add rewrite support for gen2 tags with W command

add rewrite support for gen2 tags with W command

utils/nfc-mfclassic.c

@@ -260,6 +260,8 @@ unlock_card(void)
  // now send unlock
  if (!transmit_bits(abtUnlock1, 7)) {
  printf("Warning: Unlock command [1/2]: failed / not acknowledged.\n");
+ printf("Trying to rewrite block 0 on a gen2 tag.\n");
+ magic2 = true;
  } else {
  if (transmit_bytes(abtUnlock2, 1)) {
  printf("Card unlocked\n");
@@ -270,6 +272,15 @@ unlock_card(void)
  }
 
  // reset reader
+ if (!unlocked) {
+ if (nfc_initiator_select_passive_target(pnd, nmMifare, nt.nti.nai.abtUid, nt.nti.nai.szUidLen, NULL) <= 0) {
+ printf("Error: tag was removed\n");
+ nfc_close(pnd);
+ nfc_exit(context);
+ exit(EXIT_FAILURE);
+ }
+ return true;
+ }
  // Configure the CRC
  if (nfc_device_set_property_bool(pnd, NP_HANDLE_CRC, true) < 0) {
  nfc_perror(pnd, "nfc_device_set_property_bool");
@@ -438,7 +449,7 @@ write_card(int write_block_zero)
  // If we are are writing to a chinese magic card, we've already unlocked
  // If we're writing to a One Time Write card, we need to authenticate
  // If we're writing something else, we'll need to authenticate
- if ((write_block_zero && magic3) || !write_block_zero) {
+ if ((write_block_zero && (magic2 || magic3)) || !write_block_zero) {
  if (!authenticate(uiBlock) && !bTolerateFailures) {
  printf("!\nError: authentication failed for block %02x\n", uiBlock);
  return false;
@@ -507,7 +518,7 @@ write_card(int write_block_zero)
  // If we are are writing to a chinese magic card, we've already unlocked
  // If we're writing to a One Time Write, we need to authenticate
  // If we're writing something else, we'll need to authenticate
- if ((write_block_zero && magic3) || !write_block_zero) {
+ if ((write_block_zero && (magic2 || magic3)) || !write_block_zero) {
  if (!authenticate(0) && !bTolerateFailures) {
  printf("!\nError: authentication failed for block 00\n");
  return false;