CR95HF and DESFire

[thanhphan]

Posted on April 21, 2014 at 05:45

Hi Everyone,

I'm using the CR95HF to access the DESFire card. Everything was going fine up to RATS and PPS.

However when I tried to send the GetVersion Desfire command (0x60) using the Half-duplex block transmission protocol with PCB, CID, INF...  as below:

0x04, 0x04, 0x0A, 0x00, 0x60, 0x28

header, len, PCB, CID,   INF,    control byte

I only received 0x87 0x00. The same happened with Authenticate (0x0A 0x00) command. So I think I it must be something wrong with the EDC (CRC) code.

Could anybody shed some light on this?

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Edited: According to the datasheet, the CR95HF only supports 14443-3 not 14443-4, is that correct?

#desfire #cr95hf

[thanhphan · Accepted solution]

Posted on April 21, 2014 at 08:28

OK, after setting the Extended Frame Waiting time with 020402000180

I'm able to receive response from the Half-duplex block transmission. I guess it needs to wait longer since this is half duplex session.Hope this is useful for anyone has the same issue!

[jterrien]

Hi Thanhphan

Your solution is also working on my side on a Mifare Desfire EV2, no more timeout and the getversion command works. Thanks a lot for this. Could I ask you where did you find this get version command. All sources of information that I found simply state 0x60 or 0x90 0x60 0x00 0x00 0x00 for the get version command. Actually none is working but yours (0x0A 0x00 0x60) does. You said that it is a half-duplex block transmission but I am not able to find any information about this protocol.

Thanks in advance for any information that you could give me on this particular protocol.

Regards, Jérémy

[Brian TIDAL]

Hi,

the half duplex protocol is described in ISO/IEC 14443-4 standard. This is the so-called ISO-DEP protocol. It is used to convey Command-APDUs from the reader to the tag and Response-APDUs from the tag to the reader. For NFC front-end as ST25R95, a software implementation of ISO/IEC 14443-4 is provided as part of the RF Abstraction Library (RFAL) available in X-CUBE-NFC3 or STSW-ST25R-LIB software package. This implementation manages the Frame Waiting Time according to the RATS/ATS parameters exchange as specified in ISO/IEC 14443-4.

Regarding the commands set for your tag, I would suggest to contact the device manufacturer to have access to the device datasheet. Anyway, you should find some information related to the identification procedure in AN10833 from this manufacturer.

If your application does not use authentication and encryption, I would suggest to use ST25TA tag device.

Rgds

BT