumbersome and does not give a very 
machine-friendly output...

What I am thinking of is the following:
The card with its PIN counters represents a protection against brute 
force attempts, that is not available to other software-only crypto 
applications like EncFS, Truecrypt etc. Consequently, the card PIN can 
be shorter than the overlong passphrases needed to secure those 
applications.
Now, it would be really nice to store a long passphrase into one of the 
PIN-protected data objects and have the possibility to pipe that to one 
of those applications.
This way, e.g., a Truecrypt volume would be protected by a very long 
passphrase, while the owner has the convenience of "unlocking" that 
passphrase using his/her shorter smartcard PIN.

Can this be accomplished using some scripting? Or may I suggest to add 
"--card-do1" through "--card-do4" as new commands to GnuPG which would 
print the respective string to standard output after asking for the PIN 
when applicable?

Thanks for listening :-)
  Sven