ble/milenage: fix and add tests

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

@@ -86,7 +86,7 @@ class EapAkaAttributeCustomIV(val payload: ByteArray) : EapAkaAttribute(
 ) {
 
     init {
-        require(payload.size == 4) { "AT_RES payload size has to be 8 bytes. Payload: ${payload.toHex()}" }
+        require(payload.size == 4) { "CUSTOM_IV payload size has to be 4 bytes. Payload: ${payload.toHex()}" }
     }
 
     override fun toByteArray(): ByteArray {

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

@@ -3,7 +3,6 @@ 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) {
@@ -35,11 +34,12 @@ class EapAkaMessage(
         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 serializedAttributes = attributes?.flatMap { it.toByteArray().asIterable() }
         val joinedAttributes = serializedAttributes?.toTypedArray()?.toByteArray()
 
         val attrSize = joinedAttributes?.size ?: 0
@@ -53,7 +53,7 @@ class EapAkaMessage(
             .put((totalSize and 0XFF).toByte())
             .put(AKA_PACKET_TYPE)
             .put(SUBTYPE_AKA_CHALLENGE)
-            .put(byteArrayOf(0,0))
+            .put(byteArrayOf(0, 0))
             .put(joinedAttributes ?: ByteArray(0))
 
         val ret = bb.array()

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

@@ -11,7 +11,7 @@ import javax.crypto.spec.SecretKeySpec
 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 == SEQ_SIZE) { "Milenage SEQ has to be $SEQ_SIZE long. Received: ${sqn.toHex()}" }
+        require(sqn.size == SQN) { "Milenage SQN has to be $SQN long. Received: ${sqn.toHex()}" }
     }
 
     private val secretKeySpec = SecretKeySpec(k, "AES")
@@ -31,45 +31,47 @@ class Milenage(private val aapsLogger: AAPSLogger, private val k: ByteArray, val
     }
 
     private val opc = cipher.doFinal(MILENAGE_OP) xor MILENAGE_OP
-    private val rand_opc_encrypted = cipher.doFinal(rand xor opc)
+    private val randOpcEncrypted = cipher.doFinal(rand xor opc)
-    private val rand_opc_encrypted_opc = rand_opc_encrypted xor opc
+    private val randOpcEncryptedXorOpc = randOpcEncrypted xor opc
+    private val resAkInput = randOpcEncryptedXorOpc.copyOfRange(0, KEY_SIZE)
 
     init {
-        rand_opc_encrypted_opc[15] = (rand_opc_encrypted_opc[15].toInt() xor 1).toByte()
+        resAkInput[15] = (resAkInput[15].toInt() xor 1).toByte()
     }
 
-    private val res_ak = cipher.doFinal(rand_opc_encrypted_opc) xor opc
+    private val resAk = cipher.doFinal(resAkInput) xor opc
 
-    val res = res_ak.copyOfRange(8, 16)
+    val res = resAk.copyOfRange(8, 16)
-    val ak = res_ak.copyOfRange(0, 6)
+    private val ak = resAk.copyOfRange(0, 6)
 
-    private val ck_input = ByteArray(KEY_SIZE)
+    private val ckInput = ByteArray(KEY_SIZE)
 
     init {
         for (i in 0..15) {
-            ck_input[(i + 12) % 16] = (rand_opc_encrypted[i].toInt() xor opc[i].toInt()).toByte()
+            ckInput[(i + 12) % 16] = randOpcEncryptedXorOpc[i]
         }
-        ck_input[15] = (ck_input[15].toInt() xor 2).toByte()
+        ckInput[15] = (ckInput[15].toInt() xor 2).toByte()
     }
 
-    val ck = cipher.doFinal(ck_input) xor opc
+    val ck = cipher.doFinal(ckInput) xor opc
 
+    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] = (rand_opc_encrypted[i].toInt() xor opc[i].toInt()).toByte()
+            macAInput[(i + 8) % 16] = sqnAmfXorOpc[i]
         }
     }
 
