android: Restore database from a backup when encryption fails for some reason (#1058)

* Restore database from a backup when encryption fails for some reason

* Removed unused code

* Safer way of doing some things

* Ordering

* Increased possible diff in time to 10 seconds

* update strings

* Alert confirmation

* update strings

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

apps/android/app/src/main/java/chat/simplex/app/SimplexApp.kt

@@ -53,6 +53,8 @@ class SimplexApp: Application(), LifecycleEventObserver {
     if (res.second != DBMigrationResult.OK) {
       Log.d(TAG, "Unable to migrate successfully: ${res.second}")
     } else if (startChat) {
+      // If we migrated successfully means previous re-encryption process on database level finished successfully too
+      if (appPreferences.encryptionStartedAt.get() != null) appPreferences.encryptionStartedAt.set(null)
       withApi {
         val user = chatController.apiGetActiveUser()
         if (user == null) {

apps/android/app/src/main/java/chat/simplex/app/model/SimpleXAPI.kt

@@ -110,6 +110,7 @@ class AppPreferences(val context: Context) {
   val initialRandomDBPassphrase = mkBoolPreference(SHARED_PREFS_INITIAL_RANDOM_DB_PASSPHRASE, false)
   val encryptedDBPassphrase = mkStrPreference(SHARED_PREFS_ENCRYPTED_DB_PASSPHRASE, null)
   val initializationVectorDBPassphrase = mkStrPreference(SHARED_PREFS_INITIALIZATION_VECTOR_DB_PASSPHRASE, null)
+  val encryptionStartedAt = mkDatePreference(SHARED_PREFS_ENCRYPTION_STARTED_AT, null, true)
 
   val currentTheme = mkStrPreference(SHARED_PREFS_CURRENT_THEME, DefaultTheme.SYSTEM.name)
   val primaryColor = mkIntPreference(SHARED_PREFS_PRIMARY_COLOR, LightColorPalette.primary.toArgb())
@@ -146,13 +147,19 @@ class AppPreferences(val context: Context) {
       set = fun(value) = sharedPreferences.edit().putString(prefName, value).apply()
     )
 
-  private fun mkDatePreference(prefName: String, default: Instant?): Preference<Instant?> =
+  /**
+  * Provide `[commit] = true` to save preferences right now, not after some unknown period of time.
+  * So in case of a crash this value will be saved 100%
+  * */
+  private fun mkDatePreference(prefName: String, default: Instant?, commit: Boolean = false): Preference<Instant?> =
     Preference(
       get = {
         val pref = sharedPreferences.getString(prefName, default?.toEpochMilliseconds()?.toString())
         pref?.let { Instant.fromEpochMilliseconds(pref.toLong()) }
       },
-      set = fun(value) = sharedPreferences.edit().putString(prefName, value?.toEpochMilliseconds()?.toString()).apply()
+      set = fun(value) = sharedPreferences.edit().putString(prefName, value?.toEpochMilliseconds()?.toString()).let {
+        if (commit) it.commit() else it.apply()
+      }
     )
 
   companion object {
@@ -189,6 +196,7 @@ class AppPreferences(val context: Context) {
     private const val SHARED_PREFS_INITIAL_RANDOM_DB_PASSPHRASE = "InitialRandomDBPassphrase"
     private const val SHARED_PREFS_ENCRYPTED_DB_PASSPHRASE = "EncryptedDBPassphrase"
     private const val SHARED_PREFS_INITIALIZATION_VECTOR_DB_PASSPHRASE = "InitializationVectorDBPassphrase"
+    private const val SHARED_PREFS_ENCRYPTION_STARTED_AT = "EncryptionStartedAt"
     private const val SHARED_PREFS_CURRENT_THEME = "CurrentTheme"
     private const val SHARED_PREFS_PRIMARY_COLOR = "PrimaryColor"
   }

apps/android/app/src/main/java/chat/simplex/app/views/database/DatabaseEncryptionView.kt

@@ -32,6 +32,7 @@ import chat.simplex.app.SimplexApp
 import chat.simplex.app.model.*
 import chat.simplex.app.ui.theme.*
 import chat.simplex.app.views.helpers.*
+import kotlinx.datetime.Clock
 import kotlin.math.log2
 
