use charsequence and securestring instead of string

drongo

@@ -1 +1 @@
-Subproject commit aa60e6b92e0401a27c3760cc9cb7e726a2caa845
+Subproject commit 9f5f5689bbbe85dad51be84d4a5a2e5d31562564

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

@@ -3,6 +3,7 @@ package com.sparrowwallet.sparrow;
 import com.google.common.base.Charsets;
 import com.google.common.eventbus.Subscribe;
 import com.google.common.io.ByteSource;
+import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.crypto.*;
 import com.sparrowwallet.drongo.policy.PolicyType;
@@ -10,7 +11,6 @@ import com.sparrowwallet.drongo.protocol.ScriptType;
 import com.sparrowwallet.drongo.protocol.Transaction;
 import com.sparrowwallet.drongo.psbt.PSBT;
 import com.sparrowwallet.drongo.psbt.PSBTParseException;
-import com.sparrowwallet.drongo.wallet.Keystore;
 import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.sparrow.control.*;
 import com.sparrowwallet.sparrow.event.*;
@@ -235,14 +235,14 @@ public class AppController implements Initializable {
         if(file != null) {
             try {
                 Wallet wallet;
-                String password = null;
+                CharSequence password = null;
                 Storage storage = new Storage(file);
                 FileType fileType = IOUtils.getFileType(file);
                 if(FileType.JSON.equals(fileType)) {
                     wallet = storage.loadWallet();
                 } else if(FileType.BINARY.equals(fileType)) {
                     WalletPasswordDialog dlg = new WalletPasswordDialog(WalletPasswordDialog.PasswordRequirement.LOAD);
-                    Optional<String> optionalPassword = dlg.showAndWait();
+                    Optional<SecureString> optionalPassword = dlg.showAndWait();
                     if(!optionalPassword.isPresent()) {
                         return;
                     }

src/main/java/com/sparrowwallet/sparrow/control/FileWalletExportPane.java

@@ -1,6 +1,6 @@
 package com.sparrowwallet.sparrow.control;
 
-import com.sparrowwallet.drongo.wallet.Keystore;
+import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.WalletExportEvent;
@@ -53,7 +53,7 @@ public class FileWalletExportPane extends TitledDescriptionPane {
 
         if(copy.isEncrypted()) {
             WalletPasswordDialog dlg = new WalletPasswordDialog(WalletPasswordDialog.PasswordRequirement.LOAD);
-            Optional<String> password = dlg.showAndWait();
+            Optional<SecureString> password = dlg.showAndWait();
             if(password.isPresent()) {
                copy.decrypt(password.get());
             } else {

src/main/java/com/sparrowwallet/sparrow/control/WalletPasswordDialog.java

@@ -1,5 +1,6 @@
 package com.sparrowwallet.sparrow.control;
 
+import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.sparrow.AppController;
 import javafx.application.Platform;
 import javafx.beans.binding.Bindings;
@@ -14,7 +15,7 @@ import org.controlsfx.validation.ValidationResult;
 import org.controlsfx.validation.ValidationSupport;
 import org.controlsfx.validation.decoration.StyleClassValidationDecoration;
 
-public class WalletPasswordDialog extends Dialog<String> {
+public class WalletPasswordDialog extends Dialog<SecureString> {
     private final ButtonType okButtonType;
     private final PasswordRequirement requirement;
     private final CustomPasswordField password;
@@ -80,7 +81,7 @@ public class WalletPasswordDialog extends Dialog<String> {
         password.requestFocus();
         passwordConfirm.setPromptText("Password Confirmation");
 
-        setResultConverter(dialogButton -> dialogButton == okButtonType ? password.getText() : null);
+        setResultConverter(dialogButton -> dialogButton == okButtonType ? new SecureString(password.getText()) : null);
     }
 
     public enum PasswordRequirement {

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

@@ -8,6 +8,8 @@ import com.sparrowwallet.drongo.wallet.Keystore;
 import com.sparrowwallet.drongo.wallet.MnemonicException;
 import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.sparrow.control.KeystorePassphraseDialog;
+import javafx.concurrent.Service;
+import javafx.concurrent.Task;
 
 import java.io.*;
 import java.lang.reflect.Type;
@@ -71,7 +73,7 @@ public class Storage {
         return wallet;
     }
 
-    public Wallet loadWallet(String password) throws IOException, MnemonicException, StorageException {
+    public Wallet loadWallet(CharSequence password) throws IOException, MnemonicException, StorageException {
         InputStream fileStream = new FileInputStream(walletFile);
         ECKey encryptionKey = getEncryptionKey(password, fileStream);
 
@@ -198,11 +200,11 @@ public class Storage {
         this.encryptionPubKey = encryptionPubKey;
     }
 
-    public ECKey getEncryptionKey(String password) throws IOException, StorageException {
+    public ECKey getEncryptionKey(CharSequence password) throws IOException, StorageException {
         return getEncryptionKey(password, null);
     }
 
-    private ECKey getEncryptionKey(String password, InputStream inputStream) throws IOException, StorageException {
+    private ECKey getEncryptionKey(CharSequence password, InputStream inputStream) throws IOException, StorageException {
         if(password.equals("")) {
             return NO_PASSWORD_KEY;
         }
@@ -312,4 +314,23 @@ public class Storage {
             return jsonObject;
         }
     }
+
+    public static class KeyDerivationService extends Service<ECKey> {
+        private final Storage storage;
+        private final String password;
+
+        public KeyDerivationService(Storage storage, String password) {
+            this.storage = storage;
+            this.password = password;
+        }
+
+        @Override
+        protected Task<ECKey> createTask() {
+            return new Task<>() {
+                protected ECKey call() throws IOException, StorageException {
+                    return storage.getEncryptionKey(password);
+                }
+            };
+        }
+    }
 }

src/main/java/com/sparrowwallet/sparrow/wallet/SettingsController.java

@@ -1,6 +1,7 @@
 package com.sparrowwallet.sparrow.wallet;
 
 import com.google.common.eventbus.Subscribe;
+import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.drongo.crypto.*;
 import com.sparrowwallet.drongo.policy.Policy;
 import com.sparrowwallet.drongo.policy.PolicyType;
@@ -266,9 +267,9 @@ public class SettingsController extends WalletFormController implements Initiali
         }
 
         WalletPasswordDialog dlg = new WalletPasswordDialog(requirement);
-        Optional<String> password = dlg.showAndWait();
+        Optional<SecureString> password = dlg.showAndWait();
         if(password.isPresent()) {
-            if(password.get().isEmpty()) {
+            if(password.get().length() == 0) {
                 return Optional.of(Storage.NO_PASSWORD_KEY);
             }