我想开发一个 Android 应用程序，其中一台设备充当 NFC 标签，另一台移动设备读取它。 我有两个 Android 设备，A 和 B - NFC HCE 功能适用于设备 A，即使用正确的 NDEF 数据模拟标签，设备 B 可以读取它。设备 A 的 NFC 标签 (HCE) 的规格为 -
但是现在，当我尝试使用设备 B 执行此操作时，NDEF 数据未写入且无法被设备 A 读取。设备 B 的 NFC 标签 (HCE) 的规格为 -
HostApduService代码如下-
package com.example.cn
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 CardService : 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", "NFC Clock", 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")) {
Log.i(TAG, "Set NFC tag as " + intent.getStringExtra("ndefMessage"))
NDEF_URI =
NdefMessage(createTextRecord("en", intent.getStringExtra("ndefMessage"), 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.records[0].payload);
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.wtf(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 String.hexStringToByteArray(): ByteArray {
val result = ByteArray(length / 2)
for (i in 0 until length step 2) {
val firstIndex = HEX_CHARS.indexOf(this[i]);
val secondIndex = HEX_CHARS.indexOf(this[i + 1]);
val octet = firstIndex.shl(4).or(secondIndex)
result.set(i.shr(1), octet.toByte())
}
return result
}
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)
}
}
（从this获得帮助）
使用的AID -
<aid-filter android:name="D2760000850101"/>
编辑：NXP TagInfo 在读取设备 B 的标签时显示此信息 - ScreenShot
编辑： 这可能是与 NFC 标签 B 相关的任何东西吗？
@Techie Baba 你的问题解决了吗？我目前正在开发一个类似的应用程序，我和你也有同样的问题。
