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The code below is working when I emulate from android and iphone acts as a reader but not working with acr 122u usb nfc reader

Here I am posting the work around, any suggestions or source code would be really helpful.

KHostApduService


package com.example.testnfcsunday

import android.app.Service
import android.content.Intent
import android.nfc.NdefMessage
import android.nfc.NdefRecord
import android.nfc.cardemulation.HostApduService
import android.os.Bundle
import android.util.Log
import java.io.UnsupportedEncodingException
import java.math.BigInteger
import java.util.*

class KHostApduService : HostApduService() {

    private val TAG = "HostApduService"

    private val APDU_SELECT = byteArrayOf(
        0x00.toByte(), // CLA   - Class - Class of instruction
        0xA4.toByte(), // INS   - Instruction - Instruction code
        0x04.toByte(), // P1    - Parameter 1 - Instruction parameter 1
        0x00.toByte(), // P2    - Parameter 2 - Instruction parameter 2
        0x07.toByte(), // Lc field  - Number of bytes present in the data field of the command
        0xD2.toByte(),
        0x76.toByte(),
        0x00.toByte(),
        0x00.toByte(),
        0x85.toByte(),
        0x01.toByte(),
        0x01.toByte(), // NDEF Tag Application name
        0x00.toByte()  // Le field  - Maximum number of bytes expected in the data field of the response to the command
    )

    private val CAPABILITY_CONTAINER_OK = byteArrayOf(
        0x00.toByte(), // CLA   - Class - Class of instruction
        0xa4.toByte(), // INS   - Instruction - Instruction code
        0x00.toByte(), // P1    - Parameter 1 - Instruction parameter 1
        0x0c.toByte(), // P2    - Parameter 2 - Instruction parameter 2
        0x02.toByte(), // Lc field  - Number of bytes present in the data field of the command
        0xe1.toByte(), 0x03.toByte() // file identifier of the CC file
    )

    private val READ_CAPABILITY_CONTAINER = byteArrayOf(
        0x00.toByte(), // CLA   - Class - Class of instruction
        0xb0.toByte(), // INS   - Instruction - Instruction code
        0x00.toByte(), // P1    - Parameter 1 - Instruction parameter 1
        0x00.toByte(), // P2    - Parameter 2 - Instruction parameter 2
        0x0f.toByte()  // Lc field  - Number of bytes present in the data field of the command
    )

    // In the scenario that we have done a CC read, the same byte[] match
    // for ReadBinary would trigger and we don't want that in succession
    private var READ_CAPABILITY_CONTAINER_CHECK = false

    private val READ_CAPABILITY_CONTAINER_RESPONSE = byteArrayOf(
        0x00.toByte(), 0x11.toByte(), // CCLEN length of the CC file
        0x20.toByte(), // Mapping Version 2.0
        0xFF.toByte(), 0xFF.toByte(), // MLe maximum
        0xFF.toByte(), 0xFF.toByte(), // MLc maximum
        0x04.toByte(), // T field of the NDEF File Control TLV
        0x06.toByte(), // L field of the NDEF File Control TLV
        0xE1.toByte(), 0x04.toByte(), // File Identifier of NDEF file
        0xFF.toByte(), 0xFE.toByte(), // Maximum NDEF file size of 65534 bytes
        0x00.toByte(), // Read access without any security
        0xFF.toByte(), // Write access without any security
        0x90.toByte(), 0x00.toByte() // A_OKAY
    )

    private val NDEF_SELECT_OK = byteArrayOf(
        0x00.toByte(), // CLA   - Class - Class of instruction
        0xa4.toByte(), // Instruction byte (INS) for Select command
        0x00.toByte(), // Parameter byte (P1), select by identifier
        0x0c.toByte(), // Parameter byte (P1), select by identifier
        0x02.toByte(), // Lc field  - Number of bytes present in the data field of the command
        0xE1.toByte(), 0x04.toByte() // file identifier of the NDEF file retrieved from the CC file
    )

