Add support for implicit bonding

kable-core/api/android/kable-core.api

@@ -13,6 +13,7 @@ public abstract interface class com/juul/kable/Advertisement {
 
 public abstract interface class com/juul/kable/AndroidPeripheral : com/juul/kable/Peripheral {
 	public abstract fun getAddress ()Ljava/lang/String;
+	public abstract fun getBondState ()Lkotlinx/coroutines/flow/StateFlow;
 	public abstract fun getMtu ()Lkotlinx/coroutines/flow/StateFlow;
 	public abstract fun getType ()Lcom/juul/kable/AndroidPeripheral$Type;
 	public abstract fun requestConnectionPriority (Lcom/juul/kable/AndroidPeripheral$Priority;)Z
@@ -21,6 +22,15 @@ public abstract interface class com/juul/kable/AndroidPeripheral : com/juul/kabl
 	public abstract fun write (Lcom/juul/kable/Descriptor;[BLkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
+public final class com/juul/kable/AndroidPeripheral$Bond : java/lang/Enum {
+	public static final field Bonded Lcom/juul/kable/AndroidPeripheral$Bond;
+	public static final field Bonding Lcom/juul/kable/AndroidPeripheral$Bond;
+	public static final field None Lcom/juul/kable/AndroidPeripheral$Bond;
+	public static fun getEntries ()Lkotlin/enums/EnumEntries;
+	public static fun valueOf (Ljava/lang/String;)Lcom/juul/kable/AndroidPeripheral$Bond;
+	public static fun values ()[Lcom/juul/kable/AndroidPeripheral$Bond;
+}
+
 public final class com/juul/kable/AndroidPeripheral$Priority : java/lang/Enum {
 	public static final field Balanced Lcom/juul/kable/AndroidPeripheral$Priority;
 	public static final field High Lcom/juul/kable/AndroidPeripheral$Priority;

kable-core/src/androidMain/kotlin/AndroidPeripheral.kt

@@ -20,6 +20,8 @@ public interface AndroidPeripheral : Peripheral {
 
     public enum class Priority { Low, Balanced, High }
 
+    public enum class Bond { None, Bonding, Bonded }
+
     public enum class Type {
 
         /** https://developer.android.com/reference/android/bluetooth/BluetoothDevice#DEVICE_TYPE_CLASSIC */
@@ -160,4 +162,6 @@ public interface AndroidPeripheral : Peripheral {
      * is negotiated.
      */
     public val mtu: StateFlow<Int?>
+
+    public val bondState: StateFlow<Bond>
 }

kable-core/src/androidMain/kotlin/BluetoothDeviceAndroidPeripheral.kt

@@ -15,6 +15,7 @@ import android.bluetooth.BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE
 import android.bluetooth.BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE
 import android.bluetooth.BluetoothGattDescriptor.ENABLE_INDICATION_VALUE
 import android.bluetooth.BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE
+import com.juul.kable.AndroidPeripheral.Bond
 import com.juul.kable.AndroidPeripheral.Priority
 import com.juul.kable.AndroidPeripheral.Type
 import com.juul.kable.State.Disconnected
@@ -36,10 +37,14 @@ import com.juul.kable.logs.detail
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.stateIn
 import kotlin.coroutines.cancellation.CancellationException
 import kotlin.time.Duration
 
@@ -67,6 +72,13 @@ internal class BluetoothDeviceAndroidPeripheral(
             }
             disconnect()
         }
+
+        onBondState { state ->
+            logger.debug {
+                message = "Bond state"
+                detail("state", state.toString())
+            }
+        }
     }
 
     private val connectAction = sharedRepeatableAction(::establishConnection)
@@ -100,6 +112,9 @@ internal class BluetoothDeviceAndroidPeripheral(
     override val name: String?
         get() = bluetoothDevice.name
 
+    override val bondState: StateFlow<Bond> = bondStateFor(bluetoothDevice)
+        .stateIn(this, SharingStarted.Eagerly, Bond(bluetoothDevice.bondState))
+
     private suspend fun establishConnection(scope: CoroutineScope): CoroutineScope {
         checkBluetoothIsSupported()
         checkBluetoothIsOn()
@@ -123,6 +138,10 @@ internal class BluetoothDeviceAndroidPeripheral(
                 disconnectTimeout,
             )
 
