Type B NFC Chip in US Passport MRTD

Question

I am trying to read a US Passport, issued 2010. It has an NFC chip in it using type B modulation. Most countries use Type A so I am just trying Type B now for the first time.

Answer 1

In the first APDU response you probably get the FCP and FCI data back from the chip. This is weird because you explicitly told the application that you didn't want it (by specifying P2=0C in the SELECT by NAME APDU that you send).

What you get back is ASN.1 encoded, check the link here. The explanation of these bytes is in ISO/IEC 7816-4. You probably need to get that standard somehow.

As for the get challenge, you specify an Le with value 00. This translates into an Ne with value 256. As Ne is the maximum size, you basically ask the eMRTD to return everything it can, up to 256 bytes. The 22 bytes you get (+9000) is civil, it could have returned the full 256 bytes. Usually you need a challenge of 8 bytes, so try Le set to 08 instead.

The good thing to notice is that this is all at the ISO/IEC 7816-4 level, so your ISO/IEC 14443 type B code is probably alright.