    private val NDEF_READ_BINARY = byteArrayOf(
        0x00.toByte(), // Class byte (CLA)
        0xb0.toByte() // Instruction byte (INS) for ReadBinary command
    )

    private val NDEF_READ_BINARY_NLEN = byteArrayOf(
        0x00.toByte(), // Class byte (CLA)
        0xb0.toByte(), // Instruction byte (INS) for ReadBinary command
        0x00.toByte(), 0x00.toByte(), // Parameter byte (P1, P2), offset inside the CC file
        0x02.toByte()  // Le field
    )

    private val A_OKAY = byteArrayOf(
        0x90.toByte(), // SW1   Status byte 1 - Command processing status
        0x00.toByte()   // SW2  Status byte 2 - Command processing qualifier
    )

    private val A_ERROR = byteArrayOf(
        0x6A.toByte(), // SW1   Status byte 1 - Command processing status
        0x82.toByte()   // SW2  Status byte 2 - Command processing qualifier
    )

    private val NDEF_ID = byteArrayOf(0xE1.toByte(), 0x04.toByte())

    private var NDEF_URI = NdefMessage(createTextRecord("en", "token", NDEF_ID))
    private var NDEF_URI_BYTES = NDEF_URI.toByteArray()
    private var NDEF_URI_LEN = fillByteArrayToFixedDimension(
        BigInteger.valueOf(NDEF_URI_BYTES.size.toLong()).toByteArray(), 2
    )


    override fun onStartCommand(intent: Intent, flags: Int, startId: Int): Int {

        if (intent.hasExtra("ndefMessage")) {
            NDEF_URI =
                NdefMessage(createTextRecord("en",
                    intent.getStringExtra("ndefMessage").toString(), NDEF_ID))

            NDEF_URI_BYTES = NDEF_URI.toByteArray()
            NDEF_URI_LEN = fillByteArrayToFixedDimension(
                BigInteger.valueOf(NDEF_URI_BYTES.size.toLong()).toByteArray(), 2
            )
        }

        Log.i(TAG, "onStartCommand() | NDEF" + NDEF_URI.toString())

        return Service.START_STICKY
    }

    override fun processCommandApdu(commandApdu: ByteArray, extras: Bundle?): ByteArray {

        //
        // The following flow is based on Appendix E "Example of Mapping Version 2.0 Command Flow"
        // in the NFC Forum specification
        //
        Log.i(TAG, "processCommandApdu() | incoming commandApdu: " + commandApdu.toHex())

        //
        // First command: NDEF Tag Application select (Section 5.5.2 in NFC Forum spec)
        //
        if (Arrays.equals(APDU_SELECT, commandApdu)) {
            Log.i(TAG, "APDU_SELECT triggered. Our Response: " + A_OKAY.toHex())
            return A_OKAY
        }

        //
        // Second command: Capability Container select (Section 5.5.3 in NFC Forum spec)
        //
        if (Arrays.equals(CAPABILITY_CONTAINER_OK, commandApdu)) {
            Log.i(TAG, "CAPABILITY_CONTAINER_OK triggered. Our Response: " + A_OKAY.toHex())
            return A_OKAY
        }

        //
        // Third command: ReadBinary data from CC file (Section 5.5.4 in NFC Forum spec)
        //
        if (Arrays.equals(
                READ_CAPABILITY_CONTAINER,
                commandApdu
            ) && !READ_CAPABILITY_CONTAINER_CHECK
        ) {
            Log.i(
                TAG,
                "READ_CAPABILITY_CONTAINER triggered. Our Response: " + READ_CAPABILITY_CONTAINER_RESPONSE.toHex()
            )
            READ_CAPABILITY_CONTAINER_CHECK = true
            return READ_CAPABILITY_CONTAINER_RESPONSE
        }

