dash/ble: start implement EAP-AKA

This commit is contained in:
Andrei Vereha 2021-03-01 15:15:06 +01:00
parent 0523f7c17c
commit e82826bf5a
9 changed files with 261 additions and 4 deletions

View file

@ -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

View file

@ -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) {

View file

@ -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
)
}

View file

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

View file

@ -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()}" }
}

View file

@ -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
}
}

View file

@ -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()
}
}

View file

@ -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()
}
}

View file

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