Merge pull request #17 from stevesoltys/feature/encryption

Add support for encrypted backups

app/src/main/java/com/stevesoltys/backup/activity/PackageListActivity.java

@@ -0,0 +1,50 @@
+package com.stevesoltys.backup.activity;
+
+import android.app.Activity;
+import android.view.MenuItem;
+import android.view.View;
+import android.widget.AdapterView;
+import android.widget.ListView;
+import com.stevesoltys.backup.R;
+
+import java.util.Set;
+import java.util.stream.IntStream;
+
+/**
+ * @author Steve Soltys
+ */
+public abstract class PackageListActivity extends Activity implements AdapterView.OnItemClickListener {
+
+    protected ListView packageListView;
+
+    protected Set<String> selectedPackageList;
+
+    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+        String clickedPackage = (String) packageListView.getItemAtPosition(position);
+
+        if (!selectedPackageList.remove(clickedPackage)) {
+            selectedPackageList.add(clickedPackage);
+            packageListView.setItemChecked(position, true);
+
+        } else {
+            packageListView.setItemChecked(position, false);
+        }
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+
+        if (item.getItemId() == R.id.action_select_all) {
+
+            IntStream.range(0, packageListView.getCount())
+                    .forEach(position -> {
+                        selectedPackageList.add((String) packageListView.getItemAtPosition(position));
+                        packageListView.setItemChecked(position, true);
+                    });
+
+            return true;
+        }
+
+        return super.onOptionsItemSelected(item);
+    }
+}

app/src/main/java/com/stevesoltys/backup/activity/PopupWindowUtil.java

@@ -0,0 +1,32 @@
+package com.stevesoltys.backup.activity;
+
+import android.app.Activity;
+import android.content.Context;
+import android.graphics.Color;
+import android.graphics.drawable.ColorDrawable;
+import android.view.Gravity;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.PopupWindow;
+import com.stevesoltys.backup.R;
+
+/**
+ * @author Steve Soltys
+ */
+public class PopupWindowUtil {
+
+    public static PopupWindow showLoadingPopupWindow(Activity parent) {
+        LayoutInflater inflater = (LayoutInflater) parent.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+        ViewGroup popupViewGroup = parent.findViewById(R.id.popup_layout);
+        View popupView = inflater.inflate(R.layout.progress_popup_window, popupViewGroup);
+
+        PopupWindow popupWindow = new PopupWindow(popupView, 750, 350, true);
+        popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
+        popupWindow.setElevation(10);
+        popupWindow.setFocusable(false);
+        popupWindow.showAtLocation(popupView, Gravity.CENTER, 0, 0);
+        popupWindow.setOutsideTouchable(false);
+        return popupWindow;
+    }
+}

app/src/main/java/com/stevesoltys/backup/activity/backup/BackupPopupWindowListener.java

@@ -4,7 +4,6 @@ import android.os.RemoteException;
 import android.util.Log;
 import android.view.View;
 import android.widget.Button;
-
 import com.stevesoltys.backup.R;
 import com.stevesoltys.backup.session.backup.BackupResult;
 import com.stevesoltys.backup.session.backup.BackupSession;
@@ -12,7 +11,7 @@ import com.stevesoltys.backup.session.backup.BackupSession;
 /**
  * @author Steve Soltys
  */
-class BackupPopupWindowListener implements Button.OnClickListener {
+public class BackupPopupWindowListener implements Button.OnClickListener {
 
     private static final String TAG = BackupPopupWindowListener.class.getName();
 
@@ -26,16 +25,13 @@ class BackupPopupWindowListener implements Button.OnClickListener {
     public void onClick(View view) {
         int viewId = view.getId();
 
-        switch (viewId) {
+        if (viewId == R.id.popup_cancel_button) {
+            try {
+                backupSession.stop(BackupResult.CANCELLED);
 
-            case R.id.popup_cancel_button:
+            } catch (RemoteException e) {
-                try {
+                Log.e(TAG, "Error cancelling backup session: ", e);
-                    backupSession.stop(BackupResult.CANCELLED);
+            }
-
-                } catch (RemoteException e) {
-                    Log.e(TAG, "Error cancelling backup session: ", e);
-                }
-                break;
         }
     }
 }

app/src/main/java/com/stevesoltys/backup/activity/backup/CreateBackupActivity.java

@@ -1,39 +1,28 @@
 package com.stevesoltys.backup.activity.backup;
 
-import android.app.Activity;
 import android.net.Uri;
+import android.os.AsyncTask;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuInflater;
-import android.view.MenuItem;
 import android.view.View;
-import android.widget.AdapterView;
-import android.widget.ListView;
 import com.stevesoltys.backup.R;
+import com.stevesoltys.backup.activity.PackageListActivity;
 
 import java.util.HashSet;
-import java.util.Set;
-import java.util.stream.IntStream;
 
-public class CreateBackupActivity extends Activity implements View.OnClickListener, AdapterView.OnItemClickListener {
+public class CreateBackupActivity extends PackageListActivity implements View.OnClickListener {
 
     private CreateBackupActivityController controller;
 
-    private ListView packageListView;
-
-    private Set<String> selectedPackageList;
-
     private Uri contentUri;
 
     @Override
     public void onClick(View view) {
         int viewId = view.getId();
 
-        switch (viewId) {
+        if (viewId == R.id.create_confirm_button) {
-
+            controller.showEnterPasswordAlert(selectedPackageList, contentUri, this);
-            case R.id.create_confirm_button:
-                controller.backupPackages(selectedPackageList, contentUri, this);
-                break;
         }
     }
 
@@ -49,7 +38,7 @@ public class CreateBackupActivity extends Activity implements View.OnClickListen
         contentUri = getIntent().getData();
 
         controller = new CreateBackupActivityController();
-        controller.populatePackageList(packageListView, this);
+        AsyncTask.execute(() -> controller.populatePackageList(packageListView, CreateBackupActivity.this));
     }
 
     @Override
@@ -58,38 +47,4 @@ public class CreateBackupActivity extends Activity implements View.OnClickListen
         inflater.inflate(R.menu.backup_menu, menu);
         return true;
     }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-
-        switch (item.getItemId()) {
-
-            case R.id.action_select_all:
-
-                IntStream.range(0, packageListView.getCount())
-                        .forEach(position -> {
-                            selectedPackageList.add((String) packageListView.getItemAtPosition(position));
-                            packageListView.setItemChecked(position, true);
-                        });
-
-                return true;
-
-            default:
-                return super.onOptionsItemSelected(item);
-
-        }
-    }
-
-    @Override
-    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-        String clickedPackage = (String) packageListView.getItemAtPosition(position);
-
-        if (!selectedPackageList.remove(clickedPackage)) {
-            selectedPackageList.add(clickedPackage);
-            packageListView.setItemChecked(position, true);
-
-        } else {
-            packageListView.setItemChecked(position, false);
-        }
-    }
 }

app/src/main/java/com/stevesoltys/backup/activity/backup/CreateBackupActivityController.java

@@ -1,33 +1,23 @@
 package com.stevesoltys.backup.activity.backup;
 
 import android.app.Activity;
-import android.content.Context;
+import android.app.AlertDialog;
-import android.graphics.Color;
-import android.graphics.drawable.ColorDrawable;
 import android.net.Uri;
 import android.os.RemoteException;
+import android.text.InputType;
 import android.util.Log;
-import android.view.Gravity;
-import android.view.LayoutInflater;
 import android.view.View;
-import android.view.ViewGroup;
+import android.widget.*;
-import android.widget.ArrayAdapter;
+import com.google.android.collect.Sets;
-import android.widget.ListView;
-import android.widget.PopupWindow;
-import android.widget.Toast;
 import com.stevesoltys.backup.R;
-import com.stevesoltys.backup.session.BackupManagerController;
+import com.stevesoltys.backup.activity.PopupWindowUtil;
-import com.stevesoltys.backup.session.backup.BackupSession;
+import com.stevesoltys.backup.service.backup.BackupService;
-import com.stevesoltys.backup.transport.ConfigurableBackupTransport;
+import com.stevesoltys.backup.service.PackageService;
-import com.stevesoltys.backup.transport.ConfigurableBackupTransportService;
-import com.stevesoltys.backup.transport.component.BackupComponent;
-import com.stevesoltys.backup.transport.component.RestoreComponent;
-import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupComponent;
-import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfiguration;
-import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfigurationBuilder;
-import com.stevesoltys.backup.transport.component.provider.ContentProviderRestoreComponent;
 
-import java.util.*;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * @author Steve Soltys
@@ -36,82 +26,91 @@ class CreateBackupActivityController {
 
     private static final String TAG = CreateBackupActivityController.class.getName();
 
