dash eap-aka: complete the session key exchange

Fake pod logs
```
INFO[0021] got CK: daff384a4098571975d136a480a71b36
INFO[0021] got Nonce: 33a0c6dd0a0a0a0a
```

The application logs:
```
[OmnipodDashBleManagerImpl$connect$1.subscribe():139]: CK: daff384a4098571975d136a480a71b36
 [OmnipodDashBleManagerImpl$connect$1.subscribe():140]: noncePrefix: 33a0c6dd0a0a0a0a
```

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

@@ -26,7 +26,7 @@ data class Id(val address: ByteArray) {
     }
 
     fun toLong(): Long {
-        return ByteBuffer.wrap(address).long
+        return ByteBuffer.wrap(address).int.toLong() and 0xffffffffL
     }
 
     companion object {

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

@@ -76,7 +76,6 @@ class OmnipodDashBleManagerImpl @Inject constructor(
         val discoverer = ServiceDiscoverer(aapsLogger, gatt, bleCommCallbacks)
         val chars = discoverer.discoverServices()
         val bleIO = BleIO(aapsLogger, chars, incomingPackets, gatt, bleCommCallbacks)
-        aapsLogger.debug(LTag.PUMPBTCOMM, "Saying hello to the pod")
         bleIO.sendAndConfirmPacket(CharacteristicType.CMD, BleCommandHello(CONTROLLER_ID).data)
         bleIO.readyToRead()
         return bleIO
@@ -133,11 +132,13 @@ class OmnipodDashBleManagerImpl @Inject constructor(
 
             aapsLogger.info(LTag.PUMPCOMM, "Got LTK: ${ltk.ltk.toHex()}")
 
-           // emitter.onNext(PodEvent.EstablishingSession)
+            // emitter.onNext(PodEvent.EstablishingSession)
 
             val EapAkaExchanger = EapAkaExchanger(aapsLogger, msgIO, ltk)
             val sessionKeys = EapAkaExchanger.negotiateSessionKeys()
-            aapsLogger.info(LTag.PUMPCOMM, "Got session Key: $sessionKeys")
+            aapsLogger.info(LTag.PUMPCOMM, "CK: ${sessionKeys.ck.toHex()}")
+            aapsLogger.info(LTag.PUMPCOMM, "noncePrefix: ${sessionKeys.noncePrefix.toHex()}")
+            aapsLogger.info(LTag.PUMPCOMM, "SQN: ${sessionKeys.sqn.toHex()}")
 
             emitter.onNext(PodEvent.Connected(ltk.podId.toLong())) // TODO supply actual pod id
 

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

@@ -0,0 +1,3 @@
+package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.exceptions
+
+class SessionEstablishmentException(val msg: String) : Exception(msg)

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

@@ -15,12 +15,12 @@ data class MessagePacket(
     val sequenceNumber: Byte,
     val ack: Boolean = false,
     val ackNumber: Byte = 0.toByte(),
-    val eqos: Short = 0.toShort(), // TODO: understand
+    val eqos: Short = 0.toShort(), // TODO: understand. Seems to be set to 1 for commands
     val priority: Boolean = false,
     val lastMessage: Boolean = false,
     val gateway: Boolean = false,
-    val sas: Boolean = false, // TODO: understand
+    val sas: Boolean = true, // TODO: understand, seems to always be true
-    val tfs: Boolean = false, // TODO: understand
+    val tfs: Boolean = false, // TODO: understand, seems to be false
     val version: Short = 0.toShort()
 ) {
 

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

@@ -42,7 +42,7 @@ class BleDiscoveredDevice(val scanResult: ScanResult, private val scanRecord: Sc
         val podId = hexPodId.toLong(16)
         if (this.podId != podId) {
             throw DiscoveredInvalidPodException(
-                "This is not the POD we are looking for: ${this.podId} . Found: $podId/$hexPodId" ,
+                "This is not the POD we are looking for: ${this.podId} . Found: $podId/$hexPodId",
                 serviceUUIDs
             )
         }

