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morozj01 / react-native-ntag-424

Simplifies integration with the NTAG-424 class of NFC chips from NXP.
MIT License
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Make part one and two of authenticateEv2First public #10

Open johannesfritsch opened 4 weeks ago

johannesfritsch commented 4 weeks ago

Hey!

First of all: Thanks for your library. It helped me tremendously to understand the programming of my NTAG 424.

My scenario needs to keep the shared secret key away from the mobile app. I want to store the keys on my server and on the PICCs. Every card will have it's own key. So I need to perform parts of the authenticateEv2First function on the mobile phone (part 1) and the PICC, but then send the encrypted random to the server, where I build the encrypted message to be sent back to the mobile app and the PICC for verification (part 2).

Would you accept a PR that makes the private functions public or (even better) refactors the code a bit to allow for such a scenario? I assume that mutual authentication seldom happens between the react native app and the PICC directly.

Best regards

Johannes

morozj01 commented 2 weeks ago

Hi Johannes,

Apologies for the late reply here. I think your use case certainly makes sense and is likely a pretty common (and more secure) approach.

I think without a slight refactor it will be challenging though since you will need to generate the fields transactionId, sessionKeyMac and sessionKeyEncryption server-side and return them to the client.

If you are still interested and have an approach in mind then definitely feel free to open a PR.

Appreciate your interest either way!

Justin