fix: encrypt saved FTP/SFTP credentials

src/fileSystem/externalFs.js

@@ -1,4 +1,5 @@
 import loader from "dialogs/loader";
+import secureStorageList from "lib/secureStorageList";
 import { decode, encode, getEncodingName } from "utils/encodings";
 import helpers from "utils/helpers";
 import Url from "utils/Url";
@@ -105,7 +106,7 @@ const externalFs = {
 	},
 
 	async stats(uri) {
-		const storageList = helpers.parseJSON(localStorage.getItem("storageList"));
+		const storageList = secureStorageList.get();
 
 		if (Array.isArray(storageList)) {
 			const storage = storageList.find((s) => s.uri === uri);

src/lib/secureStorageList.js

@@ -0,0 +1,91 @@
+/**
+ * Secure persistence for the saved remote-storage list (FTP/SFTP servers).
+ *
+ * Keeps the list in a native, hardware-backed encrypted store (AES256-GCM, via
+ * the `system.secure*` bridge) instead of localStorage. The in-memory shape is
+ * unchanged, so callers behave the same; only the on-disk storage differs.
+ *
+ * Access is synchronous via an in-memory cache, hydrated once at startup by
+ * `hydrate()` — which must be awaited early in onDeviceReady, before any UI
+ * reads the list. See #2561.
+ */
+
+const SECURE_KEY = "storageList";
+const LEGACY_KEY = "storageList"; // the old localStorage key
+
+/** @type {Array|null} in-memory source of truth; null until hydrated */
+let cache = null;
+
+function parse(json) {
+	try {
+		const value = JSON.parse(json);
+		return Array.isArray(value) ? value : [];
+	} catch (_) {
+		return [];
+	}
+}
+
+/**
+ * Load the list into memory, migrating any legacy plaintext localStorage copy
+ * into the encrypted store first. Safe to call more than once.
+ * @returns {Promise<void>}
+ */
+async function hydrate() {
+	// 1. One-time migration: if a legacy plaintext list exists in localStorage,
+	//    move it into the encrypted store, then remove the plaintext copy.
+	const legacy = localStorage.getItem(LEGACY_KEY);
+	if (legacy != null) {
+		try {
+			// Only drop the plaintext copy AFTER the encrypted write succeeds,
+			// so a failure here never loses the user's saved servers.
+			await window.system.secureSet(SECURE_KEY, legacy);
+			localStorage.removeItem(LEGACY_KEY);
+		} catch (error) {
+			// Migration failed — keep the legacy copy and fall back to it this
+			// session rather than lose data. Try again next launch.
+			window.log?.("error", `secureStorageList migration failed: ${error}`);
+			cache = parse(legacy);
+			return;
+		}
+	}
+
+	// 2. Load from the encrypted store.
+	try {
+		const stored = await window.system.secureGet(SECURE_KEY);
+		cache = stored ? parse(stored) : [];
+	} catch (error) {
+		window.log?.("error", `secureStorageList hydrate failed: ${error}`);
+		cache = [];
+	}
+}
+
+/**
+ * The saved remote-storage list (synchronous).
+ * Falls back to a one-shot legacy read if called before hydrate() (defensive;
+ * should not happen in normal boot order).
+ * @returns {Array}
+ */
+function get() {
+	if (cache == null) {
+		const legacy = localStorage.getItem(LEGACY_KEY);
+		return legacy != null ? parse(legacy) : [];
+	}
+	return cache;
+}
+
+/**
+ * Persist the list. Updates the in-memory cache immediately and flushes to the
+ * encrypted store. The returned promise resolves once the flush completes;
+ * synchronous callers may ignore it (the cache is already updated).
+ * @param {Array} list
+ * @returns {Promise<void>}
+ */
+function set(list) {
+	cache = Array.isArray(list) ? list : [];
+	const json = JSON.stringify(cache);
+	return window.system.secureSet(SECURE_KEY, json).catch((error) => {
+		window.log?.("error", `secureStorageList save failed: ${error}`);
+	});
+}
+
+export default { hydrate, get, set };

src/main.js

@@ -52,6 +52,7 @@ import notificationManager from "lib/notificationManager";
 import openFolder, { addedFolder } from "lib/openFolder";
 import { registerPrettierFormatter } from "lib/registerPrettierFormatter";
 import restoreFiles from "lib/restoreFiles";
+import secureStorageList from "lib/secureStorageList";
 import settings from "lib/settings";
 import startAd, { hideAd } from "lib/startAd";
 import mustache from "mustache";
@@ -98,6 +99,10 @@ document.addEventListener("menubutton", menuButtonHandler);
 
 async function onDeviceReady() {
 	await initEncodings(); // important to load encodings before anything else
+	// Load saved remote-storage (FTP/SFTP) list from the encrypted native store,
+	// migrating any legacy plaintext localStorage copy. Must run before any UI
+	// that reads the storage list. See issue #2561.
+	await secureStorageList.hydrate();
 
 	const isFreePackage = /(free)$/.test(BuildInfo.packageName);
 	const oldResolveURL = window.resolveLocalFileSystemURL;

