* [DONE] configure support

configure script would be good to select a board and to generate
random serial number.


* Random number update

Currently, Gnuk doesn't have random number generator, but use random
bytes calculated by hosts.  After Gnuk uses random number, the entry in
Flash ROM will be cleared.  Some scheme to update random number bytes
is needed.  Possibly, private Data Objects, or by another SELECT FILE.


* Random Number Generator

RNG is needed for Data Encryption Key to encrypt private key (P and Q).
It is important to collect enough entropy.  Perhaps, it would
be possible to get entropy from USB traffic (of other devices).


* RSA

It would be good not to use malloc.


* [DONE] Manufacture ID

Get it from FSFE.


* [Mostly DONE] Serial number

The AID of the card contains serial number.  It should be unique.  USB
serial number should be unique to identify different tokens, too.


* Flash ROM recover from shutdown


* [DONE] Flash ROM garbage collection


* Flash ROM protection