Omnikey readers and 2048 bit keys

Werner Koch wk at
Mon May 11 19:38:34 CEST 2009


While testing the new 2048 bit smartcards I figured that all Omnikey
based readers (e.g. CardMan, Cherry keyboards) won't work.  SCM readers
work just fine.  See

for details.  The interesting thing is that they seem to work on Windows
(at least Cardman 3121 and 5121): This seems to be due to tricks in the
Windows driver.  I guess they are switching the reader to TPDU mode or
some raw mode.  Simply trying to use extended length APDU exchange does
not work.

I started to do a protocol analysis of the CCID data send over USB but
due to problems with Windows XP's resource manager when running under
KVM, I have postponed it for now.  If you want to work on it, there is a
little tool in GnuPG's SVN: tools/ccidmon.c to prins the CCID protocol
data in an easy readable format.



Die Gedanken sind frei.  Auschnahme regelt ein Bundeschgesetz.

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