-    private static final Set<String> IGNORED_PACKAGES = Collections.singleton("com.android.providers.downloads.ui");
+    private static final Set<String> IGNORED_PACKAGES = Sets.newArraySet(
+            "com.android.providers.downloads.ui", "com.android.providers.downloads", "com.android.providers.media",
+            "com.stevesoltys.backup"
+    );
 
-    private final BackupManagerController backupManager;
+    private final BackupService backupService = new BackupService();
 
-    CreateBackupActivityController() {
+    private final PackageService packageService = new PackageService();
-        backupManager = new BackupManagerController();
-    }
 
     void populatePackageList(ListView packageListView, CreateBackupActivity parent) {
+        AtomicReference<PopupWindow> popupWindow = new AtomicReference<>();
+
+        parent.runOnUiThread(() -> {
+            popupWindow.set(PopupWindowUtil.showLoadingPopupWindow(parent));
+            TextView textView = popupWindow.get().getContentView().findViewById(R.id.popup_text_view);
+            textView.setText(R.string.loading_packages);
+
+            View popupWindowButton = popupWindow.get().getContentView().findViewById(R.id.popup_cancel_button);
+            popupWindowButton.setOnClickListener(view -> parent.finish());
+        });
+
         List<String> eligiblePackageList = new LinkedList<>();
 
         try {
-            eligiblePackageList.addAll(backupManager.getEligiblePackages());
+            eligiblePackageList.addAll(packageService.getEligiblePackages());
             eligiblePackageList.removeAll(IGNORED_PACKAGES);
 
         } catch (RemoteException e) {
             Log.e(TAG, "Error while obtaining package list: ", e);
         }
 
-
+        parent.runOnUiThread(() -> {
-        packageListView.setOnItemClickListener(parent);
+            if (popupWindow.get() != null) {
-        packageListView.setAdapter(new ArrayAdapter<>(parent, R.layout.checked_list_item, eligiblePackageList));
+                popupWindow.get().dismiss();
-        packageListView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
-    }
-
-    void backupPackages(Set<String> selectedPackages, Uri contentUri, Activity parent) {
-        try {
-            selectedPackages.add("@pm@");
-
-            ContentProviderBackupConfiguration backupConfiguration = new ContentProviderBackupConfigurationBuilder()
-                    .setContext(parent).setOutputUri(contentUri).setPackages(selectedPackages).build();
-            boolean success = initializeBackupTransport(backupConfiguration);
-
-            if (!success) {
-                Toast.makeText(parent, R.string.backup_in_progress, Toast.LENGTH_LONG).show();
-                return;
             }
 
-            PopupWindow popupWindow = buildPopupWindow(parent);
+            packageListView.setOnItemClickListener(parent);
-            BackupObserver backupObserver = new BackupObserver(parent, popupWindow);
+            packageListView.setAdapter(new ArrayAdapter<>(parent, R.layout.checked_list_item, eligiblePackageList));
-            BackupSession backupSession = backupManager.backup(backupObserver, selectedPackages);
+            packageListView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
-
+        });
-            View popupWindowButton = popupWindow.getContentView().findViewById(R.id.popup_cancel_button);
-
-            if (popupWindowButton != null) {
-                popupWindowButton.setOnClickListener(new BackupPopupWindowListener(backupSession));
-            }
-
-        } catch (Exception e) {
-            Log.e(TAG, "Error while running backup: ", e);
-        }
     }
 
-    private boolean initializeBackupTransport(ContentProviderBackupConfiguration configuration) {
+    void showEnterPasswordAlert(Set<String> selectedPackages, Uri contentUri, Activity parent) {
-        ConfigurableBackupTransport backupTransport = ConfigurableBackupTransportService.getBackupTransport();
+        final EditText passwordTextView = new EditText(parent);
+        passwordTextView.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
 
-        if (backupTransport.isActive()) {
+        new AlertDialog.Builder(parent)
-            return false;
+                .setTitle("Enter a password")
-        }
+                .setMessage("You'll need this to restore your backup, so write it down!")
+                .setView(passwordTextView)
 
-        BackupComponent backupComponent = new ContentProviderBackupComponent(configuration);
+                .setPositiveButton("Set password", (dialog, button) ->
-        RestoreComponent restoreComponent = new ContentProviderRestoreComponent(configuration);
+                        showConfirmPasswordAlert(selectedPackages, contentUri, parent,
-        backupTransport.initialize(backupComponent, restoreComponent);
+                                passwordTextView.getText().toString()))
-        return true;
+
+                .setNegativeButton("Cancel", (dialog, button) -> dialog.cancel())
+                .show();
     }
 
-    private PopupWindow buildPopupWindow(Activity parent) {
+    private void showConfirmPasswordAlert(Set<String> selectedPackages, Uri contentUri, Activity parent,
-        LayoutInflater inflater = (LayoutInflater) parent.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+                                          String originalPassword) {
-        ViewGroup popupViewGroup = parent.findViewById(R.id.popup_layout);
+        final EditText passwordTextView = new EditText(parent);
-        View popupView = inflater.inflate(R.layout.progress_popup_window, popupViewGroup);
+        passwordTextView.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
 
-        PopupWindow popupWindow = new PopupWindow(popupView, 750, 350, true);
+        new AlertDialog.Builder(parent)
-        popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
+                .setTitle("Confirm password")
-        popupWindow.setElevation(10);
+                .setView(passwordTextView)
-        popupWindow.setFocusable(false);
+
-        popupWindow.showAtLocation(popupView, Gravity.CENTER, 0, 0);
+                .setPositiveButton("Confirm", (dialog, button) -> {
-        return popupWindow;
+                    String password = passwordTextView.getText().toString();
+
+                    if (originalPassword.equals(password)) {
+                        backupService.backupPackageData(selectedPackages, contentUri, parent, password);
+
+                    } else {
+                        new AlertDialog.Builder(parent)
+                                .setMessage("Passwords do not match, please try again.")
+                                .setPositiveButton("Ok", (dialog2, button2) -> dialog2.dismiss())
+                                .show();
+
+                        dialog.cancel();
+                    }
+                })
+
+                .setNegativeButton("Cancel", (dialog, button) -> dialog.cancel())
+                .show();
     }
 }

app/src/main/java/com/stevesoltys/backup/activity/restore/RestoreBackupActivity.java

@@ -1,39 +1,28 @@
 package com.stevesoltys.backup.activity.restore;
 
-import android.app.Activity;
 import android.net.Uri;
+import android.os.AsyncTask;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuInflater;
-import android.view.MenuItem;
 import android.view.View;
-import android.widget.AdapterView;
-import android.widget.ListView;
 import com.stevesoltys.backup.R;
+import com.stevesoltys.backup.activity.PackageListActivity;
 
 import java.util.HashSet;
-import java.util.Set;
-import java.util.stream.IntStream;
 
-public class RestoreBackupActivity extends Activity implements View.OnClickListener, AdapterView.OnItemClickListener {
+public class RestoreBackupActivity extends PackageListActivity implements View.OnClickListener {
 
     private RestoreBackupActivityController controller;
 
-    private ListView packageListView;
-
-    private Set<String> selectedPackageList;
-
     private Uri contentUri;
 
     @Override
     public void onClick(View view) {
         int viewId = view.getId();
 
-        switch (viewId) {
+        if (viewId == R.id.restore_confirm_button) {
-
+            controller.showEnterPasswordAlert(selectedPackageList, contentUri, this);
-            case R.id.restore_confirm_button:
-                controller.restorePackages(selectedPackageList, contentUri, this);
-                break;
         }
     }
 
@@ -49,7 +38,7 @@ public class RestoreBackupActivity extends Activity implements View.OnClickListe
         contentUri = getIntent().getData();
 
         controller = new RestoreBackupActivityController();
-        controller.populatePackageList(packageListView, contentUri, this);
+        AsyncTask.execute(() -> controller.populatePackageList(packageListView, contentUri, this));
     }
 
     @Override
@@ -58,38 +47,4 @@ public class RestoreBackupActivity extends Activity implements View.OnClickListe
         inflater.inflate(R.menu.backup_menu, menu);
         return true;
     }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-
-        switch (item.getItemId()) {
-
-            case R.id.action_select_all:
-
-                IntStream.range(0, packageListView.getCount())
-                        .forEach(position -> {
-                            selectedPackageList.add((String) packageListView.getItemAtPosition(position));
-                            packageListView.setItemChecked(position, true);
-                        });
-
-                return true;
-
-            default:
-                return super.onOptionsItemSelected(item);
-
-        }
-    }
-
-    @Override
-    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-        String clickedPackage = (String) packageListView.getItemAtPosition(position);
-
-        if (!selectedPackageList.remove(clickedPackage)) {
-            selectedPackageList.add(clickedPackage);
-            packageListView.setItemChecked(position, true);
-
-        } else {
-            packageListView.setItemChecked(position, false);
-        }
-    }
 }

app/src/main/java/com/stevesoltys/backup/activity/restore/RestoreBackupActivityController.java