src/pages/fileBrowser/fileBrowser.js

@@ -20,6 +20,7 @@ import openFolder from "lib/openFolder";
 import projects from "lib/projects";
 import recents from "lib/recents";
 import remoteStorage from "lib/remoteStorage";
+import secureStorageList from "lib/secureStorageList";
 import appSettings from "lib/settings";
 import { hideAd } from "lib/startAd";
 import mimeTypes from "mime-types";
@@ -65,7 +66,7 @@ function FileBrowserInclude(mode, info, doesOpenLast = true) {
 	const state = [];
 	/**@type {Array<Storage>} */
 	const allStorages = [];
-	let storageList = helpers.parseJSON(localStorage.storageList);
+	let storageList = secureStorageList.get();
 	if (!Array.isArray(storageList)) storageList = [];
 
 	let isSelectionMode = false;
@@ -1242,7 +1243,7 @@ function FileBrowserInclude(mode, info, doesOpenLast = true) {
 					}
 					return false;
 				});
-				localStorage.storageList = JSON.stringify(storageList);
+				secureStorageList.set(storageList);
 				reload();
 			}
 
@@ -1251,7 +1252,7 @@ function FileBrowserInclude(mode, info, doesOpenLast = true) {
 					if (storage.uuid === uuid) storage.name = newname;
 					return storage;
 				});
-				localStorage.storageList = JSON.stringify(storageList);
+				secureStorageList.set(storageList);
 				reload();
 			}
 
@@ -1706,7 +1707,7 @@ function FileBrowserInclude(mode, info, doesOpenLast = true) {
 			}
 
 			storageList.push(storage);
-			localStorage.storageList = JSON.stringify(storageList);
+			secureStorageList.set(storageList);
 			if (doesReload) reload();
 		}
 
@@ -1761,7 +1762,7 @@ function FileBrowserInclude(mode, info, doesOpenLast = true) {
 				.addPath()
 				.then((res) => {
 					storageList.push(res);
-					localStorage.storageList = JSON.stringify(storageList);
+					secureStorageList.set(storageList);
 					reload();
 				})
 				.catch((err) => {

src/plugins/system/android/com/foxdebug/system/SecureStore.java

@@ -0,0 +1,76 @@
+package com.foxdebug.system;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import androidx.security.crypto.EncryptedSharedPreferences;
+import androidx.security.crypto.MasterKeys;
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+
+/**
+ * Small encrypted key/value store for secrets that must not sit in cleartext on
+ * disk (e.g. saved SFTP/FTP server credentials, previously kept in the WebView's
+ * localStorage.storageList). Values are encrypted at rest with a hardware-backed
+ * master key via AndroidX Security-Crypto (AES256-GCM), the same mechanism the
+ * auth plugin already uses for the account token.
+ *
+ * Lazily initialised so a crypto/keystore failure never blocks plugin startup.
+ */
+public class SecureStore {
+
+    private static final String PREF_NAME = "acode_secure_store";
+
+    private final Context context;
+    private SharedPreferences prefs;
+
+    public SecureStore(Context context) {
+        this.context = context.getApplicationContext();
+    }
+
+    private SharedPreferences prefs() {
+        if (prefs != null) return prefs;
+        try {
+            String masterKeyAlias = MasterKeys.getOrCreate(MasterKeys.AES256_GCM_SPEC);
+            prefs = EncryptedSharedPreferences.create(
+                PREF_NAME,
+                masterKeyAlias,
+                context,
+                EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+                EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+            );
+        } catch (GeneralSecurityException | IOException e) {
+            // Same fallback the existing EncryptedPreferenceManager uses: a private
+            // (app-sandbox) prefs file. Not encrypted, but still off the WebView's
+            // localStorage and unreadable by other apps.
+            prefs = context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
+        }
+        return prefs;
+    }
+
+    /**
+     * Store a value durably. Passing null removes the key.
+     * Uses commit() (not apply()) so the write is on disk before returning:
+     * the JS migration deletes the legacy plaintext copy only after this
+     * resolves, so an unpersisted write here must not report success. See #2561.
+     * @return true if the write reached disk.
+     */
+    public boolean set(String key, String value) {
+        if (value == null) {
+            return remove(key);
+        }
+        return prefs().edit().putString(key, value).commit();
+    }
+
+    /** Return the stored value, or null if absent. */
+    public String get(String key) {
+        return prefs().getString(key, null);
+    }
+
+    public boolean remove(String key) {
+        return prefs().edit().remove(key).commit();
+    }
+
+    public boolean contains(String key) {
+        return prefs().contains(key);
+    }
+}

src/plugins/system/android/com/foxdebug/system/System.java

@@ -86,13 +86,15 @@ public class System extends CordovaPlugin {
   private CordovaWebView webView;
   private String fileProviderAuthority;
   private RewardPassManager rewardPassManager;
+  private SecureStore secureStore;
 
