dash/ble: start implement EAP-AKA

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/Id.kt

@@ -25,6 +25,10 @@ data class Id(val address: ByteArray) {
         return "$asInt/${address.toHex()}"
     }
 
+    fun toLong(): Long {
+        return ByteBuffer.wrap(address).long
+    }
+
     companion object {
 
         private val PERIPHERAL_NODE_INDEX = 1 // TODO: understand the meaning of this value. It comes from preferences

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/OmnipodDashBleManagerImpl.kt

@@ -16,6 +16,7 @@ import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.io.Chara
 import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.message.MessageIO
 import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.pair.LTKExchanger
 import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.scan.PodScanner
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session.EapAkaExchanger
 import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.status.ConnectionStatus
 import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.event.PodEvent
 import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.pod.command.base.Command
@@ -125,13 +126,20 @@ class OmnipodDashBleManagerImpl @Inject constructor(
 
             val msgIO = MessageIO(aapsLogger, bleIO)
             val ltkExchanger = LTKExchanger(aapsLogger, msgIO)
+
             emitter.onNext(PodEvent.Pairing)
 
             val ltk = ltkExchanger.negotiateLTK()
 
             aapsLogger.info(LTag.PUMPCOMM, "Got LTK: ${ltk.ltk.toHex()}")
 
-            emitter.onNext(PodEvent.Connected(PodScanner.POD_ID_NOT_ACTIVATED)) // TODO supply actual pod id
+            emitter.onNext(PodEvent.EstablishingSession)
+
+            val EapAkaExchanger = EapAkaExchanger(msgIO, ltk)
+            val sessionKeys = EapAkaExchanger.negotiateSessionKeys()
+            aapsLogger.info(LTag.PUMPCOMM, "Got session Key: $sessionKeys")
+
+            emitter.onNext(PodEvent.Connected(ltk.podId.toLong())) // TODO supply actual pod id
 
             emitter.onComplete()
         } catch (ex: Exception) {

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/pair/LTKExchanger.kt

@@ -75,7 +75,9 @@ internal class LTKExchanger(private val aapsLogger: AAPSLogger, private val msgI
         validateP0(p0)
 
         return PairResult(
-            ltk = ltk
+            ltk = ltk,
+            podId = nodeId,
+            seq = seq
         )
     }
 

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/pair/PairMessage.kt

@@ -16,5 +16,5 @@ data class PairMessage(
         payload = payload,
         sequenceNumber = sequenceNumber,
         sas = true // TODO: understand why this is true for PairMessages
-    ),
+    )
 )

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/pair/PairResult.kt

@@ -1,8 +1,9 @@
 package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.pair
 
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.Id
 import info.nightscout.androidaps.utils.extensions.toHex
 
-data class PairResult(val ltk: ByteArray) {
+data class PairResult(val ltk: ByteArray, val podId: Id, val seq: Byte) {
     init {
         require(ltk.size == 16) { "LTK length must be 16 bytes. Received LTK: ${ltk.toHex()}" }
     }

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/session/EapAkaAttribute.kt

@@ -0,0 +1,100 @@
+package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
+
+import info.nightscout.androidaps.utils.extensions.toHex
+
+enum class EapAkaAttributeType(val type: Byte) {
+    AT_RAND(1),
+    AT_AUTN(2),
+    AT_RES(3),
+    AT_CUSTOM_IV(126);
+
+    companion object {
+
+        fun byValue(value: Byte): EapAkaAttributeType =
+            EapAkaAttributeType.values().firstOrNull { it.type == value }
+                ?: throw IllegalArgumentException("Unknown EAP-AKA attribute type: $value")
+    }
+}
+
+abstract class EapAkaAttribute(val type: EapAkaAttributeType) {
+
+    abstract fun toByteArray(): ByteArray
+
+    companion object {
+
+        const val SIZE_MULTIPLIER = 4 // The length for EAP-AKA attributes is a multiple of 4
+    }
+}
+
+class EapAkaAttributeRand(val payload: ByteArray) : EapAkaAttribute(
+    type = EapAkaAttributeType.AT_RAND
+) {
+
+    init {
+        require(payload.size == 16) { "AT_RAND payload size has to be 16 bytes. Payload: ${payload.toHex()}" }
+    }
+
+    override fun toByteArray(): ByteArray {
+        return byteArrayOf(type.type, SIZE, 0, 0) + payload
+    }
+
+    companion object {
+
+        private const val SIZE = (20 / SIZE_MULTIPLIER).toByte() // type, size, 2 reserved bytes, payload=16
+    }
+}
+
+class EapAkaAttributeAutn(val payload: ByteArray) : EapAkaAttribute(
+    type = EapAkaAttributeType.AT_AUTN
+) {
+
+    init {
+        require(payload.size == 16) { "AT_AUTN payload size has to be 16 bytes. Payload: ${payload.toHex()}" }
+    }
+
+    override fun toByteArray(): ByteArray {
+        return byteArrayOf(type.type, SIZE, 0, 0) + payload
+    }
+
+    companion object {
+
+        private const val SIZE = (20 / SIZE_MULTIPLIER).toByte() // type, size, 2 reserved bytes, payload=16
+    }
+}
+
+class EapAkaAttributeRes(val payload: ByteArray) : EapAkaAttribute(
+    type = EapAkaAttributeType.AT_AUTN
+) {
+
+    init {
+        require(payload.size == 8) { "AT_RES payload size has to be 8 bytes. Payload: ${payload.toHex()}" }
+    }
+
+    override fun toByteArray(): ByteArray {
+        return byteArrayOf(type.type, SIZE, 0, PAYLOAD_SIZE_BITS) + payload
+    }
+
+    companion object {
+
+        private const val SIZE = (12 / SIZE_MULTIPLIER).toByte() // type, size, len in bits=2, payload=8
+        private const val PAYLOAD_SIZE_BITS = 64.toByte() // type, size, 2 reserved bytes, payload
+    }
+}
+
+class EapAkaAttributeCustomIV(val payload: ByteArray) : EapAkaAttribute(
+    type = EapAkaAttributeType.AT_CUSTOM_IV
+) {
+
+    init {
+        require(payload.size == 4) { "AT_RES payload size has to be 8 bytes. Payload: ${payload.toHex()}" }
+    }
+
+    override fun toByteArray(): ByteArray {
+        return byteArrayOf(type.type, SIZE, 0, 0) + payload
+    }
+
+    companion object {
+
+        private const val SIZE = (8 / SIZE_MULTIPLIER).toByte() // type, size, 2 reserved bytes, payload=4
+    }
+}