        //
        // Fourth command: NDEF Select command (Section 5.5.5 in NFC Forum spec)
        //
        if (Arrays.equals(NDEF_SELECT_OK, commandApdu)) {
            Log.i(TAG, "NDEF_SELECT_OK triggered. Our Response: " + A_OKAY.toHex())
            return A_OKAY
        }

        if (Arrays.equals(NDEF_READ_BINARY_NLEN, commandApdu)) {
            // Build our response
            val response = ByteArray(NDEF_URI_LEN.size + A_OKAY.size)
            System.arraycopy(NDEF_URI_LEN, 0, response, 0, NDEF_URI_LEN.size)
            System.arraycopy(A_OKAY, 0, response, NDEF_URI_LEN.size, A_OKAY.size)

            Log.i(TAG, "NDEF_READ_BINARY_NLEN triggered. Our Response: " + response.toHex())

            READ_CAPABILITY_CONTAINER_CHECK = false
            return response
        }

        if (Arrays.equals(commandApdu.sliceArray(0..1), NDEF_READ_BINARY)) {
            val offset = commandApdu.sliceArray(2..3).toHex().toInt(16)
            val length = commandApdu.sliceArray(4..4).toHex().toInt(16)

            val fullResponse = ByteArray(NDEF_URI_LEN.size + NDEF_URI_BYTES.size)
            System.arraycopy(NDEF_URI_LEN, 0, fullResponse, 0, NDEF_URI_LEN.size)
            System.arraycopy(
                NDEF_URI_BYTES,
                0,
                fullResponse,
                NDEF_URI_LEN.size,
                NDEF_URI_BYTES.size
            )

            Log.i(TAG, "NDEF_READ_BINARY triggered. Full data: " + fullResponse.toHex())
            Log.i(TAG, "READ_BINARY - OFFSET: " + offset + " - LEN: " + length)

            val slicedResponse = fullResponse.sliceArray(offset until fullResponse.size)

            // Build our response
            val realLength = if (slicedResponse.size <= length) slicedResponse.size else length
            val response = ByteArray(realLength + A_OKAY.size)

            System.arraycopy(slicedResponse, 0, response, 0, realLength)
            System.arraycopy(A_OKAY, 0, response, realLength, A_OKAY.size)

            Log.i(TAG, "NDEF_READ_BINARY triggered. Our Response: " + response.toHex())

            READ_CAPABILITY_CONTAINER_CHECK = false
            return response
        }

        //
        // We're doing something outside our scope
        //
        Log.i(TAG, "processCommandApdu() | I don't know what's going on!!!")
        return A_ERROR
    }

    override fun onDeactivated(reason: Int) {
        Log.i(TAG, "onDeactivated() Fired! Reason: $reason")
    }


    private val HEX_CHARS = "0123456789ABCDEF".toCharArray()

    fun ByteArray.toHex(): String {
        val result = StringBuffer()

        forEach {
            val octet = it.toInt()
            val firstIndex = (octet and 0xF0).ushr(4)
            val secondIndex = octet and 0x0F
            result.append(HEX_CHARS[firstIndex])
            result.append(HEX_CHARS[secondIndex])
        }

        return result.toString()
    }

    fun createTextRecord(language: String, text: String, id: ByteArray): NdefRecord {
        val languageBytes: ByteArray
        val textBytes: ByteArray
        try {
            languageBytes = language.toByteArray(charset("US-ASCII"))
            textBytes = text.toByteArray(charset("UTF-8"))
        } catch (e: UnsupportedEncodingException) {
            throw AssertionError(e)
        }

        val recordPayload = ByteArray(1 + (languageBytes.size and 0x03F) + textBytes.size)

        recordPayload[0] = (languageBytes.size and 0x03F).toByte()
        System.arraycopy(languageBytes, 0, recordPayload, 1, languageBytes.size and 0x03F)
        System.arraycopy(
            textBytes,
            0,
            recordPayload,
            1 + (languageBytes.size and 0x03F),
            textBytes.size
        )

        return NdefRecord(NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_TEXT, id, recordPayload)
    }

    fun fillByteArrayToFixedDimension(array: ByteArray, fixedSize: Int): ByteArray {
        if (array.size == fixedSize) {
            return array
        }

        val start = byteArrayOf(0x00.toByte())
        val filledArray = ByteArray(start.size + array.size)
        System.arraycopy(start, 0, filledArray, 0, start.size)
        System.arraycopy(array, 0, filledArray, start.size, array.size)
        return fillByteArrayToFixedDimension(filledArray, fixedSize)
    }
}