@@ -1,32 +1,17 @@
 package com.stevesoltys.backup.activity.restore;
 
 import android.app.Activity;
-import android.content.Context;
+import android.app.AlertDialog;
-import android.graphics.Color;
-import android.graphics.drawable.ColorDrawable;
 import android.net.Uri;
 import android.os.ParcelFileDescriptor;
-import android.os.RemoteException;
+import android.text.InputType;
 import android.util.Log;
-import android.view.Gravity;
-import android.view.LayoutInflater;
 import android.view.View;
-import android.view.ViewGroup;
+import android.widget.*;
-import android.widget.ArrayAdapter;
-import android.widget.ListView;
-import android.widget.PopupWindow;
-import android.widget.Toast;
 import com.stevesoltys.backup.R;
-import com.stevesoltys.backup.session.BackupManagerController;
+import com.stevesoltys.backup.activity.PopupWindowUtil;
-import com.stevesoltys.backup.session.restore.RestoreSession;
+import com.stevesoltys.backup.service.restore.RestoreService;
-import com.stevesoltys.backup.transport.ConfigurableBackupTransport;
-import com.stevesoltys.backup.transport.ConfigurableBackupTransportService;
-import com.stevesoltys.backup.transport.component.BackupComponent;
-import com.stevesoltys.backup.transport.component.RestoreComponent;
-import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfiguration;
 import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfigurationBuilder;
-import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupComponent;
-import com.stevesoltys.backup.transport.component.provider.ContentProviderRestoreComponent;
 import libcore.io.IoUtils;
 
 import java.io.File;
@@ -35,6 +20,7 @@ import java.io.IOException;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
@@ -45,14 +31,22 @@ class RestoreBackupActivityController {
 
     private static final String TAG = RestoreBackupActivityController.class.getName();
 
-    private final BackupManagerController backupManager;
+    private final RestoreService restoreService = new RestoreService();
-
-    RestoreBackupActivityController() {
-        backupManager = new BackupManagerController();
-    }
 
     void populatePackageList(ListView packageListView, Uri contentUri, RestoreBackupActivity parent) {
+        AtomicReference<PopupWindow> popupWindow = new AtomicReference<>();
+
+        parent.runOnUiThread(() -> {
+            popupWindow.set(PopupWindowUtil.showLoadingPopupWindow(parent));
+            TextView textView = popupWindow.get().getContentView().findViewById(R.id.popup_text_view);
+            textView.setText(R.string.loading_backup);
+
+            View popupWindowButton = popupWindow.get().getContentView().findViewById(R.id.popup_cancel_button);
+            popupWindowButton.setOnClickListener(view -> parent.finish());
+        });
+
         List<String> eligiblePackageList = new LinkedList<>();
+
         try {
             eligiblePackageList.addAll(getEligiblePackages(contentUri, parent));
 
@@ -60,9 +54,15 @@ class RestoreBackupActivityController {
             Log.e(TAG, "Error while obtaining package list: ", e);
         }
 
-        packageListView.setOnItemClickListener(parent);
+        parent.runOnUiThread(() -> {
-        packageListView.setAdapter(new ArrayAdapter<>(parent, R.layout.checked_list_item, eligiblePackageList));
+            if (popupWindow.get() != null) {
-        packageListView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
+                popupWindow.get().dismiss();
+            }
+
+            packageListView.setOnItemClickListener(parent);
+            packageListView.setAdapter(new ArrayAdapter<>(parent, R.layout.checked_list_item, eligiblePackageList));
+            packageListView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
+        });
     }
 
     private List<String> getEligiblePackages(Uri contentUri, Activity context) throws IOException {
@@ -89,53 +89,20 @@ class RestoreBackupActivityController {
         return results;
     }
 
-    void restorePackages(Set<String> selectedPackages, Uri contentUri, Activity parent) {
+    void showEnterPasswordAlert(Set<String> selectedPackages, Uri contentUri, Activity parent) {
-        try {
+        final EditText passwordTextView = new EditText(parent);
-            ContentProviderBackupConfiguration backupConfiguration = new ContentProviderBackupConfigurationBuilder().
+        passwordTextView.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
-                    setContext(parent).setOutputUri(contentUri).setPackages(selectedPackages).build();
-            boolean success = initializeBackupTransport(backupConfiguration);
 
-            if(!success) {
+        new AlertDialog.Builder(parent)
-                Toast.makeText(parent, R.string.restore_in_progress, Toast.LENGTH_LONG).show();
+                .setTitle("Enter a password")
-                return;
+                .setMessage("If you didn't enter one while creating the backup, you can leave this blank.")
-            }
+                .setView(passwordTextView)
 
-            PopupWindow popupWindow = buildPopupWindow(parent);
+                .setPositiveButton("Confirm", (dialog, button) ->
-            RestoreObserver restoreObserver = new RestoreObserver(parent, popupWindow, selectedPackages.size());
+                        restoreService.restorePackages(selectedPackages, contentUri, parent,
-            RestoreSession restoreSession = backupManager.restore(restoreObserver, selectedPackages);
+                                passwordTextView.getText().toString()))
 
-            View popupWindowButton = popupWindow.getContentView().findViewById(R.id.popup_cancel_button);
+                .setNegativeButton("Cancel", (dialog, button) -> dialog.cancel())
-            if (popupWindowButton != null) {
+                .show();
-                popupWindowButton.setOnClickListener(new RestorePopupWindowListener(restoreSession));
-            }
-        } catch (RemoteException e) {
-            Log.e(TAG, "Error while running restore: ", e);
-        }
-    }
-
-    private boolean initializeBackupTransport(ContentProviderBackupConfiguration configuration) {
-        ConfigurableBackupTransport backupTransport = ConfigurableBackupTransportService.getBackupTransport();
-
-        if(backupTransport.isActive()) {
-            return false;
-        }
-
-        BackupComponent backupComponent = new ContentProviderBackupComponent(configuration);
-        RestoreComponent restoreComponent = new ContentProviderRestoreComponent(configuration);
-        backupTransport.initialize(backupComponent, restoreComponent);
-        return true;
-    }
-
-    private PopupWindow buildPopupWindow(Activity parent) {
-        LayoutInflater inflater = (LayoutInflater) parent.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
-        ViewGroup popupViewGroup = parent.findViewById(R.id.popup_layout);
-        View popupView = inflater.inflate(R.layout.progress_popup_window, popupViewGroup);
-
-        PopupWindow popupWindow = new PopupWindow(popupView, 750, 350, true);
-        popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
-        popupWindow.setElevation(10);
-        popupWindow.setFocusable(false);
-        popupWindow.showAtLocation(popupView, Gravity.CENTER, 0, 0);
-        return popupWindow;
     }
 }

app/src/main/java/com/stevesoltys/backup/activity/restore/RestorePopupWindowListener.java

@@ -12,13 +12,13 @@ import com.stevesoltys.backup.session.restore.RestoreSession;
 /**
  * @author Steve Soltys
  */
-class RestorePopupWindowListener implements Button.OnClickListener {
+public class RestorePopupWindowListener implements Button.OnClickListener {
 
     private static final String TAG = RestorePopupWindowListener.class.getName();
 
     private final RestoreSession restoreSession;
 
-    RestorePopupWindowListener(RestoreSession restoreSession) {
+    public RestorePopupWindowListener(RestoreSession restoreSession) {
         this.restoreSession = restoreSession;
     }
 

app/src/main/java/com/stevesoltys/backup/security/CipherUtil.java

@@ -0,0 +1,52 @@
+package com.stevesoltys.backup.security;
+
+import javax.crypto.*;
+import javax.crypto.spec.IvParameterSpec;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+/**
+ * A utility class for encrypting and decrypting data using a {@link Cipher}.
+ *
+ * @author Steve Soltys
+ */
+public class CipherUtil {
+
+    /**
+     * The cipher algorithm.
+     */
+    public static final String CIPHER_ALGORITHM = "AES/CFB/PKCS5Padding";
+
+    /**.
+     * Encrypts the given payload using the provided secret key.
+     *
+     * @param payload  The payload.
+     * @param secretKey The secret key.
+     * @param iv        The initialization vector.
+     */
+    public static byte[] encrypt(byte[] payload, SecretKey secretKey, byte[] iv) throws NoSuchPaddingException,
+            NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException,
+            InvalidAlgorithmParameterException, InvalidKeyException {
+
+        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
+        cipher.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(iv));
+        return cipher.doFinal(payload);
+    }
+
+    /**
+     * Decrypts the given payload using the provided secret key.
+     *
+     * @param payload   The payload.
+     * @param secretKey The secret key.
+     * @param iv        The initialization vector.
+     */
+    public static byte[] decrypt(byte[] payload, SecretKey secretKey, byte[] iv) throws NoSuchPaddingException,
+            NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException,
+            InvalidAlgorithmParameterException, InvalidKeyException {
+
+        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
+        cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(iv));
+        return cipher.doFinal(payload);
+    }
+}