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

@@ -1,6 +1,9 @@
 package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
 
+import info.nightscout.androidaps.logging.AAPSLogger
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.exceptions.MessageIOException
 import info.nightscout.androidaps.utils.extensions.toHex
+import java.util.*
 
 enum class EapAkaAttributeType(val type: Byte) {
     AT_RAND(1),
@@ -16,26 +19,49 @@ enum class EapAkaAttributeType(val type: Byte) {
     }
 }
 
-abstract class EapAkaAttribute(val type: EapAkaAttributeType) {
+sealed class EapAkaAttribute {
 
     abstract fun toByteArray(): ByteArray
 
     companion object {
 
         const val SIZE_MULTIPLIER = 4 // The length for EAP-AKA attributes is a multiple of 4
+
+        fun parseAttributes(aapsLogger: AAPSLogger, payload: ByteArray): List<EapAkaAttribute> {
+            var tail = payload
+            val ret = LinkedList<EapAkaAttribute>()
+            while (tail.size > 0) {
+                if (tail.size < 2) {
+                    throw MessageIOException("Could not parse EAP attributes: ${payload.toHex()}")
+                }
+                val size = SIZE_MULTIPLIER * tail[1].toInt()
+                if (tail.size < size) {
+                    throw MessageIOException("Could not parse EAP attributes: ${payload.toHex()}")
+                }
+                val type = EapAkaAttributeType.byValue(tail[0])
+                when (type) {
+                    EapAkaAttributeType.AT_RES ->
+                        ret.add(EapAkaAttributeRes.parse(tail.copyOfRange(2, size)))
+                    EapAkaAttributeType.AT_CUSTOM_IV ->
+                        ret.add(EapAkaAttributeCustomIV.parse(tail.copyOfRange(2, size)))
+                    else                             ->
+                        throw MessageIOException("Could not parse EAP attributes: ${payload.toHex()}. Expecting only AT_RES or CUSTOM_IV attribute types from the POD")
+                }
+                tail = tail.copyOfRange(size, tail.size)
+            }
+            return ret
+        }
     }
 }
 
-class EapAkaAttributeRand(val payload: ByteArray) : EapAkaAttribute(
+data 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
+        return byteArrayOf(EapAkaAttributeType.AT_RAND.type, SIZE, 0, 0) + payload
     }
 
     companion object {
@@ -44,16 +70,14 @@ class EapAkaAttributeRand(val payload: ByteArray) : EapAkaAttribute(
     }
 }
 
-class EapAkaAttributeAutn(val payload: ByteArray) : EapAkaAttribute(
+data 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
+        return byteArrayOf(EapAkaAttributeType.AT_AUTN.type, SIZE, 0, 0) + payload
     }
 
     companion object {
@@ -62,39 +86,50 @@ class EapAkaAttributeAutn(val payload: ByteArray) : EapAkaAttribute(
     }
 }
 
-class EapAkaAttributeRes(val payload: ByteArray) : EapAkaAttribute(
+data 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
+        return byteArrayOf(EapAkaAttributeType.AT_RES.type, SIZE, 0, PAYLOAD_SIZE_BITS) + payload
+
     }
 
     companion object {
 
+        fun parse(payload: ByteArray): EapAkaAttributeRes {
+            if (payload.size < 2 + 8) {
+                throw MessageIOException("Could not parse RES attribute: ${payload.toHex()}")
+            }
+            return EapAkaAttributeRes(payload.copyOfRange(2, 2 + 8))
+        }
+
         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(
+data class EapAkaAttributeCustomIV(val payload: ByteArray) : EapAkaAttribute() {
-    type = EapAkaAttributeType.AT_CUSTOM_IV
-) {
 
     init {
         require(payload.size == 4) { "CUSTOM_IV payload size has to be 4 bytes. Payload: ${payload.toHex()}" }
     }
 
     override fun toByteArray(): ByteArray {
-        return byteArrayOf(type.type, SIZE, 0, 0) + payload
+        return byteArrayOf(EapAkaAttributeType.AT_CUSTOM_IV.type, SIZE, 0, 0) + payload
     }
 
     companion object {
 
+        fun parse(payload: ByteArray): EapAkaAttributeCustomIV {
+            if (payload.size < 2 + 4) {
+                throw MessageIOException("Could not parse CUSTOM_IV attribute: ${payload.toHex()}")
+            }
+            return EapAkaAttributeCustomIV(payload.copyOfRange(2, 2 + 4))
+        }
+
         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

