Added safetynet implementation

The implementation itself was moved from fragment to self contained event. The result resolution might be moved to the event as well

app/src/main/java/com/topjohnwu/magisk/di/RedesignModule.kt

@@ -22,7 +22,7 @@ val redesignModule = module {
     viewModel { LogViewModel() }
     viewModel { ModuleViewModel() }
     viewModel { RequestViewModel() }
-    viewModel { SafetynetViewModel() }
+    viewModel { SafetynetViewModel(get()) }
     viewModel { SettingsViewModel() }
     viewModel { SuperuserViewModel(get(), get(), get(), get()) }
     viewModel { ThemeViewModel() }

app/src/main/java/com/topjohnwu/magisk/model/events/RxEvents.kt

@@ -15,3 +15,5 @@ sealed class PolicyUpdateEvent(val item: MagiskPolicy) : RxBus.Event {
 }
 
 class ModuleUpdatedEvent(val item: ModuleRvItem) : RxBus.Event
+
+data class SafetyNetResult(val responseCode: Int) : RxBus.Event

app/src/main/java/com/topjohnwu/magisk/model/events/ViewEvents.kt

@@ -1,6 +1,7 @@
 package com.topjohnwu.magisk.model.events
 
 import android.app.Activity
+import android.content.Context
 import android.content.Intent
 import androidx.appcompat.app.AppCompatActivity
 import com.karumi.dexter.Dexter
@@ -8,9 +9,25 @@ import com.karumi.dexter.MultiplePermissionsReport
 import com.karumi.dexter.PermissionToken
 import com.karumi.dexter.listener.PermissionRequest
 import com.karumi.dexter.listener.multi.MultiplePermissionsListener
+import com.topjohnwu.magisk.Const
+import com.topjohnwu.magisk.R
+import com.topjohnwu.magisk.data.repository.MagiskRepository
+import com.topjohnwu.magisk.extensions.DynamicClassLoader
+import com.topjohnwu.magisk.extensions.subscribeK
+import com.topjohnwu.magisk.extensions.writeTo
 import com.topjohnwu.magisk.model.entity.module.Repo
 import com.topjohnwu.magisk.model.permissions.PermissionRequestBuilder
+import com.topjohnwu.magisk.utils.RxBus
+import com.topjohnwu.magisk.utils.SafetyNetHelper
+import com.topjohnwu.magisk.view.MagiskDialog
+import com.topjohnwu.superuser.Shell
+import dalvik.system.DexFile
+import io.reactivex.Completable
 import io.reactivex.subjects.PublishSubject
+import org.koin.core.KoinComponent
+import org.koin.core.inject
+import java.io.File
+import java.lang.reflect.InvocationHandler
 
 /**
  * Class for passing events from ViewModels to Activities/Fragments
@@ -34,7 +51,88 @@ class MagiskChangelogEvent : ViewEvent()
 class UninstallEvent : ViewEvent()
 class EnvFixEvent : ViewEvent()
 
