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

   1 /*
   2  * Copyright © 2018-2019 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.content.Intent;
  25 import android.content.SharedPreferences;
  26 import android.content.pm.PackageManager;
  27 import android.media.MediaScannerConnection;
  28 import android.net.Uri;
  29 import android.os.Build;
  30 import android.os.Bundle;
  31 import android.os.Environment;
  32 import android.preference.PreferenceManager;
  33 import android.provider.DocumentsContract;
  34 import android.text.Editable;
  35 import android.text.TextWatcher;
  36 import android.view.View;
  37 import android.view.WindowManager;
  38 import android.widget.AdapterView;
  39 import android.widget.ArrayAdapter;
  40 import android.widget.Button;
  41 import android.widget.EditText;
  42 import android.widget.LinearLayout;
  43 import android.widget.RadioButton;
  44 import android.widget.Spinner;
  45 import android.widget.TextView;
  46
  47 import androidx.annotation.NonNull;
  48 import androidx.appcompat.app.ActionBar;
  49 import androidx.appcompat.app.AppCompatActivity;
  50 import androidx.appcompat.widget.Toolbar;
  51 import androidx.cardview.widget.CardView;
  52 import androidx.core.app.ActivityCompat;
  53 import androidx.core.content.ContextCompat;
  54 import androidx.core.content.FileProvider;
  55 import androidx.fragment.app.DialogFragment;
  56
  57 import com.google.android.material.snackbar.Snackbar;
  58 import com.google.android.material.textfield.TextInputLayout;
  59
  60 import com.stoutner.privacybrowser.R;
  61 import com.stoutner.privacybrowser.dialogs.StoragePermissionDialog;
  62 import com.stoutner.privacybrowser.helpers.ImportExportDatabaseHelper;
  63
  64 import java.io.File;
  65 import java.io.FileInputStream;
  66 import java.io.FileOutputStream;
  67 import java.nio.charset.StandardCharsets;
  68 import java.security.MessageDigest;
  69 import java.security.SecureRandom;
  70 import java.util.Arrays;
  71
  72 import javax.crypto.Cipher;
  73 import javax.crypto.CipherInputStream;
  74 import javax.crypto.CipherOutputStream;
  75 import javax.crypto.spec.GCMParameterSpec;
  76 import javax.crypto.spec.SecretKeySpec;
  77
  78 public class ImportExportActivity extends AppCompatActivity implements StoragePermissionDialog.StoragePermissionDialogListener {
  79     // Create the encryption constants.
  80     private final int NO_ENCRYPTION = 0;
  81     private final int PASSWORD_ENCRYPTION = 1;
  82     private final int OPENPGP_ENCRYPTION = 2;
  83
  84     // Create the activity result constants.
  85     private final int BROWSE_RESULT_CODE = 0;
  86     private final int OPENPGP_EXPORT_RESULT_CODE = 1;
  87
  88     // `openKeychainInstalled` is accessed from an inner class.
  89     private boolean openKeychainInstalled;
  90
  91     @Override
  92     public void onCreate(Bundle savedInstanceState) {
  93         // Get a handle for the shared preferences.
  94         SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
  95
  96         // Get the theme and screenshot preferences.
  97         boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);
  98         boolean allowScreenshots = sharedPreferences.getBoolean("allow_screenshots", false);
  99
 100         // Disable screenshots if not allowed.
 101         if (!allowScreenshots) {
 102             getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);
 103         }
 104
 105         // Set the activity theme.
 106         if (darkTheme) {
 107             setTheme(R.style.PrivacyBrowserDark_SecondaryActivity);
 108         } else {
 109             setTheme(R.style.PrivacyBrowserLight_SecondaryActivity);
 110         }
 111
 112         // Run the default commands.
 113         super.onCreate(savedInstanceState);
 114
 115         // Set the content view.
 116         setContentView(R.layout.import_export_coordinatorlayout);
 117
 118         // Use the `SupportActionBar` from `android.support.v7.app.ActionBar` until the minimum API is >= 21.
 119         Toolbar toolbar = findViewById(R.id.import_export_toolbar);
 120         setSupportActionBar(toolbar);
 121
 122         // Get a handle for the action bar.
 123         ActionBar actionBar = getSupportActionBar();
 124
 125         // Remove the incorrect lint warning that the action bar might be null.
 126         assert actionBar != null;
 127
 128         // Display the home arrow on the support action bar.
 129         actionBar.setDisplayHomeAsUpEnabled(true);
 130
 131         // Find out if we are running KitKat
 132         boolean runningKitKat = (Build.VERSION.SDK_INT == 19);
 133
 134         // Find out if OpenKeychain is installed.
 135         try {
 136             openKeychainInstalled = !getPackageManager().getPackageInfo("org.sufficientlysecure.keychain", 0).versionName.isEmpty();
 137         } catch (PackageManager.NameNotFoundException exception) {
 138             openKeychainInstalled = false;
 139         }
 140
 141         // Get handles for the views that need to be modified.