@@ -4,14 +4,14 @@ import info.nightscout.androidaps.logging.AAPSLogger
 import info.nightscout.androidaps.logging.LTag
 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.exceptions.SessionEstablishmentException
 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.message.MessageType
 import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.pair.PairResult
 import info.nightscout.androidaps.utils.extensions.toHex
 import org.spongycastle.util.encoders.Hex
 import java.security.SecureRandom
-import javax.crypto.Cipher
-import javax.crypto.spec.SecretKeySpec
 
 class EapAkaExchanger(private val aapsLogger: AAPSLogger, private val msgIO: MessageIO, private val ltk: PairResult) {
 
@@ -21,7 +21,7 @@ class EapAkaExchanger(private val aapsLogger: AAPSLogger, private val msgIO: Mes
     private var nodeIV = ByteArray(IV_SIZE)
 
     private val controllerId = Id.fromInt(OmnipodDashBleManagerImpl.CONTROLLER_ID)
-    private val sqn = byteArrayOf(0, 0, 0, 0, 0, 1)
+    private val sqn = byteArrayOf(0, 0, 0, 0, 0, 2)
     private val milenage = Milenage(aapsLogger, ltk.ltk, sqn)
 
     init {
@@ -32,62 +32,85 @@ class EapAkaExchanger(private val aapsLogger: AAPSLogger, private val msgIO: Mes
 
     fun negotiateSessionKeys(): SessionKeys {
         // send EAP-AKA challenge
-        seq++
+        seq++ // TODO: get from pod state. This only works for activating a new pod
         var challenge = eapAkaChallenge()
-        msgIO.sendMesssage(challenge.messagePacket)
+        msgIO.sendMesssage(challenge)
 
-        // 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)
+        msgIO.sendMesssage(success)
 
-        return SessionKeys()
+        return SessionKeys(
+            milenage.ck,
+            controllerIV + nodeIV,
+            sqn,
+        )
     }
 
-    private fun eapAkaChallenge(): EapAkaMessage {
+    private fun eapAkaChallenge(): MessagePacket {
-        val payload = ByteArray(0)
+        val attributes = arrayOf(
-        val attributes =
+            EapAkaAttributeAutn(milenage.autn),
-            arrayOf(
+            EapAkaAttributeRand(milenage.rand),
-                // TODO: verify the order or attributes
+            EapAkaAttributeCustomIV(controllerIV),
-                EapAkaAttributeRand(milenage.rand),
+        )
-                EapAkaAttributeAutn(milenage.autn),
-                EapAkaAttributeCustomIV(controllerIV),
-            )
 
-        return EapAkaMessage(
+        val eapMsg = EapMessage(
             code = EapCode.REQUEST,
-            identifier = 42, // TODO: find what value we need here
+            identifier = 42, // TODO: find what value we need here, it's probably random
-            attributes = attributes,
+            attributes = attributes
+        )
+        return MessagePacket(
+            type = MessageType.SESSION_ESTABLISHMENT,
             sequenceNumber = seq,
             source = controllerId,
             destination = ltk.podId,
-            payload = payload
+            payload = eapMsg.toByteArray()
         )
     }
 
     private fun processChallengeResponse(challengeResponse: MessagePacket) {
+        //TODO verify that identifier matches identifer from the Challenge
+        val eapMsg = EapMessage.parse(aapsLogger, challengeResponse.payload)
+        if (eapMsg.attributes.size != 2) {
+            aapsLogger.debug(LTag.PUMPBTCOMM, "EAP-AKA: got RES message: $eapMsg")
+            throw SessionEstablishmentException("Expecting two attributes, got: ${eapMsg.attributes.size}")
+
+        }
+        for (attr in eapMsg.attributes) {
+            when (attr) {
+                is EapAkaAttributeRes ->
+                    if (!milenage.res.contentEquals(attr.payload)) {
+                        throw SessionEstablishmentException("RES missmatch. Expected: ${milenage.res.toHex()} Actual: ${attr.payload.toHex()} ")
+                    }
+                is EapAkaAttributeCustomIV ->
+                    nodeIV = attr.payload.copyOfRange(0, IV_SIZE)
+                else                       ->
+                    throw SessionEstablishmentException("Unknown attribute received: ${attr}")
+            }
+        }
 
