Class MifareClassic

java.lang.Object
com.codename1.nfc.TagTechnology
com.codename1.nfc.MifareClassic
public class MifareClassic extends TagTechnology

NXP MIFARE Classic 1K/4K technology view. Block-level read and write with key A or key B authentication.

Android-only -- iOS Core NFC intentionally rejects MIFARE Classic. On iOS, Tag.getMifareClassic() returns null for the same physical tag and the caller should fall back to Tag.getNfcA() or fail gracefully.

The default factory keys are widely published; use them only on untransitioned demo / blank cards.

  • Constructor Details

    • MifareClassic

      public MifareClassic()

  • Method Details

    • keyDefault

      public static byte[] keyDefault()
      Default MIFARE Classic key A used by NXP shipping cards (FF FF FF FF FF FF). Returns a fresh defensive copy.

    • keyMifareApplicationDirectory

      public static byte[] keyMifareApplicationDirectory()
      MIFARE Application Directory (MAD) key A from NXP AN10787 (A0 A1 A2 A3 A4 A5). Returns a fresh defensive copy.

    • keyNfcForum

      public static byte[] keyNfcForum()
      NFC Forum key A for NDEF-formatted MIFARE Classic blocks (D3 F7 D3 F7 D3 F7). Returns a fresh defensive copy.

    • getSectorCount

      public int getSectorCount()
      Total sectors on the tag (16 on Classic 1K, 40 on Classic 4K).

    • getBlockCount

      public int getBlockCount()
      Total addressable blocks (each 16 bytes).

    • sectorToBlock

      public int sectorToBlock(int sectorIndex)
      First block index inside the given sector. Sectors 0-31 contain 4 blocks each; sectors 32-39 (4K cards only) contain 16 blocks.

    • authenticateSectorWithKeyA

      public AsyncResource<Boolean> authenticateSectorWithKeyA(int sector, byte[] key)
      Authenticates a sector with the given key A. Required before any read/write on the sector. Fails with NfcError.IO_ERROR when the key is wrong.

    • authenticateSectorWithKeyB

      public AsyncResource<Boolean> authenticateSectorWithKeyB(int sector, byte[] key)
      Authenticates a sector with the given key B.

    • readBlock

      public AsyncResource<byte[]> readBlock(int block)
      Reads a single 16-byte data block. The sector containing the block must have been authenticated first.

    • writeBlock

      public AsyncResource<Boolean> writeBlock(int block, byte[] data)
      Writes the 16-byte payload to the given data block. Fails with NfcError.READ_ONLY when access bits forbid the write.

    • getType

      public final TagType getType()
      Description copied from class: TagTechnology
      The technology variant this view represents.
      Specified by:
      getType in class TagTechnology