app/src/main/java/com/stoutner/privacybrowser/activities/ImportExportActivity.java

   1 /*
   2  * Copyright © 2018 Soren Stoutner <soren@stoutner.com>.
   3  *
   4  * This file is part of Privacy Browser <https://www.stoutner.com/privacy-browser>.
   5  *
   6  * Privacy Browser is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Privacy Browser is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with Privacy Browser.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 package com.stoutner.privacybrowser.activities;
  21
  22 import android.Manifest;
  23 import android.app.Activity;
  24 import android.app.DialogFragment;
  25 import android.content.Intent;
  26 import android.content.pm.PackageManager;
  27 import android.net.Uri;
  28 import android.os.Build;
  29 import android.os.Bundle;
  30 import android.os.Environment;
  31 import android.provider.DocumentsContract;
  32 import android.support.annotation.NonNull;
  33 import android.support.design.widget.Snackbar;
  34 import android.support.design.widget.TextInputLayout;
  35 import android.support.v4.app.ActivityCompat;
  36 import android.support.v4.content.ContextCompat;
  37 import android.support.v4.content.FileProvider;
  38 import android.support.v7.app.ActionBar;
  39 import android.support.v7.app.AppCompatActivity;
  40 import android.support.v7.widget.CardView;
  41 import android.support.v7.widget.Toolbar;
  42 import android.text.Editable;
  43 import android.text.TextWatcher;
  44 import android.view.View;
  45 import android.view.WindowManager;
  46 import android.widget.AdapterView;
  47 import android.widget.ArrayAdapter;
  48 import android.widget.Button;
  49 import android.widget.EditText;
  50 import android.widget.LinearLayout;
  51 import android.widget.RadioButton;
  52 import android.widget.Spinner;
  53 import android.widget.TextView;
  54
  55 import com.stoutner.privacybrowser.R;
  56 import com.stoutner.privacybrowser.dialogs.ImportExportStoragePermissionDialog;
  57 import com.stoutner.privacybrowser.helpers.ImportExportDatabaseHelper;
  58
  59 import java.io.File;
  60 import java.io.FileInputStream;
  61 import java.io.FileOutputStream;
  62 import java.security.MessageDigest;
  63 import java.security.SecureRandom;
  64 import java.util.Arrays;
  65
  66 import javax.crypto.Cipher;
  67 import javax.crypto.CipherInputStream;
  68 import javax.crypto.CipherOutputStream;
  69 import javax.crypto.spec.GCMParameterSpec;
  70 import javax.crypto.spec.SecretKeySpec;
  71
  72 public class ImportExportActivity extends AppCompatActivity implements ImportExportStoragePermissionDialog.ImportExportStoragePermissionDialogListener {
  73     // Create the encryption constants.
  74     private final int NO_ENCRYPTION = 0;
  75     private final int PASSWORD_ENCRYPTION = 1;
  76     private final int OPENPGP_ENCRYPTION = 2;
  77
  78     // Create the activity result constants.
  79     private final int BROWSE_RESULT_CODE = 0;
  80     private final int OPENPGP_EXPORT_RESULT_CODE = 1;
  81
  82     // `openKeychainInstalled` is accessed from an inner class.
  83     boolean openKeychainInstalled;
  84
  85     @Override
  86     public void onCreate(Bundle savedInstanceState) {
  87         // Disable screenshots if not allowed.
  88         if (!MainWebViewActivity.allowScreenshots) {
  89             getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);
  90         }
  91
  92         // Set the activity theme.
  93         if (MainWebViewActivity.darkTheme) {
  94             setTheme(R.style.PrivacyBrowserDark_SecondaryActivity);
  95         } else {
  96             setTheme(R.style.PrivacyBrowserLight_SecondaryActivity);
  97         }
  98
  99         // Run the default commands.
 100         super.onCreate(savedInstanceState);
 101
 102         // Set the content view.
 103         setContentView(R.layout.import_export_coordinatorlayout);
 104
 105         // Use the `SupportActionBar` from `android.support.v7.app.ActionBar` until the minimum API is >= 21.
 106         Toolbar importExportAppBar = findViewById(R.id.import_export_toolbar);
 107         setSupportActionBar(importExportAppBar);
 108
 109         // Display the home arrow on the support action bar.
 110         ActionBar appBar = getSupportActionBar();
 111         assert appBar != null;// This assert removes the incorrect warning in Android Studio on the following line that `appBar` might be null.
 112         appBar.setDisplayHomeAsUpEnabled(true);
 113
 114         // Find out if we are running KitKat
 115         boolean runningKitKat = (Build.VERSION.SDK_INT == 19);
 116
 117         // Find out if OpenKeychain is installed.
 118         try {
 119             openKeychainInstalled = !getPackageManager().getPackageInfo("org.sufficientlysecure.keychain", 0).versionName.isEmpty();
 120         } catch (PackageManager.NameNotFoundException exception) {
 121             openKeychainInstalled = false;
 122         }
 123
 124         // Get handles for the views that need to be modified.
