Add more tests for AirPods data decryption

This commit adds a test case to `AirPodsProTest` to verify the decryption of AirPods Pro data with and without encryption/IRK keys. It also introduces a new test class `RPACheckerTest` to validate the RPA checking mechanism.

Helper functions for converting hex strings to byte arrays and setting mock keys have been added to `BaseAirPodsTest` to simplify test setup.

app-common/src/main/java/eu/darken/capod/pods/core/apple/AppleFactory.kt

@@ -58,10 +58,10 @@ class AppleFactory @Inject constructor(
 
     suspend fun create(scanResult: BleScanResult): PodDevice? = lock.withLock {
         val proximityMessage = getMessage(scanResult) ?: return@withLock null
+        val payload = getPayload(scanResult, proximityMessage)
 
         val factory = podFactories.firstOrNull { it.isResponsible(proximityMessage) }
 
-        val payload = getPayload(scanResult, proximityMessage)
 
         return@withLock (factory ?: unknownAppleFactory).create(
             scanResult = scanResult,

app-common/src/main/java/eu/darken/capod/pods/core/apple/airpods/AirPodsGen1.kt

@@ -42,7 +42,6 @@ data class AirPodsGen1(
             getModelInfo().full == DEVICE_CODE && length == ProximityPairing.PAIRING_MESSAGE_LENGTH
         }
 
-
         override fun create(
             scanResult: BleScanResult,
             payload: ProximityPayload

app-common/src/test/java/eu/darken/capod/monitor/core/RPACheckerTest.kt

@@ -0,0 +1,20 @@
+package eu.darken.capod.monitor.core
+
+import io.kotest.matchers.shouldBe
+import org.junit.jupiter.api.Test
+import testhelpers.BaseTest
+
+class RPACheckerTest : BaseTest() {
+
+    @Test
+    fun `test check`() {
+        val checker = RPAChecker()
+        checker.verify(
+            address = "5A:16:2B:91:D1:CD",
+            irk = "79-04-65-1E-E2-CC-D9-26-F2-6E-20-EE-3E-CC-DE-79"
+                .replace("-", "")
+                .also { require(it.length % 2 == 0) { "Not a HEX string" } }
+                .chunked(2).map { it.toInt(16).toByte() }.toByteArray()
+        ) shouldBe true
+    }
+}

app-common/src/test/java/eu/darken/capod/pods/core/apple/BaseAirPodsTest.kt

@@ -33,19 +33,34 @@ abstract class BaseAirPodsTest : BaseTest() {
         }
     }
 
-    private val baseBleScanResult = BleScanResult(
-        receivedAt = Instant.now(),
-        address = "77:49:4C:D8:25:0C",
-        rssi = -66,
-        generatedAtNanos = 136136027721826,
-        manufacturerSpecificData = emptyMap()
-    )
-
     val generalSettings = mockk<GeneralSettings>().apply {
         every { mainDeviceIdentityKey } returns mockFlowPreference(null)
         every { mainDeviceEncryptionKey } returns mockFlowPreference(null)
     }
 
+    private fun hexToByteArray(hex: String): ByteArray = hex
+        .replace(" ", "")
+        .replace(">", "")
+        .replace("<", "")
+        .replace("-", "")
+        .also { require(it.length % 2 == 0) { "Not a HEX string" } }
+        .chunked(2).map { it.toInt(16).toByte() }.toByteArray()
+
+    private fun cleanKey(key: String): ByteArray = hexToByteArray(key)
+        .also { require(it.size == 16) { "Not a valid key: ${it.size} byte" } }
+
+    fun setKeyIRK(key: String?) {
+        generalSettings.apply {
+            every { mainDeviceIdentityKey } returns mockFlowPreference(key?.let { cleanKey(it) })
+        }
+    }
+
+    fun setKeyEnc(key: String?) {
+        generalSettings.apply {
+            every { mainDeviceEncryptionKey } returns mockFlowPreference(key?.let { cleanKey(it) })
+        }
+    }
+
     val factory: AppleFactory = DaggerBaseAirPodsTest_AppleFactoryTestComponent.factory().create(
         generalSettings = generalSettings
     ).appleFactory
@@ -58,30 +73,21 @@ abstract class BaseAirPodsTest : BaseTest() {
         every { SystemClockWrap.elapsedRealtimeNanos } returns 1000L
     }
 
-    suspend inline fun <reified T : PodDevice?> create(hex: String, block: T.() -> Unit) {
-        val trimmed = hex
-            .replace(" ", "")
-            .replace(">", "")
-            .replace("<", "")
-        require(trimmed.length % 2 == 0) { "Not a HEX string" }
-        val bytes = trimmed.chunked(2).map { it.toInt(16).toByte() }.toByteArray()
-        val result = mockData(bytes)
+    internal suspend inline fun <reified T : PodDevice?> create(
+        hex: String,
+        address: String = "77:49:4C:D8:25:0C",
+        block: T.() -> Unit
+    ) {
+        val result = BleScanResult(
+            receivedAt = Instant.now(),
+            address = address,
+            rssi = -66,
+            generatedAtNanos = 136136027721826,
+            manufacturerSpecificData = mutableMapOf<Int, ByteArray>().apply {
+                this[ContinuityProtocol.APPLE_COMPANY_IDENTIFIER] = hexToByteArray(hex)
+            }
+        )
+
         block.invoke(factory.create(result) as T)
     }
-
-    fun mockData(hex: String): BleScanResult {
-        val trimmed = hex
-            .replace(" ", "")
-            .replace(">", "")
-            .replace("<", "")
-        require(trimmed.length % 2 == 0) { "Not a HEX string" }
-        val bytes = trimmed.chunked(2).map { it.toInt(16).toByte() }.toByteArray()
-        return mockData(bytes)
-    }
-
-    fun mockData(data: ByteArray): BleScanResult = baseBleScanResult.copy(
-        manufacturerSpecificData = mutableMapOf<Int, ByteArray>().apply {
-            this[ContinuityProtocol.APPLE_COMPANY_IDENTIFIER] = data
-        }
-    )
 }

app-common/src/test/java/eu/darken/capod/pods/core/apple/airpods/AirPodsProTest.kt

@@ -188,4 +188,30 @@ class AirPodsProTest : BaseAirPodsTest() {
             batteryCasePercent shouldBe null
         }
     }
+
+    @Test
+    fun `decrypt data`() = runTest {
+        val data = "07 19 01 0E 20 51 9A 98 33 00 04 0C 14 E0 EB 43 3F 4B 22 C0 A9 ED CB 33 E7 09 71"
+        val address = "5A:16:2B:91:D1:CD"
+        create<AirPodsPro>(data, address) {
+            batteryLeftPodPercent shouldBe 0.9f
+            isLeftPodCharging shouldBe false
+            batteryRightPodPercent shouldBe 1.0f
+            isRightPodCharging shouldBe true
+
+            batteryCasePercent shouldBe 0.8f
+            isCaseCharging shouldBe false
+        }
+        setKeyIRK("79-04-65-1E-E2-CC-D9-26-F2-6E-20-EE-3E-CC-DE-79")
+        setKeyEnc("3B-9C-80-57-E6-45-7F-F2-1B-8E-07-63-6C-99-E0-29")
+        create<AirPodsPro>(data, address) {
+            batteryLeftPodPercent shouldBe 0.98f
+            isLeftPodCharging shouldBe false
+            batteryRightPodPercent shouldBe 1.0f
+            isRightPodCharging shouldBe true
+
+            batteryCasePercent shouldBe 0.86f
+            isCaseCharging shouldBe false
+        }
+    }
 }