     }
 
-    private fun eapSuccess(): EapAkaMessage {
+    private fun eapSuccess(): MessagePacket {
-        val payload = ByteArray(0)
+        val eapMsg = EapMessage(
-        return EapAkaMessage(
             code = EapCode.SUCCESS,
-            attributes = null,
+            attributes = arrayOf(),
-            identifier = 42, // TODO: find what value we need here
+            identifier = 44, // TODO: find what value we need here
+        )
+
+        return MessagePacket(
+            type = MessageType.SESSION_ESTABLISHMENT,
             sequenceNumber = seq,
             source = controllerId,
             destination = ltk.podId,
-            payload = payload
+            payload = eapMsg.toByteArray()
         )
     }
 
-
     companion object {
 
         private val MILENAGE_OP = Hex.decode("cdc202d5123e20f62b6d676ac72cb318")

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

@@ -1,68 +0,0 @@
-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 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/EapMessage.kt

@@ -0,0 +1,89 @@
+package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
+
+import info.nightscout.androidaps.logging.AAPSLogger
+import info.nightscout.androidaps.logging.LTag
+import info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.exceptions.MessageIOException
+import info.nightscout.androidaps.utils.extensions.toHex
+import okio.ByteString.Companion.toByteString
+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")
+    }
+}
+
+data class EapMessage(
+    val code: EapCode,
+    val identifier: Byte,
+    val attributes: Array<EapAkaAttribute>,
+) {
+
+    fun toByteArray(): ByteArray {
+
+        val serializedAttributes = attributes.flatMap { it.toByteArray().asIterable() }
+        val joinedAttributes = serializedAttributes.toTypedArray().toByteArray()
+
+        val attrSize = joinedAttributes.size
+        if (attrSize == 0) {
+            return byteArrayOf(code.code, identifier, 0, 4)
+        }
+        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)
+
+        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()
+
+        fun parse(aapsLogger: AAPSLogger, payload: ByteArray): EapMessage {
+            if (payload.size < 4) {
+                throw MessageIOException("Invalid eap payload: ${payload.toHex()}")
+            }
+            val totalSize = (payload[2].toInt() shl 1) or payload[3].toInt()
+            if (totalSize > payload.size) {
+                throw MessageIOException("Invalid eap payload. Too short: ${payload.toHex()}")
+            }
+            if (payload.size == 4) { // SUCCESS/FAILURE
+                return EapMessage(
+                    code = EapCode.byValue(payload[0]),
+                    identifier = payload[1],
+                    attributes = arrayOf()
+                )
+            }
+            if (totalSize > 0 && payload[4] != AKA_PACKET_TYPE) {
+                throw MessageIOException("Invalid eap payload. Expected AKA packet type: ${payload.toHex()}")
+            }
+            val attributesPayload = payload.copyOfRange(8, totalSize)
+            aapsLogger.debug(LTag.PUMPBTCOMM, "EAP attributes: ${attributesPayload.toByteString()}")
+            return EapMessage(
+                code = EapCode.byValue(payload[0]),
+                identifier = payload[1],
+                attributes = EapAkaAttribute.parseAttributes(aapsLogger, attributesPayload).toTypedArray()
+            )
+        }
+    }
+}

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

@@ -8,7 +8,13 @@ import java.security.SecureRandom
 import javax.crypto.Cipher
 import javax.crypto.spec.SecretKeySpec
 
