SSH/server utility cleanup and small code security improvements (#1221)

* Update dartssh2 package

* Remove dead code: DecyptPem and tryParseCompletedOutput

- Remove unused DecyptPem function (zero call sites)
- Remove unused tryParseCompletedOutput static method (only used in tests)
- Fix typo: loadIndentity -> loadIdentity
- Update persistent_shell_test.dart to drop tests for removed method

* Harden security: avoid password in process args, use system temp for keys

- sftp_sudo: use shell builtin printf instead of echo to pipe sudo
  password, so the password does not appear in the process argument
  list visible via ps
- server_func_btns: write temp private key to system temp directory
  instead of the predictable app doc path, and extend retention to
  5s for SSH connection establishment
- server_func_btns: unconditionally clear clipboard after password
  copy timeout instead of skipping when content changed

* Reduce redundant store fetches and reuse listEquals

- server_dedup: accept optional existingServers param to avoid
  duplicate ServerStore.fetch() calls in _resolveServers
- all.dart: replace manual _isSameOrder with listEquals
- server_private_info: replace _sameStringList with listEquals

* Improve robustness: fix async void, skip empty workers, narrow failover

- chan: change updateHomeWidget from void async to Future<void> with
  try-catch so callers can use unawaited properly
- home: mark updateHomeWidget calls with unawaited
- main: skip Computer.shared.turnOn when no servers configured
- server: narrow _isJumpFailoverError keyword matching to avoid
  false positives on unrelated errors containing 'network' or 'socket'

* Fix naming inconsistencies and document enum ordering

- setting: rename backupasswd -> backupPassword
- misc: rename multiBlankreg -> multiBlankReg for consistency
- server: add ordering invariant comment for ServerConn operator<

* Restore decryptPem and fix typo in caller

- Restore decryptPem (was wrongly removed as dead code, actually
  called in private_key/edit.dart via Computer.shared.start)
- Fix typo: decyptPem -> decryptPem in both definition and call site

* Preserve user clipboard content when clearing SSH password

Revert to checking clipboard content before clearing: only wipe
the clipboard if it still holds the password. If the user copied
something else during the 25s window, preserve their content.

* Revert dartssh2 package

* Address review findings: failover match, Computer init, temp key, dedup

- server.dart: add 'network is unreachable' to failover error matching
- main.dart: restore unconditional Computer.shared.turnOn to avoid
  hangs when backup/private-key flows call Computer.shared.start with
  zero servers configured
- server_func_btns: use unique temp directory per launch instead of
  stable filename, and extend key cleanup delay to 30s, delete the
  whole temp directory on cleanup
- ssh.dart: reuse a single Stores.server.fetch() call in
  _processSSHServers for both deduplicateServers and
  resolveNameConflicts

* Delete temp SSH key dir immediately when launch fails

Track whether SSH actually started via sshLaunched flag set after
each successful Process.start. On failure paths (exception, unsupported
platform, or key prep error) the temp key directory is deleted right
away in the finally block instead of waiting 30 seconds.

Author: GT-610

lib/core/chan.dart

@@ -18,10 +18,14 @@ abstract final class MethodChans {
     _channel.invokeMethod('stopService');
   }
 
-  static void updateHomeWidget() async {
+  static Future<void> updateHomeWidget() async {
     if (!isIOS && !isAndroid) return;
     if (!Stores.setting.autoUpdateHomeWidget.fetch()) return;
-    await _channel.invokeMethod('updateHomeWidget');
+    try {
+      await _channel.invokeMethod('updateHomeWidget');
+    } catch (e, s) {
+      Loggers.app.warning('Failed to update home widget', e, s);
+    }
   }
 
   /// Update Android foreground service notifications for SSH sessions

lib/core/utils/server.dart

@@ -17,12 +17,17 @@ import 'package:server_box/data/res/store.dart';
 /// Because of this function is called by [compute].
 ///
 /// https://stackoverflow.com/questions/51998995/invalid-arguments-illegal-argument-in-isolate-message-object-is-a-closure
-List<SSHKeyPair> loadIndentity(String key) {
+List<SSHKeyPair> loadIdentity(String key) {
   return SSHKeyPair.fromPem(key);
 }
 
