Merge pull request #111 from andOTP/google-backups

Allow auto backups to Google sync

app/src/main/AndroidManifest.xml

@@ -6,7 +6,9 @@
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
     <application
-        android:allowBackup="false"
+        android:allowBackup="true"
+        android:backupAgent=".Utilities.BackupAgent"
+        android:fullBackupOnly="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:supportsRtl="true"

app/src/main/java/org/shadowice/flocke/andotp/Activities/SettingsActivity.java

@@ -22,18 +22,26 @@
 
 package org.shadowice.flocke.andotp.Activities;
 
+import android.app.KeyguardManager;
+import android.app.backup.BackupManager;
+import android.app.backup.RestoreObserver;
 import android.app.AlertDialog;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
+import android.preference.CheckBoxPreference;
 import android.preference.ListPreference;
 import android.preference.Preference;
 import android.preference.PreferenceCategory;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceManager;
+import android.support.design.widget.Snackbar;
 import android.support.v7.widget.Toolbar;
+import android.util.Log;
+import android.view.View;
 import android.view.ViewStub;
+import android.widget.CheckBox;
 import android.widget.Toast;
 
 import org.openintents.openpgp.util.OpenPgpAppPreference;
@@ -114,10 +122,24 @@ public class SettingsActivity extends BaseActivity
     }
 
     public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
+        BackupManager backupManager = new BackupManager(this);
+        backupManager.dataChanged();
+
         if (key.equals(getString(R.string.settings_key_theme)) ||
                 key.equals(getString(R.string.settings_key_locale)) ||
                 key.equals(getString(R.string.settings_key_special_features))) {
             recreate();
+        }else if(key.equals(getString(R.string.settings_key_encryption))) {
+            if(settings.getEncryption() != EncryptionType.PASSWORD) {
+                boolean wasSyncEnabled = settings.getAndroidBackupServiceEnabled();
+                settings.setAndroidBackupServiceEnabled(false);
+
+                if(wasSyncEnabled) {
+                    UIHelper.showGenericDialog(this,
+                            R.string.settings_dialog_title_android_sync,
+                            R.string.settings_dialog_msg_android_sync_disabled_encryption);
+                }
+            }
         }
     }
 
@@ -207,7 +229,8 @@ public class SettingsActivity extends BaseActivity
         }
     }
 
-    public static class SettingsFragment extends PreferenceFragment {
+    public static class SettingsFragment extends PreferenceFragment
+            implements SharedPreferences.OnSharedPreferenceChangeListener{
         PreferenceCategory catSecurity;
 
         Settings settings;
@@ -216,6 +239,13 @@ public class SettingsActivity extends BaseActivity
         OpenPgpAppPreference pgpProvider;
         OpenPgpKeyPreference pgpKey;
 
+        public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
+            CheckBoxPreference useAndroidSync = (CheckBoxPreference) findPreference(getString(R.string.settings_key_enable_android_backup_service));
+            useAndroidSync.setEnabled(settings.getEncryption() == EncryptionType.PASSWORD);
+            if(!useAndroidSync.isEnabled())
+                useAndroidSync.setChecked(false);
+        }
+
         @Override
         public void onCreate(Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
@@ -223,6 +253,7 @@ public class SettingsActivity extends BaseActivity
             settings = new Settings(getActivity());
 
             final SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getActivity().getBaseContext());
+            sharedPref.registerOnSharedPreferenceChangeListener(this);
             addPreferencesFromResource(R.xml.preferences);
 
             CredentialsPreference credentialsPreference = (CredentialsPreference) findPreference(getString(R.string.settings_key_auth));
@@ -278,6 +309,8 @@ public class SettingsActivity extends BaseActivity
             });
             pgpKey.setDefaultUserId("Alice <alice@example.com>");
 
