From d33391ebce1997012283eacb50f114f305e0df3b Mon Sep 17 00:00:00 2001
From: Marvin W <git@larma.de>
Date: Sat, 5 Sep 2020 23:51:00 +0200
Subject: [PATCH] EN: Handle confirmation via resolution/pending intent instead
 of new task

---
 .../ExposureNotificationsConfirmActivity.kt   | 20 +++--
 .../nearby/exposurenotification/Constants.kt  |  1 +
 .../exposurenotification/ExposureDatabase.kt  | 24 ++++-
 .../ExposureNotificationServiceImpl.kt        | 87 ++++++++++---------
 4 files changed, 82 insertions(+), 50 deletions(-)

diff --git a/play-services-core/src/main/kotlin/org/microg/gms/ui/ExposureNotificationsConfirmActivity.kt b/play-services-core/src/main/kotlin/org/microg/gms/ui/ExposureNotificationsConfirmActivity.kt
index 3b2988c7..2c8fcaa4 100644
--- a/play-services-core/src/main/kotlin/org/microg/gms/ui/ExposureNotificationsConfirmActivity.kt
+++ b/play-services-core/src/main/kotlin/org/microg/gms/ui/ExposureNotificationsConfirmActivity.kt
@@ -11,12 +11,14 @@ import android.widget.Button
 import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
 import com.google.android.gms.R
-import com.google.android.gms.nearby.exposurenotification.ExposureNotificationStatusCodes.*
 import org.microg.gms.nearby.exposurenotification.*
 
 class ExposureNotificationsConfirmActivity : AppCompatActivity() {
-    private var resultCode: Int = FAILED
-    private val resultData: Bundle = Bundle()
+    private var resultCode: Int = RESULT_CANCELED
+        set(value) {
+            setResult(value)
+            field = value
+        }
     private val receiver: ResultReceiver?
         get() = intent.getParcelableExtra(KEY_CONFIRM_RECEIVER)
     private val action: String?
@@ -47,22 +49,22 @@ class ExposureNotificationsConfirmActivity : AppCompatActivity() {
                 findViewById<Button>(android.R.id.button1).text = getString(R.string.exposure_confirm_keys_button)
             }
             else -> {
-                resultCode = INTERNAL_ERROR
+                resultCode = RESULT_CANCELED
                 finish()
             }
         }
         findViewById<Button>(android.R.id.button1).setOnClickListener {
-            resultCode = SUCCESS
+            resultCode = RESULT_OK
             finish()
         }
         findViewById<Button>(android.R.id.button2).setOnClickListener {
-            resultCode = FAILED_REJECTED_OPT_IN
+            resultCode = RESULT_CANCELED
             finish()
         }
     }
 
-    override fun onStop() {
-        super.onStop()
-        receiver?.send(resultCode, resultData)
+    override fun finish() {
+        receiver?.send(resultCode, Bundle())
+        super.finish()
     }
 }
diff --git a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/Constants.kt b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/Constants.kt
index 891d80c1..48e63e94 100644
--- a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/Constants.kt
+++ b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/Constants.kt
@@ -25,6 +25,7 @@ const val KEY_CONFIRM_PACKAGE = "package"
 const val CONFIRM_ACTION_START = "start"
 const val CONFIRM_ACTION_STOP = "stop"
 const val CONFIRM_ACTION_KEYS = "keys"
+const val CONFIRM_PERMISSION_VALIDITY = 60 * 60 * 1000L
 
 const val PERMISSION_EXPOSURE_CALLBACK = "com.google.android.gms.nearby.exposurenotification.EXPOSURE_CALLBACK"
 
diff --git a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureDatabase.kt b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureDatabase.kt
index 04515f29..93dc60af 100644
--- a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureDatabase.kt
+++ b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureDatabase.kt
@@ -54,6 +54,9 @@ class ExposureDatabase private constructor(private val context: Context) : SQLit
             db.execSQL("CREATE TABLE IF NOT EXISTS $TABLE_DIAGNOSIS(package TEXT NOT NULL, token TEXT NOT NULL, tcid INTEGER REFERENCES $TABLE_TEK_CHECK(tcid) ON DELETE CASCADE, transmissionRiskLevel INTEGER NOT NULL);")
             db.execSQL("CREATE INDEX IF NOT EXISTS index_${TABLE_DIAGNOSIS}_package_token ON $TABLE_DIAGNOSIS(package, token);")
         }
+        if (oldVersion < 3) {
+            db.execSQL("CREATE TABLE $TABLE_APP_PERMS(package TEXT NOT NULL, sig TEXT NOT NULL, perm TEXT NOT NULL, timestamp INTEGER NOT NULL);")
+        }
     }
 