+/// Decrypts an encrypted PEM private key.
+///
+/// Must also be a top-level function because it is called via [Computer]
+/// (isolate) — see comment on [loadIdentity].
+///
 /// [args] : [key, pwd]
-String decyptPem(List<String> args) {
+String decryptPem(List<String> args) {
   /// skip when the key is not encrypted, or will throw exception
   if (!SSHKeyPair.isEncryptedPem(args[0])) return args[0];
   final sshKey = SSHKeyPair.fromPem(args[0], args[1]);
@@ -214,7 +219,7 @@ Future<SSHClient> genClient(
     socket,
     username: spi.user,
     // Must use [compute] here, instead of [Computer.shared.start]
-    identities: await compute(loadIndentity, privateKey),
+    identities: await compute(loadIdentity, privateKey),
     onUserInfoRequest: onKeyboardInteractive,
     onVerifyHostKey: hostKeyVerifier.call,
   );
@@ -249,10 +254,11 @@ bool _isJumpFailoverError(Object error) {
       errStr.contains('connection reset') ||
       errStr.contains('connection closed') ||
       errStr.contains('no route to host') ||
-      errStr.contains('network') ||
-      errStr.contains('socket') ||
+      errStr.contains('network unreachable') ||
+      errStr.contains('network is unreachable') ||
+      errStr.contains('socketexception') ||
       errStr.contains('failed host lookup') ||
-      errStr.contains('forward') ||
+      errStr.contains('forwardlocal') ||
       errStr.contains('proxycommand exited') ||
       errStr.contains('proxycommand timed out');
 }

lib/core/utils/server_dedup.dart

@@ -8,12 +8,15 @@ import 'package:server_box/data/store/server.dart';
 class ServerDeduplication {
   /// Remove duplicate servers from the import list based on existing servers
   /// Returns the deduplicated list
-  static List<Spi> deduplicateServers(List<Spi> importedServers) {
-    final existingServers = ServerStore.instance.fetch();
+  static List<Spi> deduplicateServers(
+    List<Spi> importedServers, {
+    List<Spi>? existingServers,
+  }) {
+    final existing = existingServers ?? ServerStore.instance.fetch();
     final deduplicated = <Spi>[];
 
     for (final imported in importedServers) {
-      if (!_isDuplicate(imported, existingServers)) {
+      if (!_isDuplicate(imported, existing)) {
         deduplicated.add(imported);
       }
     }
@@ -33,9 +36,12 @@ class ServerDeduplication {
   }
 
   /// Resolve name conflicts by appending suffixes
-  static List<Spi> resolveNameConflicts(List<Spi> importedServers) {
-    final existingServers = ServerStore.instance.fetch();
-    final existingNames = existingServers.map((s) => s.name).toSet();
+  static List<Spi> resolveNameConflicts(
+    List<Spi> importedServers, {
+    List<Spi>? existingServers,
+  }) {
+    final existing = existingServers ?? ServerStore.instance.fetch();
+    final existingNames = existing.map((s) => s.name).toSet();
     final processedNames = <String>{};
     final result = <Spi>[];
 
@@ -111,8 +117,12 @@ class ServerDeduplication {
   }
 
   static List<Spi> _resolveServers(List<Spi> servers) {
-    final deduplicated = deduplicateServers(servers);
-    final resolved = resolveNameConflicts(deduplicated);
+    final existing = ServerStore.instance.fetch();
+    final deduplicated = deduplicateServers(servers, existingServers: existing);
+    final resolved = resolveNameConflicts(
+      deduplicated,
+      existingServers: existing,
+    );
     return resolved;
   }
 }

lib/core/utils/sftp_sudo.dart

@@ -237,10 +237,13 @@ final class SftpSudoHelper {
   }
 
   static String _buildSudoCommand(String command, String password) {
-    final pwdBase64 = base64Encode(utf8.encode(password));
     final wrapped = '($command) 2>&1';
     final escapedWrapped = wrapped.replaceAll("'", "'\\''");
-    return 'echo "$pwdBase64" | base64 -d | sudo -S -- sh -c \'$escapedWrapped\'';
+    // Use shell builtin printf to pipe password to sudo -S.
+    // printf is a shell builtin so the password does not appear in
+    // the process argument list (unlike external `echo`).
+    final escapedPwd = password.replaceAll("'", "'\\''");
+    return "printf '%s\\n' '$escapedPwd' | sudo -S -- sh -c '$escapedWrapped'";
   }
 