 125         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 126         TextInputLayout passwordEncryptionTextInputLayout = findViewById(R.id.password_encryption_textinputlayout);
 127         EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 128         TextView kitKatPasswordEncryptionTextView = findViewById(R.id.kitkat_password_encryption_textview);
 129         TextView openKeychainRequiredTextView = findViewById(R.id.openkeychain_required_textview);
 130         CardView fileLocationCardView = findViewById(R.id.file_location_cardview);
 131         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 132         RadioButton exportRadioButton = findViewById(R.id.export_radiobutton);
 133         LinearLayout fileNameLinearLayout = findViewById(R.id.file_name_linearlayout);
 134         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 135         TextView openKeychainImportInstructionsTextView = findViewById(R.id.openkeychain_import_instructions_textview);
 136         Button importExportButton = findViewById(R.id.import_export_button);
 137         TextView storagePermissionTextView = findViewById(R.id.import_export_storage_permission_textview);
 138
 139         // Create an array adapter for the spinner.
 140         ArrayAdapter<CharSequence> encryptionArrayAdapter = ArrayAdapter.createFromResource(this, R.array.encryption_type, R.layout.spinner_item);
 141
 142         // Set the drop down view resource on the spinner.
 143         encryptionArrayAdapter.setDropDownViewResource(R.layout.spinner_dropdown_items);
 144
 145         // Set the array adapter for the spinner.
 146         encryptionSpinner.setAdapter(encryptionArrayAdapter);
 147
 148         // Initially hide the unneeded views.
 149         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 150         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 151         openKeychainRequiredTextView.setVisibility(View.GONE);
 152         fileNameLinearLayout.setVisibility(View.GONE);
 153         openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 154         importExportButton.setVisibility(View.GONE);
 155
 156         // Create strings for the default file paths.
 157         String defaultFilePath;
 158         String defaultPasswordEncryptionFilePath;
 159
 160         // Set the default file paths according to the storage permission status.
 161         if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // The storage permission has been granted.
 162             // Set the default file paths to use the external public directory.
 163             defaultFilePath = Environment.getExternalStorageDirectory() + "/" + getString(R.string.privacy_browser_settings);
 164             defaultPasswordEncryptionFilePath = defaultFilePath + ".aes";
 165         } else {  // The storage permission has not been granted.
 166             // Set the default file paths to use the external private directory.
 167             defaultFilePath = getApplicationContext().getExternalFilesDir(null) + "/" + getString(R.string.privacy_browser_settings);
 168             defaultPasswordEncryptionFilePath = defaultFilePath + ".aes";
 169         }
 170
 171         // Set the default file path.
 172         fileNameEditText.setText(defaultFilePath);
 173
 174         // Display the encryption information when the spinner changes.
 175         encryptionSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
 176             @Override
 177             public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
 178                 switch (position) {
 179                     case NO_ENCRYPTION:
 180                         // Hide the unneeded layout items.
 181                         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 182                         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 183                         openKeychainRequiredTextView.setVisibility(View.GONE);
 184                         openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 185
 186                         // Show the file location card.
 187                         fileLocationCardView.setVisibility(View.VISIBLE);
 188
 189                         // Show the file name linear layout if either import or export is checked.
 190                         if (importRadioButton.isChecked() || exportRadioButton.isChecked()) {
 191                             fileNameLinearLayout.setVisibility(View.VISIBLE);
 192                         }
 193
 194                         // Reset the text of the import button, which may have been changed to `Decrypt`.
 195                         if (importRadioButton.isChecked()) {
 196                             importExportButton.setText(R.string.import_button);
 197                         }
 198
 199                         // Reset the default file path.
 200                         fileNameEditText.setText(defaultFilePath);
 201
 202                         // Enable the import/export button if a file name exists.
 203                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 204                         break;
 205
 206                     case PASSWORD_ENCRYPTION:
 207                         if (runningKitKat) {
 208                             // Show the KitKat password encryption message.
 209                             kitKatPasswordEncryptionTextView.setVisibility(View.VISIBLE);
 210
 211                             // Hide the OpenPGP required text view and the file location card.
 212                             openKeychainRequiredTextView.setVisibility(View.GONE);
 213                             fileLocationCardView.setVisibility(View.GONE);
 214                         } else {
 215                             // Hide the OpenPGP layout items.
 216                             openKeychainRequiredTextView.setVisibility(View.GONE);
 217                             openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 218
 219                             // Show the password encryption layout items.
 220                             passwordEncryptionTextInputLayout.setVisibility(View.VISIBLE);
 221
 222                             // Show the file location card.
 223                             fileLocationCardView.setVisibility(View.VISIBLE);
 224
 225                             // Show the file name linear layout if either import or export is checked.
 226                             if (importRadioButton.isChecked() || exportRadioButton.isChecked()) {
 227                                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 228                             }
 229
 230                             // Reset the text of the import button, which may have been changed to `Decrypt`.
 231                             if (importRadioButton.isChecked()) {
 232                                 importExportButton.setText(R.string.import_button);
 233                             }
 234
 235                             // Update the default file path.
 236                             fileNameEditText.setText(defaultPasswordEncryptionFilePath);
 237
 238                             // Enable the import/export button if a password exists.
 239                             importExportButton.setEnabled(!encryptionPasswordEditText.getText().toString().isEmpty());
 240                         }
 241                         break;
 242
 243                     case OPENPGP_ENCRYPTION:
 244                         // Hide the password encryption layout items.
 245                         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 246                         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 247
 248                         // Updated items based on the installation status of OpenKeychain.
 249                         if (openKeychainInstalled) {  // OpenKeychain is installed.
