ssh: simplify passphrase implementation

app/src/main/java/app/trigger/MainActivity.java

@@ -72,7 +72,6 @@ public class MainActivity extends AppCompatActivity implements OnTaskCompleted {
     private Bitmap state_unknown_default_image;
 
     private int ignore_wifi_check_for_setup_id = -1;
-    private HashMap<Integer, String> ssh_passphrases_cache = new HashMap<>();
 
     public enum Action {
         open_door,
@@ -457,27 +456,25 @@ private boolean checkConnectedWifi(Setup setup, Action action) {
     private boolean checkSshPassphrase(Setup setup, Action action) {
         if (setup instanceof SshDoorSetup) {
             SshDoorSetup door = (SshDoorSetup) setup;
-            Integer id = door.getId();
 
-            // check if passphrase is needed
-            if (door.keypair == null || !door.keypair.encrypted) {
+            // check if passphrase is not needed
+            if (!door.needsPassphrase() || !Utils.isEmpty(door.passphrase_tmp)) {
                 return true;
             }
 
-            // try specific passphrase
-            if (ssh_passphrases_cache.containsKey(id)) {
-                String passphrase = ssh_passphrases_cache.get(id);
-                if (SshRequestHandler.testPassphrase(door.keypair, passphrase)) {
-                    return true;
+            // try other passphrases
+            for (Setup s : Settings.getSetups()) {
+                if (s instanceof SshDoorSetup) {
+                    continue;
                 }
-            }
 
-            // try other passphrases
-            for (String passphrase : ssh_passphrases_cache.values()) {
-                if (SshRequestHandler.testPassphrase(door.keypair, passphrase)) {
-                    showMessage("Use previous passphrase");
-                    ssh_passphrases_cache.put(id, passphrase);
-                    return true;
+                SshDoorSetup ss = (SshDoorSetup) s;
+                if (ss.needsPassphrase() && !Utils.isEmpty(ss.passphrase_tmp)) {
+                    if (SshRequestHandler.testPassphrase(door.keypair, ss.passphrase_tmp)) {
+                        showMessage("Reuse passphrase from " + door.getName());
+                        door.passphrase_tmp = ss.passphrase_tmp;
+                        return true;
+                    }
                 }
             }
 
@@ -492,7 +489,7 @@ private boolean checkSshPassphrase(Setup setup, Action action) {
             okButton.setOnClickListener((View v) -> {
                 String passphrase = passphraseEditText.getText().toString();
                 if (SshRequestHandler.testPassphrase(door.keypair, passphrase)) {
-                    ssh_passphrases_cache.put(id, passphrase);
+                    door.passphrase_tmp = passphrase;
                     showMessage("Passphrase accepted");
                     callRequestHandler(action);
                 } else {
@@ -529,8 +526,7 @@ private void callRequestHandler(Action action) {
             HttpsRequestHandler handler = new HttpsRequestHandler(this, (HttpsDoorSetup) setup, action);
             handler.start();
         } else if (setup instanceof SshDoorSetup) {
-            String passphrase = ssh_passphrases_cache.get(setup.getId());
-            SshRequestHandler handler = new SshRequestHandler(this, (SshDoorSetup) setup, action, passphrase);
+            SshRequestHandler handler = new SshRequestHandler(this, (SshDoorSetup) setup, action);
             handler.start();
         } else if (setup instanceof BluetoothDoorSetup) {
             BluetoothRequestHandler handler = new BluetoothRequestHandler(this, (BluetoothDoorSetup) setup, action);

app/src/main/java/app/trigger/Settings.java

@@ -345,7 +345,9 @@ static JSONObject toJsonObject(Setup setup) {
                 Class<?> type = field.getType();
                 Object value = field.get(setup);
 
-                if (type == String.class) {
+                if (name.endsWith("_tmp")) {
+                    // field is not meant to be stored
+                } else if (type == String.class) {
                     obj.put(name, (String) value);
                 } else if (type == Boolean.class) {
                     obj.put(name, (Boolean) value);
@@ -389,7 +391,9 @@ private static void setSetupField(Setup setup, JSONObject object, String name)
         for (Field field : fields) {
             if (field.getName().equals(name)) {
                 Class<?> type = field.getType();
-                if (type == String.class && value_type == String.class) {
+                if (name.endsWith("_tmp")) {
+                    // field is not meant to be loaded
+                } else if (type == String.class && value_type == String.class) {
                     field.set(setup, value);
                 } else if (type == Boolean.class && value_type == Boolean.class) {
                     field.set(setup, (Boolean) value);
@@ -578,8 +582,8 @@ private static Setup loadSetup_pre_172(int id) {
             try {
                 String value = sharedPreferences.getString(key, "");
 
-                if (name.equals("type")) {
-                    // ignore, object field is read only
+                if (name.equals("type") || name.endsWith("_tmp")) {
+                    // ignore, object field is not meant to be stored
                 } else if (type == String.class) {
                     field.set(setup, value);
                 } else if (type == Boolean.class) {

app/src/main/java/app/trigger/SshDoorSetup.java

@@ -35,6 +35,7 @@ public class SshDoorSetup implements Setup {
     public String ssids;
 
     public int timeout; // milliseconds
+    public String passphrase_tmp;
 
     public SshDoorSetup(int id, String name) {
         this.id = id;
@@ -129,4 +130,8 @@ public boolean canClose() {
     public boolean canRing() {
         return !Utils.isEmpty(ring_command);
     }
+
+    boolean needsPassphrase() {
+        return this.keypair != null && this.keypair.encrypted;
+    }
 }

app/src/main/java/app/trigger/ssh/SshRequestHandler.java

@@ -32,19 +32,17 @@ public class SshRequestHandler extends Thread implements ConnectionMonitor {
     private final OnTaskCompleted listener;
     private final SshDoorSetup setup;
     private final Action action;
-    private final String passphrase;
 
     static {
         Log.d(TAG, "Ed25519Provider.insertIfNeeded2");
         // Since this class deals with Ed25519 keys, we need to make sure this is available.
         Ed25519Provider.insertIfNeeded();
     }
 
-    public SshRequestHandler(OnTaskCompleted listener, SshDoorSetup setup, Action action, String passphrase) {
+    public SshRequestHandler(OnTaskCompleted listener, SshDoorSetup setup, Action action) {
         this.listener = listener;
         this.setup = setup;
         this.action = action;
-        this.passphrase = passphrase;
     }
 
     public void run() {
@@ -100,11 +98,12 @@ public void run() {
 
             // authentication by key pair
             if (keypair != null && !connection.isAuthenticationComplete()) {
-                KeyPair kp = decodeKeyPair(setup.keypair, this.passphrase);
+                KeyPair kp = decodeKeyPair(setup.keypair, setup.passphrase_tmp);
                 if (kp != null) {
                     connection.authenticateWithPublicKey(username, kp);
                 } else {
                     if (keypair.encrypted) {
+                        setup.passphrase_tmp = ""; // reset (incorrect) passphrase
                         listener.onTaskResult(setup.getId(), ReplyCode.LOCAL_ERROR, "Key pair passphrase was not accepted.");
                     } else {
                         listener.onTaskResult(setup.getId(), ReplyCode.LOCAL_ERROR, "Failed to decode key pair.");