+            if (bondState.value == Bond.Bonding) {
+                logger.debug { message = "Awaiting bond state" }
+                awaitNotBonding()
+            }
             suspendUntil<State.Connecting.Services>()
             discoverServices()
             configureCharacteristicObservations()
@@ -197,8 +216,22 @@ internal class BluetoothDeviceAndroidPeripheral(
         }
 
         val platformCharacteristic = servicesOrThrow().obtain(characteristic, writeType.properties)
-        connectionOrThrow().execute<OnCharacteristicWrite> {
-            writeCharacteristicOrThrow(platformCharacteristic, data, writeType.intValue)
+        try {
+            connectionOrThrow().execute<OnCharacteristicWrite> {
+                writeCharacteristicOrThrow(platformCharacteristic, data, writeType.intValue)
+            }
+        } catch (e: BondRequiredException) {
+            logInsufficientAuthentication(e)
+            awaitNotBonding()
+            logger.debug {
+                message = "Retrying write"
+                detail(characteristic)
+                detail(writeType)
+                detail(data, Operation.Write)
+            }
+            connectionOrThrow().execute<OnCharacteristicWrite> {
+                writeCharacteristicOrThrow(platformCharacteristic, data, writeType.intValue)
+            }
         }
     }
 
@@ -211,8 +244,20 @@ internal class BluetoothDeviceAndroidPeripheral(
         }
 
         val platformCharacteristic = servicesOrThrow().obtain(characteristic, Read)
-        return connectionOrThrow().execute<OnCharacteristicRead> {
-            readCharacteristicOrThrow(platformCharacteristic)
+        return try {
+            connectionOrThrow().execute<OnCharacteristicRead> {
+                readCharacteristicOrThrow(platformCharacteristic)
+            }
+        } catch (e: BondRequiredException) {
+            logInsufficientAuthentication(e)
+            awaitNotBonding()
+            logger.debug {
+                message = "Retrying read"
+                detail(characteristic)
+            }
+            connectionOrThrow().execute<OnCharacteristicRead> {
+                readCharacteristicOrThrow(platformCharacteristic)
+            }
         }.value!!
     }
 
@@ -233,8 +278,21 @@ internal class BluetoothDeviceAndroidPeripheral(
             detail(data, Operation.Write)
         }
 
-        connectionOrThrow().execute<OnDescriptorWrite> {
-            writeDescriptorOrThrow(platformDescriptor, data)
+        try {
+            connectionOrThrow().execute<OnDescriptorWrite> {
+                writeDescriptorOrThrow(platformDescriptor, data)
+            }
+        } catch (e: BondRequiredException) {
+            logInsufficientAuthentication(e)
+            awaitNotBonding()
+            logger.debug {
+                message = "Retrying write"
+                detail(platformDescriptor)
+                detail(data, Operation.Write)
+            }
+            connectionOrThrow().execute<OnDescriptorWrite> {
+                writeDescriptorOrThrow(platformDescriptor, data)
+            }
         }
     }
 
@@ -247,8 +305,20 @@ internal class BluetoothDeviceAndroidPeripheral(
         }
 
         val platformDescriptor = servicesOrThrow().obtain(descriptor)
-        return connectionOrThrow().execute<OnDescriptorRead> {
-            readDescriptorOrThrow(platformDescriptor)
+        return try {
+            connectionOrThrow().execute<OnDescriptorRead> {
+                readDescriptorOrThrow(platformDescriptor)
+            }
+        } catch (e: BondRequiredException) {
+            logInsufficientAuthentication(e)
+            awaitNotBonding()
+            logger.debug {
+                message = "Retrying read"
+                detail(descriptor)
+            }
+            connectionOrThrow().execute<OnDescriptorRead> {
+                readDescriptorOrThrow(platformDescriptor)
+            }
         }.value!!
     }
 
@@ -339,13 +409,28 @@ internal class BluetoothDeviceAndroidPeripheral(
         }
     }
 
+    private suspend fun awaitNotBonding(): Bond = bondState.first { it != Bond.Bonding }
+
+    private fun logInsufficientAuthentication(exception: BondRequiredException) {
+        logger.warn {
+            message = "Insufficient authentication"
+            detail(exception.status)
+        }
+    }
+
     private fun onBluetoothDisabled(action: suspend (bluetoothState: Int) -> Unit) {
         bluetoothState
             .filter { state -> state == STATE_TURNING_OFF || state == STATE_OFF }
             .onEach(action)
             .launchIn(this)
     }
 
