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CLA byte of the select APDU command

Posted: Mon Jul 17, 2017 11:40 pm
by poinonche
Why can't I use 0xBC as the CLA byte of a select APDU command? I will get 6E 00 (SW_CLA_NOT_SUPPORTED) if I use 0xBC.
Is there any special requirement for CLA bytes?

Re: CLA byte of the select APDU command

Posted: Tue Jul 18, 2017 3:13 am
by mabel
SELECT APDU command 00 A4 04 00 is a standard APDU defined in ISO 7816-4 spec.

Regarding CLA bytes, you can check ISO 7816-4 spec to learn which values can be used as CLA.

Re: CLA byte of the select APDU command

Posted: Tue Jul 18, 2017 7:54 am
by tay00000
Which card are you using when you do CLA = (byte) 0xBC ?

I have used CLA = (byte) 0xBC and CLA = (byte) 0xB0 and have never hit any problems on NXP JCOP, Feitian cards or any other cards for now.