 250                             // Remove the default file path.
 251                             fileNameEditText.setText("");
 252
 253                             // Show the file location card.
 254                             fileLocationCardView.setVisibility(View.VISIBLE);
 255
 256                             if (importRadioButton.isChecked()) {
 257                                 // Show the file name linear layout and the OpenKeychain import instructions.
 258                                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 259                                 openKeychainImportInstructionsTextView.setVisibility(View.VISIBLE);
 260
 261                                 // Set the text of the import button to be `Decrypt`.
 262                                 importExportButton.setText(R.string.decrypt);
 263
 264                                 // Disable the import/export button.  The user needs to select a file to import first.
 265                                 importExportButton.setEnabled(false);
 266                             } else if (exportRadioButton.isChecked()) {
 267                                 // Hide the file name linear layout and the OpenKeychain import instructions.
 268                                 fileNameLinearLayout.setVisibility(View.GONE);
 269                                 openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 270
 271                                 // Enable the import/export button.
 272                                 importExportButton.setEnabled(true);
 273                             }
 274                         } else {  // OpenKeychain is not installed.
 275                             // Show the OpenPGP required layout item.
 276                             openKeychainRequiredTextView.setVisibility(View.VISIBLE);
 277
 278                             // Hide the file location card.
 279                             fileLocationCardView.setVisibility(View.GONE);
 280                         }
 281                         break;
 282                 }
 283             }
 284
 285             @Override
 286             public void onNothingSelected(AdapterView<?> parent) {
 287
 288             }
 289         });
 290
 291         // Update the status of the import/export button when the password changes.
 292         encryptionPasswordEditText.addTextChangedListener(new TextWatcher() {
 293             @Override
 294             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 295                 // Do nothing.
 296             }
 297
 298             @Override
 299             public void onTextChanged(CharSequence s, int start, int before, int count) {
 300                 // Do nothing.
 301             }
 302
 303             @Override
 304             public void afterTextChanged(Editable s) {
 305                 // Enable the import/export button if a file name and password exists.
 306                 importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty() && !encryptionPasswordEditText.getText().toString().isEmpty());
 307             }
 308         });
 309
 310         // Update the status of the import/export button when the file name EditText changes.
 311         fileNameEditText.addTextChangedListener(new TextWatcher() {
 312             @Override
 313             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 314                 // Do nothing.
 315             }
 316
 317             @Override
 318             public void onTextChanged(CharSequence s, int start, int before, int count) {
 319                 // Do nothing.
 320             }
 321
 322             @Override
 323             public void afterTextChanged(Editable s) {
 324                 // Adjust the export button according to the encryption spinner position.
 325                 switch (encryptionSpinner.getSelectedItemPosition()) {
 326                     case NO_ENCRYPTION:
 327                         // Enable the import/export button if a file name exists.
 328                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 329                         break;
 330
 331                     case PASSWORD_ENCRYPTION:
 332                         // Enable the import/export button if a file name and password exists.
 333                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty() && !encryptionPasswordEditText.getText().toString().isEmpty());
 334                         break;
 335
 336                     case OPENPGP_ENCRYPTION:
 337                         // Enable the import/export button if OpenKeychain is installed and a file name exists.
 338                         importExportButton.setEnabled(openKeychainInstalled && !fileNameEditText.getText().toString().isEmpty());
 339                         break;
 340                 }
 341             }
 342         });
 343
 344         // Hide the storage permissions TextView on API < 23 as permissions on older devices are automatically granted.
 345         if (Build.VERSION.SDK_INT < 23) {
 346             storagePermissionTextView.setVisibility(View.GONE);
 347         }
 348     }
 349
 350     public void onClickRadioButton(View view) {
 351         // Get handles for the views.
 352         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 353         LinearLayout fileNameLinearLayout = findViewById(R.id.file_name_linearlayout);
 354         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 355         TextView openKeychainImportInstructionTextView = findViewById(R.id.openkeychain_import_instructions_textview);
 356         Button importExportButton = findViewById(R.id.import_export_button);
 357
 358         // Check to see if import or export was selected.
 359         switch (view.getId()) {
 360             case R.id.import_radiobutton:
 361                 // Check to see if OpenPGP encryption is selected.
 362                 if (encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) {  // OpenPGP encryption selected.
 363                     // Show the OpenKeychain import instructions.
 364                     openKeychainImportInstructionTextView.setVisibility(View.VISIBLE);
 365
 366                     // Set the text on the import/export button to be `Decrypt`.
 367                     importExportButton.setText(R.string.decrypt);
 368
 369                     // Enable the decrypt button if there is a file name.
 370                     importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 371                 } else {  // OpenPGP encryption not selected.
 372                     // Hide the OpenKeychain import instructions.
 373                     openKeychainImportInstructionTextView.setVisibility(View.GONE);
 374
 375                     // Set the text on the import/export button to be `Import`.
 376                     importExportButton.setText(R.string.import_button);
 377                 }
 378
 379                 // Display the file name views.
 380                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 381                 importExportButton.setVisibility(View.VISIBLE);
 382                 break;
 383
 384             case R.id.export_radiobutton:
 385                 // Hide the OpenKeychain import instructions.
 386                 openKeychainImportInstructionTextView.setVisibility(View.GONE);
 387
 388                 // Set the text on the import/export button to be `Export`.
