app-common/src/main/java/im/angry/openeuicc/core/EuiccChannel.kt

@@ -1,7 +1,6 @@
 package im.angry.openeuicc.core
 
 import im.angry.openeuicc.util.*
-import net.typeblog.lpac_jni.ApduInterface
 import net.typeblog.lpac_jni.LocalProfileAssistant
 
 interface EuiccChannel {
@@ -29,10 +28,5 @@ interface EuiccChannel {
      */
     val intrinsicChannelName: String?
 
-    /**
-     * The underlying APDU interface for this channel
-     */
-    val apduInterface: ApduInterface
-
     fun close()
 }

app-common/src/main/java/im/angry/openeuicc/core/EuiccChannelImpl.kt

@@ -1,7 +1,6 @@
 package im.angry.openeuicc.core
 
-import im.angry.openeuicc.util.UiccPortInfoCompat
-import im.angry.openeuicc.util.decodeHex
+import im.angry.openeuicc.util.*
 import kotlinx.coroutines.flow.Flow
 import net.typeblog.lpac_jni.ApduInterface
 import net.typeblog.lpac_jni.LocalProfileAssistant
@@ -12,7 +11,7 @@ class EuiccChannelImpl(
     override val type: String,
     override val port: UiccPortInfoCompat,
     override val intrinsicChannelName: String?,
-    override val apduInterface: ApduInterface,
+    private val apduInterface: ApduInterface,
     verboseLoggingFlow: Flow<Boolean>,
     ignoreTLSCertificateFlow: Flow<Boolean>
 ) : EuiccChannel {

app-common/src/main/java/im/angry/openeuicc/core/EuiccChannelWrapper.kt

@@ -1,7 +1,6 @@
 package im.angry.openeuicc.core
 
 import im.angry.openeuicc.util.*
-import net.typeblog.lpac_jni.ApduInterface
 import net.typeblog.lpac_jni.LocalProfileAssistant
 
 class EuiccChannelWrapper(orig: EuiccChannel) : EuiccChannel {
@@ -34,8 +33,6 @@ class EuiccChannelWrapper(orig: EuiccChannel) : EuiccChannel {
         get() = channel.valid
     override val intrinsicChannelName: String?
         get() = channel.intrinsicChannelName
-    override val apduInterface: ApduInterface
-        get() = channel.apduInterface
     override val atr: ByteArray?
         get() = channel.atr
 

app-common/src/main/java/im/angry/openeuicc/core/OmapiApduInterface.kt

@@ -7,6 +7,7 @@ import android.util.Log
 import im.angry.openeuicc.util.*
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.single
 import kotlinx.coroutines.runBlocking
 import net.typeblog.lpac_jni.ApduInterface
 
@@ -20,12 +21,7 @@ class OmapiApduInterface(
     }
 
     private lateinit var session: Session
-    private val channels = arrayOf<Channel?>(
-        null,
-        null,
-        null,
-        null,
-    )
+    private lateinit var lastChannel: Channel
 
     override val valid: Boolean
         get() = service.isConnected && (this::session.isInitialized && !session.isClosed)
@@ -42,24 +38,24 @@ class OmapiApduInterface(
     }
 
     override fun logicalChannelOpen(aid: ByteArray): Int {
-        val channel = session.openLogicalChannel(aid)
-        check(channel != null) { "Failed to open logical channel (${aid.encodeHex()})" }
-        val index = channels.indexOf(null)
-        check(index != -1) { "No free logical channel slots" }
-        synchronized(channels) { channels[index] = channel }
-        return index
+        check(!this::lastChannel.isInitialized) {
+            "Can only open one channel"
+        }
+        lastChannel = session.openLogicalChannel(aid)!!
+        return 1
     }
 
     override fun logicalChannelClose(handle: Int) {
-        val channel = channels.getOrNull(handle)
-        check(channel != null) { "Invalid logical channel handle $handle" }
-        if (channel.isOpen) channel.close()
-        synchronized(channels) { channels[handle] = null }
+        check(handle == 1 && !this::lastChannel.isInitialized) {
+            "Unknown channel"
+        }
+        lastChannel.close()
     }
 