 @Composable
@@ -63,7 +64,9 @@ fun DatabaseEncryptionView(m: ChatModel) {
         progressIndicator.value = true
         withApi {
           try {
+            prefs.encryptionStartedAt.set(Clock.System.now())
             val error = m.controller.apiStorageEncryption(currentKey.value, newKey.value)
+            prefs.encryptionStartedAt.set(null)
             val sqliteError = ((error?.chatError as? ChatError.ChatErrorDatabase)?.databaseError as? DatabaseError.ErrorExport)?.sqliteError
             when {
               sqliteError is SQLiteError.ErrorNotADatabase -> {

apps/android/app/src/main/java/chat/simplex/app/views/database/DatabaseErrorView.kt

@@ -2,6 +2,7 @@ package chat.simplex.app.views.database
 
 import SectionSpacer
 import SectionView
+import android.content.Context
 import android.util.Log
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.rememberScrollState
@@ -11,6 +12,7 @@ import androidx.compose.material.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import chat.simplex.app.*
@@ -20,6 +22,11 @@ import chat.simplex.app.ui.theme.*
 import chat.simplex.app.views.helpers.*
 import chat.simplex.app.views.usersettings.NotificationsMode
 import kotlinx.coroutines.*
+import kotlinx.datetime.Clock
+import java.io.File
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
+import kotlin.io.path.Path
 
 @Composable
 fun DatabaseErrorView(
@@ -30,6 +37,8 @@ fun DatabaseErrorView(
   val dbKey = remember { mutableStateOf("") }
   var storedDBKey by remember { mutableStateOf(DatabaseUtils.getDatabaseKey()) }
   var useKeychain by remember { mutableStateOf(appPreferences.storeDBPassphrase.get()) }
+  val context = LocalContext.current
+  val restoreDbFromBackup = remember { mutableStateOf(shouldShowRestoreDbButton(appPreferences, context)) }
   val saveAndRunChatOnClick: () -> Unit = {
     DatabaseUtils.setDatabaseKey(dbKey.value)
     storedDBKey = dbKey.value
@@ -102,6 +111,20 @@ fun DatabaseErrorView(
           null -> {
           }
         }
+        if (restoreDbFromBackup.value) {
+          SectionSpacer()
+          Text(generalGetString(R.string.database_backup_can_be_restored))
+          Spacer(Modifier.size(16.dp))
+          RestoreDbButton {
+            AlertManager.shared.showAlertDialog(
+              title = generalGetString(R.string.restore_database_alert_title),
+              text = generalGetString(R.string.restore_database_alert_desc),
+              confirmText = generalGetString(R.string.restore_database_alert_confirm),
+              onConfirm = { restoreDb(restoreDbFromBackup, appPreferences, context) },
+              destructive = true,
+            )
+          }
+        }
       }
     }
   }
@@ -160,6 +183,31 @@ private fun runChat(
   }
 }
 
+private fun shouldShowRestoreDbButton(prefs: AppPreferences, context: Context): Boolean {
+  val startedAt = prefs.encryptionStartedAt.get() ?: return false
+  /** Just in case there is any small difference between reported Java's [Clock.System.now] and Linux's time on a file */
+  val safeDiffInTime = 10_000L
+  val filesChat = File(context.dataDir.absolutePath + File.separator + "files_chat.db.bak")
+  val filesAgent = File(context.dataDir.absolutePath + File.separator + "files_agent.db.bak")
+  return filesChat.exists() &&
+      filesAgent.exists() &&
+      startedAt.toEpochMilliseconds() - safeDiffInTime <= filesChat.lastModified() &&
+      startedAt.toEpochMilliseconds() - safeDiffInTime <= filesAgent.lastModified()
+}
+
+private fun restoreDb(restoreDbFromBackup: MutableState<Boolean>, prefs: AppPreferences, context: Context) {
+  val filesChatBase = context.dataDir.absolutePath + File.separator + "files_chat.db"
+  val filesAgentBase = context.dataDir.absolutePath + File.separator + "files_agent.db"
+  try {
+    Files.move(Path("$filesChatBase.bak"), Path(filesChatBase), StandardCopyOption.REPLACE_EXISTING)
+    Files.move(Path("$filesAgentBase.bak"), Path(filesAgentBase), StandardCopyOption.REPLACE_EXISTING)
+    restoreDbFromBackup.value = false
+    prefs.encryptionStartedAt.set(null)
+  } catch (e: Exception) {
+    AlertManager.shared.showAlertMsg(generalGetString(R.string.database_restore_error), e.stackTraceToString())
+  }
+}
+
 @Composable
 private fun DatabaseKeyField(text: MutableState<String>, enabled: Boolean, onClick: (() -> Unit)? = null) {
   DatabaseKeyField(
@@ -187,6 +235,13 @@ private fun ColumnScope.OpenChatButton(enabled: Boolean, onClick: () -> Unit) {
   }
 }
 
