Remember last used key within KeyConfusionAttackDialog.

src/main/java/com/blackberry/jwteditor/presenter/EditorPresenter.java

@@ -212,6 +212,7 @@ public void onAttackKeyConfusionClicked() {
                 view.window(),
                 logging,
                 attackKeys,
+                lastSigningKeys,
                 getJWS()
         );
 

src/main/java/com/blackberry/jwteditor/view/dialog/operations/KeyConfusionAttackDialog.java

@@ -32,10 +32,16 @@
 import java.awt.*;
 import java.util.List;
 
+import static com.blackberry.jwteditor.view.dialog.operations.LastSigningKeys.Signer.KEY_CONFUSION;
+
 /**
  * Attack > HMAC Key Confusion dialog from the Editor tab
  */
 public class KeyConfusionAttackDialog extends OperationDialog<JWS> {
+    private static final JWSAlgorithm[] ALGORITHMS = {JWSAlgorithm.HS256, JWSAlgorithm.HS384, JWSAlgorithm.HS512};
+
+    private final LastSigningKeys lastSigningKeys;
+
     private JPanel contentPane;
     private JButton buttonOK;
     private JButton buttonCancel;
@@ -47,25 +53,30 @@ public KeyConfusionAttackDialog(
             Window parent,
             Logging logging,
             List<Key> signingKeys,
+            LastSigningKeys lastSigningKeys,
             JWS jws) {
         super(parent, logging, "key_confusion_attack_dialog_title", jws, "error_title_unable_to_sign");
 
+        this.lastSigningKeys = lastSigningKeys;
+
         configureUI(contentPane, buttonOK, buttonCancel);
 
-        comboBoxSigningKey.setModel(new DefaultComboBoxModel<>(signingKeys.toArray(Key[]::new)));
+        int lastUsedKeyIndex = lastSigningKeys.lastKeyFor(KEY_CONFUSION).map(signingKeys::indexOf).orElse(-1);
+        lastUsedKeyIndex = lastUsedKeyIndex == -1 ? 0 : lastUsedKeyIndex;
 
-        // Populate the Signing Algorithm dropdown
-        comboBoxSigningAlgorithm.setModel(new DefaultComboBoxModel<>(new JWSAlgorithm[] {JWSAlgorithm.HS256, JWSAlgorithm.HS384, JWSAlgorithm.HS512}));
+        comboBoxSigningKey.setModel(new DefaultComboBoxModel<>(signingKeys.toArray(Key[]::new)));
+        comboBoxSigningKey.setSelectedIndex(lastUsedKeyIndex);
 
-        // Select the first signing key
-        comboBoxSigningKey.setSelectedIndex(0);
+        comboBoxSigningAlgorithm.setModel(new DefaultComboBoxModel<>(ALGORITHMS));
     }
 
     @Override
     JWS performOperation() throws SigningException, PemException, UnsupportedKeyException {
         JWKKey selectedKey = (JWKKey) comboBoxSigningKey.getSelectedItem();
         JWSAlgorithm selectedAlgorithm = (JWSAlgorithm) comboBoxSigningAlgorithm.getSelectedItem();
 
+        lastSigningKeys.recordKeyUse(KEY_CONFUSION, selectedKey);
+
         return Attacks.hmacKeyConfusion(jwt, selectedKey, selectedAlgorithm, checkBoxTrailingNewline.isSelected());
     }
 }

src/main/java/com/blackberry/jwteditor/view/dialog/operations/LastSigningKeys.java

@@ -1,20 +1,21 @@
 package com.blackberry.jwteditor.view.dialog.operations;
 
 import com.blackberry.jwteditor.model.keys.Key;
-import com.blackberry.jwteditor.view.dialog.operations.SigningDialog.Mode;
 
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
 
 public class LastSigningKeys {
-    private final Map<Mode, Key> lastKeyMap = new HashMap<>();
+    enum Signer { NORMAL, EMBED_JWK, KEY_CONFUSION }
 
-    Optional<Key> lastKeyFor(Mode mode) {
+    private final Map<Signer, Key> lastKeyMap = new HashMap<>();
+
+    Optional<Key> lastKeyFor(Signer mode) {
         return Optional.ofNullable(lastKeyMap.get(mode));
     }
 
-    void recordKeyUse(Mode mode, Key key) {
+    void recordKeyUse(Signer mode, Key key) {
         lastKeyMap.put(mode, key);
     }
 }

src/main/java/com/blackberry/jwteditor/view/dialog/operations/SigningDialog.java

@@ -26,6 +26,7 @@
 import com.blackberry.jwteditor.model.keys.JWKKey;
 import com.blackberry.jwteditor.model.keys.Key;
 import com.blackberry.jwteditor.operations.Attacks;
+import com.blackberry.jwteditor.view.dialog.operations.LastSigningKeys.Signer;
 import com.nimbusds.jose.JWSAlgorithm;
 
 import javax.swing.*;
@@ -40,13 +41,16 @@
 public class SigningDialog extends OperationDialog<JWS> {
 
     public enum Mode {
-        NORMAL("sign_dialog_title"),
-        EMBED_JWK("embed_jwk_attack_dialog_title");
+        NORMAL("sign_dialog_title", Signer.NORMAL),
+        EMBED_JWK("embed_jwk_attack_dialog_title", Signer.EMBED_JWK);
+
+        final Signer signer;
 
         private final String titleResourceId;
 
-        Mode(String titleResourceId) {
+        Mode(String titleResourceId, Signer embedJwk) {
             this.titleResourceId = titleResourceId;
+            this.signer = embedJwk;
         }
     }
 
@@ -91,7 +95,7 @@ public SigningDialog(
             buttonOK.setEnabled(true);
         });
 
-        int lastUsedKeyIndex = lastSigningKeys.lastKeyFor(mode).map(signingKeys::indexOf).orElse(-1);
+        int lastUsedKeyIndex = lastSigningKeys.lastKeyFor(mode.signer).map(signingKeys::indexOf).orElse(-1);
         lastUsedKeyIndex = lastUsedKeyIndex == -1 ? 0 : lastUsedKeyIndex;
         comboBoxSigningKey.setSelectedIndex(lastUsedKeyIndex);
 
@@ -107,7 +111,7 @@ JWS performOperation() throws SigningException, NoSuchFieldException, IllegalAcc
         JWKKey selectedKey = (JWKKey) comboBoxSigningKey.getSelectedItem();
         JWSAlgorithm selectedAlgorithm = (JWSAlgorithm) comboBoxSigningAlgorithm.getSelectedItem();
 
-        lastSigningKeys.recordKeyUse(mode, selectedKey);
+        lastSigningKeys.recordKeyUse(mode.signer, selectedKey);
 
         // Get the header update mode based on the selected radio button, convert to the associated enum value
         SigningUpdateMode signingUpdateMode;