 389                 importExportButton.setText(R.string.export);
 390
 391                 // Show the import/export button.
 392                 importExportButton.setVisibility(View.VISIBLE);
 393
 394                 // Check to see if OpenPGP encryption is selected.
 395                 if (encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) {  // OpenPGP encryption is selected.
 396                     // Hide the file name views.
 397                     fileNameLinearLayout.setVisibility(View.GONE);
 398
 399                     // Enable the export button.
 400                     importExportButton.setEnabled(true);
 401                 } else {  // OpenPGP encryption is not selected.
 402                     // Show the file name views.
 403                     fileNameLinearLayout.setVisibility(View.VISIBLE);
 404                 }
 405                 break;
 406         }
 407     }
 408
 409     public void browse(View view) {
 410         // Get a handle for the import radiobutton.
 411         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 412
 413         // Check to see if import or export is selected.
 414         if (importRadioButton.isChecked()) {  // Import is selected.
 415             // Create the file picker intent.
 416             Intent importBrowseIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
 417
 418             // Set the intent MIME type to include all files.
 419             importBrowseIntent.setType("*/*");
 420
 421             // Set the initial directory if API >= 26.
 422             if (Build.VERSION.SDK_INT >= 26) {
 423                 importBrowseIntent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, Environment.getExternalStorageDirectory());
 424             }
 425
 426             // Specify that a file that can be opened is requested.
 427             importBrowseIntent.addCategory(Intent.CATEGORY_OPENABLE);
 428
 429             // Launch the file picker.
 430             startActivityForResult(importBrowseIntent, BROWSE_RESULT_CODE);
 431         } else {  // Export is selected
 432             // Create the file picker intent.
 433             Intent exportBrowseIntent = new Intent(Intent.ACTION_CREATE_DOCUMENT);
 434
 435             // Set the intent MIME type to include all files.
 436             exportBrowseIntent.setType("*/*");
 437
 438             // Set the initial export file name.
 439             exportBrowseIntent.putExtra(Intent.EXTRA_TITLE, getString(R.string.privacy_browser_settings));
 440
 441             // Set the initial directory if API >= 26.
 442             if (Build.VERSION.SDK_INT >= 26) {
 443                 exportBrowseIntent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, Environment.getExternalStorageDirectory());
 444             }
 445
 446             // Specify that a file that can be opened is requested.
 447             exportBrowseIntent.addCategory(Intent.CATEGORY_OPENABLE);
 448
 449             // Launch the file picker.
 450             startActivityForResult(exportBrowseIntent, BROWSE_RESULT_CODE);
 451         }
 452     }
 453
 454     public void importExport(View view) {
 455         // Get a handle for the views.
 456         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 457         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 458         RadioButton exportRadioButton = findViewById(R.id.export_radiobutton);
 459
 460         // Check to see if the storage permission is needed.
 461         if ((encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) && exportRadioButton.isChecked()) {  // Permission not needed to export via OpenKeychain.
 462             // Export the settings.
 463             exportSettings();
 464         } else if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // The storage permission has been granted.
 465             // Check to see if import or export is selected.
 466             if (importRadioButton.isChecked()) {  // Import is selected.
 467                 // Import the settings.
 468                 importSettings();
 469             } else {  // Export is selected.
 470                 // Export the settings.
 471                 exportSettings();
 472             }
 473         } else {  // The storage permission has not been granted.
 474             // Get a handle for the file name EditText.
 475             EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 476
 477             // Get the file name string.
 478             String fileNameString = fileNameEditText.getText().toString();
 479
 480             // Get the external private directory `File`.
 481             File externalPrivateDirectoryFile = getApplicationContext().getExternalFilesDir(null);
 482
 483             // Remove the lint error below that the `File` might be null.
 484             assert externalPrivateDirectoryFile != null;
 485
 486             // Get the external private directory string.
 487             String externalPrivateDirectory = externalPrivateDirectoryFile.toString();
 488
 489             // Check to see if the file path is in the external private directory.
 490             if (fileNameString.startsWith(externalPrivateDirectory)) {  // The file path is in the external private directory.
 491                 // Check to see if import or export is selected.
 492                 if (importRadioButton.isChecked()) {  // Import is selected.
 493                     // Import the settings.
 494                     importSettings();
 495                 } else {  // Export is selected.
 496                     // Export the settings.
 497                     exportSettings();
 498                 }
 499             } else {  // The file path is in a public directory.
 500                 // Check if the user has previously denied the storage permission.
 501                 if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {  // Show a dialog explaining the request first.
 502                     // Instantiate the storage permission alert dialog.
 503                     DialogFragment importExportStoragePermissionDialogFragment = new ImportExportStoragePermissionDialog();
 504
 505                     // Show the storage permission alert dialog.  The permission will be requested when the dialog is closed.
 506                     importExportStoragePermissionDialogFragment.show(getFragmentManager(), getString(R.string.storage_permission));
 507                 } else {  // Show the permission request directly.
 508                     // Request the storage permission.  The export will be run when it finishes.
 509                     ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0);
 510                 }
 511             }
 512         }
 513     }
 514
 515     @Override
 516     public void onCloseImportExportStoragePermissionDialog() {
 517         // Request the write external storage permission.  The import/export will be run when it finishes.
 518         ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0);
 519     }
 520
 521     @Override
 522     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
 523         // Get a handle for the import radiobutton.
