CODEWITHSUNDEEP
nfcsmartcardapduemv
Peter
Peter

Reputation: 648

Why is the card refusing the GPO command?

I am working with a Visa CDET contact-less test card. I have successfully selected the Application, which gave me the following result:

<= 6f 29 84 07 a0 00 00 00 03 10 10 a5 1e 50 0b 56 49 53 41 20 43 52 45 44 49 54 5f 2d 02 65 6e 9f 38 09 9f 66 04 9f 02 06 9f 37 04

The result included a PDOL which asked for the following items:

Terminal Transaction Qualifiers
Length: 4 bytes

Authorised Amount
Length: 6 bytes

Unpredictable Number
Length: 4 bytes

When it comes to the GPO command, I do have all the elements needed as shown below:

=> 80 a8 00 00 10 83 0e f3 20 40 00 00 00 00 00 12 00 bc 4b a2 3f 00

But when i run the command, I received a 67 00 error: Wrong Lc length. What could be the issue? Keep in mind the same program works perfectly when working with Visa CDET Contact test cards from the same kit.

EDIT: About the same problem, I have a test reader that I use to confirm my readings. The reader and its program can get the GPO options and return the result for other cards, but my program is not giving me any results when I try the EXACT same command using the EXACT same card in my custom program. The result is a blank, yet the status words are 90 00 (they are separate from the returned data). Why is that?

Upvotes: 0

Views: 1032

Answers (2)

Oleg Moiseenko
Oleg Moiseenko

Reputation: 23

I received a 67 00 error: Wrong Lc length.

ok, its because you dont have Lc=0x00 in APDU just add 0x00 to APDU

Upvotes: 0

guidot
guidot

Reputation: 5333

Just assume first, that the card is right: If the length of data object 83 is 0x0F (instead of 0x0E) if I counted correctly, then the total length to be supplied in LC has to be 0x11 instead of 0x10 (tag and length to be added). This does not explain, why the contact version works, but possibly it still will work after the adjustment.

Upvotes: 1

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