 142         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 143         TextInputLayout passwordEncryptionTextInputLayout = findViewById(R.id.password_encryption_textinputlayout);
 144         EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 145         TextView kitKatPasswordEncryptionTextView = findViewById(R.id.kitkat_password_encryption_textview);
 146         TextView openKeychainRequiredTextView = findViewById(R.id.openkeychain_required_textview);
 147         CardView fileLocationCardView = findViewById(R.id.file_location_cardview);
 148         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 149         RadioButton exportRadioButton = findViewById(R.id.export_radiobutton);
 150         LinearLayout fileNameLinearLayout = findViewById(R.id.file_name_linearlayout);
 151         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 152         TextView openKeychainImportInstructionsTextView = findViewById(R.id.openkeychain_import_instructions_textview);
 153         Button importExportButton = findViewById(R.id.import_export_button);
 154         TextView storagePermissionTextView = findViewById(R.id.import_export_storage_permission_textview);
 155
 156         // Create an array adapter for the spinner.
 157         ArrayAdapter<CharSequence> encryptionArrayAdapter = ArrayAdapter.createFromResource(this, R.array.encryption_type, R.layout.spinner_item);
 158
 159         // Set the drop down view resource on the spinner.
 160         encryptionArrayAdapter.setDropDownViewResource(R.layout.spinner_dropdown_items);
 161
 162         // Set the array adapter for the spinner.
 163         encryptionSpinner.setAdapter(encryptionArrayAdapter);
 164
 165         // Initially hide the unneeded views.
 166         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 167         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 168         openKeychainRequiredTextView.setVisibility(View.GONE);
 169         fileNameLinearLayout.setVisibility(View.GONE);
 170         openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 171         importExportButton.setVisibility(View.GONE);
 172
 173         // Create strings for the default file paths.
 174         String defaultFilePath;
 175         String defaultPasswordEncryptionFilePath;
 176
 177         // Set the default file paths according to the storage permission status.
 178         if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // The storage permission has been granted.
 179             // Set the default file paths to use the external public directory.
 180             defaultFilePath = Environment.getExternalStorageDirectory() + "/" + getString(R.string.settings_pbs);
 181             defaultPasswordEncryptionFilePath = defaultFilePath + ".aes";
 182         } else {  // The storage permission has not been granted.
 183             // Set the default file paths to use the external private directory.
 184             defaultFilePath = getApplicationContext().getExternalFilesDir(null) + "/" + getString(R.string.settings_pbs);
 185             defaultPasswordEncryptionFilePath = defaultFilePath + ".aes";
 186         }
 187
 188         // Set the default file path.
 189         fileNameEditText.setText(defaultFilePath);
 190
 191         // Display the encryption information when the spinner changes.
 192         encryptionSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
 193             @Override
 194             public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
 195                 switch (position) {
 196                     case NO_ENCRYPTION:
 197                         // Hide the unneeded layout items.
 198                         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 199                         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 200                         openKeychainRequiredTextView.setVisibility(View.GONE);
 201                         openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 202
 203                         // Show the file location card.
 204                         fileLocationCardView.setVisibility(View.VISIBLE);
 205
 206                         // Show the file name linear layout if either import or export is checked.
 207                         if (importRadioButton.isChecked() || exportRadioButton.isChecked()) {
 208                             fileNameLinearLayout.setVisibility(View.VISIBLE);
 209                         }
 210
 211                         // Reset the text of the import button, which may have been changed to `Decrypt`.
 212                         if (importRadioButton.isChecked()) {
 213                             importExportButton.setText(R.string.import_button);
 214                         }
 215
 216                         // Reset the default file path.
 217                         fileNameEditText.setText(defaultFilePath);
 218
 219                         // Enable the import/export button if a file name exists.
 220                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 221                         break;
 222
 223                     case PASSWORD_ENCRYPTION:
 224                         if (runningKitKat) {
 225                             // Show the KitKat password encryption message.
 226                             kitKatPasswordEncryptionTextView.setVisibility(View.VISIBLE);
 227
 228                             // Hide the OpenPGP required text view and the file location card.
 229                             openKeychainRequiredTextView.setVisibility(View.GONE);
 230                             fileLocationCardView.setVisibility(View.GONE);
 231                         } else {
 232                             // Hide the OpenPGP layout items.
 233                             openKeychainRequiredTextView.setVisibility(View.GONE);
 234                             openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 235
 236                             // Show the password encryption layout items.
 237                             passwordEncryptionTextInputLayout.setVisibility(View.VISIBLE);
 238
 239                             // Show the file location card.
 240                             fileLocationCardView.setVisibility(View.VISIBLE);
 241
 242                             // Show the file name linear layout if either import or export is checked.
 243                             if (importRadioButton.isChecked() || exportRadioButton.isChecked()) {
 244                                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 245                             }
 246
 247                             // Reset the text of the import button, which may have been changed to `Decrypt`.
 248                             if (importRadioButton.isChecked()) {
 249                                 importExportButton.setText(R.string.import_button);
 250                             }
 251
 252                             // Update the default file path.
 253                             fileNameEditText.setText(defaultPasswordEncryptionFilePath);
 254
 255                             // Enable the import/export button if a password exists.
 256                             importExportButton.setEnabled(!encryptionPasswordEditText.getText().toString().isEmpty());
 257                         }
 258                         break;
 259
 260                     case OPENPGP_ENCRYPTION:
 261                         // Hide the password encryption layout items.