 524         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 525
 526         // Check to see if import or export is selected.
 527         if (importRadioButton.isChecked()) {  // Import is selected.
 528             // Check to see if the storage permission was granted.  If the dialog was canceled the grant results will be empty.
 529             if ((grantResults.length > 0) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) {  // The storage permission was granted.
 530                 // Import the settings.
 531                 importSettings();
 532             } else {  // The storage permission was not granted.
 533                 // Display an error snackbar.
 534                 Snackbar.make(importRadioButton, getString(R.string.cannot_import), Snackbar.LENGTH_LONG).show();
 535             }
 536         } else {  // Export is selected.
 537             // Check to see if the storage permission was granted.  If the dialog was canceled the grant results will be empty.
 538             if ((grantResults.length > 0) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) {  // The storage permission was granted.
 539                 // Export the settings.
 540                 exportSettings();
 541             } else {  // The storage permission was not granted.
 542                 // Display an error snackbar.
 543                 Snackbar.make(importRadioButton, getString(R.string.cannot_export), Snackbar.LENGTH_LONG).show();
 544             }
 545         }
 546     }
 547
 548     @Override
 549     public void onActivityResult(int requestCode, int resultCode, Intent data) {
 550         switch (requestCode) {
 551             case (BROWSE_RESULT_CODE):
 552                 // Don't do anything if the user pressed back from the file picker.
 553                 if (resultCode == Activity.RESULT_OK) {
 554                     // Get a handle for the file name EditText.
 555                     EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 556
 557                     // Get the file name URI.
 558                     Uri fileNameUri = data.getData();
 559
 560                     // Remove the lint warning that the file name URI might be null.
 561                     assert fileNameUri != null;
 562
 563                     // Get the raw file name path.
 564                     String rawFileNamePath = fileNameUri.getPath();
 565
 566                     // Remove the warning that the file name path might be null.
 567                     assert rawFileNamePath != null;
 568
 569                     // Check to see if the file name Path includes a valid storage location.
 570                     if (rawFileNamePath.contains(":")) {  // The path is valid.
 571                         // Split the path into the initial content uri and the final path information.
 572                         String fileNameContentPath = rawFileNamePath.substring(0, rawFileNamePath.indexOf(":"));
 573                         String fileNameFinalPath = rawFileNamePath.substring(rawFileNamePath.indexOf(":") + 1);
 574
 575                         // Create the file name path string.
 576                         String fileNamePath;
 577
 578                         // Construct the file name path.
 579                         switch (fileNameContentPath) {
 580                             // The documents home has a special content path.
 581                             case "/document/home":
 582                                 fileNamePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS) + "/" + fileNameFinalPath;
 583                                 break;
 584
 585                             // Everything else for the primary user should be in `/document/primary`.
 586                             case "/document/primary":
 587                                 fileNamePath = Environment.getExternalStorageDirectory() + "/" + fileNameFinalPath;
 588                                 break;
 589
 590                             // Just in case, catch everything else and place it in the external storage directory.
 591                             default:
 592                                 fileNamePath = Environment.getExternalStorageDirectory() + "/" + fileNameFinalPath;
 593                                 break;
 594                         }
 595
 596                         // Set the file name path as the text of the file name EditText.
 597                         fileNameEditText.setText(fileNamePath);
 598                     } else {  // The path is invalid.
 599                         Snackbar.make(fileNameEditText, rawFileNamePath + " " + getString(R.string.invalid_location), Snackbar.LENGTH_INDEFINITE).show();
 600                     }
 601                 }
 602                 break;
 603
 604             case OPENPGP_EXPORT_RESULT_CODE:
 605                 // Get the temporary unencrypted export file.
 606                 File temporaryUnencryptedExportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.privacy_browser_settings));
 607
 608                 // Delete the temporary unencrypted export file if it exists.
 609                 if (temporaryUnencryptedExportFile.exists()) {
 610                     //noinspection ResultOfMethodCallIgnored
 611                     temporaryUnencryptedExportFile.delete();
 612                 }
 613                 break;
 614         }
 615     }
 616
 617     private void exportSettings() {
 618         // Get a handle for the views.
 619         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 620         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 621
 622         // Instantiate the import export database helper.
 623         ImportExportDatabaseHelper importExportDatabaseHelper = new ImportExportDatabaseHelper();
 624
 625         // Get the export and temporary unencrypted export files.
 626         File exportFile = new File(fileNameEditText.getText().toString());
 627         File temporaryUnencryptedExportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.privacy_browser_settings));
 628
 629         // Initialize the export status string.
 630         String exportStatus;
 631
 632         // Export according to the encryption type.
 633         switch (encryptionSpinner.getSelectedItemPosition()) {
 634             case NO_ENCRYPTION:
 635                 // Export the unencrypted file.
 636                 exportStatus = importExportDatabaseHelper.exportUnencrypted(exportFile, this);
 637
 638                 // Show a disposition snackbar.
 639                 if (exportStatus.equals(ImportExportDatabaseHelper.EXPORT_SUCCESSFUL)) {
 640                     Snackbar.make(fileNameEditText, getString(R.string.export_successful), Snackbar.LENGTH_SHORT).show();
 641                 } else {
 642                     Snackbar.make(fileNameEditText, getString(R.string.export_failed) + "  " + exportStatus, Snackbar.LENGTH_INDEFINITE).show();
 643                 }
 644                 break;
 645
 646             case PASSWORD_ENCRYPTION:
 647                 // Create an unencrypted export in a private directory.