-class Milenage(private val aapsLogger: AAPSLogger, private val k: ByteArray, val sqn: ByteArray, val _rand: ByteArray? = null) {
+class Milenage(
+    private val aapsLogger: AAPSLogger,
+    private val k: ByteArray,
+    val sqn: ByteArray,
+    val _rand: ByteArray? = null
+) {
+
     init {
         require(k.size == KEY_SIZE) { "Milenage key has to be $KEY_SIZE bytes long. Received: ${k.toHex()}" }
         require(sqn.size == SQN) { "Milenage SQN has to be $SQN long. Received: ${sqn.toHex()}" }
@@ -24,7 +30,7 @@ class Milenage(private val aapsLogger: AAPSLogger, private val k: ByteArray, val
     val rand = _rand ?: ByteArray(KEY_SIZE)
 
     init {
-        if (_rand == null ){
+        if (_rand == null) {
             val random = SecureRandom()
             random.nextBytes(rand)
         }
@@ -55,9 +61,10 @@ class Milenage(private val aapsLogger: AAPSLogger, private val k: ByteArray, val
 
     val ck = cipher.doFinal(ckInput) xor opc
 
-    private val sqnAmf = sqn + MILENAGE_AMF +  sqn + MILENAGE_AMF
+    private val sqnAmf = sqn + MILENAGE_AMF + sqn + MILENAGE_AMF
     private val sqnAmfXorOpc = sqnAmf xor opc
     private val macAInput = ByteArray(KEY_SIZE)
+
     init {
         for (i in 0..15) {
             macAInput[(i + 8) % 16] = sqnAmfXorOpc[i]

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

@@ -1,3 +1,9 @@
 package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
 
-class SessionKeys
+data class SessionKeys(val ck: ByteArray, val noncePrefix: ByteArray, val sqn: ByteArray) {
+    init {
+        require(ck.size == 16) { "CK has to be 16 bytes long" }
+        require(noncePrefix.size == 8) { "noncePrefix has to be 8 bytes long" }
+        require(sqn.size == 6) { "SQN has to be 6 bytes long" }
+    }
+}

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/pod/command/ProgramInsulinCommand.kt

@@ -13,7 +13,7 @@ class ProgramInsulinCommand internal constructor(
     multiCommandFlag: Boolean,
     nonce: Int,
     insulinProgramElements:
-    List<ShortInsulinProgramElement>,
+        List<ShortInsulinProgramElement>,
     private val checksum: Short,
     private val byte9: Byte,
     private val byte10And11: Short,

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/driver/pod/definition/AlertConfiguration.kt

@@ -35,7 +35,7 @@ class AlertConfiguration(
                             trigger.thresholdInMicroLiters
                         }
 
-                        is AlertTrigger.TimerTrigger           -> {
+                        is AlertTrigger.TimerTrigger -> {
                             trigger.offsetInMinutes
                         }
                     }

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/history/DashHistory.kt

@@ -47,7 +47,7 @@ class DashHistory @Inject constructor(
         val id = ULID.random()
 
         when {
-            commandType == SET_BOLUS && bolusRecord == null               ->
+            commandType == SET_BOLUS && bolusRecord == null ->
                 return Single.error(IllegalArgumentException("bolusRecord missing on SET_BOLUS"))
             commandType == SET_TEMPORARY_BASAL && tempBasalRecord == null ->
                 return Single.error(IllegalArgumentException("tempBasalRecord missing on SET_TEMPORARY_BASAL"))

omnipod-dash/src/main/java/info/nightscout/androidaps/plugins/pump/omnipod/dash/ui/OmnipodDashOverviewFragment.kt

@@ -477,9 +477,12 @@ class OmnipodDashOverviewFragment : DaggerFragment() {
     }
 
     private fun updateResumeDeliveryButton() {
-        if (podStateManager.isPodRunning && (podStateManager.isSuspended || commandQueue.isCustomCommandInQueue(
+        if (podStateManager.isPodRunning && (
-                CommandResumeDelivery::class.java
+                podStateManager.isSuspended || commandQueue.isCustomCommandInQueue(
-            ))) {
+                    CommandResumeDelivery::class.java
+                )
+                )
+        ) {
             buttonBinding.buttonResumeDelivery.visibility = View.VISIBLE
             buttonBinding.buttonResumeDelivery.isEnabled = isQueueEmpty()
         } else {
@@ -488,9 +491,12 @@ class OmnipodDashOverviewFragment : DaggerFragment() {
     }
 