-    override fun transmit(handle: Int, tx: ByteArray): ByteArray {
-        val channel = channels.getOrNull(handle)
-        check(channel != null) { "Invalid logical channel handle $handle" }
+    override fun transmit(tx: ByteArray): ByteArray {
+        check(this::lastChannel.isInitialized) {
+            "Unknown channel"
+        }
 
         if (runBlocking { verboseLoggingFlow.first() }) {
             Log.d(TAG, "OMAPI APDU: ${tx.encodeHex()}")
@@ -67,7 +63,7 @@ class OmapiApduInterface(
 
         try {
             for (i in 0..10) {
-                val res = channel.transmit(tx)
+                val res = lastChannel.transmit(tx)
                 if (runBlocking { verboseLoggingFlow.first() }) {
                     Log.d(TAG, "OMAPI APDU response: ${res.encodeHex()}")
                 }

app-common/src/main/java/im/angry/openeuicc/core/usb/UsbApduInterface.kt

@@ -21,13 +21,10 @@ class UsbApduInterface(
     private lateinit var ccidDescription: UsbCcidDescription
     private lateinit var transceiver: UsbCcidTransceiver
 
+    private var channelId = -1
+
     override var atr: ByteArray? = null
 
-    override val valid: Boolean
-        get() = channels.isNotEmpty()
-
-    private var channels = mutableSetOf<Int>()
-
     override fun connect() {
         ccidDescription = UsbCcidDescription.fromRawDescriptors(conn.rawDescriptors)!!
 
@@ -49,11 +46,11 @@ class UsbApduInterface(
 
     override fun disconnect() {
         conn.close()
-
-        atr = null
     }
 
     override fun logicalChannelOpen(aid: ByteArray): Int {
+        check(channelId == -1) { "Logical channel already opened" }
+
         // OPEN LOGICAL CHANNEL
         val req = manageChannelCmd(true, 0)
 
@@ -69,7 +66,7 @@ class UsbApduInterface(
             return -1
         }
 
-        val channelId = resp[0].toInt()
+        channelId = resp[0].toInt()
         Log.d(TAG, "channelId = $channelId")
 
         // Then, select AID
@@ -81,32 +78,32 @@ class UsbApduInterface(
             return -1
         }
 
-        channels.add(channelId)
-
         return channelId
     }
 
     override fun logicalChannelClose(handle: Int) {
-        check(channels.contains(handle)) {
-            "Invalid logical channel handle $handle"
-        }
+        check(handle == channelId) { "Logical channel ID mismatch" }
+        check(channelId != -1) { "Logical channel is not opened" }
+
         // CLOSE LOGICAL CHANNEL
-        val req = manageChannelCmd(false, handle.toByte())
-        val resp = transmitApduByChannel(req, handle.toByte())
+        val req = manageChannelCmd(false, channelId.toByte())
+        val resp = transmitApduByChannel(req, channelId.toByte())
 
         if (!isSuccessResponse(resp)) {
             Log.d(TAG, "CLOSE LOGICAL CHANNEL failed: ${resp.encodeHex()}")
         }
-        channels.remove(handle)
+
+        channelId = -1
     }
 
-    override fun transmit(handle: Int, tx: ByteArray): ByteArray {
-        check(channels.contains(handle)) {
-            "Invalid logical channel handle $handle"
-        }
-        return transmitApduByChannel(tx, handle.toByte())
+    override fun transmit(tx: ByteArray): ByteArray {
+        check(channelId != -1) { "Logical channel is not opened" }
+        return transmitApduByChannel(tx, channelId.toByte())
     }
 
+    override val valid: Boolean
+        get() = channelId != -1
+
     private fun isSuccessResponse(resp: ByteArray): Boolean =
         resp.size >= 2 && resp[resp.size - 2] == 0x90.toByte() && resp[resp.size - 1] == 0x00.toByte()
 

app/src/main/java/im/angry/openeuicc/core/TelephonyManagerApduInterface.kt

@@ -18,10 +18,12 @@ class TelephonyManagerApduInterface(
         const val TAG = "TelephonyManagerApduInterface"
     }
 
-    override val valid: Boolean
-        get() = channels.isNotEmpty()
+    private var lastChannel: Int = -1
 
-    private var channels = mutableSetOf<Int>()
+    override val valid: Boolean
+        // TelephonyManager channels will never become truly "invalid",
+        // just that transactions might return errors or nonsense
+        get() = lastChannel != -1
 
     override fun connect() {
         // Do nothing
@@ -29,39 +31,52 @@ class TelephonyManagerApduInterface(
 
     override fun disconnect() {
         // Do nothing
+        lastChannel = -1
     }
 
     override fun logicalChannelOpen(aid: ByteArray): Int {
+        check(lastChannel == -1) { "Already initialized" }
         val hex = aid.encodeHex()
         val channel = tm.iccOpenLogicalChannelByPortCompat(port.card.physicalSlotIndex, port.portIndex, hex, 0)
         if (channel.status != IccOpenLogicalChannelResponse.STATUS_NO_ERROR || channel.channel == IccOpenLogicalChannelResponse.INVALID_CHANNEL) {
-            throw IllegalArgumentException("Cannot open logical channel $hex via TelephonyManager on slot ${port.card.physicalSlotIndex} port ${port.portIndex}")
+            throw IllegalArgumentException("Cannot open logical channel $hex via TelephonManager on slot ${port.card.physicalSlotIndex} port ${port.portIndex}")
         }
-        channels.add(channel.channel)
-        return channel.channel
+        lastChannel = channel.channel
+        return lastChannel
     }
 
