Hi,
I am referring to
AN11350 NTAG Originality Signature Validation
and the described example to verify an NXP originality signature with lib Easy-Ecc, Chapter 2.2.1.3 C code example.
I am using a NTAG213 and want to verify the originality signature.
If I exactly do what is described in this chapter, using the pubKey, UID and Sig, the function ecdsa_verify() reports an invalid signature.
What makes me a bit surprised is that the function ecdsa_verify() expects a key input of size: ECC_BYTES+1, which is 17 in case of the proposed curve secp128r1. The given NXP public key has a length of 33 instead.
So, does anyone got this going with a successful verification???
To clarify, I am using the pubKey, UID and SIg provided by the application note example for a first test.
Thanks and best regards
Andreas