app/src/main/java/com/stevesoltys/backup/security/KeyGenerator.java

@@ -0,0 +1,44 @@
+package com.stevesoltys.backup.security;
+
+import javax.crypto.SecretKey;
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+import javax.crypto.spec.SecretKeySpec;
+import java.security.NoSuchAlgorithmException;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
+
+/**
+ * A utility class which can be used for generating an AES secret key using PBKDF2.
+ *
+ * @author Steve Soltys
+ */
+public class KeyGenerator {
+
+    /**
+     * The number of iterations for key generation.
+     */
+    private static final int ITERATIONS = 25;
+
+    /**
+     * The generated key length.
+     */
+    private static final int KEY_LENGTH = 256;
+
+    /**
+     * Generates an AES secret key using PBKDF2.
+     *
+     * @param password The password.
+     * @param salt     The salt.
+     * @return The generated key.
+     */
+    public static SecretKey generate(String password, byte[] salt)
+            throws NoSuchAlgorithmException, InvalidKeySpecException {
+
+        SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
+        KeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt, ITERATIONS, KEY_LENGTH);
+
+        SecretKey secretKey = secretKeyFactory.generateSecret(keySpec);
+        return new SecretKeySpec(secretKey.getEncoded(), "AES");
+    }
+}

app/src/main/java/com/stevesoltys/backup/service/PackageService.java

@@ -0,0 +1,42 @@
+package com.stevesoltys.backup.service;
+
+import android.app.backup.IBackupManager;
+import android.content.pm.IPackageManager;
+import android.content.pm.PackageInfo;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.os.UserHandle;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author Steve Soltys
+ */
+public class PackageService {
+
+    private final IBackupManager backupManager;
+
+    private final IPackageManager packageManager;
+
+    public PackageService() {
+        backupManager = IBackupManager.Stub.asInterface(ServiceManager.getService("backup"));
+        packageManager = IPackageManager.Stub.asInterface(ServiceManager.getService("package"));
+    }
+
+    public List<String> getEligiblePackages() throws RemoteException {
+        List<String> results = new ArrayList<>();
+        List<PackageInfo> packages = packageManager.getInstalledPackages(0, UserHandle.USER_SYSTEM).getList();
+
+        if (packages != null) {
+            for (PackageInfo packageInfo : packages) {
+
+                if (backupManager.isAppEligibleForBackup(packageInfo.packageName)) {
+                    results.add(packageInfo.packageName);
+                }
+            }
+        }
+
+        return results;
+    }
+}

app/src/main/java/com/stevesoltys/backup/service/TransportService.java

@@ -1,35 +1,46 @@
-package com.stevesoltys.backup.session;
+package com.stevesoltys.backup.service;
 
 import android.app.backup.IBackupManager;
-import android.content.pm.IPackageManager;
-import android.content.pm.PackageInfo;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import com.stevesoltys.backup.session.backup.BackupSession;
 import com.stevesoltys.backup.session.backup.BackupSessionObserver;
 import com.stevesoltys.backup.session.restore.RestoreSession;
 import com.stevesoltys.backup.session.restore.RestoreSessionObserver;
+import com.stevesoltys.backup.transport.ConfigurableBackupTransport;
+import com.stevesoltys.backup.transport.ConfigurableBackupTransportService;
+import com.stevesoltys.backup.transport.component.BackupComponent;
+import com.stevesoltys.backup.transport.component.RestoreComponent;
+import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupComponent;
+import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfiguration;
+import com.stevesoltys.backup.transport.component.provider.ContentProviderRestoreComponent;
 
-import java.util.ArrayList;
-import java.util.List;
 import java.util.Set;
 
-import static android.os.UserHandle.USER_SYSTEM;
-
 /**
  * @author Steve Soltys
  */
-public class BackupManagerController {
+public class TransportService {
 
     private static final String BACKUP_TRANSPORT = "com.stevesoltys.backup.transport.ConfigurableBackupTransport";
 
     private final IBackupManager backupManager;
 
-    private final IPackageManager packageManager;
+    public TransportService() {
-
-    public BackupManagerController() {
         backupManager = IBackupManager.Stub.asInterface(ServiceManager.getService("backup"));
-        packageManager = IPackageManager.Stub.asInterface(ServiceManager.getService("package"));
+    }
+
+    public boolean initializeBackupTransport(ContentProviderBackupConfiguration configuration) {
+        ConfigurableBackupTransport backupTransport = ConfigurableBackupTransportService.getBackupTransport();
+
+        if (backupTransport.isActive()) {
+            return false;
+        }
+
+        BackupComponent backupComponent = new ContentProviderBackupComponent(configuration);
+        RestoreComponent restoreComponent = new ContentProviderRestoreComponent(configuration);
+        backupTransport.initialize(backupComponent, restoreComponent);
+        return true;
     }
 
     public BackupSession backup(BackupSessionObserver observer, Set<String> packages) throws RemoteException {
@@ -61,20 +72,4 @@ public class BackupManagerController {
         restoreSession.start();
         return restoreSession;
     }
-
-    public List<String> getEligiblePackages() throws RemoteException {
-        List<String> results = new ArrayList<>();
-        List<PackageInfo> packages = packageManager.getInstalledPackages(0, USER_SYSTEM).getList();
-
-        if (packages != null) {
-            for (PackageInfo packageInfo : packages) {
-
-                if (backupManager.isAppEligibleForBackup(packageInfo.packageName)) {
-                    results.add(packageInfo.packageName);
-                }
-            }
-        }
-
-        return results;
-    }
 }

app/src/main/java/com/stevesoltys/backup/service/backup/BackupObserver.java

@@ -1,4 +1,4 @@
-package com.stevesoltys.backup.activity.backup;
+package com.stevesoltys.backup.service.backup;
 
 import android.app.Activity;
 import android.app.backup.BackupProgress;
@@ -13,6 +13,8 @@ import com.stevesoltys.backup.session.backup.BackupSessionObserver;
 import com.stevesoltys.backup.transport.ConfigurableBackupTransport;
 import com.stevesoltys.backup.transport.ConfigurableBackupTransportService;
 
+import java.net.URI;
+
 /**
  * @author Steve Soltys
  */
@@ -22,9 +24,12 @@ class BackupObserver implements BackupSessionObserver {
 
     private final PopupWindow popupWindow;
 
-    BackupObserver(Activity context, PopupWindow popupWindow) {
+    private final URI contentUri;
+
+    BackupObserver(Activity context, PopupWindow popupWindow, URI contentUri) {
         this.context = context;
         this.popupWindow = popupWindow;
+        this.contentUri = contentUri;
     }
 
     @Override

app/src/main/java/com/stevesoltys/backup/service/backup/BackupService.java

@@ -0,0 +1,67 @@
+package com.stevesoltys.backup.service.backup;
+
+import android.app.Activity;
+import android.net.Uri;
+import android.util.Log;
+import android.view.View;
+import android.widget.PopupWindow;
+import android.widget.TextView;
+import android.widget.Toast;
+import com.stevesoltys.backup.R;
+import com.stevesoltys.backup.activity.backup.BackupPopupWindowListener;
+import com.stevesoltys.backup.activity.PopupWindowUtil;
+import com.stevesoltys.backup.service.TransportService;
+import com.stevesoltys.backup.session.backup.BackupSession;
+import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfiguration;
+import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfigurationBuilder;
+
+import java.net.URI;
+import java.util.Set;
+
+/**
+ * @author Steve Soltys
+ */
+public class BackupService {
+
+    private static final String TAG = BackupService.class.getName();
+
+    private final TransportService transportService = new TransportService();
+
+    public void backupPackageData(Set<String> selectedPackages, Uri contentUri, Activity parent,
+                                  String selectedPassword) {
+        try {
+            selectedPackages.add("@pm@");
+
+            ContentProviderBackupConfiguration backupConfiguration = new ContentProviderBackupConfigurationBuilder()
+                    .setContext(parent)
+                    .setOutputUri(contentUri)
+                    .setPackages(selectedPackages)
+                    .setPassword(selectedPassword)
+                    .build();
+
+            boolean success = transportService.initializeBackupTransport(backupConfiguration);
+
+            if (!success) {
+                Toast.makeText(parent, R.string.backup_in_progress, Toast.LENGTH_LONG).show();
+                return;
+            }
+
+            PopupWindow popupWindow = PopupWindowUtil.showLoadingPopupWindow(parent);
+            BackupObserver backupObserver = new BackupObserver(parent, popupWindow, new URI(contentUri.getPath()));
+            BackupSession backupSession = transportService.backup(backupObserver, selectedPackages);
+
+            View popupWindowButton = popupWindow.getContentView().findViewById(R.id.popup_cancel_button);
+            popupWindowButton.setOnClickListener(new BackupPopupWindowListener(backupSession));
+
+            TextView textView = popupWindow.getContentView().findViewById(R.id.popup_text_view);
+            textView.setText(R.string.initializing);
+
+        } catch (Exception e) {
+            Log.e(TAG, "Error while running backup: ", e);
+        }
+    }
+
+    public void backupPackages() {
+
+    }
+}

app/src/main/java/com/stevesoltys/backup/service/restore/RestoreObserver.java

@@ -1,11 +1,10 @@
-package com.stevesoltys.backup.activity.restore;
+package com.stevesoltys.backup.service.restore;
 
 import android.app.Activity;
 import android.widget.PopupWindow;
 import android.widget.ProgressBar;
 import android.widget.TextView;
 import android.widget.Toast;
-
 import com.stevesoltys.backup.R;
 import com.stevesoltys.backup.session.restore.RestoreResult;
 import com.stevesoltys.backup.session.restore.RestoreSessionObserver;
@@ -31,6 +30,10 @@ class RestoreObserver implements RestoreSessionObserver {
 