 262                         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 263                         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 264
 265                         // Updated items based on the installation status of OpenKeychain.
 266                         if (openKeychainInstalled) {  // OpenKeychain is installed.
 267                             // Remove the default file path.
 268                             fileNameEditText.setText("");
 269
 270                             // Show the file location card.
 271                             fileLocationCardView.setVisibility(View.VISIBLE);
 272
 273                             if (importRadioButton.isChecked()) {
 274                                 // Show the file name linear layout and the OpenKeychain import instructions.
 275                                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 276                                 openKeychainImportInstructionsTextView.setVisibility(View.VISIBLE);
 277
 278                                 // Set the text of the import button to be `Decrypt`.
 279                                 importExportButton.setText(R.string.decrypt);
 280
 281                                 // Disable the import/export button.  The user needs to select a file to import first.
 282                                 importExportButton.setEnabled(false);
 283                             } else if (exportRadioButton.isChecked()) {
 284                                 // Hide the file name linear layout and the OpenKeychain import instructions.
 285                                 fileNameLinearLayout.setVisibility(View.GONE);
 286                                 openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 287
 288                                 // Enable the import/export button.
 289                                 importExportButton.setEnabled(true);
 290                             }
 291                         } else {  // OpenKeychain is not installed.
 292                             // Show the OpenPGP required layout item.
 293                             openKeychainRequiredTextView.setVisibility(View.VISIBLE);
 294
 295                             // Hide the file location card.
 296                             fileLocationCardView.setVisibility(View.GONE);
 297                         }
 298                         break;
 299                 }
 300             }
 301
 302             @Override
 303             public void onNothingSelected(AdapterView<?> parent) {
 304
 305             }
 306         });
 307
 308         // Update the status of the import/export button when the password changes.
 309         encryptionPasswordEditText.addTextChangedListener(new TextWatcher() {
 310             @Override
 311             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 312                 // Do nothing.
 313             }
 314
 315             @Override
 316             public void onTextChanged(CharSequence s, int start, int before, int count) {
 317                 // Do nothing.
 318             }
 319
 320             @Override
 321             public void afterTextChanged(Editable s) {
 322                 // Enable the import/export button if a file name and password exists.
 323                 importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty() && !encryptionPasswordEditText.getText().toString().isEmpty());
 324             }
 325         });
 326
 327         // Update the status of the import/export button when the file name EditText changes.
 328         fileNameEditText.addTextChangedListener(new TextWatcher() {
 329             @Override
 330             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 331                 // Do nothing.
 332             }
 333
 334             @Override
 335             public void onTextChanged(CharSequence s, int start, int before, int count) {
 336                 // Do nothing.
 337             }
 338
 339             @Override
 340             public void afterTextChanged(Editable s) {
 341                 // Adjust the export button according to the encryption spinner position.
 342                 switch (encryptionSpinner.getSelectedItemPosition()) {
 343                     case NO_ENCRYPTION:
 344                         // Enable the import/export button if a file name exists.
 345                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 346                         break;
 347
 348                     case PASSWORD_ENCRYPTION:
 349                         // Enable the import/export button if a file name and password exists.
 350                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty() && !encryptionPasswordEditText.getText().toString().isEmpty());
 351                         break;
 352
 353                     case OPENPGP_ENCRYPTION:
 354                         // Enable the import/export button if OpenKeychain is installed and a file name exists.
 355                         importExportButton.setEnabled(openKeychainInstalled && !fileNameEditText.getText().toString().isEmpty());
 356                         break;
 357                 }
 358             }
 359         });
 360
 361         // Hide the storage permissions text view on API < 23 as permissions on older devices are automatically granted.
 362         if (Build.VERSION.SDK_INT < 23) {
 363             storagePermissionTextView.setVisibility(View.GONE);
 364         }
 365     }
 366
 367     public void onClickRadioButton(View view) {
 368         // Get handles for the views.
 369         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 370         LinearLayout fileNameLinearLayout = findViewById(R.id.file_name_linearlayout);
 371         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 372         TextView openKeychainImportInstructionTextView = findViewById(R.id.openkeychain_import_instructions_textview);
 373         Button importExportButton = findViewById(R.id.import_export_button);
 374
 375         // Check to see if import or export was selected.
 376         switch (view.getId()) {
 377             case R.id.import_radiobutton:
 378                 // Check to see if OpenPGP encryption is selected.
 379                 if (encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) {  // OpenPGP encryption selected.
 380                     // Show the OpenKeychain import instructions.
 381                     openKeychainImportInstructionTextView.setVisibility(View.VISIBLE);
 382
 383                     // Set the text on the import/export button to be `Decrypt`.
 384                     importExportButton.setText(R.string.decrypt);
 385
 386                     // Enable the decrypt button if there is a file name.
 387                     importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 388                 } else {  // OpenPGP encryption not selected.
 389                     // Hide the OpenKeychain import instructions.
 390                     openKeychainImportInstructionTextView.setVisibility(View.GONE);
 391
 392                     // Set the text on the import/export button to be `Import`.
 393                     importExportButton.setText(R.string.import_button);
 394                 }
 395
 396                 // Display the file name views.
