• Registered: 2010-05-05
  • Posts: 11

Topic: [SOLVED] ATS of ISO14443-A too long?

I am using libnfc with an ACS ACR 38U-CCID. When connecting to a nfc target, pcscd shows the following APDUs:

APDU: FF 00 00 00 04 D4 4A 01 00
SW: 61 17
APDU: FF C0 00 00 17
SW: D5 4B 01 01 00 08 20 04 08 13 FF 01 09 78 77 D4 02 00 00 90 00 90 00

libnfc now reports the following ATS:

78 77 D4 02 00 00 90 00 00 (the length of the ATS is taken from nti.nai.szAtsLen)

Compared with the response code above it seems like this ATS is one byte too long. Additionally I know from independent sources that the card has only 5 historical bytes, but the ATS above would suggest 3 interface bytes and 6 historical bytes.

Could please someone (familiar with libnfc internals) check the ATS calculation?

Last edited by frankmpunkt (2010-05-09 16:28:51)

  • roel
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  • Registered: 2009-02-18
  • Posts: 151

Re: [SOLVED] ATS of ISO14443-A too long?

Would it be possible to use "--enable-debug" as ./configure parameter, run the same test and post the debug log here in this thread?

This would help us a lot while investigating this problem.

  • rconty
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  • Registered: 2009-04-22
  • Posts: 673

Re: [SOLVED] ATS of ISO14443-A too long?

Hello,

frankmpunkt wrote:

Could please someone (familiar with libnfc internals) check the ATS calculation?

You are right. Thanks for report ! This is now fixed in r424.

Romuald Conty