add delete wallet functionality, overwriting wallet file data first

src/main/java/com/sparrowwallet/sparrow/AppController.java

@@ -111,6 +111,12 @@ public class AppController implements Initializable {
     @FXML
     private MenuItem exportWallet;
 
+    @FXML
+    private MenuItem deleteWallet;
+
+    @FXML
+    private MenuItem closeTab;
+
     @FXML
     private Menu fileMenu;
 
@@ -294,11 +300,13 @@ public class AppController implements Initializable {
                     EventManager.get().post(new TransactionTabsClosedEvent(closedTransactionTabs));
                 }
 
+                closeTab.setDisable(tabs.getTabs().isEmpty());
                 if(tabs.getTabs().isEmpty()) {
                     Stage tabStage = (Stage)tabs.getScene().getWindow();
                     tabStage.setTitle("Sparrow");
                     saveTransaction.setVisible(true);
                     saveTransaction.setDisable(true);
+                    exportWallet.setDisable(true);
                 }
             }
         });
@@ -349,6 +357,8 @@ public class AppController implements Initializable {
         savePSBTBinary.disableProperty().bind(saveTransaction.visibleProperty());
         showPSBT.visibleProperty().bind(saveTransaction.visibleProperty().not());
         exportWallet.setDisable(true);
+        deleteWallet.disableProperty().bind(exportWallet.disableProperty());
+        closeTab.setDisable(true);
         lockWallet.setDisable(true);
         searchWallet.disableProperty().bind(exportWallet.disableProperty());
         refreshWallet.disableProperty().bind(Bindings.or(exportWallet.disableProperty(), Bindings.or(serverToggle.disableProperty(), AppServices.onlineProperty().not())));
@@ -792,6 +802,10 @@ public class AppController implements Initializable {
         }
     }
 
+    public void deleteWallet(ActionEvent event) {
+        deleteWallet(getSelectedWalletForm());
+    }
+
     public void closeTab(ActionEvent event) {
         tabs.getTabs().remove(tabs.getSelectionModel().getSelectedItem());
     }
@@ -1851,10 +1865,65 @@ public class AppController implements Initializable {
             tabs.getTabs().removeAll(tabs.getTabs());
         });
 
-        contextMenu.getItems().addAll(close, closeOthers, closeAll);
+        MenuItem delete = new MenuItem("Delete...");
+        delete.setOnAction(event -> {
+            deleteWallet(getSelectedWalletForm());
+        });
+
+        contextMenu.getItems().addAll(close, closeOthers, closeAll, delete);
         return contextMenu;
     }
 
+    private void deleteWallet(WalletForm selectedWalletForm) {
+        Optional<ButtonType> optButtonType = AppServices.showWarningDialog("Delete Wallet?", "The wallet file and any backups will be deleted. Are you sure?", ButtonType.NO, ButtonType.YES);
+        if(optButtonType.isPresent() && optButtonType.get() == ButtonType.YES) {
+            Storage storage = selectedWalletForm.getStorage();
+            if(selectedWalletForm.getMasterWallet().isEncrypted()) {
+                WalletPasswordDialog dlg = new WalletPasswordDialog(selectedWalletForm.getWallet().getMasterName(), WalletPasswordDialog.PasswordRequirement.LOAD);
+                Optional<SecureString> password = dlg.showAndWait();
+                if(password.isPresent()) {
+                    Storage.KeyDerivationService keyDerivationService = new Storage.KeyDerivationService(storage, password.get(), true);
+                    keyDerivationService.setOnSucceeded(workerStateEvent -> {
+                        EventManager.get().post(new StorageEvent(selectedWalletForm.getWalletId(), TimedEvent.Action.END, "Done"));
+                        ECKey encryptionFullKey = keyDerivationService.getValue();
+
+                        try {
+                            tabs.getTabs().remove(tabs.getSelectionModel().getSelectedItem());
+                            deleteStorage(storage);
+                        } finally {
+                            encryptionFullKey.clear();
+                            password.get().clear();
+                        }
+                    });
+                    keyDerivationService.setOnFailed(workerStateEvent -> {
+                        EventManager.get().post(new StorageEvent(selectedWalletForm.getWalletId(), TimedEvent.Action.END, "Failed"));
+                        if(keyDerivationService.getException() instanceof InvalidPasswordException) {
+                            Optional<ButtonType> optResponse = showErrorDialog("Invalid Password", "The wallet password was invalid. Try again?", ButtonType.CANCEL, ButtonType.OK);
+                            if(optResponse.isPresent() && optResponse.get().equals(ButtonType.OK)) {
+                                Platform.runLater(() -> deleteWallet(getSelectedWalletForm()));
+                            }
+                        } else {
+                            log.error("Error deriving wallet key", keyDerivationService.getException());
+                        }
+                    });
+                    EventManager.get().post(new StorageEvent(selectedWalletForm.getWalletId(), TimedEvent.Action.START, "Decrypting wallet..."));
+                    keyDerivationService.start();
+                }
+            } else {
+                tabs.getTabs().remove(tabs.getSelectionModel().getSelectedItem());
+                deleteStorage(storage);
+            }
+        }
+    }
+
+    private void deleteStorage(Storage storage) {
+        if(storage.isClosed()) {
+            Platform.runLater(storage::delete);
+        } else {
+            Platform.runLater(() -> deleteStorage(storage));
+        }
+    }
+
     private ContextMenu getSubTabContextMenu(Wallet wallet, TabPane subTabs, Tab subTab) {
         ContextMenu contextMenu = new ContextMenu();
         MenuItem rename = new MenuItem("Rename Account");