 397                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 398                 importExportButton.setVisibility(View.VISIBLE);
 399                 break;
 400
 401             case R.id.export_radiobutton:
 402                 // Hide the OpenKeychain import instructions.
 403                 openKeychainImportInstructionTextView.setVisibility(View.GONE);
 404
 405                 // Set the text on the import/export button to be `Export`.
 406                 importExportButton.setText(R.string.export);
 407
 408                 // Show the import/export button.
 409                 importExportButton.setVisibility(View.VISIBLE);
 410
 411                 // Check to see if OpenPGP encryption is selected.
 412                 if (encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) {  // OpenPGP encryption is selected.
 413                     // Hide the file name views.
 414                     fileNameLinearLayout.setVisibility(View.GONE);
 415
 416                     // Enable the export button.
 417                     importExportButton.setEnabled(true);
 418                 } else {  // OpenPGP encryption is not selected.
 419                     // Show the file name views.
 420                     fileNameLinearLayout.setVisibility(View.VISIBLE);
 421                 }
 422                 break;
 423         }
 424     }
 425
 426     public void browse(View view) {
 427         // Get a handle for the import radiobutton.
 428         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 429
 430         // Check to see if import or export is selected.
 431         if (importRadioButton.isChecked()) {  // Import is selected.
 432             // Create the file picker intent.
 433             Intent importBrowseIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
 434
 435             // Set the intent MIME type to include all files so that everything is visible.
 436             importBrowseIntent.setType("*/*");
 437
 438             // Set the initial directory if the minimum API >= 26.
 439             if (Build.VERSION.SDK_INT >= 26) {
 440                 importBrowseIntent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, Environment.getExternalStorageDirectory());
 441             }
 442
 443             // Request a file that can be opened.
 444             importBrowseIntent.addCategory(Intent.CATEGORY_OPENABLE);
 445
 446             // Launch the file picker.
 447             startActivityForResult(importBrowseIntent, BROWSE_RESULT_CODE);
 448         } else {  // Export is selected
 449             // Create the file picker intent.
 450             Intent exportBrowseIntent = new Intent(Intent.ACTION_CREATE_DOCUMENT);
 451
 452             // Set the intent MIME type to include all files so that everything is visible.
 453             exportBrowseIntent.setType("*/*");
 454
 455             // Set the initial export file name.
 456             exportBrowseIntent.putExtra(Intent.EXTRA_TITLE, getString(R.string.settings_pbs));
 457
 458             // Set the initial directory if the minimum API >= 26.
 459             if (Build.VERSION.SDK_INT >= 26) {
 460                 exportBrowseIntent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, Environment.getExternalStorageDirectory());
 461             }
 462
 463             // Request a file that can be opened.
 464             exportBrowseIntent.addCategory(Intent.CATEGORY_OPENABLE);
 465
 466             // Launch the file picker.
 467             startActivityForResult(exportBrowseIntent, BROWSE_RESULT_CODE);
 468         }
 469     }
 470
 471     public void importExport(View view) {
 472         // Get a handle for the views.
 473         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 474         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 475         RadioButton exportRadioButton = findViewById(R.id.export_radiobutton);
 476
 477         // Check to see if the storage permission is needed.
 478         if ((encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) && exportRadioButton.isChecked()) {  // Permission not needed to export via OpenKeychain.
 479             // Export the settings.
 480             exportSettings();
 481         } else if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // The storage permission has been granted.
 482             // Check to see if import or export is selected.
 483             if (importRadioButton.isChecked()) {  // Import is selected.
 484                 // Import the settings.
 485                 importSettings();
 486             } else {  // Export is selected.
 487                 // Export the settings.
 488                 exportSettings();
 489             }
 490         } else {  // The storage permission has not been granted.
 491             // Get a handle for the file name EditText.
 492             EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 493
 494             // Get the file name string.
 495             String fileNameString = fileNameEditText.getText().toString();
 496
 497             // Get the external private directory `File`.
 498             File externalPrivateDirectoryFile = getExternalFilesDir(null);
 499
 500             // Remove the incorrect lint error below that the file might be null.
 501             assert externalPrivateDirectoryFile != null;
 502
 503             // Get the external private directory string.
 504             String externalPrivateDirectory = externalPrivateDirectoryFile.toString();
 505
 506             // Check to see if the file path is in the external private directory.
 507             if (fileNameString.startsWith(externalPrivateDirectory)) {  // The file path is in the external private directory.
 508                 // Check to see if import or export is selected.
 509                 if (importRadioButton.isChecked()) {  // Import is selected.
 510                     // Import the settings.
 511                     importSettings();
 512                 } else {  // Export is selected.
 513                     // Export the settings.
 514                     exportSettings();
 515                 }
 516             } else {  // The file path is in a public directory.
 517                 // Check if the user has previously denied the storage permission.
 518                 if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {  // Show a dialog explaining the request first.
 519                     // Instantiate the storage permission alert dialog.
 520                     DialogFragment storagePermissionDialogFragment = new StoragePermissionDialog();
 521
 522                     // Show the storage permission alert dialog.  The permission will be requested when the dialog is closed.
 523                     storagePermissionDialogFragment.show(getSupportFragmentManager(), getString(R.string.storage_permission));
 524                 } else {  // Show the permission request directly.