     @Override
     public void restoreSessionStarted(int packageCount) {
+        context.runOnUiThread(() -> {
+            TextView textView = popupWindow.getContentView().findViewById(R.id.popup_text_view);
+            textView.setText(R.string.initializing);
+        });
     }
 
     @Override
@@ -55,7 +58,7 @@ class RestoreObserver implements RestoreSessionObserver {
     public void restoreSessionCompleted(RestoreResult restoreResult) {
         ConfigurableBackupTransport backupTransport = ConfigurableBackupTransportService.getBackupTransport();
 
-        if(!backupTransport.isActive()) {
+        if (!backupTransport.isActive()) {
             return;
         }
 

app/src/main/java/com/stevesoltys/backup/service/restore/RestoreService.java

@@ -0,0 +1,59 @@
+package com.stevesoltys.backup.service.restore;
+
+import android.app.Activity;
+import android.net.Uri;
+import android.os.RemoteException;
+import android.util.Log;
+import android.view.View;
+import android.widget.PopupWindow;
+import android.widget.Toast;
+import com.stevesoltys.backup.R;
+import com.stevesoltys.backup.activity.PopupWindowUtil;
+import com.stevesoltys.backup.activity.restore.RestorePopupWindowListener;
+import com.stevesoltys.backup.service.TransportService;
+import com.stevesoltys.backup.session.restore.RestoreSession;
+import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfiguration;
+import com.stevesoltys.backup.transport.component.provider.ContentProviderBackupConfigurationBuilder;
+
+import java.util.Set;
+
+/**
+ * @author Steve Soltys
+ */
+public class RestoreService {
+
+    private static final String TAG = RestoreService.class.getName();
+
+    private final TransportService transportService = new TransportService();
+
+    public void restorePackages(Set<String> selectedPackages, Uri contentUri, Activity parent, String password) {
+        try {
+            ContentProviderBackupConfiguration backupConfiguration = new ContentProviderBackupConfigurationBuilder().
+                    setContext(parent)
+                    .setOutputUri(contentUri)
+                    .setPackages(selectedPackages)
+                    .setPassword(password)
+                    .build();
+
+            boolean success = transportService.initializeBackupTransport(backupConfiguration);
+
+            if (!success) {
+                Toast.makeText(parent, R.string.restore_in_progress, Toast.LENGTH_LONG).show();
+                return;
+            }
+
+            PopupWindow popupWindow = PopupWindowUtil.showLoadingPopupWindow(parent);
+            RestoreObserver restoreObserver = new RestoreObserver(parent, popupWindow, selectedPackages.size());
+            RestoreSession restoreSession = transportService.restore(restoreObserver, selectedPackages);
+
+            View popupWindowButton = popupWindow.getContentView().findViewById(R.id.popup_cancel_button);
+
+            if (popupWindowButton != null) {
+                popupWindowButton.setOnClickListener(new RestorePopupWindowListener(restoreSession));
+            }
+
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error while running restore: ", e);
+        }
+    }
+}

app/src/main/java/com/stevesoltys/backup/transport/component/provider/ContentProviderBackupComponent.java

@@ -6,15 +6,18 @@ import android.content.pm.PackageInfo;
 import android.os.ParcelFileDescriptor;
 import android.util.Base64;
 import android.util.Log;
+import com.stevesoltys.backup.security.CipherUtil;
+import com.stevesoltys.backup.security.KeyGenerator;
 import com.stevesoltys.backup.transport.component.BackupComponent;
-
+import libcore.io.IoUtils;
 import org.apache.commons.io.IOUtils;
 
-import libcore.io.IoUtils;
+import javax.crypto.SecretKey;
-
+import java.io.FileInputStream;
-import java.io.*;
+import java.io.FileOutputStream;
-import java.security.InvalidAlgorithmParameterException;
+import java.io.IOException;
-import java.security.InvalidKeyException;
+import java.io.InputStream;
+import java.util.Arrays;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
@@ -41,11 +44,6 @@ public class ContentProviderBackupComponent implements BackupComponent {
         this.configuration = configuration;
     }
 
-    @Override
-    public long requestBackupTime() {
-        return 0;
-    }
-
     @Override
     public String currentDestinationString() {
         return DESTINATION_DESCRIPTION;
@@ -67,33 +65,8 @@ public class ContentProviderBackupComponent implements BackupComponent {
     }
 
     @Override
-    public long getBackupQuota(String packageName, boolean fullBackup) {
+    public int finishBackup() {
-        return configuration.getBackupSizeQuota();
+        return clearBackupState(false);
-    }
-
-    @Override
-    public long requestFullBackupTime() {
-        return 0;
-    }
-
-    private void initializeBackupState() throws IOException {
-        if (backupState == null) {
-            backupState = new ContentProviderBackupState();
-        }
-
-        if (backupState.getOutputStream() == null) {
-            initializeOutputStream();
-        }
-    }
-
-    private void initializeOutputStream() throws FileNotFoundException {
-        ContentResolver contentResolver = configuration.getContext().getContentResolver();
-        ParcelFileDescriptor outputFileDescriptor = contentResolver.openFileDescriptor(configuration.getUri(), "w");
-        backupState.setOutputFileDescriptor(outputFileDescriptor);
-
-        FileOutputStream fileOutputStream = new FileOutputStream(outputFileDescriptor.getFileDescriptor());
-        ZipOutputStream zipOutputStream = new ZipOutputStream(fileOutputStream);
-        backupState.setOutputStream(zipOutputStream);
     }
 
     @Override
@@ -113,44 +86,55 @@ public class ContentProviderBackupComponent implements BackupComponent {
         }
     }
 
-    private int transferIncrementalBackupData(BackupDataInput backupDataInput)
+    private int clearBackupState(boolean closeFile) {
-            throws IOException, InvalidAlgorithmParameterException, InvalidKeyException {
 
-        ZipOutputStream outputStream = backupState.getOutputStream();
+        if (backupState == null) {
+            return TRANSPORT_OK;
+        }
 
-        int bufferSize = INITIAL_BUFFER_SIZE;
+        try {
-        byte[] buffer = new byte[bufferSize];
+            IoUtils.closeQuietly(backupState.getInputFileDescriptor());
+            backupState.setInputFileDescriptor(null);
 
-        while (backupDataInput.readNextHeader()) {
+            ZipOutputStream outputStream = backupState.getOutputStream();
-            String chunkFileName = Base64.encodeToString(backupDataInput.getKey().getBytes(), Base64.DEFAULT);
-            int dataSize = backupDataInput.getDataSize();
 
-            if (dataSize >= 0) {
+            if (outputStream != null) {
-                ZipEntry zipEntry = new ZipEntry(configuration.getIncrementalBackupDirectory() +
+                outputStream.closeEntry();
-                        backupState.getPackageName() + "/" + chunkFileName);
-                outputStream.putNextEntry(zipEntry);
-
-                if (dataSize > bufferSize) {
-                    bufferSize = dataSize;
-                    buffer = new byte[bufferSize];
-                }
-
-                backupDataInput.readEntityData(buffer, 0, dataSize);
-
-                try {
-                    outputStream.write(buffer, 0, dataSize);
-
-                } catch (Exception ex) {
-                    Log.e(TAG, "Error performing incremental backup for " + backupState.getPackageName() + ": ", ex);
-                    clearBackupState(true);
-                    return TRANSPORT_ERROR;
-                }
             }
+
+            if (backupState.getPackageIndex() == configuration.getPackageCount() || closeFile) {
+                if (outputStream != null) {
+                    outputStream.finish();
+                    outputStream.close();
+                }
+
+                IoUtils.closeQuietly(backupState.getOutputFileDescriptor());
+                backupState = null;
+            }
+
+        } catch (IOException ex) {
+            Log.e(TAG, "Error cancelling full backup: ", ex);
+            return TRANSPORT_ERROR;
         }
 
         return TRANSPORT_OK;
     }
 
+    @Override
+    public long getBackupQuota(String packageName, boolean fullBackup) {
+        return configuration.getBackupSizeQuota();
+    }
+
+    @Override
+    public long requestBackupTime() {
+        return 0;
+    }
+
+    @Override
+    public long requestFullBackupTime() {
+        return 0;
+    }
+
     @Override
     public int performFullBackup(PackageInfo targetPackage, ParcelFileDescriptor fileDescriptor) {
 
