Support resetting user's master password.

platform-independent/java/algorithm/src/main/java/com/lyndir/masterpassword/MPMasterKey.java

@@ -82,11 +82,15 @@ public class MPMasterKey {
         Arrays.fill( masterPassword, (char) 0 );
     }
 
+    public boolean isValid() {
+        return !invalidated;
+    }
+
     private byte[] masterKey(final MPAlgorithm algorithm)
             throws MPKeyUnavailableException, MPAlgorithmException {
         Preconditions.checkArgument( masterPassword.length > 0 );
 
-        if (invalidated)
+        if (!isValid())
             throw new MPKeyUnavailableException( "Master key was invalidated." );
 
         byte[] masterKey = keyByVersion.get( algorithm.version() );

platform-independent/java/gui/src/main/java/com/lyndir/masterpassword/gui/util/Components.java

@@ -21,6 +21,7 @@ package com.lyndir.masterpassword.gui.util;
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -91,11 +92,21 @@ public abstract class Components {
         return new GradientPanel( layout, color );
     }
 
-    public static JDialog showDialog(@Nullable final Component owner, @Nullable final String title, final JOptionPane pane) {
+    public static int showDialog(@Nullable final Component owner, @Nullable final String title, final JOptionPane pane) {
         JDialog dialog = pane.createDialog( owner, title );
         dialog.setModalityType( Dialog.ModalityType.DOCUMENT_MODAL );
+        showDialog( dialog );
 
-        return showDialog( dialog );
+        Object selectedValue = pane.getValue();
+        if(selectedValue == null)
+            return JOptionPane.CLOSED_OPTION;
+
+        Object[] options = pane.getOptions();
+        if(options == null)
+            return (selectedValue instanceof Integer)? (Integer) selectedValue: JOptionPane.CLOSED_OPTION;
+
+        int option = Arrays.binarySearch( options, selectedValue );
+        return (option < 0)? JOptionPane.CLOSED_OPTION: option;
     }
 
     public static JDialog showDialog(@Nullable final Component owner, @Nullable final String title, final Container content) {

platform-independent/java/gui/src/main/java/com/lyndir/masterpassword/gui/util/Res.java

@@ -132,6 +132,10 @@ public abstract class Res {
             return icon( "media/icon_lock.png" );
         }
 
+        public Icon reset() {
+            return icon( "media/icon_reset.png" );
+        }
+
         public Icon settings() {
             return icon( "media/icon_settings.png" );
         }

platform-independent/java/gui/src/main/java/com/lyndir/masterpassword/gui/view/UserContentPanel.java

@@ -37,8 +37,8 @@ public class UserContentPanel extends JPanel implements FilesPanel.Listener, MPU
     private static final Logger  logger     = Logger.get( UserContentPanel.class );
     private static final JButton iconButton = Components.button( Res.icons().user(), null, null );
 
-    private final JButton addButton    = Components.button( Res.icons().add(), event -> addUser(),
+    private final JButton addButton = Components.button( Res.icons().add(), event -> addUser(),
-                                                            "Add a new user to Master Password." );
+                                                         "Add a new user to Master Password." );
 
     private final JPanel userToolbar = Components.panel( BoxLayout.PAGE_AXIS );
     private final JPanel siteToolbar = Components.panel( BoxLayout.PAGE_AXIS );
@@ -142,6 +142,8 @@ public class UserContentPanel extends JPanel implements FilesPanel.Listener, MPU
 
         private final JButton deleteButton = Components.button( Res.icons().delete(), event -> deleteUser(),
                                                                 "Delete this user from Master Password." );
+        private final JButton resetButton  = Components.button( Res.icons().reset(), event -> resetUser(),
+                                                                "Change the master password for this user." );
 
         private final JPasswordField masterPasswordField = Components.passwordField();
         private final JLabel         errorLabel          = Components.label();
@@ -156,6 +158,7 @@ public class UserContentPanel extends JPanel implements FilesPanel.Listener, MPU
 
             userToolbar.add( addButton );
             userToolbar.add( deleteButton );
+            userToolbar.add( resetButton );
 
             add( Components.heading( user.getFullName(), SwingConstants.CENTER ) );
             add( Components.strut() );
@@ -180,12 +183,48 @@ public class UserContentPanel extends JPanel implements FilesPanel.Listener, MPU
                 return;
 
             if (JOptionPane.YES_OPTION == JOptionPane.showConfirmDialog(
-                    this, strf( "<html>Delete the user <strong>%s</strong>?<br><br><em>%s</em></html>",
+                    SwingUtilities.windowForComponent( this ), strf( "<html>Delete the user <strong>%s</strong>?<br><br><em>%s</em></html>",
-                                fileUser.getFullName(), fileUser.getFile().getName() ),
+                                                                     fileUser.getFullName(), fileUser.getFile().getName() ),
                     "Delete User", JOptionPane.YES_NO_OPTION ))
                 MPFileUserManager.get().delete( fileUser );
         }
 
