Should the CLA of GET_RESPONSE(0xC0) command still be 0x00 for ctap2 case? - Githubissues

Yubico / libfido2

Provides library functionality for FIDO2, including communication with a device over USB or NFC.

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Should the CLA of GET_RESPONSE(0xC0) command still be 0x00 for ctap2 case? #816

Closed nuno0529 closed 1 day ago

nuno0529 commented 2 weeks ago

libfido2 code here force use 0x00, https://github.com/Yubico/libfido2/blob/main/src/nfc.c#L187

ctap2 spec examples use 0x80, https://fidoalliance.org/specs/fido-v2.2-rd-20230321/fido-client-to-authenticator-protocol-v2.2-rd-20230321.html#nfc-fragmentation
u2f spec examples use 0x00, https://fidoalliance.org/specs/fido-u2f-v1.2-ps-20170411/fido-u2f-nfc-protocol-v1.2-ps-20170411.html#apdu-length

As ISO7816-4, the CLA of GET_RESPONSE(0xC0) command is not fixed to 0x00, https://cardwerk.com/smart-card-standard-iso7816-4-section-7-transmission-interindustry-commands/

kongeo commented 2 weeks ago

Hi @nuno0529, thanks for bringing this up. Yes I think that makes sense. We will merge a fix as soon as possible.

kongeo commented 1 day ago

addressed in https://github.com/Yubico/libfido2/pull/817