 648                 exportStatus = importExportDatabaseHelper.exportUnencrypted(temporaryUnencryptedExportFile, this);
 649
 650                 try {
 651                     // Create an unencrypted export file input stream.
 652                     FileInputStream unencryptedExportFileInputStream = new FileInputStream(temporaryUnencryptedExportFile);
 653
 654                     // Delete the encrypted export file if it exists.
 655                     if (exportFile.exists()) {
 656                         //noinspection ResultOfMethodCallIgnored
 657                         exportFile.delete();
 658                     }
 659
 660                     // Create an encrypted export file output stream.
 661                     FileOutputStream encryptedExportFileOutputStream = new FileOutputStream(exportFile);
 662
 663                     // Get a handle for the encryption password EditText.
 664                     EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 665
 666                     // Get the encryption password.
 667                     String encryptionPasswordString = encryptionPasswordEditText.getText().toString();
 668
 669                     // Initialize a secure random number generator.
 670                     SecureRandom secureRandom = new SecureRandom();
 671
 672                     // Get a 256 bit (32 byte) random salt.
 673                     byte[] saltByteArray = new byte[32];
 674                     secureRandom.nextBytes(saltByteArray);
 675
 676                     // Convert the encryption password to a byte array.
 677                     byte[] encryptionPasswordByteArray = encryptionPasswordString.getBytes("UTF-8");
 678
 679                     // Append the salt to the encryption password byte array.  This protects against rainbow table attacks.
 680                     byte[] encryptionPasswordWithSaltByteArray = new byte[encryptionPasswordByteArray.length + saltByteArray.length];
 681                     System.arraycopy(encryptionPasswordByteArray, 0, encryptionPasswordWithSaltByteArray, 0, encryptionPasswordByteArray.length);
 682                     System.arraycopy(saltByteArray, 0, encryptionPasswordWithSaltByteArray, encryptionPasswordByteArray.length, saltByteArray.length);
 683
 684                     // Get a SHA-512 message digest.
 685                     MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
 686
 687                     // Hash the salted encryption password.  Otherwise, any characters after the 32nd character in the password are ignored.
 688                     byte[] hashedEncryptionPasswordWithSaltByteArray = messageDigest.digest(encryptionPasswordWithSaltByteArray);
 689
 690                     // Truncate the encryption password byte array to 256 bits (32 bytes).
 691                     byte[] truncatedHashedEncryptionPasswordWithSaltByteArray = Arrays.copyOf(hashedEncryptionPasswordWithSaltByteArray, 32);
 692
 693                     // Create an AES secret key from the encryption password byte array.
 694                     SecretKeySpec secretKey = new SecretKeySpec(truncatedHashedEncryptionPasswordWithSaltByteArray, "AES");
 695
 696                     // Generate a random 12 byte initialization vector.  According to NIST, a 12 byte initialization vector is more secure than a 16 byte one.
 697                     byte[] initializationVector = new byte[12];
 698                     secureRandom.nextBytes(initializationVector);
 699
 700                     // Get a Advanced Encryption Standard, Galois/Counter Mode, No Padding cipher instance. Galois/Counter mode protects against modification of the ciphertext.  It doesn't use padding.
 701                     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
 702
 703                     // Set the GCM tag length to be 128 bits (the maximum) and apply the initialization vector.
 704                     GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(128, initializationVector);
 705
 706                     // Initialize the cipher.
 707                     cipher.init(Cipher.ENCRYPT_MODE, secretKey, gcmParameterSpec);
 708
 709                     // Add the salt and the initialization vector to the export file.
 710                     encryptedExportFileOutputStream.write(saltByteArray);
 711                     encryptedExportFileOutputStream.write(initializationVector);
 712
 713                     // Create a cipher output stream.
 714                     CipherOutputStream cipherOutputStream = new CipherOutputStream(encryptedExportFileOutputStream, cipher);
 715
 716                     // Initialize variables to store data as it is moved from the unencrypted export file input stream to the cipher output stream.  Move 128 bits (16 bytes) at a time.
 717                     int numberOfBytesRead;
 718                     byte[] encryptedBytes = new byte[16];
 719
 720                     // Read up to 128 bits (16 bytes) of data from the unencrypted export file stream.  `-1` will be returned when the end of the file is reached.
 721                     while ((numberOfBytesRead = unencryptedExportFileInputStream.read(encryptedBytes)) != -1) {
 722                         // Write the data to the cipher output stream.
 723                         cipherOutputStream.write(encryptedBytes, 0, numberOfBytesRead);
 724                     }
 725
 726                     // Close the streams.
 727                     cipherOutputStream.flush();
 728                     cipherOutputStream.close();
 729                     encryptedExportFileOutputStream.close();
 730                     unencryptedExportFileInputStream.close();
 731
 732                     // Wipe the encryption data from memory.
 733                     //noinspection UnusedAssignment
 734                     encryptionPasswordString = "";
 735                     Arrays.fill(saltByteArray, (byte) 0);
 736                     Arrays.fill(encryptionPasswordByteArray, (byte) 0);
 737                     Arrays.fill(encryptionPasswordWithSaltByteArray, (byte) 0);
 738                     Arrays.fill(hashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 739                     Arrays.fill(truncatedHashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 740                     Arrays.fill(initializationVector, (byte) 0);
 741                     Arrays.fill(encryptedBytes, (byte) 0);
 742
 743                     // Delete the temporary unencrypted export file.
