How to authenticate NTAG213 with ACR122U

Question

I'm using an ACR122U reader with an NTAG213 card. The card is password (reading and writing) protected with the password 52 84 00 08. What are the APDU commands I should run to authenticate the card and also to read pages 30 and 31 of it once authenticated?

I know with the MiFare 1k I could load the password and authenticate a sector, but I'm not sure how authentication works with the NTAG213 cards with the ACR122U readers.

Answer 1

With the ACR122U you would need to send direct commands to the PN532 NFC controller chip inside the reader in order to exchange such low-level commands. For instance, you could use the InCommunicateThru command to send a raw command to the tag:

+-----+-----+-----+-----+--------------+-----------+-----+
| CLA | INS | P1  | P2  | Lc           | DATA      | Le  |
| FF  | 00  | 00  | 00  | 2 + len(CMD) | D4 42 CMD | --  |
+-----+-----+-----+-----+--------------+-----------+-----+

That way, you could send the password authentication command (PWD_AUTH) to the tag:

FF 00 00 00  07  D4 42  1B  52 84 00 08
                        --  -----------
                        |   |
                        |   \-> password
                        \-> command: PWD_AUTH

The response to this command should be something like

D5 43 00  PACK  90 00

Similarly, you can send a READ command to read any page:

FF 00 00 00  04  D4 42  30  XX

where XX is the 1-byte page address.

Note that the read command should also work using the (more robust?) InDataExchange command:

FF 00 00 00  05  D4 40 01  30  XX