 525                     // Request the storage permission.  The export will be run when it finishes.
 526                     ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0);
 527                 }
 528             }
 529         }
 530     }
 531
 532     @Override
 533     public void onCloseStoragePermissionDialog() {
 534         // Request the write external storage permission.  The import/export will be run when it finishes.
 535         ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0);
 536     }
 537
 538     @Override
 539     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
 540         // Get a handle for the import radiobutton.
 541         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 542
 543         // Check to see if the storage permission was granted.  If the dialog was canceled the grant results will be empty.
 544         if ((grantResults.length > 0) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) {  // The storage permission was granted.
 545             // Run the import or export methods according to which radio button is selected.
 546             if (importRadioButton.isChecked()) {  // Import is selected.
 547                 // Import the settings.
 548                 importSettings();
 549             } else {  // Export is selected.
 550                 // Export the settings.
 551                 exportSettings();
 552             }
 553         } else {  // The storage permission was not granted.
 554             // Display an error snackbar.
 555             Snackbar.make(importRadioButton, getString(R.string.cannot_use_location), Snackbar.LENGTH_LONG).show();
 556         }
 557     }
 558
 559     @Override
 560     public void onActivityResult(int requestCode, int resultCode, Intent data) {
 561         switch (requestCode) {
 562             case (BROWSE_RESULT_CODE):
 563                 // Don't do anything if the user pressed back from the file picker.
 564                 if (resultCode == Activity.RESULT_OK) {
 565                     // Get a handle for the file name edit text.
 566                     EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 567
 568                     // Get the file name URI.
 569                     Uri fileNameUri = data.getData();
 570
 571                     // Remove the lint warning that the file name URI might be null.
 572                     assert fileNameUri != null;
 573
 574                     // Get the raw file name path.
 575                     String rawFileNamePath = fileNameUri.getPath();
 576
 577                     // Remove the incorrect lint warning that the file name path might be null.
 578                     assert rawFileNamePath != null;
 579
 580                     // Check to see if the file name Path includes a valid storage location.
 581                     if (rawFileNamePath.contains(":")) {  // The path is valid.
 582                         // Split the path into the initial content uri and the final path information.
 583                         String fileNameContentPath = rawFileNamePath.substring(0, rawFileNamePath.indexOf(":"));
 584                         String fileNameFinalPath = rawFileNamePath.substring(rawFileNamePath.indexOf(":") + 1);
 585
 586                         // Create the file name path string.
 587                         String fileNamePath;
 588
 589                         // Construct the file name path.
 590                         switch (fileNameContentPath) {
 591                             // The documents home has a special content path.
 592                             case "/document/home":
 593                                 fileNamePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS) + "/" + fileNameFinalPath;
 594                                 break;
 595
 596                             // Everything else for the primary user should be in `/document/primary`.
 597                             case "/document/primary":
 598                                 fileNamePath = Environment.getExternalStorageDirectory() + "/" + fileNameFinalPath;
 599                                 break;
 600
 601                             // Just in case, catch everything else and place it in the external storage directory.
 602                             default:
 603                                 fileNamePath = Environment.getExternalStorageDirectory() + "/" + fileNameFinalPath;
 604                                 break;
 605                         }
 606
 607                         // Set the file name path as the text of the file name EditText.
 608                         fileNameEditText.setText(fileNamePath);
 609                     } else {  // The path is invalid.
 610                         Snackbar.make(fileNameEditText, rawFileNamePath + " " + getString(R.string.invalid_location), Snackbar.LENGTH_INDEFINITE).show();
 611                     }
 612                 }
 613                 break;
 614
 615             case OPENPGP_EXPORT_RESULT_CODE:
 616                 // Get the temporary unencrypted export file.
 617                 File temporaryUnencryptedExportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.settings_pbs));
 618
 619                 // Delete the temporary unencrypted export file if it exists.
 620                 if (temporaryUnencryptedExportFile.exists()) {
 621                     //noinspection ResultOfMethodCallIgnored
 622                     temporaryUnencryptedExportFile.delete();
 623                 }
 624                 break;
 625         }
 626     }
 627
 628     private void exportSettings() {
 629         // Get a handle for the views.
 630         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 631         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 632
 633         // Instantiate the import export database helper.
 634         ImportExportDatabaseHelper importExportDatabaseHelper = new ImportExportDatabaseHelper();
 635
 636         // Get the export file string.
 637         String exportFileString = fileNameEditText.getText().toString();
 638
 639         // Get the export and temporary unencrypted export files.
 640         File exportFile = new File(exportFileString);
 641         File temporaryUnencryptedExportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.settings_pbs));
 642
 643         // Create an export status string.
 644         String exportStatus;
 645
 646         // Export according to the encryption type.
 647         switch (encryptionSpinner.getSelectedItemPosition()) {
 648             case NO_ENCRYPTION:
 649                 // Export the unencrypted file.
 650                 exportStatus = importExportDatabaseHelper.exportUnencrypted(exportFile, this);
 651
 652                 // Show a disposition snackbar.
