So I am using this library: https://github.com/ekapujiw2002/... with an Atmega328P reading and writing to the Mifare 1k classic NFC tag using the RC522 chip. The tag's datasheet can be found here: https://www.nxp.com/docs/en/data...
However... No where in the datasheet I've found how to password-protect it (so that nobody can write to it unless a password is provided).
At the library, this is the authentication method used:
/*
* Function Name : MFRC522_Auth
* Description : Verify card password
* Input parameters : authMode - Password Authentication Mode
0x60 = A key authentication
0x61 = B key authentication
BlockAddr - block address
Sectorkey - Sector password
serNum - card serial number, 4-byte
* Return value: the successful return CARD_FOUND
*/
uint8_t mfrc522_auth(uint8_t authMode, uint8_t BlockAddr, uint8_t *Sectorkey, uint8_t *serNum)
{
uint8_t status;
uint32_t recvBits;
uint8_t i;
uint8_t buff[12];
// Validate instruction block address + sector + password + card serial number
buff[0] = authMode;
buff[1] = BlockAddr;
for (i = 0; i<6; i++)
{
buff[i + 2] = *(Sectorkey + i);
}
for (i = 0; i<4; i++)
{
buff[i + 8] = *(serNum + i);
}
status = mfrc522_to_card(PCD_AUTHENT, buff, 12, buff, &recvBits);
i = mfrc522_read(Status2Reg);
if ((status != CARD_FOUND) || (!(i & 0x08)))
{
status = ERROR;
}
return status;
}
The only things I see there that must be provided is the block address, the serial number and the sector key. How should I:
1) Set a password to the NFC tag
2) Once set, use that password (provide it in the mfrc522_auth function.
Have anyone used Mifare classic before? Any ideas?
