SmartCard: Encryption/Decryption problem

Georg C. F. Greve greve at
Thu May 5 11:44:21 CEST 2005

 || On Thu, 05 May 2005 10:49:18 +0200
 || Werner Koch <wk at> wrote: 

 >> Who would have to analyse this?

 wk> I did extensive code staring and could not find a problem in my
 wk> code.  Given that I don't have any problems when using a reader
 wk> with an updated firmware, I am pretty sure that it is the
 wk> reader's fault.

Do we know whether this problem reproduceable under Windows?

If not: Where is the difference?

It strikes me as odd that they would so consistently not work and
still be shipped if the problem also occured on Windows.

 wk> To develop a workaround for the readers with non-updatable
 wk> firmware, I need to talk with the vendor.

Do you know who to talk to?

I have developed some contacts with SCM because I am trying to
convince them to adopt a Free Software friendly policy and release all
their SmartCard drivers as Free Software -- so we could finally use
those PCMCIA readers, for instance.

 wk> What _might_ help is to limit the packet size even further.  In
 wk> g10/ccid-driver.c, look for

 wk>       DEBUGOUT ("enabling workaround for buggy SCM readers\n");
 handle-> max_ifsd = 48;

 wk> and change the ifsd to 45.

Okay. Will try that, thanks.


Georg C. F. Greve                                 <greve at>
Free Software Foundation Europe	                 (
Join the Fellowship and protect your freedom!     (
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