I couldn't wait to buy a Xiaomi Mi Band 4 NFC version from scalpers as soon as it was released.
The NFC function of the band has three main features: Xiao Ai, public transportation card, and simulated access card.
However, Xiao Ai on the band is difficult to use, with missing features and slow response. It even scolds me sometimes. Shanghai public transportation doesn't support it either. The access card suddenly became the hope of the whole village. Luckily, I have two access cards, so I decided to give it a try and simulate it.
This NFC thing is a complete failure, just like life itself.
The first card is an ID card, which is definitely beyond saving. I hope everything is on the second encrypted IC card. In order to save the useless NFC, I bought an NFC reader/writer PN532 from Taobao.
I put the encrypted card on the PN532 to read the data.
I used MifareOne Tool to decrypt the card.
The decryption failed... According to what I found online, it might be caused by the PN532 overheating. So, where is the coolest place?
After a long wait, it finally succeeded.
I obtained the encrypted card data.
Then, I wrote the data of sector 0, block 0 into a blank card.
After that, I wrote the data of the blank card into the band.
Now, the band has a card, but it only has the data of sector 0, block 0. So, I just need to write the remaining data into the band.
Verification: Comparing the data of the original card and the band card,
Only the data of sector 0, block 0 (vendor number) is different, and the encryption data of sector 15 is the same. This means that the simulation was successful.
Finally, the NFC was not bought in vain.