pn532_mifare_classic.cpp

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#include <array>
#include <memory>
 
#include "pn532.h"
#include "esphome/core/log.h"
 
namespace esphome::pn532 {
 
static const char *const TAG = "pn532.mifare_classic";
 
std::unique_ptr<nfc::NfcTag> PN532::read_mifare_classic_tag_(nfc::NfcTagUid &uid) {
  uint8_t current_block = 4;
  uint8_t message_start_index = 0;
  uint32_t message_length = 0;
 
  if (this->auth_mifare_classic_block_(uid, current_block, nfc::MIFARE_CMD_AUTH_A, nfc::NDEF_KEY)) {
    std::vector<uint8_t> data;
    if (this->read_mifare_classic_block_(current_block, data)) {
      if (!nfc::decode_mifare_classic_tlv(data, message_length, message_start_index)) {
        return make_unique<nfc::NfcTag>(uid, nfc::ERROR);
      }
    } else {
      ESP_LOGE(TAG, "Failed to read block %d", current_block);
      return make_unique<nfc::NfcTag>(uid, nfc::MIFARE_CLASSIC);
    }
  } else {
    ESP_LOGV(TAG, "Tag is not NDEF formatted");
    return make_unique<nfc::NfcTag>(uid, nfc::MIFARE_CLASSIC);
  }
 
  uint32_t index = 0;
  uint32_t buffer_size = nfc::get_mifare_classic_buffer_size(message_length);
  std::vector<uint8_t> buffer;
 
  while (index < buffer_size) {
    if (nfc::mifare_classic_is_first_block(current_block)) {
      if (!this->auth_mifare_classic_block_(uid, current_block, nfc::MIFARE_CMD_AUTH_A, nfc::NDEF_KEY)) {
        ESP_LOGE(TAG, "Error, Block authentication failed for %d", current_block);
      }
    }
    std::vector<uint8_t> block_data;
    if (this->read_mifare_classic_block_(current_block, block_data)) {
      buffer.insert(buffer.end(), block_data.begin(), block_data.end());
    } else {
      ESP_LOGE(TAG, "Error reading block %d", current_block);
    }
 
    index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;
    current_block++;
 
    if (nfc::mifare_classic_is_trailer_block(current_block)) {
      current_block++;
    }
  }
 
  if (buffer.begin() + message_start_index < buffer.end()) {
    buffer.erase(buffer.begin(), buffer.begin() + message_start_index);
  } else {
    return make_unique<nfc::NfcTag>(uid, nfc::MIFARE_CLASSIC);
  }
 
  return make_unique<nfc::NfcTag>(uid, nfc::MIFARE_CLASSIC, buffer);
}
 
bool PN532::read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data) {
  if (!this->write_command_({
          PN532_COMMAND_INDATAEXCHANGE,
          0x01,  // One card
          nfc::MIFARE_CMD_READ,
          block_num,
      })) {
    return false;
  }
 
  if (!this->read_response(PN532_COMMAND_INDATAEXCHANGE, data) || data[0] != 0x00) {
    return false;
  }
  data.erase(data.begin());
 
  char data_buf[nfc::FORMAT_BYTES_BUFFER_SIZE];
  ESP_LOGVV(TAG, " Block %d: %s", block_num, nfc::format_bytes_to(data_buf, data));
  return true;
}
 
bool PN532::auth_mifare_classic_block_(nfc::NfcTagUid &uid, uint8_t block_num, uint8_t key_num, const uint8_t *key) {
  std::vector<uint8_t> data({
      PN532_COMMAND_INDATAEXCHANGE,
      0x01,       // One card
      key_num,    // Mifare Key slot
      block_num,  // Block number
  });
  data.insert(data.end(), key, key + 6);
  data.insert(data.end(), uid.begin(), uid.end());
  if (!this->write_command_(data)) {
    ESP_LOGE(TAG, "Authentication failed - Block %d", block_num);
    return false;
  }
 
  std::vector<uint8_t> response;
  if (!this->read_response(PN532_COMMAND_INDATAEXCHANGE, response) || response[0] != 0x00) {
    ESP_LOGE(TAG, "Authentication failed - Block 0x%02x", block_num);
    return false;
  }
 
  return true;
}
 
bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BUFFER = {
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> TRAILER_BUFFER = {
      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x07, 0x80, 0x69, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
  bool error = false;
 
  for (int block = 0; block < 64; block += 4) {
    if (!this->auth_mifare_classic_block_(uid, block + 3, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY)) {
      continue;
    }
    if (block != 0) {
      if (!this->write_mifare_classic_block_(block, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
        ESP_LOGE(TAG, "Unable to write block %d", block);
        error = true;
      }
    }
    if (!this->write_mifare_classic_block_(block + 1, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
      ESP_LOGE(TAG, "Unable to write block %d", block + 1);
      error = true;
    }
    if (!this->write_mifare_classic_block_(block + 2, BLANK_BUFFER.data(), BLANK_BUFFER.size())) {
      ESP_LOGE(TAG, "Unable to write block %d", block + 2);
      error = true;
    }
    if (!this->write_mifare_classic_block_(block + 3, TRAILER_BUFFER.data(), TRAILER_BUFFER.size())) {
      ESP_LOGE(TAG, "Unable to write block %d", block + 3);
      error = true;
    }
  }
 
