Christophe Lallement

DESFire authentification with a SAM AV2

Discussion created by Christophe Lallement on Jun 23, 2017
Latest reply on Jul 11, 2017 by Sandra Fuchs

I try to authenticate a DESFire EV1 card with a SAM AV2 with command SAM_AuthenticatePICC, but that do not run correctly.

First of all, I want to say the card authentication run correctly when I read the session key in the SAM with the command SAM_DumpSecretKey. But it is not the goal of the developement.

Now, my problem is the SAM does not send the status word (SW) after it sent the first part of the command (it shall sent ekNo(RndA+RndB') + 0x90AF) but it sends only the 32 bytes of data.
If I send those bytes to the card, the DESFire card sends corrects data but when I send them to the SAM, it answers 0x00 0x92 0x00 0x92 and not 0x9000 as describs in the documentation.

All commands are conforms with the SAM AV2 datasheet.

Is it normal that the SAM does not sends the SW after the first command ?
Why isn't SAM send a status word at the end of the exchange ?

Thank for help