 744                     //noinspection ResultOfMethodCallIgnored
 745                     temporaryUnencryptedExportFile.delete();
 746                 } catch (Exception exception) {
 747                     exportStatus = exception.toString();
 748                 }
 749
 750                 // Show a disposition snackbar.
 751                 if (exportStatus.equals(ImportExportDatabaseHelper.EXPORT_SUCCESSFUL)) {
 752                     Snackbar.make(fileNameEditText, getString(R.string.export_successful), Snackbar.LENGTH_SHORT).show();
 753                 } else {
 754                     Snackbar.make(fileNameEditText, getString(R.string.export_failed) + "  " + exportStatus, Snackbar.LENGTH_INDEFINITE).show();
 755                 }
 756                 break;
 757
 758             case OPENPGP_ENCRYPTION:
 759                 // Create an unencrypted export in the private location.
 760                 importExportDatabaseHelper.exportUnencrypted(temporaryUnencryptedExportFile, this);
 761
 762                 // Create an encryption intent for OpenKeychain.
 763                 Intent openKeychainEncryptIntent = new Intent("org.sufficientlysecure.keychain.action.ENCRYPT_DATA");
 764
 765                 // Include the temporary unencrypted export file URI.
 766                 openKeychainEncryptIntent.setData(FileProvider.getUriForFile(this, getString(R.string.file_provider), temporaryUnencryptedExportFile));
 767
 768                 // Allow OpenKeychain to read the file URI.
 769                 openKeychainEncryptIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 770
 771                 // Send the intent to the OpenKeychain package.
 772                 openKeychainEncryptIntent.setPackage("org.sufficientlysecure.keychain");
 773
 774                 // Make it so.
 775                 startActivityForResult(openKeychainEncryptIntent, OPENPGP_EXPORT_RESULT_CODE);
 776                 break;
 777         }
 778     }
 779
 780     private void importSettings() {
 781         // Get a handle for the views.
 782         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 783         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 784
 785         // Instantiate the import export database helper.
 786         ImportExportDatabaseHelper importExportDatabaseHelper = new ImportExportDatabaseHelper();
 787
 788         // Get the import file.
 789         File importFile = new File(fileNameEditText.getText().toString());
 790
 791         // Initialize the import status string
 792         String importStatus = "";
 793
 794         // Import according to the encryption type.
 795         switch (encryptionSpinner.getSelectedItemPosition()) {
 796             case NO_ENCRYPTION:
 797                 // Import the unencrypted file.
 798                 importStatus = importExportDatabaseHelper.importUnencrypted(importFile, this);
 799                 break;
 800
 801             case PASSWORD_ENCRYPTION:
 802                 // Use a private temporary import location.
 803                 File temporaryUnencryptedImportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.privacy_browser_settings));
 804
 805                 try {
 806                     // Create an encrypted import file input stream.
 807                     FileInputStream encryptedImportFileInputStream = new FileInputStream(importFile);
 808
 809                     // Delete the temporary import file if it exists.
 810                     if (temporaryUnencryptedImportFile.exists()) {
 811                         //noinspection ResultOfMethodCallIgnored
 812                         temporaryUnencryptedImportFile.delete();
 813                     }
 814
 815                     // Create an unencrypted import file output stream.
 816                     FileOutputStream unencryptedImportFileOutputStream = new FileOutputStream(temporaryUnencryptedImportFile);
 817
 818                     // Get a handle for the encryption password EditText.
 819                     EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 820
 821                     // Get the encryption password.
 822                     String encryptionPasswordString = encryptionPasswordEditText.getText().toString();
 823
 824                     // Get the salt from the beginning of the import file.
 825                     byte[] saltByteArray = new byte[32];
 826                     //noinspection ResultOfMethodCallIgnored
 827                     encryptedImportFileInputStream.read(saltByteArray);
 828
 829                     // Get the initialization vector from the import file.
 830                     byte[] initializationVector = new byte[12];
 831                     //noinspection ResultOfMethodCallIgnored
 832                     encryptedImportFileInputStream.read(initializationVector);
 833
 834                     // Convert the encryption password to a byte array.
 835                     byte[] encryptionPasswordByteArray = encryptionPasswordString.getBytes("UTF-8");
 836
 837                     // Append the salt to the encryption password byte array.  This protects against rainbow table attacks.
 838                     byte[] encryptionPasswordWithSaltByteArray = new byte[encryptionPasswordByteArray.length + saltByteArray.length];
 839                     System.arraycopy(encryptionPasswordByteArray, 0, encryptionPasswordWithSaltByteArray, 0, encryptionPasswordByteArray.length);
 840                     System.arraycopy(saltByteArray, 0, encryptionPasswordWithSaltByteArray, encryptionPasswordByteArray.length, saltByteArray.length);
 841
 842                     // Get a SHA-512 message digest.
 843                     MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
 844
 845                     // Hash the salted encryption password.  Otherwise, any characters after the 32nd character in the password are ignored.