     override fun logicalChannelClose(handle: Int) {
-        check(channels.contains(handle)) {
-            "Invalid logical channel handle $handle"
-        }
+        check(handle == lastChannel) { "Invalid channel handle " }
         tm.iccCloseLogicalChannelByPortCompat(port.card.physicalSlotIndex, port.portIndex, handle)
-        channels.remove(handle)
+        lastChannel = -1
     }
 
-    override fun transmit(handle: Int, tx: ByteArray): ByteArray {
-        check(channels.contains(handle)) {
-            "Invalid logical channel handle $handle"
-        }
+    override fun transmit(tx: ByteArray): ByteArray {
+        check(lastChannel != -1) { "Uninitialized" }
+
         if (runBlocking { verboseLoggingFlow.first() }) {
             Log.d(TAG, "TelephonyManager APDU: ${tx.encodeHex()}")
         }
-        val result = tm.iccTransmitApduLogicalChannelByPortCompat(
-            port.card.physicalSlotIndex, port.portIndex, handle,
-            tx,
-        )
-        if (runBlocking { verboseLoggingFlow.first() })
-            Log.d(TAG, "TelephonyManager APDU response: $result")
-        return result?.decodeHex() ?: byteArrayOf()
+
+        val cla = tx[0].toUByte().toInt()
+        val instruction = tx[1].toUByte().toInt()
+        val p1 = tx[2].toUByte().toInt()
+        val p2 = tx[3].toUByte().toInt()
+        val p3 = tx[4].toUByte().toInt()
+        val p4 = tx.drop(5).toByteArray().encodeHex()
+
+        return tm.iccTransmitApduLogicalChannelByPortCompat(port.card.physicalSlotIndex, port.portIndex, lastChannel,
+            cla,
+            instruction,
+            p1,
+            p2,
+            p3,
+            p4
+        ).also {
+            if (runBlocking { verboseLoggingFlow.first() }) {
+                Log.d(TAG, "TelephonyManager APDU response: $it")
+            }
+        }?.decodeHex() ?: byteArrayOf()
     }
+
 }

app/src/main/java/im/angry/openeuicc/util/PrivilegedTelephonyCompat.kt

@@ -111,26 +111,15 @@ fun TelephonyManager.iccCloseLogicalChannelByPortCompat(
     }
 
 fun TelephonyManager.iccTransmitApduLogicalChannelByPortCompat(
-    slotIndex: Int,
-    portIndex: Int,
-    channel: Int,
-    tx: ByteArray
-): String? {
-    val cla = tx[0].toUByte().toInt()
-    val ins = tx[1].toUByte().toInt()
-    val p1 = tx[2].toUByte().toInt()
-    val p2 = tx[3].toUByte().toInt()
-    val p3 = tx[4].toUByte().toInt()
-    val p4 = tx.drop(5).toByteArray().encodeHex()
-    return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+    slotIndex: Int, portIndex: Int, channel: Int,
+    cla: Int, inst: Int, p1: Int, p2: Int, p3: Int, data: String?
+): String? =
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
         iccTransmitApduLogicalChannelByPort(
-            slotIndex, portIndex, channel,
-            cla, ins, p1, p2, p3, p4
+            slotIndex, portIndex, channel, cla, inst, p1, p2, p3, data
         )
     } else {
         iccTransmitApduLogicalChannelBySlot(
-            slotIndex, channel,
-            cla, ins, p1, p2, p3, p4
+            slotIndex, channel, cla, inst, p1, p2, p3, data
         )
     }
-}

libs/lpac-jni/src/main/java/net/typeblog/lpac_jni/ApduInterface.kt

@@ -8,7 +8,7 @@ interface ApduInterface {
     fun disconnect()
     fun logicalChannelOpen(aid: ByteArray): Int
     fun logicalChannelClose(handle: Int)
-    fun transmit(handle: Int, tx: ByteArray): ByteArray
+    fun transmit(tx: ByteArray): ByteArray
 
     /**
      * Is this APDU connection still valid?
@@ -16,13 +16,4 @@ interface ApduInterface {
      * callers should further check with the LPA to fully determine the validity of a channel
      */
     val valid: Boolean
-
-    fun <T> withLogicalChannel(aid: ByteArray, callback: ((ByteArray) -> ByteArray) -> T): T {
-        val handle = logicalChannelOpen(aid)
-        return try {
-            callback { transmit(handle, it) }
-        } finally {
-            logicalChannelClose(handle)
-        }
-    }
-}
+}

libs/lpac-jni/src/main/java/net/typeblog/lpac_jni/impl/LocalProfileAssistantImpl.kt