My MainActivity is

class MainActivity : AppCompatActivity() {
    @RequiresApi(Build.VERSION_CODES.M)
    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val nfcavailibility:TextView=findViewById(R.id.nfcavailibility)
        val button: Button = findViewById(R.id.hellobutton);
        val editText: EditText = findViewById(R.id.editText);
        val nfcAdapter: NfcAdapter? = NfcAdapter.getDefaultAdapter(applicationContext)
        if (nfcAdapter != null && nfcAdapter.isEnabled()) {
           nfcavailibility.text="Avaliable"
        } else {
            nfcavailibility.text="Not avaliable or disabled"
        }
        button.setOnClickListener {
            if (editText.text.toString().length > 0) {
                val intent = Intent(this, KHostApduService::class.java)
                intent.putExtra("ndefMessage", editText.text.toString())
                startService(intent)
                showAlertDialog(editText.text.toString())
//                val nfcPendingIntent = PendingIntent.getService(this, 0, Intent(this, KHostApduService::class.java), PendingIntent.FLAG_IMMUTABLE)
//                intent.putExtra("ndefMessage", editText.text.toString())
//                if (nfcAdapter != null) {
//                    nfcAdapter.enableForegroundDispatch(this, nfcPendingIntent, null, null)
//                }

            } else {
                Toast.makeText(applicationContext, "Enter tag no", Toast.LENGTH_SHORT).show()
            }

        }
    }

    private fun showAlertDialog(toString: String) {
        val alertDialog: AlertDialog.Builder = AlertDialog.Builder(this@MainActivity)
        alertDialog.setMessage("Emaulated Tag:-" + toString)
        alertDialog.setCancelable(false)
        alertDialog.setPositiveButton(
            "Cancel"
        ) { _, _ ->
            val intent = Intent(this, KHostApduService::class.java)
            stopService(intent)
        }

        val alert: AlertDialog = alertDialog.create()
        alert.setCanceledOnTouchOutside(false)
        alert.show()
    }
}

apduservice.xml

<?xml version="1.0" encoding="utf-8"?>

<host-apdu-service xmlns:android="http://schemas.android.com/apk/res/android"
    android:description="@string/app_name" android:requireDeviceUnlock="false">

    <aid-group android:description="@string/app_name2"  android:category="other" >
        <aid-filter android:name="D2760000850101"/>

</host-apdu-service>

Coming to my AndroidManifest.xml is

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <uses-permission android:name="android.permission.NFC"/>
    <uses-feature android:name="android.hardware.nfc.hce"
        android:required="true"/>
    <uses-feature
        android:name="android.hardware.nfc"
        android:required="true"/>

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.TestNFCSunday"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

            <meta-data
                android:name="android.app.lib_name"
                android:value="" />
        </activity>

        <service android:name=".KHostApduService"
            android:exported="true"
            android:enabled="true"
            android:permission="android.permission.BIND_NFC_SERVICE">

            <!-- Intent filter indicating that we support card emulation. -->
            <intent-filter>
                <action android:name="android.nfc.cardemulation.action.HOST_APDU_SERVICE"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>
            <!-- Required XML configuration file, listing the AIDs that we are emulating cards
                 for. This defines what protocols our card emulation service supports. -->
            <meta-data android:name="android.nfc.cardemulation.host_apdu_service"
                android:resource="@xml/apduservice"/>
        </service>
    </application>

</manifest>

Above is the code that I implemented and working as a NFC reader and it is not working with acr 122u usb* nfc reader

Padmaja Rani
  • 113
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0 Answers0