+@Composable
+private fun ColumnScope.RestoreDbButton(onClick: () -> Unit) {
+  TextButton(onClick, Modifier.align(Alignment.CenterHorizontally)) {
+    Text(generalGetString(R.string.restore_database), color = MaterialTheme.colors.error)
+  }
+}
+
 @Preview
 @Composable
 fun PreviewChatInfoLayout() {

apps/android/app/src/main/java/chat/simplex/app/views/helpers/DatabaseUtils.kt

@@ -18,7 +18,8 @@ object DatabaseUtils {
 
   private const val DATABASE_PASSWORD_ALIAS: String = "databasePassword"
 
-  fun hasDatabase(filesDirectory: String): Boolean = File(filesDirectory + File.separator + "files_chat.db").exists()
+  private fun hasDatabase(rootDir: String): Boolean =
+    File(rootDir + File.separator + "files_chat.db").exists() && File(rootDir + File.separator + "files_agent.db").exists()
 
   fun getDatabaseKey(): String? {
     return cryptor.decryptData(
@@ -42,21 +43,21 @@ object DatabaseUtils {
 
   fun migrateChatDatabase(useKey: String? = null): Pair<Boolean, DBMigrationResult> {
     Log.d(TAG, "migrateChatDatabase ${appPreferences.storeDBPassphrase.get()}")
-    val dbPath = getFilesDirectory(SimplexApp.context)
+    val dbAbsolutePathPrefix = getFilesDirectory(SimplexApp.context)
     var dbKey = ""
     val useKeychain = appPreferences.storeDBPassphrase.get()
     if (useKey != null) {
       dbKey = useKey
     } else if (useKeychain) {
-      if (!hasDatabase(dbPath)) {
+      if (!hasDatabase(SimplexApp.context.dataDir.absolutePath)) {
         dbKey = randomDatabasePassword()
         appPreferences.initialRandomDBPassphrase.set(true)
       } else {
         dbKey = getDatabaseKey() ?: ""
       }
     }
-    Log.d(TAG, "migrateChatDatabase DB path: $dbPath")
-    val migrated = chatMigrateDB(dbPath, dbKey)
+    Log.d(TAG, "migrateChatDatabase DB path: $dbAbsolutePathPrefix")
+    val migrated = chatMigrateDB(dbAbsolutePathPrefix, dbKey)
     val res: DBMigrationResult = kotlin.runCatching {
       json.decodeFromString<DBMigrationResult>(migrated)
     }.getOrElse { DBMigrationResult.Unknown(migrated) }

apps/android/app/src/main/res/values-ru/strings.xml

@@ -603,6 +603,12 @@
     <string name="enter_passphrase">Введите пароль…</string>
     <string name="save_passphrase_and_open_chat">Сохранить пароль и открыть чат</string>
     <string name="open_chat">Открыть чат</string>
+    <string name="database_backup_can_be_restored">Попытка поменять пароль базы данных не была завершена.</string>
+    <string name="restore_database">Восстановить резервную копию</string>
+    <string name="restore_database_alert_title">Восстановить резервную копию?</string>
+    <string name="restore_database_alert_desc">Введите предыдущий пароль после восстановления резервной копии. Это действие нельзя отменить.</string>
+    <string name="restore_database_alert_confirm">Восстановить</string>
+    <string name="database_restore_error">Ошибка при восстановлении базы данных</string>
 
     <!-- ChatModel.chatRunning interactions -->
     <string name="chat_is_stopped_indication">Чат остановлен</string>

apps/android/app/src/main/res/values/strings.xml

@@ -604,6 +604,12 @@
   <string name="enter_passphrase">Enter passphrase…</string>
   <string name="save_passphrase_and_open_chat">Save passphrase and open chat</string>
   <string name="open_chat">Open chat</string>
+  <string name="database_backup_can_be_restored">The attempt to change database passphrase was not completed.</string>
+  <string name="restore_database">Restore database backup</string>
+  <string name="restore_database_alert_title">Restore database backup?</string>
+  <string name="restore_database_alert_desc">Please enter the previous password after restoring database backup. This action can not be undone.</string>
+  <string name="restore_database_alert_confirm">Restore</string>
+  <string name="database_restore_error">Restore database error</string>
 
   <!-- ChatModel.chatRunning interactions -->
   <string name="chat_is_stopped_indication">Chat is stopped</string>