#include <PN532.h>

#define SCK      13
#define MOSI   11
#define SS      10
#define MISO   12
PN532 nfc(SCK, MISO, MOSI, SS);

int i = 0;
uint8_t mkey[1] = {(byte)i};
boolean encontrada = false;
boolean fin = false;


void setup()
{
   Serial.begin(9600);
   nfc.begin();
   nfc.SAMConfig();
}


void loop()
{
   byte keys[] = {mkey[0],mkey[0],mkey[0],mkey[0],mkey[0],mkey[0]};
   uint32_t id = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A);

   if( id > 0 && i <= 255 && !encontrada && !fin )
   {
      if( nfc.authenticateBlock(1, id ,0x08, KEY_A, keys) )
      {
         Serial.print("+ La clave correcta es: 0x"); Serial.println(mkey[0], HEX);
         encontrada = true;
      }
      else
      {
         Serial.print("Clave incorrecta (0x"); Serial.print(mkey[0], HEX); Serial.println(")");
         mkey[0] = (byte)++i;
      }
   }
   else if( i > 255 && !fin )
   {
      Serial.println("- Fin de combinaciones");
      fin = true;
   }
}