 653                 if (exportStatus.equals(ImportExportDatabaseHelper.EXPORT_SUCCESSFUL)) {
 654                     Snackbar.make(fileNameEditText, getString(R.string.export_successful), Snackbar.LENGTH_SHORT).show();
 655                 } else {
 656                     Snackbar.make(fileNameEditText, getString(R.string.export_failed) + "  " + exportStatus, Snackbar.LENGTH_INDEFINITE).show();
 657                 }
 658                 break;
 659
 660             case PASSWORD_ENCRYPTION:
 661                 // Create an unencrypted export in a private directory.
 662                 exportStatus = importExportDatabaseHelper.exportUnencrypted(temporaryUnencryptedExportFile, this);
 663
 664                 try {
 665                     // Create an unencrypted export file input stream.
 666                     FileInputStream unencryptedExportFileInputStream = new FileInputStream(temporaryUnencryptedExportFile);
 667
 668                     // Delete the encrypted export file if it exists.
 669                     if (exportFile.exists()) {
 670                         //noinspection ResultOfMethodCallIgnored
 671                         exportFile.delete();
 672                     }
 673
 674                     // Create an encrypted export file output stream.
 675                     FileOutputStream encryptedExportFileOutputStream = new FileOutputStream(exportFile);
 676
 677                     // Get a handle for the encryption password EditText.
 678                     EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 679
 680                     // Get the encryption password.
 681                     String encryptionPasswordString = encryptionPasswordEditText.getText().toString();
 682
 683                     // Initialize a secure random number generator.
 684                     SecureRandom secureRandom = new SecureRandom();
 685
 686                     // Get a 256 bit (32 byte) random salt.
 687                     byte[] saltByteArray = new byte[32];
 688                     secureRandom.nextBytes(saltByteArray);
 689
 690                     // Convert the encryption password to a byte array.
 691                     byte[] encryptionPasswordByteArray = encryptionPasswordString.getBytes(StandardCharsets.UTF_8);
 692
 693                     // Append the salt to the encryption password byte array.  This protects against rainbow table attacks.
 694                     byte[] encryptionPasswordWithSaltByteArray = new byte[encryptionPasswordByteArray.length + saltByteArray.length];
 695                     System.arraycopy(encryptionPasswordByteArray, 0, encryptionPasswordWithSaltByteArray, 0, encryptionPasswordByteArray.length);
 696                     System.arraycopy(saltByteArray, 0, encryptionPasswordWithSaltByteArray, encryptionPasswordByteArray.length, saltByteArray.length);
 697
 698                     // Get a SHA-512 message digest.
 699                     MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
 700
 701                     // Hash the salted encryption password.  Otherwise, any characters after the 32nd character in the password are ignored.
 702                     byte[] hashedEncryptionPasswordWithSaltByteArray = messageDigest.digest(encryptionPasswordWithSaltByteArray);
 703
 704                     // Truncate the encryption password byte array to 256 bits (32 bytes).
 705                     byte[] truncatedHashedEncryptionPasswordWithSaltByteArray = Arrays.copyOf(hashedEncryptionPasswordWithSaltByteArray, 32);
 706
 707                     // Create an AES secret key from the encryption password byte array.
 708                     SecretKeySpec secretKey = new SecretKeySpec(truncatedHashedEncryptionPasswordWithSaltByteArray, "AES");
 709
 710                     // Generate a random 12 byte initialization vector.  According to NIST, a 12 byte initialization vector is more secure than a 16 byte one.
 711                     byte[] initializationVector = new byte[12];
 712                     secureRandom.nextBytes(initializationVector);
 713
 714                     // 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.
 715                     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
 716
 717                     // Set the GCM tag length to be 128 bits (the maximum) and apply the initialization vector.
 718                     GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(128, initializationVector);
 719
 720                     // Initialize the cipher.
 721                     cipher.init(Cipher.ENCRYPT_MODE, secretKey, gcmParameterSpec);
 722
 723                     // Add the salt and the initialization vector to the export file.
 724                     encryptedExportFileOutputStream.write(saltByteArray);
 725                     encryptedExportFileOutputStream.write(initializationVector);
 726
 727                     // Create a cipher output stream.
 728                     CipherOutputStream cipherOutputStream = new CipherOutputStream(encryptedExportFileOutputStream, cipher);
 729
 730                     // 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.
 731                     int numberOfBytesRead;
 732                     byte[] encryptedBytes = new byte[16];
 733
 734                     // 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.
 735                     while ((numberOfBytesRead = unencryptedExportFileInputStream.read(encryptedBytes)) != -1) {
 736                         // Write the data to the cipher output stream.
 737                         cipherOutputStream.write(encryptedBytes, 0, numberOfBytesRead);
 738                     }
 739
 740                     // Close the streams.
 741                     cipherOutputStream.flush();
 742                     cipherOutputStream.close();
 743                     encryptedExportFileOutputStream.close();
 744                     unencryptedExportFileInputStream.close();
 745
 746                     // Wipe the encryption data from memory.
 747                     //noinspection UnusedAssignment
 748                     encryptionPasswordString = "";
 749                     Arrays.fill(saltByteArray, (byte) 0);
 750                     Arrays.fill(encryptionPasswordByteArray, (byte) 0);
 751                     Arrays.fill(encryptionPasswordWithSaltByteArray, (byte) 0);
 752                     Arrays.fill(hashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 753                     Arrays.fill(truncatedHashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 754                     Arrays.fill(initializationVector, (byte) 0);
 755                     Arrays.fill(encryptedBytes, (byte) 0);
 756
 757                     // Delete the temporary unencrypted export file.