   public void initialize(CordovaInterface cordova, CordovaWebView webView) {
     super.initialize(cordova, webView);
     this.context = cordova.getContext();
     this.activity = cordova.getActivity();
     this.webView = webView;
     this.rewardPassManager = new RewardPassManager(this.context);
+    this.secureStore = new SecureStore(this.context);
     this.activity.runOnUiThread(
       new Runnable() {
         @Override
@@ -217,6 +219,31 @@ public void run() {
       case "getFilesDir":
         callbackContext.success(getFilesDir());
         return true;
+      case "secure-set":
+        // arg1 = key, arg2 = value (null clears the key). Report failure if the
+        // durable write did not reach disk, so the JS migration keeps its
+        // fallback copy rather than deleting it. See #2561.
+        if (secureStore.set(arg1, args.isNull(1) ? null : arg2)) {
+          callbackContext.success();
+        } else {
+          callbackContext.error("secure write failed");
+        }
+        return true;
+      case "secure-get":
+        {
+          String storedValue = secureStore.get(arg1);
+          // success(String) with null would throw; send an explicit empty result
+          if (storedValue == null) {
+            callbackContext.success((String) null);
+          } else {
+            callbackContext.success(storedValue);
+          }
+        }
+        return true;
+      case "secure-remove":
+        secureStore.remove(arg1);
+        callbackContext.success();
+        return true;
       case "getRewardStatus":
         callbackContext.success(rewardPassManager.getRewardStatus());
         return true;

src/plugins/system/plugin.xml

@@ -37,11 +37,13 @@
     <resource-file src="res/android/icon.ttf" target="assets/font/icon.ttf" />
     <source-file src="android/com/foxdebug/system/Ui.java" target-dir="src/com/foxdebug/system"/>
     <source-file src="android/com/foxdebug/system/System.java" target-dir="src/com/foxdebug/system"/>
+    <source-file src="android/com/foxdebug/system/SecureStore.java" target-dir="src/com/foxdebug/system"/>
     <source-file src="android/com/foxdebug/system/SoftInputAssist.java" target-dir="src/com/foxdebug/system"/>
 
     <framework src="androidx.core:core:1.6.0" />
     <framework src="androidx.core:core-google-shortcuts:1.0.0" />
     <framework src="androidx.documentfile:documentfile:1.0.1" />
+    <framework src="androidx.security:security-crypto:1.1.0" />
     <source-file src="android/com/foxdebug/system/RewardPassManager.java" target-dir="src/com/foxdebug/system"/>
   </platform>
 </plugin>

src/plugins/system/www/plugin.js

@@ -272,5 +272,44 @@ module.exports = {
         [text1, text2]
       );
     });
+  },
+  /**
+   * Store a secret encrypted at rest (AES256-GCM, hardware-backed key).
+   * Use for credentials that must not sit in cleartext in the WebView's
+   * localStorage. Passing an empty/undefined value clears the key.
+   * @param {string} key
+   * @param {string} value
+   * @returns {Promise<void>}
+   */
+  secureSet: function (key, value) {
+    return new Promise((resolve, reject) => {
+      cordova.exec(resolve, reject, 'System', 'secure-set', [key, value == null ? null : String(value)]);
+    });
+  },
+  /**
+   * Read a secret previously stored with secureSet.
+   * @param {string} key
+   * @returns {Promise<string|null>} the value, or null if absent
+   */
+  secureGet: function (key) {
+    return new Promise((resolve, reject) => {
+      cordova.exec(
+        function (result) { resolve(result == null || result === '' ? null : result); },
+        reject,
+        'System',
+        'secure-get',
+        [key]
+      );
+    });
+  },
+  /**
+   * Remove a stored secret.
+   * @param {string} key
+   * @returns {Promise<void>}
+   */
+  secureRemove: function (key) {
+    return new Promise((resolve, reject) => {
+      cordova.exec(resolve, reject, 'System', 'secure-remove', [key]);
+    });
   }
 };

src/utils/Uri.js

@@ -1,9 +1,10 @@
 import escapeStringRegexp from "escape-string-regexp";
+import secureStorageList from "lib/secureStorageList";
 import path from "./Path";
 
 function parseStorageList() {
 	try {
-		const storageList = JSON.parse(localStorage.storageList || "[]");
+		const storageList = secureStorageList.get();
 		return Array.isArray(storageList) ? storageList : [];
 	} catch (_) {
 		return [];

src/utils/helpers.js

@@ -4,6 +4,7 @@ import alert from "dialogs/alert";
 import escapeStringRegexp from "escape-string-regexp";
 import adRewards from "lib/adRewards";
 import config from "lib/config";
+import secureStorageList from "lib/secureStorageList";
 import { bannerAd, interstitialAd } from "lib/startAd";
 import { isBinaryFile } from "./binaryExtensions";
 import { isPlayStoreInstall } from "./installSource";
@@ -245,7 +246,7 @@ export default {
 		}
 
 		/**@type {string[]} */
-		const storageList = this.parseJSON(localStorage.storageList);
+		const storageList = secureStorageList.get();
 		if (!Array.isArray(storageList)) return url;
 		const storageListLen = storageList.length;