     fun SQLiteDatabase.delete(table: String, whereClause: String, args: LongArray): Int =
@@ -68,7 +71,23 @@ class ExposureDatabase private constructor(private val context: Context) : SQLit
         val appLogEntries = delete(TABLE_APP_LOG, "timestamp < ?", longArrayOf(rollingStartTime))
         val temporaryExposureKeys = delete(TABLE_TEK, "(rollingStartNumber + rollingPeriod) < ?", longArrayOf(rollingStartTime / ROLLING_WINDOW_LENGTH_MS))
         val checkedTemporaryExposureKeys = delete(TABLE_TEK_CHECK, "(rollingStartNumber + rollingPeriod) < ?", longArrayOf(rollingStartTime / ROLLING_WINDOW_LENGTH_MS))
-        Log.d(TAG, "Deleted on daily cleanup: $advertisements adv, $appLogEntries applogs, $temporaryExposureKeys teks, $checkedTemporaryExposureKeys cteks")
+        val appPerms = delete(TABLE_APP_PERMS, "timestamp < ?", longArrayOf(System.currentTimeMillis() - CONFIRM_PERMISSION_VALIDITY))
+        Log.d(TAG, "Deleted on daily cleanup: $advertisements adv, $appLogEntries applogs, $temporaryExposureKeys teks, $checkedTemporaryExposureKeys cteks, $appPerms perms")
+    }
+
+    fun grantPermission(packageName: String, signatureDigest: String, permission: String, timestamp: Long = System.currentTimeMillis()) = writableDatabase.run {
+        insert(TABLE_APP_PERMS, "NULL", ContentValues().apply {
+            put("package", packageName)
+            put("sig", signatureDigest)
+            put("perm", permission)
+            put("timestamp", timestamp)
+        })
+    }
+
+    fun hasPermission(packageName: String, signatureDigest: String, permission: String, maxAge: Long = CONFIRM_PERMISSION_VALIDITY) = readableDatabase.run {
+        query(TABLE_APP_PERMS, arrayOf("MAX(timestamp)"), "package = ? AND sig = ? and perm = ?", arrayOf(packageName, signatureDigest, permission), null, null, null).use { cursor ->
+            cursor.moveToNext() && cursor.getLong(0) + maxAge > System.currentTimeMillis()
+        }
     }
 
     fun noteAdvertisement(rpi: ByteArray, aem: ByteArray, rssi: Int, timestamp: Long = Date().time) = writableDatabase.run {
@@ -496,13 +515,14 @@ class ExposureDatabase private constructor(private val context: Context) : SQLit
 
     companion object {
         private const val DB_NAME = "exposure.db"
-        private const val DB_VERSION = 2
+        private const val DB_VERSION = 3
         private const val TABLE_ADVERTISEMENTS = "advertisements"
         private const val TABLE_APP_LOG = "app_log"
         private const val TABLE_TEK = "tek"
         private const val TABLE_TEK_CHECK = "tek_check"
         private const val TABLE_DIAGNOSIS = "diagnosis"
         private const val TABLE_CONFIGURATIONS = "configurations"
+        private const val TABLE_APP_PERMS = "app_perms"
 
         private var instance: ExposureDatabase? = null
         fun ref(context: Context): ExposureDatabase = synchronized(this) {
diff --git a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt
index 8d573bb1..8a1512d3 100644
--- a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt
+++ b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt
@@ -5,6 +5,8 @@
 
 package org.microg.gms.nearby.exposurenotification
 
+import android.app.Activity
+import android.app.PendingIntent
 import android.content.ComponentName
 import android.content.Context
 import android.content.Intent
@@ -13,12 +15,14 @@ import android.os.*
 import android.util.Log
 import com.google.android.gms.common.api.CommonStatusCodes
 import com.google.android.gms.common.api.Status
+import com.google.android.gms.nearby.exposurenotification.ExposureNotificationStatusCodes
 import com.google.android.gms.nearby.exposurenotification.ExposureNotificationStatusCodes.*
 import com.google.android.gms.nearby.exposurenotification.ExposureSummary
 import com.google.android.gms.nearby.exposurenotification.TemporaryExposureKey
 import com.google.android.gms.nearby.exposurenotification.internal.*
 import org.json.JSONArray
 import org.json.JSONObject
+import org.microg.gms.common.PackageUtils
 import org.microg.gms.nearby.exposurenotification.Constants.*
 import org.microg.gms.nearby.exposurenotification.proto.TemporaryExposureKeyExport
 import org.microg.gms.nearby.exposurenotification.proto.TemporaryExposureKeyProto
@@ -26,48 +30,51 @@ import java.util.*
 import java.util.zip.ZipInputStream
 