 758                     //noinspection ResultOfMethodCallIgnored
 759                     temporaryUnencryptedExportFile.delete();
 760                 } catch (Exception exception) {
 761                     exportStatus = exception.toString();
 762                 }
 763
 764                 // Show a disposition snackbar.
 765                 if (exportStatus.equals(ImportExportDatabaseHelper.EXPORT_SUCCESSFUL)) {
 766                     Snackbar.make(fileNameEditText, getString(R.string.export_successful), Snackbar.LENGTH_SHORT).show();
 767                 } else {
 768                     Snackbar.make(fileNameEditText, getString(R.string.export_failed) + "  " + exportStatus, Snackbar.LENGTH_INDEFINITE).show();
 769                 }
 770                 break;
 771
 772             case OPENPGP_ENCRYPTION:
 773                 // Create an unencrypted export in the private location.
 774                 importExportDatabaseHelper.exportUnencrypted(temporaryUnencryptedExportFile, this);
 775
 776                 // Create an encryption intent for OpenKeychain.
 777                 Intent openKeychainEncryptIntent = new Intent("org.sufficientlysecure.keychain.action.ENCRYPT_DATA");
 778
 779                 // Include the temporary unencrypted export file URI.
 780                 openKeychainEncryptIntent.setData(FileProvider.getUriForFile(this, getString(R.string.file_provider), temporaryUnencryptedExportFile));
 781
 782                 // Allow OpenKeychain to read the file URI.
 783                 openKeychainEncryptIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 784
 785                 // Send the intent to the OpenKeychain package.
 786                 openKeychainEncryptIntent.setPackage("org.sufficientlysecure.keychain");
 787
 788                 // Make it so.
 789                 startActivityForResult(openKeychainEncryptIntent, OPENPGP_EXPORT_RESULT_CODE);
 790                 break;
 791         }
 792
 793         // Add the file to the list of recent files.  This doesn't currently work, but maybe it will someday.
 794         MediaScannerConnection.scanFile(this, new String[] {exportFileString}, new String[] {"application/x-sqlite3"}, null);
 795     }
 796
 797     private void importSettings() {
 798         // Get a handle for the views.
 799         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 800         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 801
 802         // Instantiate the import export database helper.
 803         ImportExportDatabaseHelper importExportDatabaseHelper = new ImportExportDatabaseHelper();
 804
 805         // Get the import file.
 806         File importFile = new File(fileNameEditText.getText().toString());
 807
 808         // Initialize the import status string
 809         String importStatus = "";
 810
 811         // Import according to the encryption type.
 812         switch (encryptionSpinner.getSelectedItemPosition()) {
 813             case NO_ENCRYPTION:
 814                 // Import the unencrypted file.
 815                 importStatus = importExportDatabaseHelper.importUnencrypted(importFile, this);
 816                 break;
 817
 818             case PASSWORD_ENCRYPTION:
 819                 // Use a private temporary import location.
 820                 File temporaryUnencryptedImportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.settings_pbs));
 821
 822                 try {
 823                     // Create an encrypted import file input stream.
 824                     FileInputStream encryptedImportFileInputStream = new FileInputStream(importFile);
 825
 826                     // Delete the temporary import file if it exists.
 827                     if (temporaryUnencryptedImportFile.exists()) {
 828                         //noinspection ResultOfMethodCallIgnored
 829                         temporaryUnencryptedImportFile.delete();
 830                     }
 831
 832                     // Create an unencrypted import file output stream.
 833                     FileOutputStream unencryptedImportFileOutputStream = new FileOutputStream(temporaryUnencryptedImportFile);
 834
 835                     // Get a handle for the encryption password EditText.
 836                     EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 837
 838                     // Get the encryption password.
 839                     String encryptionPasswordString = encryptionPasswordEditText.getText().toString();
 840
 841                     // Get the salt from the beginning of the import file.
 842                     byte[] saltByteArray = new byte[32];
 843                     //noinspection ResultOfMethodCallIgnored
 844                     encryptedImportFileInputStream.read(saltByteArray);
 845
 846                     // Get the initialization vector from the import file.
 847                     byte[] initializationVector = new byte[12];
 848                     //noinspection ResultOfMethodCallIgnored
 849                     encryptedImportFileInputStream.read(initializationVector);
 850
 851                     // Convert the encryption password to a byte array.
 852                     byte[] encryptionPasswordByteArray = encryptionPasswordString.getBytes(StandardCharsets.UTF_8);
 853
 854                     // Append the salt to the encryption password byte array.  This protects against rainbow table attacks.
 855                     byte[] encryptionPasswordWithSaltByteArray = new byte[encryptionPasswordByteArray.length + saltByteArray.length];
 856                     System.arraycopy(encryptionPasswordByteArray, 0, encryptionPasswordWithSaltByteArray, 0, encryptionPasswordByteArray.length);
 857                     System.arraycopy(saltByteArray, 0, encryptionPasswordWithSaltByteArray, encryptionPasswordByteArray.length, saltByteArray.length);
 858
 859                     // Get a SHA-512 message digest.