+            CheckBoxPreference useAndroidSync = (CheckBoxPreference) findPreference(getString(R.string.settings_key_enable_android_backup_service));
+            useAndroidSync.setEnabled(settings.getEncryption() == EncryptionType.PASSWORD);
 
             if (sharedPref.contains(getString(R.string.settings_key_special_features)) &&
                     sharedPref.getBoolean(getString(R.string.settings_key_special_features), false)) {

app/src/main/java/org/shadowice/flocke/andotp/Utilities/BackupAgent.java

@@ -0,0 +1,49 @@
+package org.shadowice.flocke.andotp.Utilities;
+
+import android.app.backup.BackupAgentHelper;
+import android.app.backup.BackupDataInput;
+import android.app.backup.BackupDataOutput;
+import android.app.backup.FileBackupHelper;
+import android.app.backup.SharedPreferencesBackupHelper;
+import android.os.ParcelFileDescriptor;
+
+import java.io.IOException;
+
+public class BackupAgent extends BackupAgentHelper {
+    static final String PREFS_BACKUP_KEY = "prefs";
+    static final String FILES_BACKUP_KEY = "files";
+
+    // PreferenceManager.getDefaultSharedPreferencesName is only available in API > 24, this is its implementation
+    String getDefaultSharedPreferencesName() {
+        return getPackageName() + "_preferences";
+    }
+
+    @Override
+    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data, ParcelFileDescriptor newState) throws IOException {
+        Settings settings = new Settings(this);
+
+        if(settings.getAndroidBackupServiceEnabled()) {
+            synchronized (DatabaseHelper.DatabaseFileLock) {
+                super.onBackup(oldState, data, newState);
+            }
+        }
+    }
+
+    @Override
+    public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState) throws IOException {
+        synchronized (DatabaseHelper.DatabaseFileLock) {
+            super.onRestore(data, appVersionCode, newState);
+        }
+    }
+
+    @Override
+    public void onCreate() {
+        String prefs = getDefaultSharedPreferencesName();
+
+        SharedPreferencesBackupHelper sharedPreferencesBackupHelper = new SharedPreferencesBackupHelper(this, prefs);
+        addHelper(PREFS_BACKUP_KEY, sharedPreferencesBackupHelper);
+
+        FileBackupHelper fileBackupHelper = new FileBackupHelper(this, Constants.FILENAME_DATABASE, Constants.FILENAME_DATABASE_BACKUP);
+        addHelper(FILES_BACKUP_KEY, fileBackupHelper);
+    }
+}

app/src/main/java/org/shadowice/flocke/andotp/Utilities/DatabaseHelper.java

@@ -23,6 +23,7 @@
 
 package org.shadowice.flocke.andotp.Utilities;
 
+import android.app.backup.BackupManager;
 import android.content.Context;
 import android.widget.Toast;
 
@@ -42,6 +43,8 @@ import javax.crypto.SecretKey;
 
 public class DatabaseHelper {
 
+    static final Object DatabaseFileLock = new Object();
+
     public static void wipeDatabase(Context context) {
         File db = new File(context.getFilesDir() + "/" + Constants.FILENAME_DATABASE);
         File dbBackup = new File(context.getFilesDir() + "/" + Constants.FILENAME_DATABASE_BACKUP);
@@ -102,15 +105,19 @@ public class DatabaseHelper {
         String jsonString = entriesToString(entries);
 
         try {
+            synchronized (DatabaseHelper.DatabaseFileLock) {
                 byte[] data = EncryptionHelper.encrypt(encryptionKey, jsonString.getBytes());
 
                 FileHelper.writeBytesToFile(new File(context.getFilesDir() + "/" + Constants.FILENAME_DATABASE), data);
-
+            }
         } catch (Exception error) {
             error.printStackTrace();
             return false;
         }
 
+        BackupManager backupManager = new BackupManager(context);
+        backupManager.dataChanged();
+
         return true;
     }
 