 846                     byte[] hashedEncryptionPasswordWithSaltByteArray = messageDigest.digest(encryptionPasswordWithSaltByteArray);
 847
 848                     // Truncate the encryption password byte array to 256 bits (32 bytes).
 849                     byte[] truncatedHashedEncryptionPasswordWithSaltByteArray = Arrays.copyOf(hashedEncryptionPasswordWithSaltByteArray, 32);
 850
 851                     // Create an AES secret key from the encryption password byte array.
 852                     SecretKeySpec secretKey = new SecretKeySpec(truncatedHashedEncryptionPasswordWithSaltByteArray, "AES");
 853
 854                     // Get a Advanced Encryption Standard, Galois/Counter Mode, No Padding cipher instance. Galois/Counter mode protects against modification of the ciphertext.  It doesn't use padding.
 855                     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
 856
 857                     // Set the GCM tag length to be 128 bits (the maximum) and apply the initialization vector.
 858                     GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(128, initializationVector);
 859
 860                     // Initialize the cipher.
 861                     cipher.init(Cipher.DECRYPT_MODE, secretKey, gcmParameterSpec);
 862
 863                     // Create a cipher input stream.
 864                     CipherInputStream cipherInputStream = new CipherInputStream(encryptedImportFileInputStream, cipher);
 865
 866                     // Initialize variables to store data as it is moved from the cipher input stream to the unencrypted import file output stream.  Move 128 bits (16 bytes) at a time.
 867                     int numberOfBytesRead;
 868                     byte[] decryptedBytes = new byte[16];
 869
 870                     // Read up to 128 bits (16 bytes) of data from the cipher input stream.  `-1` will be returned when the end fo the file is reached.
 871                     while ((numberOfBytesRead = cipherInputStream.read(decryptedBytes)) != -1) {
 872                         // Write the data to the unencrypted import file output stream.
 873                         unencryptedImportFileOutputStream.write(decryptedBytes, 0, numberOfBytesRead);
 874                     }
 875
 876                     // Close the streams.
 877                     unencryptedImportFileOutputStream.flush();
 878                     unencryptedImportFileOutputStream.close();
 879                     cipherInputStream.close();
 880                     encryptedImportFileInputStream.close();
 881
 882                     // Wipe the encryption data from memory.
 883                     //noinspection UnusedAssignment
 884                     encryptionPasswordString = "";
 885                     Arrays.fill(saltByteArray, (byte) 0);
 886                     Arrays.fill(initializationVector, (byte) 0);
 887                     Arrays.fill(encryptionPasswordByteArray, (byte) 0);
 888                     Arrays.fill(encryptionPasswordWithSaltByteArray, (byte) 0);
 889                     Arrays.fill(hashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 890                     Arrays.fill(truncatedHashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 891                     Arrays.fill(decryptedBytes, (byte) 0);
 892
 893                     // Import the unencrypted database from the private location.
 894                     importStatus = importExportDatabaseHelper.importUnencrypted(temporaryUnencryptedImportFile, this);
 895
 896                     // Delete the temporary unencrypted import file.
 897                     //noinspection ResultOfMethodCallIgnored
 898                     temporaryUnencryptedImportFile.delete();
 899                 } catch (Exception exception) {
 900                     importStatus = exception.toString();
 901                 }
 902                 break;
 903
 904             case OPENPGP_ENCRYPTION:
 905                 try {
 906                     // Create an decryption intent for OpenKeychain.
 907                     Intent openKeychainDecryptIntent = new Intent("org.sufficientlysecure.keychain.action.DECRYPT_DATA");
 908
 909                     // Include the URI to be decrypted.
 910                     openKeychainDecryptIntent.setData(FileProvider.getUriForFile(this, getString(R.string.file_provider), importFile));
 911
 912                     // Allow OpenKeychain to read the file URI.
 913                     openKeychainDecryptIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 914
 915                     // Send the intent to the OpenKeychain package.
 916                     openKeychainDecryptIntent.setPackage("org.sufficientlysecure.keychain");
 917
 918                     // Make it so.
 919                     startActivity(openKeychainDecryptIntent);
 920                 } catch (IllegalArgumentException exception) {  // The file import location is not valid.
 921                     // Display a snack bar with the import error.
 922                     Snackbar.make(fileNameEditText, getString(R.string.import_failed) + "  " + exception.toString(), Snackbar.LENGTH_INDEFINITE).show();
 923                 }
 924                 break;
 925         }
 926
 927         // Respond to the import disposition.
 928         if (importStatus.equals(ImportExportDatabaseHelper.IMPORT_SUCCESSFUL)) {  // The import was successful.
 929             // Create an intent to restart Privacy Browser.
 930             Intent restartIntent = getParentActivityIntent();
 931
 932             // Assert that the intent is not null to remove the lint error below.
 933             assert restartIntent != null;
 934
 935             // `Intent.FLAG_ACTIVITY_CLEAR_TASK` removes all activities from the stack.  It requires `Intent.FLAG_ACTIVITY_NEW_TASK`.
 936             restartIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
 937
 938             // Make it so.
 939             startActivity(restartIntent);
 940         } else if (!(encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION)){  // The import was not successful.
 941             // Display a snack bar with the import error.
 942             Snackbar.make(fileNameEditText, getString(R.string.import_failed) + "  " + importStatus, Snackbar.LENGTH_INDEFINITE).show();
 943         }
 944     }
 945 }