src/main/java/com/sparrowwallet/sparrow/io/IOUtils.java

@@ -1,5 +1,8 @@
 package com.sparrowwallet.sparrow.io;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.io.*;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -9,11 +12,14 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.FileSystems;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.security.SecureRandom;
 import java.util.*;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 
 public class IOUtils {
+    private static final Logger log = LoggerFactory.getLogger(IOUtils.class);
+
     public static FileType getFileType(File file) {
         try {
             String type = Files.probeContentType(file.toPath());
@@ -120,4 +126,28 @@ public class IOUtils {
 
         return true;
     }
+
+    public static boolean secureDelete(File file) {
+        if(file.exists()) {
+            long length = file.length();
+            SecureRandom random = new SecureRandom();
+            try(RandomAccessFile raf = new RandomAccessFile(file, "rws")) {
+                raf.seek(0);
+                raf.getFilePointer();
+                byte[] data = new byte[64];
+                int pos = 0;
+                while(pos < length) {
+                    random.nextBytes(data);
+                    raf.write(data);
+                    pos += data.length;
+                }
+            } catch(IOException e) {
+                log.warn("Error overwriting file for deletion " + file.getName(), e);
+            }
+
+            return file.delete();
+        }
+
+        return false;
+    }
 }

src/main/java/com/sparrowwallet/sparrow/io/JsonPersistence.java

@@ -305,6 +305,11 @@ public class JsonPersistence implements Persistence {
         com.google.common.io.Files.copy(walletFile, outputStream);
     }
 
+    @Override
+    public boolean isClosed() {
+        return true;
+    }
+
     @Override
     public void close() {
         //Nothing required

src/main/java/com/sparrowwallet/sparrow/io/Persistence.java

@@ -25,5 +25,6 @@ public interface Persistence {
     String getWalletId(Storage storage, Wallet wallet);
     String getWalletName(File walletFile, Wallet wallet);
     void copyWallet(File walletFile, OutputStream outputStream) throws IOException;
+    boolean isClosed();
     void close();
 }

src/main/java/com/sparrowwallet/sparrow/io/Storage.java

@@ -126,6 +126,10 @@ public class Storage {
         return persistence.isPersisted(this, wallet);
     }
 
+    public boolean isClosed() {
+        return persistence.isClosed();
+    }
+
     public void close() {
         ClosePersistenceService closePersistenceService = new ClosePersistenceService();
         closePersistenceService.start();
@@ -163,6 +167,11 @@ public class Storage {
         persistence.copyWallet(walletFile, outputStream);
     }
 
+    public void delete() {
+        deleteBackups();
+        IOUtils.secureDelete(walletFile);
+    }
+
     public void deleteBackups() {
         deleteBackups(null);
     }
@@ -181,7 +190,7 @@ public class Storage {
     private void deleteBackups(String prefix) {
         File[] backups = getBackups(prefix);
         for(File backup : backups) {
-            backup.delete();
+            IOUtils.secureDelete(backup);
         }
     }
 

src/main/java/com/sparrowwallet/sparrow/io/db/DbPersistence.java

@@ -568,6 +568,11 @@ public class DbPersistence implements Persistence {
         com.google.common.io.Files.copy(walletFile, outputStream);
     }
 
+    @Override
+    public boolean isClosed() {
+        return dataSource.isClosed();
+    }
+
     @Override
     public void close() {
         EventManager.get().unregister(this);

src/main/resources/com/sparrowwallet/sparrow/app.fxml

@@ -48,7 +48,8 @@
                         <SeparatorMenuItem styleClass="osxHide" />
                         <MenuItem styleClass="osxHide" mnemonicParsing="false" text="Preferences..." accelerator="Shortcut+P" onAction="#openPreferences"/>
                         <SeparatorMenuItem />
-                        <MenuItem mnemonicParsing="false" text="Close Tab" accelerator="Shortcut+W" onAction="#closeTab"/>
+                        <MenuItem fx:id="deleteWallet" mnemonicParsing="false" text="Delete Wallet..." onAction="#deleteWallet"/>
+                        <MenuItem fx:id="closeTab" mnemonicParsing="false" text="Close Tab" accelerator="Shortcut+W" onAction="#closeTab"/>
                         <MenuItem styleClass="osxHide" mnemonicParsing="false" text="Quit" accelerator="Shortcut+Q" onAction="#quit"/>
                     </items>
                 </Menu>