-    private val macAFull = cipher.doFinal(macAInput xor opc)
+    private val macAFull = cipher.doFinal(macAInput xor randOpcEncrypted) xor opc
     private val macA = macAFull.copyOfRange(0, 8)
     val autn = (ak xor sqn) + MILENAGE_AMF + macA
 
     init {
         aapsLogger.debug(LTag.PUMPBTCOMM, "Milenage K: ${k.toHex()}")
         aapsLogger.debug(LTag.PUMPBTCOMM, "Milenage RAND: ${rand.toHex()}")
-        aapsLogger.debug(LTag.PUMPBTCOMM, "Milenage SEQ: ${sqn.toHex()}")
+        aapsLogger.debug(LTag.PUMPBTCOMM, "Milenage SQN: ${sqn.toHex()}")
         aapsLogger.debug(LTag.PUMPBTCOMM, "Milenage CK: ${ck.toHex()}")
         aapsLogger.debug(LTag.PUMPBTCOMM, "Milenage AUTN: ${autn.toHex()}")
         aapsLogger.debug(LTag.PUMPBTCOMM, "Milenage RES: ${res.toHex()}")
@@ -83,7 +85,7 @@ class Milenage(private val aapsLogger: AAPSLogger, private val k: ByteArray, val
         private val MILENAGE_OP = Hex.decode("cdc202d5123e20f62b6d676ac72cb318")
         private val MILENAGE_AMF = Hex.decode("b9b9")
         private const val KEY_SIZE = 16
-        private const val SEQ_SIZE = 6
+        private const val SQN = 6
     }
 }
 

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

@@ -15,11 +15,39 @@ class MilenageTest {
         val m = Milenage(
             aapsLogger,
             Hex.decode("c0772899720972a314f557de66d571dd"),
-            byteArrayOf(0,0,0,0,0,1),
+            byteArrayOf(0,0,0,0,0,2),
             Hex.decode("c2cd1248451103bd77a6c7ef88c441ba")
         )
-        Assert.assertEquals(m.ck.toHex(), "55799fd26664cbf6e476525e2dee52c6")
         Assert.assertEquals(m.res.toHex(), "a40bc6d13861447e")
+        Assert.assertEquals(m.ck.toHex(), "55799fd26664cbf6e476525e2dee52c6")
         Assert.assertEquals(m.autn.toHex(), "00c55c78e8d3b9b9e935860a7259f6c0")
     }
+
+    @Test fun testMilenage2() {
+        val aapsLogger = AAPSLoggerTest()
+        val m = Milenage(
+            aapsLogger,
+            Hex.decode("78411ccad0fd0fb6f381a47fb3335ecb"),
+            byteArrayOf(0,0,0,0,0,2), // 1 + 1
+            Hex.decode("4fc01ac1a94376ae3e052339c07d9e1f")
+        )
+        Assert.assertEquals(m.res.toHex(), "ec549e00fa668a19")
+        Assert.assertEquals(m.ck.toHex(), "ee3dac761fe358a9f476cc5ee81aa3e9")
+        Assert.assertEquals(m.autn.toHex(), "a3e7a71430c8b9b95245b33b3bd679c4")
+    }
+
+    @Test fun testMilenageIncrementedSQN() {
+        val aapsLogger = AAPSLoggerTest()
+        val m = Milenage(
+            aapsLogger,
+            Hex.decode("c0772899720972a314f557de66d571dd"),
+ //           byteArrayOf(0,0,0,0,0x01,0x5d), this is in logs. SQN has to be incremented.
+            byteArrayOf(0,0,0,0,0x01,0x5e),
+            Hex.decode("d71cc44820e5419f42c62ae97c035988")
+        )
+        Assert.assertEquals(m.res.toHex(), "5f807a379a5c5d30")
+        Assert.assertEquals(m.ck.toHex(), "8dd4b3ceb849a01766e37f9d86045c39")
+        Assert.assertEquals(m.autn.toHex(), "0e0264d056fcb9b9752227365a090955")
+    }
+
 }