@@ -227,40 +211,76 @@ public class ContentProviderBackupComponent implements BackupComponent {
         clearBackupState(false);
     }
 
-    @Override
+    private void initializeBackupState() throws Exception {
-    public int finishBackup() {
-        return clearBackupState(false);
-    }
-
-    private int clearBackupState(boolean closeFile) {
-
         if (backupState == null) {
-            return TRANSPORT_OK;
+            backupState = new ContentProviderBackupState();
         }
 
-        try {
+        if (backupState.getOutputStream() == null) {
-            IoUtils.closeQuietly(backupState.getInputFileDescriptor());
+            initializeOutputStream();
-            backupState.setInputFileDescriptor(null);
 
-            ZipOutputStream outputStream = backupState.getOutputStream();
+            ZipEntry saltZipEntry = new ZipEntry(ContentProviderBackupConstants.SALT_FILE_PATH);
+            backupState.getOutputStream().putNextEntry(saltZipEntry);
+            backupState.getOutputStream().write(backupState.getSalt());
+            backupState.getOutputStream().closeEntry();
 
-            if (outputStream != null) {
+
-                outputStream.closeEntry();
+            if (configuration.getPassword() != null && !configuration.getPassword().isEmpty()) {
+                backupState.setSecretKey(KeyGenerator.generate(configuration.getPassword(), backupState.getSalt()));
             }
+        }
+    }
 
-            if (backupState.getPackageIndex() == configuration.getPackageCount() || closeFile) {
+    private void initializeOutputStream() throws IOException {
-                if (outputStream != null) {
+        ContentResolver contentResolver = configuration.getContext().getContentResolver();
-                    outputStream.finish();
+        ParcelFileDescriptor outputFileDescriptor = contentResolver.openFileDescriptor(configuration.getUri(), "w");
-                    outputStream.close();
+        backupState.setOutputFileDescriptor(outputFileDescriptor);
+
+        FileOutputStream fileOutputStream = new FileOutputStream(outputFileDescriptor.getFileDescriptor());
+        ZipOutputStream zipOutputStream = new ZipOutputStream(fileOutputStream);
+        backupState.setOutputStream(zipOutputStream);
+    }
+
+    private int transferIncrementalBackupData(BackupDataInput backupDataInput) throws IOException {
+        ZipOutputStream outputStream = backupState.getOutputStream();
+
+        int bufferSize = INITIAL_BUFFER_SIZE;
+        byte[] buffer = new byte[bufferSize];
+
+        while (backupDataInput.readNextHeader()) {
+            String chunkFileName = Base64.encodeToString(backupDataInput.getKey().getBytes(), Base64.DEFAULT);
+            int dataSize = backupDataInput.getDataSize();
+
+            if (dataSize >= 0) {
+                ZipEntry zipEntry = new ZipEntry(configuration.getIncrementalBackupDirectory() +
+                        backupState.getPackageName() + "/" + chunkFileName);
+                outputStream.putNextEntry(zipEntry);
+
+                if (dataSize > bufferSize) {
+                    bufferSize = dataSize;
+                    buffer = new byte[bufferSize];
                 }
 
-                IoUtils.closeQuietly(backupState.getOutputFileDescriptor());
+                backupDataInput.readEntityData(buffer, 0, dataSize);
-                backupState = null;
-            }
 
-        } catch (IOException ex) {
+                try {
-            Log.e(TAG, "Error cancelling full backup: ", ex);
+                    if (backupState.getSecretKey() != null) {
-            return TRANSPORT_ERROR;
+                        byte[] payload = Arrays.copyOfRange(buffer, 0, dataSize);
+                        SecretKey secretKey = backupState.getSecretKey();
+                        byte[] salt = backupState.getSalt();
+
+                        outputStream.write(CipherUtil.encrypt(payload, secretKey, salt));
+
+                    } else {
+                        outputStream.write(buffer, 0, dataSize);
+                    }
+
+                } catch (Exception ex) {
+                    Log.e(TAG, "Error performing incremental backup for " + backupState.getPackageName() + ": ", ex);
+                    clearBackupState(true);
+                    return TRANSPORT_ERROR;
+                }
+            }
         }
 
         return TRANSPORT_OK;

app/src/main/java/com/stevesoltys/backup/transport/component/provider/ContentProviderBackupConfiguration.java

@@ -14,6 +14,8 @@ public class ContentProviderBackupConfiguration {
 
     private final Uri uri;
 
+    private final String password;
+
     private final long backupSizeQuota;
 
     private final Set<String> packages;
@@ -22,30 +24,24 @@ public class ContentProviderBackupConfiguration {
 
     private final String incrementalBackupDirectory;
 
-    ContentProviderBackupConfiguration(Context context, Uri uri, Set<String> packages, long backupSizeQuota,
+    ContentProviderBackupConfiguration(Context context, Uri uri, Set<String> packages, String password,
-                                       String fullBackupDirectory, String incrementalBackupDirectory) {
+                                       long backupSizeQuota, String fullBackupDirectory,
+                                       String incrementalBackupDirectory) {
         this.context = context;
         this.uri = uri;
         this.packages = packages;
+        this.password = password;
         this.backupSizeQuota = backupSizeQuota;
         this.fullBackupDirectory = fullBackupDirectory;
         this.incrementalBackupDirectory = incrementalBackupDirectory;
     }
 
-    public Context getContext() {
-        return context;
-    }
-
-    public Uri getUri() {
-        return uri;
-    }
-
     public long getBackupSizeQuota() {
         return backupSizeQuota;
     }
 
-    public int getPackageCount() {
+    public Context getContext() {
-        return packages.size();
+        return context;
     }
 
     public String getFullBackupDirectory() {
@@ -55,4 +51,16 @@ public class ContentProviderBackupConfiguration {
     public String getIncrementalBackupDirectory() {
         return incrementalBackupDirectory;
     }
+
+    public int getPackageCount() {
+        return packages.size();
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public Uri getUri() {
+        return uri;
+    }
 }

app/src/main/java/com/stevesoltys/backup/transport/component/provider/ContentProviderBackupConfigurationBuilder.java

@@ -21,6 +21,8 @@ public class ContentProviderBackupConfigurationBuilder {
 
     private Set<String> packages;
 
+    private String password;
+
     private long backupSizeQuota = Long.MAX_VALUE;
 
     private String incrementalBackupDirectory = DEFAULT_INCREMENTAL_BACKUP_DIRECTORY;
@@ -34,15 +36,30 @@ public class ContentProviderBackupConfigurationBuilder {
         Preconditions.checkState(incrementalBackupDirectory != null, "Incremental backup directory must be set.");
         Preconditions.checkState(fullBackupDirectory != null, "Full backup directory must be set.");
 
-        return new ContentProviderBackupConfiguration(context, outputUri, packages, backupSizeQuota,
+        return new ContentProviderBackupConfiguration(context, outputUri, packages, password, backupSizeQuota,
                 fullBackupDirectory, incrementalBackupDirectory);
     }
 
+    public ContentProviderBackupConfigurationBuilder setBackupSizeQuota(long backupSizeQuota) {
+        this.backupSizeQuota = backupSizeQuota;
+        return this;
+    }
+
     public ContentProviderBackupConfigurationBuilder setContext(Context context) {
         this.context = context;
         return this;
     }
 
+    public ContentProviderBackupConfigurationBuilder setFullBackupDirectory(String fullBackupDirectory) {
+        this.fullBackupDirectory = fullBackupDirectory;
+        return this;
+    }
+
+    public ContentProviderBackupConfigurationBuilder setIncrementalBackupDirectory(String incrementalBackupDirectory) {
+        this.incrementalBackupDirectory = incrementalBackupDirectory;
+        return this;
+    }
+
     public ContentProviderBackupConfigurationBuilder setOutputUri(Uri outputUri) {
         this.outputUri = outputUri;
         return this;
@@ -53,18 +70,8 @@ public class ContentProviderBackupConfigurationBuilder {
         return this;
     }
 