 class ExposureNotificationServiceImpl(private val context: Context, private val packageName: String) : INearbyExposureNotificationService.Stub() {
-    private fun confirm(action: String, callback: (resultCode: Int, resultData: Bundle?) -> Unit) {
+    private fun pendingConfirm(permission: String): PendingIntent {
         val intent = Intent(ACTION_CONFIRM)
         intent.`package` = context.packageName
         intent.putExtra(KEY_CONFIRM_PACKAGE, packageName)
-        intent.putExtra(KEY_CONFIRM_ACTION, action)
-        intent.putExtra(KEY_CONFIRM_RECEIVER, object : ResultReceiver(Handler(Looper.getMainLooper())) {
+        intent.putExtra(KEY_CONFIRM_ACTION, permission)
+        intent.putExtra(KEY_CONFIRM_RECEIVER, object : ResultReceiver(null) {
             override fun onReceiveResult(resultCode: Int, resultData: Bundle?) {
-                Log.d(TAG, "Result from action $action: ${getStatusCodeString(resultCode)}")
-                callback(resultCode, resultData)
+                if (resultCode == Activity.RESULT_OK) {
+                    ExposureDatabase.with(context) { database -> database.grantPermission(packageName, PackageUtils.firstSignatureDigest(context, packageName)!!, permission) }
+                }
             }
         })
-        intent.addFlags(FLAG_ACTIVITY_NEW_TASK)
-        intent.addFlags(FLAG_ACTIVITY_MULTIPLE_TASK)
-        intent.addFlags(FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS)
         try {
             intent.component = ComponentName(context, context.packageManager.resolveActivity(intent, 0)?.activityInfo?.name!!)
-            context.startActivity(intent)
         } catch (e: Exception) {
             Log.w(TAG, e)
-            callback(CommonStatusCodes.INTERNAL_ERROR, null)
+        }
+        Log.d(TAG, "Pending: $intent")
+        val pi = PendingIntent.getActivity(context, permission.hashCode(), intent, PendingIntent.FLAG_ONE_SHOT)
+        Log.d(TAG, "Pending: $pi")
+        return pi
+    }
+
+    private fun confirmPermission(permission: String): Status {
+        if (packageName == context.packageName) return Status.SUCCESS
+        return ExposureDatabase.with(context) { database ->
+            if (!database.hasPermission(packageName, PackageUtils.firstSignatureDigest(context, packageName)!!, permission)) {
+                Status(RESOLUTION_REQUIRED, "Permission EN#$permission required.", pendingConfirm(permission))
+            } else {
+                Status.SUCCESS
+            }
         }
     }
 
     override fun start(params: StartParams) {
-        if (ExposurePreferences(context).enabled) {
-            params.callback.onResult(Status(FAILED_ALREADY_STARTED))
-            return
+        if (ExposurePreferences(context).enabled) return
+        val status = confirmPermission(CONFIRM_ACTION_START)
+        if (status.isSuccess) {
+            ExposurePreferences(context).enabled = true
+            ExposureDatabase.with(context) { database -> database.noteAppAction(packageName, "start") }
         }
-        confirm(CONFIRM_ACTION_START) { resultCode, resultData ->
-            if (resultCode == SUCCESS) {
-                ExposurePreferences(context).enabled = true
-            }
-            ExposureDatabase.with(context) { database ->
-                database.noteAppAction(packageName, "start", JSONObject().apply {
-                    put("result", resultCode)
-                }.toString())
-            }
-            try {
-                params.callback.onResult(Status(if (resultCode == SUCCESS) SUCCESS else FAILED_REJECTED_OPT_IN, resultData?.getString("message")))
-            } catch (e: Exception) {
-                Log.w(TAG, "Callback failed", e)
-            }
+        try {
+            params.callback.onResult(status)
+        } catch (e: Exception) {
+            Log.w(TAG, "Callback failed", e)
         }
     }
 
@@ -91,23 +98,25 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
         }
     }
 
-    override fun getTemporaryExposureKeyHistory(params: GetTemporaryExposureKeyHistoryParams): Unit = ExposureDatabase.with(context) { database ->
-        confirm(CONFIRM_ACTION_START) { resultCode, resultData ->
-            val (status, response) = if (resultCode == SUCCESS) {
-                SUCCESS to database.allKeys
-            } else {
-                FAILED_REJECTED_OPT_IN to emptyList()
+    override fun getTemporaryExposureKeyHistory(params: GetTemporaryExposureKeyHistoryParams) {
+        val status = confirmPermission(CONFIRM_ACTION_KEYS)
+        val response = when {
+            status.isSuccess -> ExposureDatabase.with(context) { database ->
+                database.allKeys
             }
+            else -> emptyList()
+        }
 
+        ExposureDatabase.with(context) { database ->
             database.noteAppAction(packageName, "getTemporaryExposureKeyHistory", JSONObject().apply {
-                put("result", resultCode)
+                put("result", status.statusCode)
                 put("response_keys_size", response.size)
             }.toString())
-            try {
-                params.callback.onResult(Status(status, resultData?.getString("message")), response)
-            } catch (e: Exception) {
-                Log.w(TAG, "Callback failed", e)
-            }
+        }
+        try {
+            params.callback.onResult(status, response)
+        } catch (e: Exception) {
+            Log.w(TAG, "Callback failed", e)
         }
     }