@@ -119,10 +126,12 @@ public class DatabaseHelper {
 
         if (encryptionKey != null) {
             try {
+                synchronized (DatabaseHelper.DatabaseFileLock) {
                     byte[] data = FileHelper.readFileToBytes(new File(context.getFilesDir() + "/" + Constants.FILENAME_DATABASE));
                     data = EncryptionHelper.decrypt(encryptionKey, data);
 
                     entries = stringToEntries(new String(data));
+                }
             } catch (Exception error) {
                 error.printStackTrace();
             }

app/src/main/java/org/shadowice/flocke/andotp/Utilities/Settings.java

@@ -469,6 +469,14 @@ public class Settings {
         setBoolean(R.string.settings_key_last_used_dialog_shown, value);
     }
 
+    public boolean getAndroidBackupServiceEnabled() {
+        return getBoolean(R.string.settings_key_enable_android_backup_service, false);
+    }
+
+    public void setAndroidBackupServiceEnabled(boolean value) {
+        setBoolean(R.string.settings_key_enable_android_backup_service, value);
+	}
+
     public boolean getIsAppendingDateTimeToBackups() {
         return getBoolean(R.string.settings_key_backup_append_date_time, false);
     }

app/src/main/res/values/settings.xml

@@ -43,6 +43,7 @@
     <string name="settings_key_tags_toggles" translatable="false">pref_tags_toggles</string>
 
     <string name="settings_key_enable_screenshot" translatable="false">pref_enable_screenshot</string>
+    <string name="settings_key_enable_android_backup_service" translatable="false">pref_enable_android_backup_service</string>
     <string name="settings_key_clear_keystore" translatable="false">pref_clear_keystore</string>
 
     <string name="settings_key_last_used_dialog_shown" translatable="false">pref_last_used_dialog_shown</string>

app/src/main/res/values/strings_settings.xml

@@ -35,6 +35,7 @@
 
     <string name="settings_title_special_features">Enable special features</string>
     <string name="settings_title_enable_screenshot">Enable screenshots</string>
+    <string name="settings_title_enable_android_backup_service">Enable android sync</string>
     <string name="settings_title_clear_keystore">Clear KeyStore</string>
 
     <!-- Descriptions -->
@@ -64,6 +65,8 @@
     <string name="settings_desc_special_features">Uncheck to disable the special features again</string>
     <string name="settings_desc_enable_screenshot">Allow to take screenshots of the main screen
         (disabled by default for security reasons)</string>
+    <string name="settings_desc_enable_android_backup_service">Enables andOTP to use android\'s
+        built in backup service to bacup keys and preferences</string>
     <string name="settings_desc_clear_keystore">Delete the encryption key from the KeyStore</string>
 
     <!-- Toasts -->
@@ -91,6 +94,7 @@
 
     <string name="settings_dialog_title_error">Error</string>
     <string name="settings_dialog_title_clear_keystore">Clear the KeyStore?</string>
+    <string name="settings_dialog_title_android_sync">Android sync</string>
 
     <string name="settings_dialog_msg_auth_invalid_with_encryption">You can only use Password or PIN as
         long as the database encryption is set to \"Password / PIN\"!</string>
@@ -110,6 +114,9 @@
         your accounts. Make sure you have a backup!\n\n<b>Are you really sure you want to clear the
         KeyStore?</b></string>
 
+    <string name="settings_dialog_msg_android_sync_disabled_encryption">Android sync can not be used with keystore
+        encryption, <b>you should perform a manual backup!</b></string>
+
     <!-- List entries -->
     <string-array name="settings_entries_auth">
         <item>None</item>

app/src/main/res/xml/preferences.xml

@@ -104,6 +104,12 @@
     <PreferenceCategory
         android:title="@string/settings_category_title_backup">
 
+		<CheckBoxPreference
+            android:key="@string/settings_key_enable_android_backup_service"
+            android:title="@string/settings_title_enable_android_backup_service"
+            android:summary="@string/settings_desc_enable_android_backup_service"
+            android:defaultValue="false" />
+
         <CheckBoxPreference
             android:key="@string/settings_key_backup_append_date_time"
             android:title="@string/settings_title_backup_append_date"