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/session/EapAkaExchanger.kt

@@ -0,0 +1,70 @@
+package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
+
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.Id
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.OmnipodDashBleManagerImpl
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.message.MessageIO
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.message.MessagePacket
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.pair.PairResult
+import okio.ByteString.Companion.decodeHex
+
+class EapAkaExchanger(private val msgIO: MessageIO, private val ltk: PairResult) {
+
+    var seq = ltk.seq
+    private val controllerId = Id.fromInt(OmnipodDashBleManagerImpl.CONTROLLER_ID)
+
+    fun negotiateSessionKeys(): SessionKeys {
+        // send EAP-AKA challenge
+        seq++
+        var challenge = eapAkaChallenge()
+        msgIO.sendMesssage(challenge.messagePacket)
+
+        // read SPS1
+        val challengeResponse = msgIO.receiveMessage()
+        processChallengeResponse(challengeResponse)
+        // now we have all the data to generate: confPod, confPdm, ltk and noncePrefix
+        // TODO: what do we have to answer if challenge response does not validate?
+
+        seq++
+        var success = eapSuccess()
+        msgIO.sendMesssage(success.messagePacket)
+
+        return SessionKeys()
+    }
+
+    private fun eapAkaChallenge(): EapAkaMessage {
+        val payload = ByteArray(0)
+        return EapAkaMessage(
+            code = EapCode.REQUEST,
+            identifier = 42, // TODO: find what value we need here
+            attributes =  null,
+            sequenceNumber = seq,
+            source = controllerId,
+            destination = ltk.podId,
+            payload = payload
+        )
+    }
+
+    private fun processChallengeResponse(challengeResponse: MessagePacket) {
+
+    }
+
+    private fun eapSuccess(): EapAkaMessage {
+        val payload = ByteArray(0)
+        return EapAkaMessage(
+            code = EapCode.SUCCESS,
+            attributes =  null,
+            identifier = 42, // TODO: find what value we need here
+            sequenceNumber = seq,
+            source = controllerId,
+            destination = ltk.podId,
+            payload = payload
+        )
+    }
+
+    companion object {
+
+        private val MILENAGE_OP = "cdc202d5123e20f62b6d676ac72cb318".decodeHex()
+        private val MILENAGE_AMF = "b9b9".decodeHex()
+
+    }
+}

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/session/EapAkaMessage.kt

@@ -0,0 +1,68 @@
+package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
+
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.Id
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.message.MessagePacket
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.message.MessageType
+import retrofit2.http.HEAD
+import java.nio.ByteBuffer
+
+enum class EapCode(val code: Byte) {
+    REQUEST(1),
+    RESPONSE(2),
+    SUCCESS(3),
+    FAILURE(4);
+
+    companion object {
+
+        fun byValue(value: Byte): EapCode =
+            EapCode.values().firstOrNull { it.code == value }
+                ?: throw IllegalArgumentException("Unknown EAP-AKA attribute type: $value")
+    }
+}
+
+class EapAkaMessage(
+    val code: EapCode,
+    val identifier: Byte,
+    val sequenceNumber: Byte,
+    val source: Id,
+    val destination: Id,
+    val payload: ByteArray,
+    val attributes: Array<EapAkaAttribute>?,
+    val messagePacket: MessagePacket = MessagePacket(
+        type = MessageType.SESSION_ESTABLISHMENT,
+        source = source,
+        destination = destination,
+        payload = payload,
+        sequenceNumber = sequenceNumber,
+        sas = true // TODO: understand why this is true for PairMessages
+    )) {
+
+    fun toByteArray(): ByteArray {
+
+        val serializedAttributes = attributes?.flatMap{ it.toByteArray().asIterable() }
+        val joinedAttributes = serializedAttributes?.toTypedArray()?.toByteArray()
+
+        val attrSize = joinedAttributes?.size ?: 0
+        val totalSize = HEADER_SIZE + attrSize
+        
+        var bb = ByteBuffer
+            .allocate(totalSize)
+            .put(code.code)
+            .put(identifier)
+            .put(((totalSize ushr 1) and 0XFF).toByte())
+            .put((totalSize and 0XFF).toByte())
+            .put(AKA_PACKET_TYPE)
+            .put(SUBTYPE_AKA_CHALLENGE)
+            .put(byteArrayOf(0,0))
+            .put(joinedAttributes ?: ByteArray(0))
+
+        val ret = bb.array()
+        return ret.copyOfRange(0, ret.size)
+    }
+
+    companion object {
+        private const val HEADER_SIZE = 8
+        private const val SUBTYPE_AKA_CHALLENGE = 1.toByte()
+        private const val AKA_PACKET_TYPE = 0x17.toByte()
+    }
+}

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/comm/session/SessionKeys.kt

@@ -0,0 +1,4 @@
+package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
+
+class SessionKeys {
+}