  return !error;
}
 
bool PN532::format_mifare_classic_ndef_(nfc::NfcTagUid &uid) {
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> EMPTY_NDEF_MESSAGE = {
      0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLANK_BLOCK = {
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_1_DATA = {
      0x14, 0x01, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_2_DATA = {
      0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1, 0x03, 0xE1};
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> BLOCK_3_TRAILER = {
      0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0x78, 0x77, 0x88, 0xC1, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
  static constexpr std::array<uint8_t, nfc::MIFARE_CLASSIC_BLOCK_SIZE> NDEF_TRAILER = {
      0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7, 0x7F, 0x07, 0x88, 0x40, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
  if (!this->auth_mifare_classic_block_(uid, 0, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY)) {
    ESP_LOGE(TAG, "Unable to authenticate block 0 for formatting!");
    return false;
  }
  if (!this->write_mifare_classic_block_(1, BLOCK_1_DATA.data(), BLOCK_1_DATA.size()))
    return false;
  if (!this->write_mifare_classic_block_(2, BLOCK_2_DATA.data(), BLOCK_2_DATA.size()))
    return false;
  if (!this->write_mifare_classic_block_(3, BLOCK_3_TRAILER.data(), BLOCK_3_TRAILER.size()))
    return false;
 
  ESP_LOGD(TAG, "Sector 0 formatted to NDEF");
 
  for (int block = 4; block < 64; block += 4) {
    if (!this->auth_mifare_classic_block_(uid, block + 3, nfc::MIFARE_CMD_AUTH_B, nfc::DEFAULT_KEY)) {
      return false;
    }
    if (block == 4) {
      if (!this->write_mifare_classic_block_(block, EMPTY_NDEF_MESSAGE.data(), EMPTY_NDEF_MESSAGE.size())) {
        ESP_LOGE(TAG, "Unable to write block %d", block);
      }
    } else {
      if (!this->write_mifare_classic_block_(block, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
        ESP_LOGE(TAG, "Unable to write block %d", block);
      }
    }
    if (!this->write_mifare_classic_block_(block + 1, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
      ESP_LOGE(TAG, "Unable to write block %d", block + 1);
    }
    if (!this->write_mifare_classic_block_(block + 2, BLANK_BLOCK.data(), BLANK_BLOCK.size())) {
      ESP_LOGE(TAG, "Unable to write block %d", block + 2);
    }
    if (!this->write_mifare_classic_block_(block + 3, NDEF_TRAILER.data(), NDEF_TRAILER.size())) {
      ESP_LOGE(TAG, "Unable to write trailer block %d", block + 3);
    }
  }
  return true;
}
 
bool PN532::write_mifare_classic_block_(uint8_t block_num, const uint8_t *data, size_t len) {
  std::vector<uint8_t> cmd({
      PN532_COMMAND_INDATAEXCHANGE,
      0x01,  // One card
      nfc::MIFARE_CMD_WRITE,
      block_num,
  });
  cmd.insert(cmd.end(), data, data + len);
  if (!this->write_command_(cmd)) {
    ESP_LOGE(TAG, "Error writing block %d", block_num);
    return false;
  }
 
  std::vector<uint8_t> response;
  if (!this->read_response(PN532_COMMAND_INDATAEXCHANGE, response)) {
    ESP_LOGE(TAG, "Error writing block %d", block_num);
    return false;
  }
 
  return true;
}
 
bool PN532::write_mifare_classic_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message) {
  auto encoded = message->encode();
 
  uint32_t message_length = encoded.size();
  uint32_t buffer_length = nfc::get_mifare_classic_buffer_size(message_length);
 
  encoded.insert(encoded.begin(), 0x03);
  if (message_length < 255) {
    encoded.insert(encoded.begin() + 1, message_length);
  } else {
    encoded.insert(encoded.begin() + 1, 0xFF);
    encoded.insert(encoded.begin() + 2, (message_length >> 8) & 0xFF);
    encoded.insert(encoded.begin() + 3, message_length & 0xFF);
  }
  encoded.push_back(0xFE);
 
  encoded.resize(buffer_length, 0);
 
  uint32_t index = 0;
  uint8_t current_block = 4;
 
  while (index < buffer_length) {
    if (nfc::mifare_classic_is_first_block(current_block)) {
      if (!this->auth_mifare_classic_block_(uid, current_block, nfc::MIFARE_CMD_AUTH_A, nfc::NDEF_KEY)) {
        return false;
      }
    }
 
    if (!this->write_mifare_classic_block_(current_block, encoded.data() + index, nfc::MIFARE_CLASSIC_BLOCK_SIZE)) {
      return false;
    }
    index += nfc::MIFARE_CLASSIC_BLOCK_SIZE;
    current_block++;
 
    if (nfc::mifare_classic_is_trailer_block(current_block)) {
      // Skipping as cannot write to trailer
      current_block++;
    }
  }
  return true;
}
 
}  // namespace esphome::pn532