DesfireEV1 Change the Default DES Key (all 0's) to AES

[scard project]

everything is working on my side ,
i have one problem in changing the Default PICC Master Key from DES to AES (iam
stuck at this point from 5 days!!),, below is my logs : please take a look and let

me know what iam doing wrong

 

CMD=0A00

Res = AF5039C16807AB67FE

RNDB=9B9E37C66B060449

RNDA=9B2B0E915D85DF96

DesSessionKey= 9B2B0E919B9E37C69B2B0E919B9E37C6



ChangeKey:



CMD=C4



KEYNO= 80 (Aes)



NewKey=00000000000000000000000000000000



CRC16=C8B6



Data To Decrypt=00000000000000000000000000000000C8B6000000000000



Decrypted Dta = 90133EAF84AA8BC5D9EEBA4BDD20CE93C97026E54C44738C



CMD=C48090133EAF84AA8BC5D9EEBA4BDD20CE93C97026E



RES= 1E !!

Please Advise

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[Sandra Fuchs]

Dear User,

What I can see here is that you forget to include the KeyVersion into the data preparation before encryption. When updating a key from 2K3DES or 3K3DES to AES, the 16 bytes long key needs to be concatenated with the key version (which I guess is 00 in your case), the CRC16, and filled up with padding in order to reach a multiple of the blocksize.

The data to encrypt would look like this = 0000000000000000000000000000000000 C8B60000000000, so one more bytes of zeros needs to be added before the CRC16 and the padding.
Afterwards you need to encrypt it and send the command Cmd = C4 || encrypted data.

I hope with including the key version it is working for you.

Best regards,
Sandra

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