Authentication error in NXP Library

[raj_shinde]

I am developing an android app to authenticate mifare UltraLightC chip ,but the problem i am facing while authenticating  chip is , it always  throws an exception, every time even if it is authenticated or not (i.e .authenticate() method  of NXPlibrary), and how can we confirm that our key is being successfully authenticated as per an example in  datasheet provided by mifare, they are just using an log below the .authenticate() method so, is this a proper way to authenticate an key ?  while debugging i found that this method always throws an exception message(i.e NxpNFCLibException)  rather than ideally an authenticating method should give an response for example authenticated true or false, it do not return anything, so how can we confirm whether our key is properly authenticated  i am attaching my debugging logs with it ? Please provide me a solution or an example  on how to authenticate key and how to check whether it is authenticating properly or not ? 

Version of NXP Library  i am using 

nxpnfcandroidlib-1.7

[marcoperrone]

Hi  to all,

I tried to use the code suggested by NXP TechSupport @jimmychan to authenticate a Mifare Ultralight C with an Android smartphone.
Here the the data between the the app and the tag:

My Key is: 42 52 45 41 4B 4D 45 49 46 59 4F 55 43 41 4E 21

I start communication  TAG : 1A 00

The TAG answer with (encoded) RndB: AF 69 EC C8 F7 CA DC 1A C8

so the the IV for next communication become: 69 EC C8 F7 CA DC 1A C8

the RndB (decoded) is: CB 0C AC EE F2 76 F1 7E

the RndB' (rotate) is: 0C AC EE F2 76 F1 7E CB

the RndA is: C9 60 0A DC EB 08 FD C4

The value sent to the tag is: AF encoded (RndA + RndB')

AF 90 79 9A 6D 73 E9 51 49 C7 AA 66 D9 0C 08 BE C5

When I sent this I have an exception Transceive failed (like the data sent is not correct)

I check on this site http://tripledes.online-domain-tools.com/

And the value sent is correct

I hope You can help me

Best Regards

Marco

[jimmychan]

This may help you. authentication - Android: Authenticating with NXP MiFare Ultralight C - Stack Overflow 

[marcoperrone]

Hi @jimmychan,

Did You use the code suggested successfully, because I have an exception during the authentication, I explained all in my other post.
Thank You 

Best Regards

Marco