-    public ContentProviderBackupConfigurationBuilder setBackupSizeQuota(long backupSizeQuota) {
+    public ContentProviderBackupConfigurationBuilder setPassword(String password) {
-        this.backupSizeQuota = backupSizeQuota;
+        this.password = password;
-        return this;
-    }
-
-    public ContentProviderBackupConfigurationBuilder setIncrementalBackupDirectory(String incrementalBackupDirectory) {
-        this.incrementalBackupDirectory = incrementalBackupDirectory;
-        return this;
-    }
-
-    public ContentProviderBackupConfigurationBuilder setFullBackupDirectory(String fullBackupDirectory) {
-        this.fullBackupDirectory = fullBackupDirectory;
         return this;
     }
 }

app/src/main/java/com/stevesoltys/backup/transport/component/provider/ContentProviderBackupConstants.java

@@ -0,0 +1,9 @@
+package com.stevesoltys.backup.transport.component.provider;
+
+/**
+ * @author Steve Soltys
+ */
+class ContentProviderBackupConstants {
+
+    static final String SALT_FILE_PATH = "salt";
+}

app/src/main/java/com/stevesoltys/backup/transport/component/provider/ContentProviderBackupState.java

@@ -2,7 +2,9 @@ package com.stevesoltys.backup.transport.component.provider;
 
 import android.os.ParcelFileDescriptor;
 
+import javax.crypto.SecretKey;
 import java.io.InputStream;
+import java.security.SecureRandom;
 import java.util.zip.ZipOutputStream;
 
 /**
@@ -10,6 +12,8 @@ import java.util.zip.ZipOutputStream;
  */
 class ContentProviderBackupState {
 
+    private static final SecureRandom SECURE_RANDOM = new SecureRandom();
+
     private ParcelFileDescriptor inputFileDescriptor;
 
     private ParcelFileDescriptor outputFileDescriptor;
@@ -24,36 +28,13 @@ class ContentProviderBackupState {
 
     private int packageIndex;
 
-    ParcelFileDescriptor getInputFileDescriptor() {
+    private byte[] salt;
-        return inputFileDescriptor;
-    }
 
-    void setInputFileDescriptor(ParcelFileDescriptor inputFileDescriptor) {
+    private SecretKey secretKey;
-        this.inputFileDescriptor = inputFileDescriptor;
-    }
 
-    ParcelFileDescriptor getOutputFileDescriptor() {
+    public ContentProviderBackupState() {
-        return outputFileDescriptor;
+        salt = new byte[16];
-    }
+        SECURE_RANDOM.nextBytes(salt);
-
-    void setOutputFileDescriptor(ParcelFileDescriptor outputFileDescriptor) {
-        this.outputFileDescriptor = outputFileDescriptor;
-    }
-
-    InputStream getInputStream() {
-        return inputStream;
-    }
-
-    void setInputStream(InputStream inputStream) {
-        this.inputStream = inputStream;
-    }
-
-    ZipOutputStream getOutputStream() {
-        return outputStream;
-    }
-
-    void setOutputStream(ZipOutputStream outputStream) {
-        this.outputStream = outputStream;
     }
 
     long getBytesTransferred() {
@@ -64,12 +45,36 @@ class ContentProviderBackupState {
         this.bytesTransferred = bytesTransferred;
     }
 
-    String getPackageName() {
+    ParcelFileDescriptor getInputFileDescriptor() {
-        return packageName;
+        return inputFileDescriptor;
     }
 
-    void setPackageName(String packageName) {
+    void setInputFileDescriptor(ParcelFileDescriptor inputFileDescriptor) {
-        this.packageName = packageName;
+        this.inputFileDescriptor = inputFileDescriptor;
+    }
+
+    InputStream getInputStream() {
+        return inputStream;
+    }
+
+    void setInputStream(InputStream inputStream) {
+        this.inputStream = inputStream;
+    }
+
+    ParcelFileDescriptor getOutputFileDescriptor() {
+        return outputFileDescriptor;
+    }
+
+    void setOutputFileDescriptor(ParcelFileDescriptor outputFileDescriptor) {
+        this.outputFileDescriptor = outputFileDescriptor;
+    }
+
+    ZipOutputStream getOutputStream() {
+        return outputStream;
+    }
+
+    void setOutputStream(ZipOutputStream outputStream) {
+        this.outputStream = outputStream;
     }
 
     int getPackageIndex() {
@@ -79,4 +84,24 @@ class ContentProviderBackupState {
     void setPackageIndex(int packageIndex) {
         this.packageIndex = packageIndex;
     }
+
+    String getPackageName() {
+        return packageName;
+    }
+
+    void setPackageName(String packageName) {
+        this.packageName = packageName;
+    }
+
+    byte[] getSalt() {
+        return salt;
+    }
+
+    public SecretKey getSecretKey() {
+        return secretKey;
+    }
+
+    public void setSecretKey(SecretKey secretKey) {
+        this.secretKey = secretKey;
+    }
 }

app/src/main/java/com/stevesoltys/backup/transport/component/provider/ContentProviderRestoreComponent.java

@@ -9,13 +9,16 @@ import android.os.ParcelFileDescriptor;
 import android.util.Base64;
 import android.util.Log;
 import com.android.internal.util.Preconditions;
+import com.stevesoltys.backup.security.CipherUtil;
+import com.stevesoltys.backup.security.KeyGenerator;
 import com.stevesoltys.backup.transport.component.RestoreComponent;
 import libcore.io.IoUtils;
 import libcore.io.Streams;
 
+import javax.crypto.SecretKey;
 import java.io.*;
-import java.security.InvalidAlgorithmParameterException;
+import java.util.LinkedList;
-import java.security.InvalidKeyException;
+import java.util.List;
 import java.util.Optional;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
@@ -48,6 +51,45 @@ public class ContentProviderRestoreComponent implements RestoreComponent {
         restoreState = new ContentProviderRestoreState();
         restoreState.setPackages(packages);
         restoreState.setPackageIndex(-1);
+
+        if (configuration.getPassword() != null && !configuration.getPassword().isEmpty()) {
+            try {
+                ParcelFileDescriptor inputFileDescriptor = buildInputFileDescriptor();
+                ZipInputStream inputStream = buildInputStream(inputFileDescriptor);
+                seekToEntry(inputStream, ContentProviderBackupConstants.SALT_FILE_PATH);
+
+                restoreState.setSalt(Streams.readFullyNoClose(inputStream));
+                restoreState.setSecretKey(KeyGenerator.generate(configuration.getPassword(), restoreState.getSalt()));
+
+                IoUtils.closeQuietly(inputFileDescriptor);
+                IoUtils.closeQuietly(inputStream);
+
+            } catch (Exception ex) {
+                Log.e(TAG, "Salt not found", ex);
+            }
+        }
+
+        try {
+            List<ZipEntry> zipEntries = new LinkedList<>();
+
+            ParcelFileDescriptor inputFileDescriptor = buildInputFileDescriptor();
+            ZipInputStream inputStream = buildInputStream(inputFileDescriptor);
+
+            ZipEntry zipEntry;
+            while ((zipEntry = inputStream.getNextEntry()) != null) {
+                zipEntries.add(zipEntry);
+                inputStream.closeEntry();
+            }
+
+            IoUtils.closeQuietly(inputFileDescriptor);
+            IoUtils.closeQuietly(inputStream);
+
+            restoreState.setZipEntries(zipEntries);
+
+        } catch (Exception ex) {
+            Log.e(TAG, "Error while caching zip entries", ex);
+        }
+
         return TRANSPORT_OK;
     }
 
@@ -62,32 +104,66 @@ public class ContentProviderRestoreComponent implements RestoreComponent {
             restoreState.setPackageIndex(packageIndex);
             String name = packages[packageIndex].packageName;
 
-            try {
+            if (containsPackageFile(configuration.getIncrementalBackupDirectory() + name)) {
-                if (containsPackageFile(configuration.getIncrementalBackupDirectory() + name)) {
+                restoreState.setRestoreType(TYPE_KEY_VALUE);
-                    restoreState.setRestoreType(TYPE_KEY_VALUE);
+                return new RestoreDescription(name, restoreState.getRestoreType());
-                    return new RestoreDescription(name, restoreState.getRestoreType());
 
-                } else if (containsPackageFile(configuration.getFullBackupDirectory() + name)) {
+            } else if (containsPackageFile(configuration.getFullBackupDirectory() + name)) {
-                    restoreState.setRestoreType(TYPE_FULL_STREAM);
+                restoreState.setRestoreType(TYPE_FULL_STREAM);
-                    return new RestoreDescription(name, restoreState.getRestoreType());
+                return new RestoreDescription(name, restoreState.getRestoreType());
-                }
-
-            } catch (IOException | InvalidKeyException | InvalidAlgorithmParameterException ex) {
-                Log.e(TAG, "Error choosing package  " + name + "  at index " + packageIndex + "failed selection:", ex);
             }
         }
         return RestoreDescription.NO_MORE_PACKAGES;
     }
 