+        private void resetUser() {
+            JPasswordField passwordField = Components.passwordField();
+            if (JOptionPane.OK_OPTION == Components.showDialog( this, "Reset User", new JOptionPane( Components.panel(
+                    BoxLayout.PAGE_AXIS,
+                    Components.label( strf( "<html>Enter the new master password for <strong>%s</strong>:</html>",
+                                            user.getFullName() ) ),
+                    Components.strut(),
+                    passwordField,
+                    Components.strut(),
+                    Components.label( strf( "<html><em><strong>Note:</strong><br>Changing the master password "
+                                            + "will change all of the user's passwords.<br>"
+                                            + "Changing back to the original master password will also restore<br>"
+                                            + "the user's original passwords.</em></html>",
+                                            user.getFullName() ) ) ), JOptionPane.QUESTION_MESSAGE, JOptionPane.OK_CANCEL_OPTION ) {
+                @Override
+                public void selectInitialValue() {
+                    passwordField.requestFocusInWindow();
+                }
+            } )) {
+                char[] masterPassword = passwordField.getPassword();
+                if ((masterPassword != null) && (masterPassword.length > 0))
+                    try {
+                        user.reset();
+                        user.authenticate( masterPassword );
+                    }
+                    catch (final MPIncorrectMasterPasswordException e) {
+                        errorLabel.setText( e.getLocalizedMessage() );
+                        throw logger.bug( e );
+                    }
+                    catch (final MPAlgorithmException e) {
+                        logger.err( e, "While resetting master password." );
+                        errorLabel.setText( e.getLocalizedMessage() );
+                    }
+            }
+        }
+
         @Override
         public void actionPerformed(final ActionEvent event) {
             updateIdenticon();

platform-independent/java/model/src/main/java/com/lyndir/masterpassword/model/MPUser.java

@@ -77,8 +77,18 @@ public interface MPUser<S extends MPSite<?>> extends Comparable<MPUser<?>> {
     void authenticate(MPMasterKey masterKey)
             throws MPIncorrectMasterPasswordException, MPKeyUnavailableException, MPAlgorithmException;
 
+    /**
+     * Clear all authentication tokens and secrets from memory, effectively logging the user out.
+     */
     void invalidate();
 
+    /**
+     * Wipe the key ID, allowing the user to {@link #authenticate(char[])} with any master password.
+     *
+     * Note: Authenticating with a different master password will cause all of the user's results to change.
+     */
+    void reset();
+
     boolean isMasterKeyAvailable();
 
     @Nonnull

platform-independent/java/model/src/main/java/com/lyndir/masterpassword/model/impl/MPBasicUser.java

@@ -97,12 +97,14 @@ public abstract class MPBasicUser<S extends MPBasicSite<?, ?>> extends Changeabl
     @Override
     public byte[] getKeyID() {
         try {
-            return getMasterKey().getKeyID( getAlgorithm() );
+            if (isMasterKeyAvailable())
+                return getMasterKey().getKeyID( getAlgorithm() );
         }
         catch (final MPException e) {
             logger.wrn( e, "While deriving key ID for user: %s", this );
-            return null;
         }
+
+        return null;
     }
 
     @Nullable
@@ -143,23 +145,29 @@ public abstract class MPBasicUser<S extends MPBasicSite<?, ?>> extends Changeabl
     public void invalidate() {
         if (masterKey == null)
             return;
-        
+
-        this.masterKey = null;
+        masterKey.invalidate();
+        masterKey = null;
 
         for (final Listener listener : listeners)
             listener.onUserInvalidated( this );
     }
 
+    @Override
+    public void reset() {
+        invalidate();
+    }
+
     @Override
     public boolean isMasterKeyAvailable() {
-        return masterKey != null;
+        return (masterKey != null) && masterKey.isValid();
     }
 
     @Nonnull
     @Override
     public MPMasterKey getMasterKey()
             throws MPKeyUnavailableException {
-        if (masterKey == null)
+        if ((masterKey == null) || !masterKey.isValid())
             throw new MPKeyUnavailableException( "Master key was not yet set for: " + this );
 
         return masterKey;

platform-independent/java/model/src/main/java/com/lyndir/masterpassword/model/impl/MPFileUser.java

@@ -169,6 +169,13 @@ public class MPFileUser extends MPBasicUser<MPFileSite> {
         }
     }
 
+    @Override
+    public void reset() {
+        keyID = null;
+
+        super.reset();
+    }
+
     @Override
     public MPFileSite addSite(final String siteName) {
         return addSite( new MPFileSite( this, siteName ) );