Re: [Opensc-devel] Bug in PIN_VERIFY_STRUCTURE and???PIN_MODIFY_STRUCTURE

[Frank M. <mo...@in...>]

On Tuesday, May 28 at 10:22AM, Ludovic Rousseau wrote:
> 
> 2013/5/28 Ludovic Rousseau <lud...@gm...>:
> > 2013/5/27 Frank Morgner <mo...@in...>:
> >> Hi!
> >
> > Hello,
> >
> >> Enabling compiler warnings, I just found a bug in OpenSC. An array is
> >> accessed out of bounds. The pull request is issued, but the same bug
> >> also exists in PCSC-Lite (Drivers/ccid/MacOSX/reader.h and
> >> PCSC/src/PCSC/reader.h). Ludovic, you might want to have a look:
> >>
> >> https://github.com/frankmorgner/OpenSC/commit/e74d33441e87826b3409446d2e7b5c917b2697c4
> >
> > It is not a bug but a feature.
> > Ideally I would like to use  abData[0] or abData[] but some compilers complain.
> > It is called "C99 flexible array member"
> >
> > Maybe I should use something like
> > https://github.com/LudovicRousseau/libusbx/commit/53134e90f2f8fc516cc9794d79e754703da9e894
> 
> Done in revision 6638
> http://lists.alioth.debian.org/pipermail/pcsclite-cvs-commit/2013-May/006191.html

OK, good. I adapted your patch for OpenSC and made sure, that the buffer
which gets casted to a pin_verification_structure is always big enough
for holding an additional APDU.

> >> And by the way, do you think it is usefull to add
> >> __attribute__((packed)) to the struct? Otherwise there might be some
> >> padding between the members...
> >
> > Good idea. I will have a look.
> 
> I already use a packed structure using:
> 
> /* Set structure elements aligment on bytes
>  * http://gcc.gnu.org/onlinedocs/gcc/Structure_002dPacking-Pragmas.html */
> #if defined(__APPLE__) | defined(sun)
> #pragma pack(1)
> #else
> #pragma pack(push, 1)
> #endif

OK, fine.


--
Frank Morgner

Virtual Smart Card Architecture http://vsmartcard.sourceforge.net
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