-    private boolean containsPackageFile(String fileName) throws IOException, InvalidKeyException,
+    private boolean containsPackageFile(String fileName) {
-            InvalidAlgorithmParameterException {
+        return restoreState.getZipEntries().stream()
+                .anyMatch(zipEntry -> zipEntry.getName().startsWith(fileName));
+    }
+
+    @Override
+    public int getRestoreData(ParcelFileDescriptor outputFileDescriptor) {
+        Preconditions.checkState(restoreState != null, "startRestore() not called");
+        Preconditions.checkState(restoreState.getPackageIndex() >= 0, "nextRestorePackage() not called");
+        Preconditions.checkState(restoreState.getRestoreType() == TYPE_KEY_VALUE,
+                "getRestoreData() for non-key/value dataset");
+
+        PackageInfo packageInfo = restoreState.getPackages()[restoreState.getPackageIndex()];
+
+        try {
+            return transferIncrementalRestoreData(packageInfo.packageName, outputFileDescriptor);
+
+        } catch (Exception ex) {
+            Log.e(TAG, "Unable to read backup records: ", ex);
+            return TRANSPORT_ERROR;
+        }
+    }
+
+    private int transferIncrementalRestoreData(String packageName, ParcelFileDescriptor outputFileDescriptor)
+            throws Exception {
+
         ParcelFileDescriptor inputFileDescriptor = buildInputFileDescriptor();
         ZipInputStream inputStream = buildInputStream(inputFileDescriptor);
+        BackupDataOutput backupDataOutput = new BackupDataOutput(outputFileDescriptor.getFileDescriptor());
+
+        Optional<ZipEntry> zipEntryOptional = seekToEntry(inputStream,
+                configuration.getIncrementalBackupDirectory() + packageName);
+
+        while (zipEntryOptional.isPresent()) {
+            String fileName = new File(zipEntryOptional.get().getName()).getName();
+            String blobKey = new String(Base64.decode(fileName, Base64.DEFAULT));
+
+            byte[] backupData = readBackupData(inputStream);
+            backupDataOutput.writeEntityHeader(blobKey, backupData.length);
+            backupDataOutput.writeEntityData(backupData, backupData.length);
+            inputStream.closeEntry();
+
+            zipEntryOptional = seekToEntry(inputStream, configuration.getIncrementalBackupDirectory() + packageName);
+        }
 
-        Optional<ZipEntry> zipEntry = seekToEntry(inputStream, fileName);
         IoUtils.closeQuietly(inputFileDescriptor);
-        IoUtils.closeQuietly(inputStream);
+        IoUtils.closeQuietly(outputFileDescriptor);
-        return zipEntry.isPresent();
+        return TRANSPORT_OK;
     }
 
     private ParcelFileDescriptor buildInputFileDescriptor() throws FileNotFoundException {
@@ -113,48 +189,16 @@ public class ContentProviderRestoreComponent implements RestoreComponent {
         return Optional.empty();
     }
 
-    @Override
+    private byte[] readBackupData(ZipInputStream inputStream) throws Exception {
-    public int getRestoreData(ParcelFileDescriptor outputFileDescriptor) {
+        byte[] backupData = Streams.readFullyNoClose(inputStream);
-        Preconditions.checkState(restoreState != null, "startRestore() not called");
+        SecretKey secretKey = restoreState.getSecretKey();
-        Preconditions.checkState(restoreState.getPackageIndex() >= 0, "nextRestorePackage() not called");
+        byte[] initializationVector = restoreState.getSalt();
-        Preconditions.checkState(restoreState.getRestoreType() == TYPE_KEY_VALUE,
-                "getRestoreData() for non-key/value dataset");
 
-        PackageInfo packageInfo = restoreState.getPackages()[restoreState.getPackageIndex()];
+        if (secretKey != null) {
-
+            backupData = CipherUtil.decrypt(backupData, secretKey, initializationVector);
-        try {
-            return transferIncrementalRestoreData(packageInfo.packageName, outputFileDescriptor);
-
-        } catch (Exception ex) {
-            Log.e(TAG, "Unable to read backup records: ", ex);
-            return TRANSPORT_ERROR;
-        }
-    }
-
-    private int transferIncrementalRestoreData(String packageName, ParcelFileDescriptor outputFileDescriptor)
-            throws IOException, InvalidAlgorithmParameterException, InvalidKeyException {
-
-        ParcelFileDescriptor inputFileDescriptor = buildInputFileDescriptor();
-        ZipInputStream inputStream = buildInputStream(inputFileDescriptor);
-        BackupDataOutput backupDataOutput = new BackupDataOutput(outputFileDescriptor.getFileDescriptor());
-
-        Optional<ZipEntry> zipEntryOptional = seekToEntry(inputStream,
-                configuration.getIncrementalBackupDirectory() + packageName);
-        while (zipEntryOptional.isPresent()) {
-            String fileName = new File(zipEntryOptional.get().getName()).getName();
-            String blobKey = new String(Base64.decode(fileName, Base64.DEFAULT));
-
-            byte[] backupData = Streams.readFullyNoClose(inputStream);
-            backupDataOutput.writeEntityHeader(blobKey, backupData.length);
-            backupDataOutput.writeEntityData(backupData, backupData.length);
-            inputStream.closeEntry();
-
-            zipEntryOptional = seekToEntry(inputStream, configuration.getIncrementalBackupDirectory() + packageName);
         }
 
-        IoUtils.closeQuietly(inputFileDescriptor);
+        return backupData;
-        IoUtils.closeQuietly(outputFileDescriptor);
-        return TRANSPORT_OK;
     }
 
     @Override

app/src/main/java/com/stevesoltys/backup/transport/component/provider/ContentProviderRestoreState.java

@@ -3,6 +3,9 @@ package com.stevesoltys.backup.transport.component.provider;
 import android.content.pm.PackageInfo;
 import android.os.ParcelFileDescriptor;
 
+import javax.crypto.SecretKey;
+import java.util.List;
+import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
 /**
@@ -20,28 +23,18 @@ class ContentProviderRestoreState {
 
     private ZipInputStream inputStream;
 
-    PackageInfo[] getPackages() {
+    private byte[] salt;
-        return packages;
+
+    private SecretKey secretKey;
+
+    private List<ZipEntry> zipEntries;
+
+    ParcelFileDescriptor getInputFileDescriptor() {
+        return inputFileDescriptor;
     }
 
-    void setPackages(PackageInfo[] packages) {
+    void setInputFileDescriptor(ParcelFileDescriptor inputFileDescriptor) {
-        this.packages = packages;
+        this.inputFileDescriptor = inputFileDescriptor;
-    }
-
-    int getPackageIndex() {
-        return packageIndex;
-    }
-
-    void setPackageIndex(int packageIndex) {
-        this.packageIndex = packageIndex;
-    }
-
-    int getRestoreType() {
-        return restoreType;
-    }
-
-    void setRestoreType(int restoreType) {
-        this.restoreType = restoreType;
     }
 
     ZipInputStream getInputStream() {
@@ -52,11 +45,51 @@ class ContentProviderRestoreState {
         this.inputStream = inputStream;
     }
 
-    ParcelFileDescriptor getInputFileDescriptor() {
+    int getPackageIndex() {
-        return inputFileDescriptor;
+        return packageIndex;
     }
 
-    void setInputFileDescriptor(ParcelFileDescriptor inputFileDescriptor) {
+    void setPackageIndex(int packageIndex) {
-        this.inputFileDescriptor = inputFileDescriptor;
+        this.packageIndex = packageIndex;
+    }
+
+    PackageInfo[] getPackages() {
+        return packages;
+    }
+
+    void setPackages(PackageInfo[] packages) {
+        this.packages = packages;
+    }
+
+    int getRestoreType() {
+        return restoreType;
+    }
+
+    void setRestoreType(int restoreType) {
+        this.restoreType = restoreType;
+    }
+
+    byte[] getSalt() {
+        return salt;
+    }
+
+    void setSalt(byte[] salt) {
+        this.salt = salt;
+    }
+
+    public SecretKey getSecretKey() {
+        return secretKey;
+    }
+
+    public void setSecretKey(SecretKey secretKey) {
+        this.secretKey = secretKey;
+    }
+
+    public List<ZipEntry> getZipEntries() {
+        return zipEntries;
+    }
+
+    public void setZipEntries(List<ZipEntry> zipEntries) {
+        this.zipEntries = zipEntries;
     }
 }

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

@@ -19,5 +19,8 @@
     <string name="popup_cancel">Cancel</string>
 
     <string name="select_all">Select all</string>
+    <string name="loading_backup">Loading backup…</string>
+    <string name="loading_packages">Loading packages…</string>
+    <string name="initializing">Initializing…</string>
 
 </resources>