-class UpdateSafetyNetEvent : ViewEvent()
+class UpdateSafetyNetEvent : ViewEvent(), ContextExecutor, KoinComponent, SafetyNetHelper.Callback {
+
+    private val magiskRepo by inject<MagiskRepository>()
+    private val rxBus by inject<RxBus>()
+
+    private lateinit var EXT_APK: File
+    private lateinit var EXT_DEX: File
+
+    override fun invoke(context: Context) {
+        val die = ::EXT_APK.isInitialized
+
+        EXT_APK = File("${context.filesDir.parent}/snet", "snet.jar")
+        EXT_DEX = File(EXT_APK.parent, "snet.dex")
+
+        Completable.fromAction {
+            val loader = DynamicClassLoader(EXT_APK)
+            val dex = DexFile.loadDex(EXT_APK.path, EXT_DEX.path, 0)
+
+            // Scan through the dex and find our helper class
+            var helperClass: Class<*>? = null
+            for (className in dex.entries()) {
+                if (className.startsWith("x.")) {
+                    val cls = loader.loadClass(className)
+                    if (InvocationHandler::class.java.isAssignableFrom(cls)) {
+                        helperClass = cls
+                        break
+                    }
+                }
+            }
+            helperClass ?: throw Exception()
+
+            val helper = helperClass.getMethod(
+                "get",
+                Class::class.java, Context::class.java, Any::class.java
+            )
+                .invoke(null, SafetyNetHelper::class.java, context, this) as SafetyNetHelper
+
+            if (helper.version < Const.SNET_EXT_VER)
+                throw Exception()
+
+            helper.attest()
+        }.subscribeK(onError = {
+            if (die) {
+                rxBus.post(SafetyNetResult(-1))
+            } else {
+                Shell.sh("rm -rf " + EXT_APK.parent).exec()
+                EXT_APK.parentFile?.mkdir()
+                download(context, true)
+            }
+        })
+    }
+
+    @Suppress("SameParameterValue")
+    private fun download(context: Context, askUser: Boolean) {
+        fun downloadInternal() = magiskRepo.fetchSafetynet()
+            .map { it.byteStream().writeTo(EXT_APK) }
+            .subscribeK { invoke(context) }
+
+        if (!askUser) {
+            downloadInternal()
+            return
+        }
+
+        MagiskDialog(context)
+            .applyTitle(R.string.proprietary_title)
+            .applyMessage(R.string.proprietary_notice)
+            .cancellable(false)
+            .applyButton(MagiskDialog.ButtonType.POSITIVE) {
+                titleRes = R.string.yes
+                onClick { downloadInternal() }
+            }
+            .applyButton(MagiskDialog.ButtonType.NEGATIVE) {
+                titleRes = R.string.no_thanks
+                onClick { rxBus.post(SafetyNetResult(-2)) }
+            }
+            .reveal()
+    }
+
+    override fun onResponse(responseCode: Int) {
+        rxBus.post(SafetyNetResult(responseCode))
+    }
+}
 
 class ViewActionEvent(val action: Activity.() -> Unit) : ViewEvent(), ActivityExecutor {
     override fun invoke(activity: AppCompatActivity) = activity.run(action)

app/src/main/java/com/topjohnwu/magisk/redesign/safetynet/SafetynetViewModel.kt

@@ -1,5 +1,62 @@
 package com.topjohnwu.magisk.redesign.safetynet
 
+import com.topjohnwu.magisk.R
+import com.topjohnwu.magisk.extensions.subscribeK
+import com.topjohnwu.magisk.model.events.SafetyNetResult
+import com.topjohnwu.magisk.model.events.UpdateSafetyNetEvent
 import com.topjohnwu.magisk.redesign.compat.CompatViewModel
+import com.topjohnwu.magisk.ui.home.SafetyNetState.*
+import com.topjohnwu.magisk.utils.KObservableField
+import com.topjohnwu.magisk.utils.RxBus
+import com.topjohnwu.magisk.utils.SafetyNetHelper
 
-class SafetynetViewModel : CompatViewModel()
+class SafetynetViewModel(
+    rxBus: RxBus
+) : CompatViewModel() {
+
+    val safetyNetTitle = KObservableField(R.string.empty)
+    val ctsState = KObservableField(IDLE)
+    val basicIntegrityState = KObservableField(IDLE)
+
+    init {
+        rxBus.register<SafetyNetResult>()
+            .subscribeK { resolveResponse(it.responseCode) }
+            .add()
+    }
+
+    fun attest() = UpdateSafetyNetEvent().publish()
+
+    private fun resolveResponse(response: Int) = when {
+        //todo animate (reveal) to result (green/error)
+        response and 0x0F == 0 -> {
+            val hasCtsPassed = response and SafetyNetHelper.CTS_PASS != 0
+            val hasBasicIntegrityPassed = response and SafetyNetHelper.BASIC_PASS != 0
+            safetyNetTitle.value = R.string.safetyNet_check_success
+            ctsState.value = if (hasCtsPassed) {
+                PASS
+            } else {
+                FAILED
+            }
+            basicIntegrityState.value = if (hasBasicIntegrityPassed) {
+                PASS
+            } else {
+                FAILED
+            }
+        }
+        //todo animate (collapse) back to initial (fade error)
+        response == -2 -> {
+            ctsState.value = IDLE
+            basicIntegrityState.value = IDLE
+        }
+        //todo animate (collapse) back to initial (surface)
+        else -> {
+            ctsState.value = IDLE
+            basicIntegrityState.value = IDLE
+            safetyNetTitle.value = when (response) {
+                SafetyNetHelper.RESPONSE_ERR -> R.string.safetyNet_res_invalid
+                else -> R.string.safetyNet_api_error
+            }
+        }
+    }
+
+}