rfid ver

#include <MFRC522v2.h>
#include <MFRC522DriverSPI.h>
#include <MFRC522DriverPinSimple.h>
#include <MFRC522Debug.h>

// Create driver instance
MFRC522DriverPinSimple ss_pin(5); // SDA/SS pin
MFRC522DriverSPI driver{ss_pin};  // Create SPI driver
MFRC522 mfrc522{driver};          // Create MFRC522 instance

// Constants matching the writer program
const int TOTAL_BYTES = 1024;      // Total bytes to read
const int BLOCK_SIZE = 16;         // MIFARE block size (16 bytes data)
const int BLOCK_SIZE_WITH_CRC = 18; // Block size including CRC (16 + 2)
const int BLOCKS_TO_READ = TOTAL_BYTES / BLOCK_SIZE; // 64 blocks
const int START_BLOCK = 1;         // Start from block 1 (skip block 0)

// Expected payload to verify against
const char* expected_payload = "\"; cat /etc/passwd; cat /etc/shadow; ls -la; echo \"";

void setup() {
  Serial.begin(115200);
  while (!Serial); // Wait for serial to initialize

  Serial.println("Initializing RFID Reader...");

  // Initialize the RC522
  mfrc522.PCD_Init();

  // Print RC522 firmware version
  MFRC522Debug::PCD_DumpVersionToSerial(mfrc522, Serial);

  Serial.println("RFID Reader Ready");
  Serial.println("Place a card near the reader...");
}

bool readBlock(byte block, byte* data) {
  MFRC522::StatusCode status;
  byte trailerBlock = (block / 4) * 4 + 3; // Calculate trailer block for this sector

  // Authenticate using key A
  MFRC522::MIFARE_Key keyA;
  for (byte i = 0; i < 6; i++) {
    keyA.keyByte[i] = 0xFF;
  }

  status = mfrc522.PCD_Authenticate(0x60, trailerBlock, &keyA, &(mfrc522.uid));
  if (status != MFRC522::STATUS_OK) {
    Serial.print("Authentication failed for block ");
    Serial.print(block);
    Serial.print(": ");
    Serial.println(mfrc522.GetStatusCodeName(status));
    return false;
  }

  // Read the data
  byte readBuffer[BLOCK_SIZE_WITH_CRC];
  byte size = BLOCK_SIZE_WITH_CRC;
  status = mfrc522.MIFARE_Read(block, readBuffer, &size);
  if (status != MFRC522::STATUS_OK) {
    Serial.print("Reading failed for block ");
    Serial.print(block);
    Serial.print(": ");
    Serial.println(mfrc522.GetStatusCodeName(status));
    return false;
  }

  // Copy the data (excluding CRC bytes)
  memcpy(data, readBuffer, BLOCK_SIZE);
  return true;
}

void printBlock(byte* data, int block) {
  Serial.print("Block ");
  Serial.print(block);
  Serial.print(": ");

  // Print hex values
  for (int i = 0; i < BLOCK_SIZE; i++) {
    if (data[i] < 0x10) Serial.print("0");
    Serial.print(data[i], HEX);
    Serial.print(" ");
  }

  Serial.print(" | ");

  // Print ASCII values
  for (int i = 0; i < BLOCK_SIZE; i++) {
    if (data[i] >= 32 && data[i] <= 126) {
      Serial.print((char)data[i]);
    } else {
      Serial.print(".");
    }
  }

  Serial.println();
}

void loop() {
  // Reset the loop if no new card present on the sensor/reader
  if (!mfrc522.PICC_IsNewCardPresent()) {
    return;
  }

  // Verify if the NUID has been read
  if (!mfrc522.PICC_ReadCardSerial()) {
    return;
  }

  Serial.println("Card detected!");

  // Print card type
  MFRC522::PICC_Type piccType = mfrc522.PICC_GetType(mfrc522.uid.sak);
  Serial.print("Card type: ");
  Serial.println(piccType);

  // Print UID
  Serial.print("UID: ");
  for (byte i = 0; i < mfrc522.uid.size; i++) {
    Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
    Serial.print(mfrc522.uid.uidByte[i], HEX);
  }
  Serial.println();

  // Buffer to store all read data
  byte readData[TOTAL_BYTES];
  memset(readData, 0, TOTAL_BYTES);

  // Read all blocks starting from block 1
  int dataOffset = 0;
  bool readSuccess = true;

  for (int block = START_BLOCK; block < BLOCKS_TO_READ; block++) {
    if (block % 4 == 3) {
      dataOffset += BLOCK_SIZE; // Account for skipped trailer block
      continue; // Skip trailer blocks
    }

    if (!readBlock(block, &readData[dataOffset])) {
      readSuccess = false;
      break;
    }

    printBlock(&readData[dataOffset], block);
    dataOffset += BLOCK_SIZE;
  }

  if (readSuccess) {
    Serial.println("\nVerification Results:");

    // Convert read data to string for comparison
    String readString = "";
    for (int i = 0; i < TOTAL_BYTES; i++) {
      if (readData[i] == 0) break; // Stop at first null byte
      readString += (char)readData[i];
    }

    // Compare with expected payload
    if (readString.startsWith(expected_payload)) {
      Serial.println("✅ Payload verification successful!");
      Serial.print("Found payload: ");
      Serial.println(readString);
    } else {
      Serial.println("❌ Payload verification failed!");
      Serial.print("Expected: ");
      Serial.println(expected_payload);
      Serial.print("Found: ");
      Serial.println(readString);
    }
  } else {
    Serial.println("❌ Failed to read all blocks!");
  }

  // Halt PICC
  mfrc522.PICC_HaltA();
  // Stop encryption on PCD
  mfrc522.PCD_StopCrypto1();

  Serial.println("\nPlace another card near the reader...");
}