     private fun updateSilenceAlertsButton() {
-        if (isAutomaticallySilenceAlertsEnabled() && podStateManager.isPodRunning && (podStateManager.activeAlerts!!.size > 0 || commandQueue.isCustomCommandInQueue(
+        if (isAutomaticallySilenceAlertsEnabled() && podStateManager.isPodRunning && (
-                CommandAcknowledgeAlerts::class.java
+                podStateManager.activeAlerts!!.size > 0 || commandQueue.isCustomCommandInQueue(
-            ))) {
+                    CommandAcknowledgeAlerts::class.java
+                )
+                )
+        ) {
             buttonBinding.buttonSilenceAlerts.visibility = View.VISIBLE
             buttonBinding.buttonSilenceAlerts.isEnabled = isQueueEmpty()
         } else {
@@ -500,9 +506,12 @@ class OmnipodDashOverviewFragment : DaggerFragment() {
 
     private fun updateSuspendDeliveryButton() {
         // If the Pod is currently suspended, we show the Resume delivery button instead.
-        if (isSuspendDeliveryButtonEnabled() && podStateManager.isPodRunning && (!podStateManager.isSuspended || commandQueue.isCustomCommandInQueue(
+        if (isSuspendDeliveryButtonEnabled() && podStateManager.isPodRunning && (
-                CommandSuspendDelivery::class.java
+                !podStateManager.isSuspended || commandQueue.isCustomCommandInQueue(
-            ))) {
+                    CommandSuspendDelivery::class.java
+                )
+                )
+        ) {
             buttonBinding.buttonSuspendDelivery.visibility = View.VISIBLE
             buttonBinding.buttonSuspendDelivery.isEnabled =
                 podStateManager.isPodRunning && !podStateManager.isSuspended && isQueueEmpty()

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

@@ -2,9 +2,7 @@ package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.session
 
 import info.nightscout.androidaps.logging.AAPSLoggerTest
 import info.nightscout.androidaps.utils.extensions.toHex
-import okio.ByteString.Companion.decodeHex
 import org.junit.Assert
-import org.junit.Assert.*
 import org.junit.Test
 import org.spongycastle.util.encoders.Hex
 
@@ -15,7 +13,7 @@ class MilenageTest {
         val m = Milenage(
             aapsLogger,
             Hex.decode("c0772899720972a314f557de66d571dd"),
-            byteArrayOf(0,0,0,0,0,2),
+            byteArrayOf(0, 0, 0, 0, 0, 2),
             Hex.decode("c2cd1248451103bd77a6c7ef88c441ba")
         )
         Assert.assertEquals(m.res.toHex(), "a40bc6d13861447e")
@@ -28,7 +26,7 @@ class MilenageTest {
         val m = Milenage(
             aapsLogger,
             Hex.decode("78411ccad0fd0fb6f381a47fb3335ecb"),
-            byteArrayOf(0,0,0,0,0,2), // 1 + 1
+            byteArrayOf(0, 0, 0, 0, 0, 2), // 1 + 1
             Hex.decode("4fc01ac1a94376ae3e052339c07d9e1f")
         )
         Assert.assertEquals(m.res.toHex(), "ec549e00fa668a19")
@@ -41,8 +39,8 @@ class MilenageTest {
         val m = Milenage(
             aapsLogger,
             Hex.decode("c0772899720972a314f557de66d571dd"),
- //           byteArrayOf(0,0,0,0,0x01,0x5d), this is in logs. SQN has to be incremented.
+            //           byteArrayOf(0,0,0,0,0x01,0x5d), this is in logs. SQN has to be incremented.
-            byteArrayOf(0,0,0,0,0x01,0x5e),
+            byteArrayOf(0, 0, 0, 0, 0x01, 0x5e),
             Hex.decode("d71cc44820e5419f42c62ae97c035988")
         )
         Assert.assertEquals(m.res.toHex(), "5f807a379a5c5d30")