dash eap: bugfix

Shift the MSB of the lenght by 1 byte, not one bit.

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

@@ -1,20 +0,0 @@
-package info.nightscout.androidaps.plugins.pump.omnipod.dash.driver.comm.endecrypt
-
-import java.nio.ByteBuffer
-
-class CryptSequence(var sqn: Long) {
-
-    fun incrementForEnDecrypt(fromPdmToPod: Boolean): ByteArray {
-        sqn++
-        val ret = ByteBuffer.allocate(8)
-            .putLong(sqn)
-            .array()
-            .copyOfRange(3, 8)
-        if (fromPdmToPod) {
-            ret[0] = (ret[0].toInt() and 127).toByte()
-        } else {
-            ret[0] = (ret[0].toInt() or 128).toByte()
-        }
-        return ret
-    }
-}

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

@@ -9,6 +9,7 @@ enum class EapAkaAttributeType(val type: Byte) {
     AT_RAND(1),
     AT_AUTN(2),
     AT_RES(3),
+    AT_CLIENT_ERROR_CODE(22),
     AT_CUSTOM_IV(126);
 
     companion object {
@@ -30,7 +31,7 @@ sealed class EapAkaAttribute {
         fun parseAttributes(aapsLogger: AAPSLogger, payload: ByteArray): List<EapAkaAttribute> {
             var tail = payload
             val ret = LinkedList<EapAkaAttribute>()
-            while (tail.size > 0) {
+            while (tail.isNotEmpty()) {
                 if (tail.size < 2) {
                     throw MessageIOException("Could not parse EAP attributes: ${payload.toHex()}")
                 }
@@ -41,11 +42,15 @@ sealed class EapAkaAttribute {
                 val type = EapAkaAttributeType.byValue(tail[0])
                 when (type) {
                     EapAkaAttributeType.AT_RES ->
-                        ret.add(EapAkaAttributeRes.parse(tail.copyOfRange(2, size)))
+                        ret.add(EapAkaAttributeRes.parse(tail.copyOfRange(2, EapAkaAttributeRes.SIZE)))
                     EapAkaAttributeType.AT_CUSTOM_IV ->
-                        ret.add(EapAkaAttributeCustomIV.parse(tail.copyOfRange(2, size)))
+                        ret.add(EapAkaAttributeCustomIV.parse(tail.copyOfRange(2, EapAkaAttributeCustomIV.SIZE)))
-                    else ->
+                    EapAkaAttributeType.AT_AUTN ->
-                        throw MessageIOException("Could not parse EAP attributes: ${payload.toHex()}. Expecting only AT_RES or CUSTOM_IV attribute types from the POD")
+                        ret.add(EapAkaAttributeAutn.parse(tail.copyOfRange(2, EapAkaAttributeAutn.SIZE)))
+                    EapAkaAttributeType.AT_RAND ->
+                        ret.add(EapAkaAttributeRand.parse(tail.copyOfRange(2, EapAkaAttributeRand.SIZE)))
+                    EapAkaAttributeType.AT_CLIENT_ERROR_CODE ->
+                        ret.add(EapAkaAttributeClientErrorCode.parse(tail.copyOfRange(2, EapAkaAttributeClientErrorCode.SIZE)))
                 }
                 tail = tail.copyOfRange(size, tail.size)
             }
@@ -61,12 +66,17 @@ data class EapAkaAttributeRand(val payload: ByteArray) : EapAkaAttribute() {
     }
 
     override fun toByteArray(): ByteArray {
-        return byteArrayOf(EapAkaAttributeType.AT_RAND.type, SIZE, 0, 0) + payload
+        return byteArrayOf(EapAkaAttributeType.AT_RAND.type, (SIZE / SIZE_MULTIPLIER).toByte(), 0, 0) + payload
     }
 
     companion object {
-
+        fun parse(payload: ByteArray): EapAkaAttribute {
-        private const val SIZE = (20 / SIZE_MULTIPLIER).toByte() // type, size, 2 reserved bytes, payload=16
+            if (payload.size < 2 + 16) {
+                throw MessageIOException("Could not parse RAND attribute: ${payload.toHex()}")
+            }
+            return EapAkaAttributeRand(payload.copyOfRange(2, 2 + 16))
+        }
+        const val SIZE = 20 // type, size, 2 reserved bytes, payload=16
     }
 }
 
@@ -77,12 +87,19 @@ data class EapAkaAttributeAutn(val payload: ByteArray) : EapAkaAttribute() {
     }
 
     override fun toByteArray(): ByteArray {
-        return byteArrayOf(EapAkaAttributeType.AT_AUTN.type, SIZE, 0, 0) + payload
+        return byteArrayOf(EapAkaAttributeType.AT_AUTN.type, (SIZE / SIZE_MULTIPLIER).toByte(), 0, 0) + payload
     }
 
     companion object {
 
-        private const val SIZE = (20 / SIZE_MULTIPLIER).toByte() // type, size, 2 reserved bytes, payload=16
+        fun parse(payload: ByteArray): EapAkaAttribute {
+            if (payload.size < 2 + 16) {
+                throw MessageIOException("Could not parse AUTN attribute: ${payload.toHex()}")
+            }
+            return EapAkaAttributeAutn(payload.copyOfRange(2, 2 + 16))
+        }
+
+        const val SIZE = 20 // type, size, 2 reserved bytes, payload=16
     }
 }
 