+    private fun onBondState(action: (bondState: Bond) -> Unit) {
+        bondState
+            .onEach(action)
+            .launchIn(this)
+    }
+
     override fun toString(): String = "Peripheral(bluetoothDevice=$bluetoothDevice)"
 }
 

kable-core/src/androidMain/kotlin/Bond.kt

@@ -0,0 +1,37 @@
+package com.juul.kable
+
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothDevice.ACTION_BOND_STATE_CHANGED
+import android.bluetooth.BluetoothDevice.BOND_BONDED
+import android.bluetooth.BluetoothDevice.BOND_BONDING
+import android.bluetooth.BluetoothDevice.BOND_NONE
+import android.bluetooth.BluetoothDevice.ERROR
+import android.bluetooth.BluetoothDevice.EXTRA_BOND_STATE
+import android.bluetooth.BluetoothDevice.EXTRA_DEVICE
+import android.content.Intent
+import android.content.IntentFilter
+import androidx.core.content.IntentCompat
+import com.juul.kable.AndroidPeripheral.Bond
+import com.juul.tuulbox.coroutines.flow.broadcastReceiverFlow
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.map
+
+internal fun bondStateFor(bluetoothDevice: BluetoothDevice): Flow<Bond> =
+    broadcastReceiverFlow(IntentFilter(ACTION_BOND_STATE_CHANGED))
+        .filter { intent -> bluetoothDevice == intent.bluetoothDevice }
+        .map { intent -> intent.bondState }
+        .map(::Bond)
+
+internal fun Bond(state: Int): Bond = when (state) {
+    BOND_NONE -> Bond.None
+    BOND_BONDING -> Bond.Bonding
+    BOND_BONDED -> Bond.Bonded
+    else -> error("Unsupported bond state: $state")
+}
+
+private val Intent.bluetoothDevice: BluetoothDevice?
+    get() = IntentCompat.getParcelableExtra(this, EXTRA_DEVICE, BluetoothDevice::class.java)
+
+private val Intent.bondState: Int
+    get() = getIntExtra(EXTRA_BOND_STATE, ERROR)

kable-core/src/androidMain/kotlin/Connection.kt

@@ -1,10 +1,13 @@
 package com.juul.kable
 
 import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGatt.GATT_INSUFFICIENT_AUTHENTICATION
+import android.bluetooth.BluetoothGatt.GATT_INSUFFICIENT_ENCRYPTION
 import android.bluetooth.BluetoothGatt.GATT_SUCCESS
 import android.os.Handler
 import com.juul.kable.State.Disconnected
 import com.juul.kable.coroutines.childSupervisor
+import com.juul.kable.external.GATT_AUTH_FAIL
 import com.juul.kable.gatt.Callback
 import com.juul.kable.gatt.GattStatus
 import com.juul.kable.gatt.Response
@@ -42,8 +45,16 @@ import kotlin.reflect.KClass
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.ZERO
 
+internal class BondRequiredException(val status: GattStatus) : IllegalStateException()
+
 private val GattSuccess = GattStatus(GATT_SUCCESS)
 
+private val BondingStatuses = listOf(
+    GattStatus(GATT_AUTH_FAIL),
+    GattStatus(GATT_INSUFFICIENT_AUTHENTICATION),
+    GattStatus(GATT_INSUFFICIENT_ENCRYPTION),
+)
+
 /**
  * Represents a Bluetooth Low Energy connection. [Connection] should be initialized with the
  * provided [BluetoothGatt] in a connecting or connected state. When a disconnect occurs (either by
@@ -178,7 +189,8 @@ internal class Connection(
                 coroutineContext.ensureActive()
                 throw e.unwrapCancellationException()
             }
-        }.also(::checkResponse)
+        }.also(::checkBondingStatus)
+            .also(::checkResponse)
 
         // `guard` should always enforce a 1:1 matching of request-to-response, but if an Android
         // `BluetoothGattCallback` method is called out-of-order then we'll cast to the wrong type.
@@ -271,6 +283,10 @@ internal class Connection(
     private fun dispose(cause: Throwable) = connectionJob.completeExceptionally(cause)
 }
 
+private fun checkBondingStatus(response: Response) {
+    if (response.status in BondingStatuses) throw BondRequiredException(response.status)
+}
+
 private fun checkResponse(response: Response) {
     if (response.status != GattSuccess) throw GattStatusException(response.toString())
 }