 860                     MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
 861
 862                     // Hash the salted encryption password.  Otherwise, any characters after the 32nd character in the password are ignored.
 863                     byte[] hashedEncryptionPasswordWithSaltByteArray = messageDigest.digest(encryptionPasswordWithSaltByteArray);
 864
 865                     // Truncate the encryption password byte array to 256 bits (32 bytes).
 866                     byte[] truncatedHashedEncryptionPasswordWithSaltByteArray = Arrays.copyOf(hashedEncryptionPasswordWithSaltByteArray, 32);
 867
 868                     // Create an AES secret key from the encryption password byte array.
 869                     SecretKeySpec secretKey = new SecretKeySpec(truncatedHashedEncryptionPasswordWithSaltByteArray, "AES");
 870
 871                     // 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.
 872                     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
 873
 874                     // Set the GCM tag length to be 128 bits (the maximum) and apply the initialization vector.
 875                     GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(128, initializationVector);
 876
 877                     // Initialize the cipher.
 878                     cipher.init(Cipher.DECRYPT_MODE, secretKey, gcmParameterSpec);
 879
 880                     // Create a cipher input stream.
 881                     CipherInputStream cipherInputStream = new CipherInputStream(encryptedImportFileInputStream, cipher);
 882
 883                     // 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.
 884                     int numberOfBytesRead;
 885                     byte[] decryptedBytes = new byte[16];
 886
 887                     // 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.
 888                     while ((numberOfBytesRead = cipherInputStream.read(decryptedBytes)) != -1) {
 889                         // Write the data to the unencrypted import file output stream.
 890                         unencryptedImportFileOutputStream.write(decryptedBytes, 0, numberOfBytesRead);
 891                     }
 892
 893                     // Close the streams.
 894                     unencryptedImportFileOutputStream.flush();
 895                     unencryptedImportFileOutputStream.close();
 896                     cipherInputStream.close();
 897                     encryptedImportFileInputStream.close();
 898
 899                     // Wipe the encryption data from memory.
 900                     //noinspection UnusedAssignment
 901                     encryptionPasswordString = "";
 902                     Arrays.fill(saltByteArray, (byte) 0);
 903                     Arrays.fill(initializationVector, (byte) 0);
 904                     Arrays.fill(encryptionPasswordByteArray, (byte) 0);
 905                     Arrays.fill(encryptionPasswordWithSaltByteArray, (byte) 0);
 906                     Arrays.fill(hashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 907                     Arrays.fill(truncatedHashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 908                     Arrays.fill(decryptedBytes, (byte) 0);
 909
 910                     // Import the unencrypted database from the private location.
 911                     importStatus = importExportDatabaseHelper.importUnencrypted(temporaryUnencryptedImportFile, this);
 912
 913                     // Delete the temporary unencrypted import file.
 914                     //noinspection ResultOfMethodCallIgnored
 915                     temporaryUnencryptedImportFile.delete();
 916                 } catch (Exception exception) {
 917                     importStatus = exception.toString();
 918                 }
 919                 break;
 920
 921             case OPENPGP_ENCRYPTION:
 922                 try {
 923                     // Create an decryption intent for OpenKeychain.
 924                     Intent openKeychainDecryptIntent = new Intent("org.sufficientlysecure.keychain.action.DECRYPT_DATA");
 925
 926                     // Include the URI to be decrypted.
 927                     openKeychainDecryptIntent.setData(FileProvider.getUriForFile(this, getString(R.string.file_provider), importFile));
 928
 929                     // Allow OpenKeychain to read the file URI.
 930                     openKeychainDecryptIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 931
 932                     // Send the intent to the OpenKeychain package.
 933                     openKeychainDecryptIntent.setPackage("org.sufficientlysecure.keychain");
 934
 935                     // Make it so.
 936                     startActivity(openKeychainDecryptIntent);
 937                 } catch (IllegalArgumentException exception) {  // The file import location is not valid.
 938                     // Display a snack bar with the import error.
 939                     Snackbar.make(fileNameEditText, getString(R.string.import_failed) + "  " + exception.toString(), Snackbar.LENGTH_INDEFINITE).show();
 940                 }
 941                 break;
 942         }
 943
 944         // Respond to the import disposition.
 945         if (importStatus.equals(ImportExportDatabaseHelper.IMPORT_SUCCESSFUL)) {  // The import was successful.
 946             // Create an intent to restart Privacy Browser.
 947             Intent restartIntent = getParentActivityIntent();
 948
 949             // Assert that the intent is not null to remove the lint error below.
 950             assert restartIntent != null;
 951
 952             // `Intent.FLAG_ACTIVITY_CLEAR_TASK` removes all activities from the stack.  It requires `Intent.FLAG_ACTIVITY_NEW_TASK`.
 953             restartIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
 954
 955             // Make it so.
 956             startActivity(restartIntent);
 957         } else if (!(encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION)){  // The import was not successful.
 958             // Display a snack bar with the import error.
 959             Snackbar.make(fileNameEditText, getString(R.string.import_failed) + "  " + importStatus, Snackbar.LENGTH_INDEFINITE).show();
 960         }
 961     }
 962 }