Re: [Opensc-devel] Question about multiple applications

[Bob B. <fig...@gm...>]

Hi Douglas,

Thank you for your reply.

I understand that the "OpenSC PKCS#11 relies on the PCSC layer to lock
access" but I think the issue lies on the lock used for the Windows system,
on the pkcs11-global.c, I can see that the type of lock used is Critical
Section as opposed to Mutex. It was mentioned on the Microsoft
documentation that ;

*A critical section object provides synchronization similar to that
provided by a mutex object, except that a critical section can be used only
by the threads of a single process. Critical section objects cannot be
shared across processes.*

Correct me if I'm wrong, but I think, to be able to handle "multiple
applications" we may need to use Mutex instead of the default Critical
Section. If that is the case how am able to do it in the OpenSC layer, do I
just change the implementation to use Mutex instead of Critical Section (by
changing the flow in the function pointer)?

I am not sure if what I am saying makes sense, my apologies if this is
something I over complicate.

I appreciate your help on this.

*Source:
https://docs.microsoft.com/en-us/windows/desktop/Sync/critical-section-objects
<https://docs.microsoft.com/en-us/windows/desktop/Sync/critical-section-objects>*


Thanks,

Jared

On Wed, Dec 19, 2018 at 9:05 PM Douglas E Engert <dee...@gm...> wrote:

> The OpenSC PKCS#11 relies on the PCSC layer to lock access to the card
> across multiple applications.
>
> https://github.com/OpenSC/OpenSC/wiki/PCSC-and-pcsc-lite
>
> http://ludovic.rousseau.free.fr/softwares/pcsc-tools/
>
>
> https://docs.microsoft.com/en-us/windows/desktop/secauthn/smart-card-and-reader-access-functions
>
> In regards to one application modifying the card while another application
> is waiting for events,
> the event will contain a SCARD_W_* return.
>
> The application (A) that modified the card in such a drastic way should do
> a card reset,
> that will cause the the event returned to (B) will cause (B) to start over.
>
>
> https://docs.microsoft.com/en-us/windows/desktop/SecAuthN/authentication-return-values
>
> Doing do a C_InitToken is like formatting your hard drive. Most
> applications can not copy with this.
> In other words don't do it while other applications are running.
>
>
> On 12/18/2018 9:06 PM, Bob Backlund wrote:
> > Hi,
> >
> > Just some question about how the OpenSC PKCS# 11 (DLL) handles the
> multiple applications using it.
> >
> > The scenario is I have two applications, application A and application B
> loading the same DLL.
> >
> > Application B loops continuously, calling C_WaitForSlotEvent and
> C_GetTokenInfo, basically it just checks for the insert and remove events
> from the smart card.
> >
> > Application A can call C_InitPIN and C_InitToken.
> >
> > The conflict happens when, while the application B is checking for smart
> card events, application A then calls C_InitToken, which deletes the smart
> card contents, and formats it to be a new card, (and
> > possibly deleting the PKCS# 15 objects) and the next call to
> C_OpenSession fails returning CKR_TOKEN_NOT_PRESENT error.
> >
> > When I try to check the logs, the state of the smart card become ABSENT
> , I can see this during the C_InitToken, when sc_detect_card_presence is
> called.
> >
> > When I try to run application A, and call C_InitToken without the
> application B running, I do not encounter this issue, and the smart card
> does not become ABSENT but instead I can see from the logs
> > that its state become CHANGED.
> >
> > I am not sure if this is the expected behavior or where or how I should
> handle it. I am not sure if this is also an issue on the OpenSC PKCS# 11
> DLL or the smart card. I tried to look at the available
> > documentation but couldn't find an answer to this,
> >
> > Your expert opinion is greatly appreciated.
> >
> >
> > Thanks,
> >
> > fightingsibuyas
> >
> >
> > _______________________________________________
> > Opensc-devel mailing list
> > Ope...@li...
> > https://lists.sourceforge.net/lists/listinfo/opensc-devel
> >
>
> --
>
>   Douglas E. Engert  <DEE...@gm...>
>
>
>
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