   static SftpFileMode _buildMode(String typeChar, int permOct) {

lib/data/model/container/ps.dart

@@ -149,7 +149,7 @@ final class DockerPs implements ContainerPs {
   /// CONTAINER ID                   NAMES                          IMAGE                          STATUS
   /// a049d689e7a1                   aria2-pro                      p3terx/aria2-pro               Up 3 weeks
   factory DockerPs.parse(String raw) {
-    final parts = raw.split(Miscs.multiBlankreg);
+    final parts = raw.split(Miscs.multiBlankReg);
     return DockerPs(
       id: parts[0],
       state: parts[1],

lib/data/model/server/server.dart

@@ -64,5 +64,8 @@ enum ServerConn {
   /// Status parsing finished
   finished;
 
+  /// Orders by declaration index: failed < disconnected < connecting <
+  /// connected < loading < finished. Do NOT reorder the enum values
+  /// above without auditing all call sites that rely on this ordering.
   bool operator <(ServerConn other) => index < other.index;
 }

lib/data/model/server/server_private_info.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
 
 import 'package:fl_lib/fl_lib.dart';
+import 'package:flutter/foundation.dart' show listEquals;
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:server_box/data/model/app/error.dart';
 import 'package:server_box/data/model/server/custom.dart';
@@ -148,7 +149,7 @@ extension Spix on Spi {
         port == other.port &&
         pwd == other.pwd &&
         keyId == other.keyId &&
-        _sameStringList(resolvedJumpIds, other.resolvedJumpIds) &&
+        listEquals(resolvedJumpIds, other.resolvedJumpIds) &&
         proxyCommand == other.proxyCommand;
   }
 
@@ -208,11 +209,3 @@ extension Spix on Spi {
   /// Returns true if the user is 'root'.
   bool get isRoot => user == 'root';
 }
-
-bool _sameStringList(List<String> a, List<String> b) {
-  if (a.length != b.length) return false;
-  for (var i = 0; i < a.length; i++) {
-    if (a[i] != b[i]) return false;
-  }
-  return true;
-}

lib/data/provider/server/all.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:fl_lib/fl_lib.dart';
+import 'package:flutter/foundation.dart' show listEquals;
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
 import 'package:server_box/core/sync.dart';
@@ -335,18 +336,8 @@ class ServersNotifier extends _$ServersNotifier {
   }
 
   bool _isSameOrder(List<String> a, List<String> b) {
-    if (identical(a, b)) {
-      return true;
-    }
-    if (a.length != b.length) {
-      return false;
-    }
-    for (var i = 0; i < a.length; i++) {
-      if (a[i] != b[i]) {
-        return false;
-      }
-    }
-    return true;
+    if (identical(a, b)) return true;
+    return listEquals(a, b);
   }
 
   Future<void> updateServer(Spi old, Spi newSpi) async {

lib/data/res/misc.dart

@@ -2,7 +2,7 @@ import 'dart:convert';
 
 abstract final class Miscs {
   static final blankReg = RegExp(r'\s+');
-  static final multiBlankreg = RegExp(r'\s{2,}');
+  static final multiBlankReg = RegExp(r'\s{2,}');
 
   /// RegExp for password request
   static final pwdRequestWithUserReg = RegExp(r'\[sudo\] password for (.+):');

lib/data/ssh/persistent_shell.dart

@@ -287,16 +287,6 @@ printf '\\n$_donePrefix$commandId:%s\\n' "\$__server_box_exit"
     }
   }
 
-  static PersistentShellCommandResult? tryParseCompletedOutput(
-    String raw, {
-    required String expectedCommandId,
-  }) {
-    return _parseCompletedOutput(
-      raw,
-      expectedCommandId: expectedCommandId,
-    )?.result;
-  }
-
   static _ParsedCompletedOutput? _parseCompletedOutput(
     String raw, {
     required String expectedCommandId,