Hi everyone, what I'm trying to create a sketch that will automaticaly authenticate with MiFare and Mifare Classic NFC/RFID cards.
First off, I am using the PN532 RFID/NFC Breakout and Shield from Adafruit:
The card I am using is the ISO14443A MiFare calssic 1K. The 1K MiFare card i use has 64 blocks of memory laid out across 15 sectors.
The 1K MiFare card uses 4 byte hex value for the UID and a 6 byte hex value password for each sector of memory.
This is output from a memory dump sketch:
Waiting for an ISO14443A Card ...
Found an ISO14443A card
UID Length: 4 bytes
UID Value: 0xFF 0xFF 0xFF 0x86
I am using this code from Adafruits website to attempt to authenticate and read each sector:
#include <Wire.h>
#include <Adafruit_NFCShield_I2C.h>
#define IRQ (2)
#define RESET (3) // Not connected by default on the NFC Shield
Adafruit_NFCShield_I2C nfc(IRQ, RESET);
void setup(void) {
// has to be fast to dump the entire memory contents!
Serial.begin(115200);
Serial.println("Looking for PN532...");
nfc.begin();
uint32_t versiondata = nfc.getFirmwareVersion();
if (! versiondata) {
Serial.print("Didn't find PN53x board");
while (1); // halt
}
// Got ok data, print it out!
Serial.print("Found chip PN5"); Serial.println((versiondata>>24) & 0xFF, HEX);
Serial.print("Firmware ver. "); Serial.print((versiondata>>16) & 0xFF, DEC);
Serial.print('.'); Serial.println((versiondata>>8) & 0xFF, DEC);
// configure board to read RFID tags
nfc.SAMConfig();
Serial.println("Waiting for an ISO14443A Card ...");
}
void loop(void) {
uint8_t success; // Flag to check if there was an error with the PN532
uint8_t uid[] = { 0, 0, 0, 0, 0, 0, 0 }; // Buffer to store the returned UID
uint8_t uidLength; // Length of the UID (4 or 7 bytes depending on ISO14443A card type)
uint8_t currentblock; // Counter to keep track of which block we're on
bool authenticated = false; // Flag to indicate if the sector is authenticated
uint8_t data[16]; // Array to store block data during reads
// Keyb on NDEF and Mifare Classic should be the same
uint8_t keyuniversal[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
// Wait for an ISO14443A type cards (Mifare, etc.). When one is found
// 'uid' will be populated with the UID, and uidLength will indicate
// if the uid is 4 bytes (Mifare Classic) or 7 bytes (Mifare Ultralight)
success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength);
if (success) {
// Display some basic information about the card
Serial.println("Found an ISO14443A card");
Serial.print(" UID Length: ");Serial.print(uidLength, DEC);Serial.println(" bytes");
Serial.print(" UID Value: ");
nfc.PrintHex(uid, uidLength);
Serial.println("");
if (uidLength == 4)
{
// We probably have a Mifare Classic card ...
Serial.println("Seems to be a Mifare Classic card (4 byte UID)");
// Now we try to go through all 16 sectors (each having 4 blocks)
// authenticating each sector, and then dumping the blocks
for (currentblock = 0; currentblock < 64; currentblock++)
{
// Check if this is a new block so that we can reauthenticate
if (nfc.mifareclassic_IsFirstBlock(currentblock)) authenticated = false;
// If the sector hasn't been authenticated, do so first
if (!authenticated)
{
// Starting of a new sector ... try to to authenticate
Serial.print("------------------------Sector ");Serial.print(currentblock/4, DEC);Serial.println("-------------------------");
if (currentblock == 0)
{
// This will be 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF for Mifare Classic (non-NDEF!)
// or 0xA0 0xA1 0xA2 0xA3 0xA4 0xA5 for NDEF formatted cards using key a,
// but keyb should be the same for both (0xFF 0xFF 0xFF 0xFF 0xFF 0xFF)
success = nfc.mifareclassic_AuthenticateBlock (uid, uidLength, currentblock, 1, keyuniversal);
}
else
{
// This will be 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF for Mifare Classic (non-NDEF!)
// or 0xD3 0xF7 0xD3 0xF7 0xD3 0xF7 for NDEF formatted cards using key a,
// but keyb should be the same for both (0xFF 0xFF 0xFF 0xFF 0xFF 0xFF)
success = nfc.mifareclassic_AuthenticateBlock (uid, uidLength, currentblock, 1, keyuniversal);
}
if (success)
{
authenticated = true;
}
else
{
Serial.println("Authentication error");
}
}
// If we're still not authenticated just skip the block
if (!authenticated)
{
Serial.print("Block ");Serial.print(currentblock, DEC);Serial.println(" unable to authenticate");
}
else
{
// Authenticated ... we should be able to read the block now
// Dump the data into the 'data' array
success = nfc.mifareclassic_ReadDataBlock(currentblock, data);
if (success)
{
// Read successful
Serial.print("Block ");Serial.print(currentblock, DEC);
if (currentblock < 10)
{
Serial.print(" ");
}
else
{
Serial.print(" ");
}
// Dump the raw data
nfc.PrintHexChar(data, 16);
}
else
{
// Oops ... something happened
Serial.print("Block ");Serial.print(currentblock, DEC);
Serial.println(" unable to read this block");
}
}
}
}
else
{
Serial.println("Ooops ... this doesn't seem to be a Mifare Classic card!");
}
}
// Wait a bit before trying again
Serial.println("\n\nSend a character to run the mem dumper again!");
Serial.flush();
while (!Serial.available());
while (Serial.available()) {
Serial.read();
}
Serial.flush();
}
The interesting part to note is this value:
uint8_t keyuniversal[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF } ;
Which is used to store the key value for the block. I was wondering if there is a way to use the "for" or "while" commands to loop over all possible hex values from 0x00 => 0xFF in an attempt to discover the key for each block and print it to the serial output.
Can This be done? Is there any chance this code could be modifyed to read all sectors?
Any input is greatly appreciated.