@@ -93,7 +110,7 @@ data class EapAkaAttributeRes(val payload: ByteArray) : EapAkaAttribute() {
     }
 
     override fun toByteArray(): ByteArray {
-        return byteArrayOf(EapAkaAttributeType.AT_RES.type, SIZE, 0, PAYLOAD_SIZE_BITS) + payload
+        return byteArrayOf(EapAkaAttributeType.AT_RES.type, (SIZE / SIZE_MULTIPLIER).toByte(), 0, PAYLOAD_SIZE_BITS) + payload
     }
 
     companion object {
@@ -105,7 +122,7 @@ data class EapAkaAttributeRes(val payload: ByteArray) : EapAkaAttribute() {
             return EapAkaAttributeRes(payload.copyOfRange(2, 2 + 8))
         }
 
-        private const val SIZE = (12 / SIZE_MULTIPLIER).toByte() // type, size, len in bits=2, payload=8
+        const val SIZE = 12 // type, size, len in bits=2, payload=8
         private const val PAYLOAD_SIZE_BITS = 64.toByte() // type, size, 2 reserved bytes, payload
     }
 }
@@ -117,7 +134,7 @@ data class EapAkaAttributeCustomIV(val payload: ByteArray) : EapAkaAttribute() {
     }
 
     override fun toByteArray(): ByteArray {
-        return byteArrayOf(EapAkaAttributeType.AT_CUSTOM_IV.type, SIZE, 0, 0) + payload
+        return byteArrayOf(EapAkaAttributeType.AT_CUSTOM_IV.type, (SIZE / SIZE_MULTIPLIER).toByte(), 0, 0) + payload
     }
 
     companion object {
@@ -128,7 +145,29 @@ data class EapAkaAttributeCustomIV(val payload: ByteArray) : EapAkaAttribute() {
             }
             return EapAkaAttributeCustomIV(payload.copyOfRange(2, 2 + 4))
         }
-
+        const val SIZE = 8 // type, size, 2 reserved bytes, payload=4
-        private const val SIZE = (8 / SIZE_MULTIPLIER).toByte() // type, size, 2 reserved bytes, payload=4
+    }
+}
+
+data class EapAkaAttributeClientErrorCode(val payload: ByteArray) : EapAkaAttribute() {
+
+    init {
+        require(payload.size == 2) { "Error code hast to be 2 bytes. Payload: ${payload.toHex()}" }
+    }
+
+    override fun toByteArray(): ByteArray {
+        return byteArrayOf(EapAkaAttributeType.AT_CLIENT_ERROR_CODE.type, (SIZE / SIZE_MULTIPLIER).toByte(), 0, 0) + payload
+    }
+
+    companion object {
+
+        fun parse(payload: ByteArray): EapAkaAttributeClientErrorCode {
+            if (payload.size < 2 + 2) {
+                throw MessageIOException("Could not parse CLIENT_ERROR_CODE attribute: ${payload.toHex()}")
+            }
+            return EapAkaAttributeClientErrorCode(payload.copyOfRange(2, 4))
+        }
+
+        const val SIZE = 4 // type, size=1, payload:2
     }
 }

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

@@ -41,7 +41,7 @@ data class EapMessage(
             .allocate(totalSize)
             .put(code.code)
             .put(identifier)
-            .put(((totalSize ushr 1) and 0XFF).toByte())
+            .put(((totalSize ushr 8) and 0XFF).toByte())
             .put((totalSize and 0XFF).toByte())
             .put(AKA_PACKET_TYPE)
             .put(SUBTYPE_AKA_CHALLENGE)
@@ -62,7 +62,7 @@ data class EapMessage(
             if (payload.size < 4) {
                 throw MessageIOException("Invalid eap payload: ${payload.toHex()}")
             }
-            val totalSize = (payload[2].toInt() shl 1) or payload[3].toInt()
+            val totalSize = (payload[2].toInt() shl 8) or payload[3].toInt()
             if (totalSize > payload.size) {
                 throw MessageIOException("Invalid eap payload. Too short: ${payload.toHex()}")
             }

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

@@ -83,7 +83,11 @@ class SessionEstablisher(
         // 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")
+            aapsLogger.debug(LTag.PUMPBTCOMM, "EAP-AKA: got message: $eapMsg")
+            if (eapMsg.attributes.size == 1 && eapMsg.attributes[0] is EapAkaAttributeClientErrorCode) {
+                // TODO: special exception for this
+                throw SessionEstablishmentException("Received CLIENT_ERROR_CODE for EAP-AKA challenge: ${eapMsg.attributes[0].toByteArray().toHex()}")
+            }
             throw SessionEstablishmentException("Expecting two attributes, got: ${eapMsg.attributes.size}")
         }
         for (attr in eapMsg.attributes) {

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

@@ -16,7 +16,7 @@ class EnDecryptTest {
             aapsLogger,
             Nonce(
                 Hex.decode("dda23c090a0a0a0a"),
-                Hex.decode("0000000001")
+                0
             ),
             Hex.decode("ba1283744b6de9fab6d9b77d95a71d6e"),
         )
@@ -39,7 +39,7 @@ class EnDecryptTest {
             aapsLogger,
             Nonce(
                 Hex.decode("dda23c090a0a0a0a"),
-                Hex.decode("0000000001")
+                0
             ),
             Hex.decode("ba1283744b6de9fab6d9b77d95a71d6e"),
         )

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

@@ -0,0 +1,19 @@
+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 org.junit.Assert
+import org.junit.Assert.*
+import org.junit.Test
+import org.spongycastle.util.encoders.Hex
+
+class EapMessageTest {
+
+    @Test fun testParseAndBack() {
+        val aapsLogger = AAPSLoggerTest()
+        val payload = Hex.decode("01bd0038170100000205000000c55c78e8d3b9b9e935860a7259f6c001050000c2cd1248451103bd77a6c7ef88c441ba7e0200006cff5d18")
+        val eapMsg = EapMessage.parse(aapsLogger, payload)
+        val back = eapMsg.toByteArray()
+        Assert.assertEquals(back.toHex(), payload.toHex())
+    }
+}