@@ -28,9 +28,9 @@ class LocalProfileAssistantImpl(
         var lastApduResponse: ByteArray? = null
         var lastApduException: Exception? = null
 
-        override fun transmit(handle: Int, tx: ByteArray): ByteArray =
+        override fun transmit(tx: ByteArray): ByteArray =
             try {
-                apduInterface.transmit(handle, tx).also {
+                apduInterface.transmit(tx).also {
                     lastApduException = null
                     lastApduResponse = it
                 }

libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.c

@@ -22,7 +22,7 @@ void interface_wrapper_init() {
                                                            "([B)I");
     method_apdu_logical_channel_close = (*env)->GetMethodID(env, apdu_class, "logicalChannelClose",
                                                             "(I)V");
-    method_apdu_transmit = (*env)->GetMethodID(env, apdu_class, "transmit", "(I[B)[B");
+    method_apdu_transmit = (*env)->GetMethodID(env, apdu_class, "transmit", "([B)[B");
 
     jclass http_class = (*env)->FindClass(env, "net/typeblog/lpac_jni/HttpInterface");
     method_http_transmit = (*env)->GetMethodID(env, http_class, "transmit",
@@ -53,30 +53,24 @@ apdu_interface_logical_channel_open(struct euicc_ctx *ctx, const uint8_t *aid, u
     jint ret = (*env)->CallIntMethod(env, LPAC_JNI_CTX(ctx)->apdu_interface,
                                      method_apdu_logical_channel_open, jbarr);
     LPAC_JNI_EXCEPTION_RETURN;
-    LPAC_JNI_CTX(ctx)->logical_channel_id = ret;
     return ret;
 }
 
-static void apdu_interface_logical_channel_close(struct euicc_ctx *ctx,
-                                                 __attribute__((unused)) uint8_t channel) {
+static void apdu_interface_logical_channel_close(struct euicc_ctx *ctx, uint8_t channel) {
     LPAC_JNI_SETUP_ENV;
-    jint logical_channel_id = LPAC_JNI_CTX(ctx)->logical_channel_id;
     (*env)->CallVoidMethod(env, LPAC_JNI_CTX(ctx)->apdu_interface,
-                           method_apdu_logical_channel_close, logical_channel_id);
+                           method_apdu_logical_channel_close, channel);
     (*env)->ExceptionClear(env);
 }
 
 static int
 apdu_interface_transmit(struct euicc_ctx *ctx, uint8_t **rx, uint32_t *rx_len, const uint8_t *tx,
                         uint32_t tx_len) {
-    const int logic_channel = LPAC_JNI_CTX(ctx)->logical_channel_id;
     LPAC_JNI_SETUP_ENV;
     jbyteArray txArr = (*env)->NewByteArray(env, tx_len);
     (*env)->SetByteArrayRegion(env, txArr, 0, tx_len, (const jbyte *) tx);
-    jbyteArray ret = (jbyteArray) (*env)->CallObjectMethod(
-            env, LPAC_JNI_CTX(ctx)->apdu_interface,
-            method_apdu_transmit, logic_channel, txArr
-    );
+    jbyteArray ret = (jbyteArray) (*env)->CallObjectMethod(env, LPAC_JNI_CTX(ctx)->apdu_interface,
+                                                           method_apdu_transmit, txArr);
     LPAC_JNI_EXCEPTION_RETURN;
     *rx_len = (*env)->GetArrayLength(env, ret);
     *rx = calloc(*rx_len, sizeof(uint8_t));

libs/lpac-jni/src/main/jni/lpac-jni/lpac-jni.c

@@ -28,7 +28,7 @@ jint JNI_OnLoad(JavaVM *vm, void *reserved) {
     string_constructor = (*env)->GetMethodID(env, string_class, "<init>",
                                              "([BLjava/lang/String;)V");
 
-    const jchar _unused[1];
+    const char _unused[1];
     empty_string = (*env)->NewString(env, _unused, 0);
     empty_string = (*env)->NewGlobalRef(env, empty_string);
 

libs/lpac-jni/src/main/jni/lpac-jni/lpac-jni.h

@@ -8,7 +8,6 @@ _Static_assert(sizeof(void *) <= sizeof(jlong),
                "jlong must be big enough to hold a platform raw pointer");
 
 struct lpac_jni_ctx {
-    jint logical_channel_id;
     jobject apdu_interface;
     jobject http_interface;
 };