OIDC로 빠지는 분기 점검 login_challenge 복구 fallback 추가

userfront/lib/core/services/web_window_stub.dart

@@ -3,6 +3,14 @@ class WebWindow {
 
   void redirectTo(String url) {}
 
+  String currentHref() {
+    return '';
+  }
+
+  String currentSearch() {
+    return '';
+  }
+
   void alert(String message) {}
 
   void close() {}

userfront/lib/core/services/web_window_web.dart

@@ -1,6 +1,7 @@
 // ignore_for_file: avoid_web_libraries_in_flutter, deprecated_member_use
 
 import 'dart:html' as html;
+import 'package:flutter/foundation.dart';
 
 class WebWindow {
   void setTitle(String title) {
@@ -8,7 +9,48 @@ class WebWindow {
   }
 
   void redirectTo(String url) {
+    final currentHref = html.window.location.href;
+    Uri? targetUri;
+    try {
+      targetUri = Uri.parse(url);
+    } catch (_) {
+      debugPrint("[WebWindow] redirectTo parse failed: url=$url");
+    }
+
+    final currentPort = int.tryParse(html.window.location.port);
+    final sameOrigin =
+        targetUri != null &&
+        targetUri.scheme == html.window.location.protocol.replaceAll(':', '') &&
+        targetUri.host == html.window.location.hostname &&
+        (!targetUri.hasPort || targetUri.port == currentPort);
+
+    debugPrint(
+      "[WebWindow] redirectTo start: current=$currentHref, target=$url, target_host=${targetUri?.host ?? ''}, target_path=${targetUri?.path ?? ''}, same_origin=$sameOrigin",
+    );
+
     html.window.location.href = url;
+
+    // 이동이 차단되거나 즉시 원위치되는 경우를 추적하기 위한 후속 로그입니다.
+    Future<void>.delayed(const Duration(milliseconds: 800), () {
+      final nowHref = html.window.location.href;
+      if (nowHref == currentHref) {
+        debugPrint(
+          "[WebWindow] redirectTo no-op detected: current URL did not change after navigation attempt",
+        );
+      } else {
+        debugPrint(
+          "[WebWindow] redirectTo post-check: location changed to $nowHref",
+        );
+      }
+    });
+  }
+
+  String currentHref() {
+    return html.window.location.href;
+  }
+
+  String currentSearch() {
+    return html.window.location.search ?? '';
   }
 
   void alert(String message) {

userfront/lib/features/auth/domain/login_challenge_resolver.dart

@@ -0,0 +1,195 @@
+enum LoginChallengeSource { widget, uriQuery, rawSearch, rawHref, missing }
+
+class LoginChallengeResolution {
+  final String? value;
+  final LoginChallengeSource source;
+  final bool uriHasLoginChallenge;
+  final bool rawSearchHasLoginChallenge;
+  final bool rawHrefHasLoginChallenge;
+
+  const LoginChallengeResolution({
+    required this.value,
+    required this.source,
+    required this.uriHasLoginChallenge,
+    required this.rawSearchHasLoginChallenge,
+    required this.rawHrefHasLoginChallenge,
+  });
+
+  Map<String, Object?> toDiagnostics() {
+    return {
+      'resolved_value_len': value?.length ?? 0,
+      'resolved_source': source.name,
+      'uri_has_login_challenge': uriHasLoginChallenge,
+      'raw_search_has_login_challenge': rawSearchHasLoginChallenge,
+      'raw_href_has_login_challenge': rawHrefHasLoginChallenge,
+    };
+  }
+}
+
+LoginChallengeResolution resolveLoginChallenge({
+  String? widgetLoginChallenge,
+  required Uri uri,
+  String? rawSearch,
+  String? rawHref,
+}) {
+  final widgetValue = _normalizeChallenge(widgetLoginChallenge);
+  if (widgetValue != null) {
+    return const LoginChallengeResolution(
+      value: null,
+      source: LoginChallengeSource.widget,
+      uriHasLoginChallenge: false,
+      rawSearchHasLoginChallenge: false,
+      rawHrefHasLoginChallenge: false,
+    ).copyWith(value: widgetValue);
+  }
+
+  final uriValue = _normalizeChallenge(uri.queryParameters['login_challenge']);
+  if (uriValue != null) {
+    return const LoginChallengeResolution(
+      value: null,
+      source: LoginChallengeSource.uriQuery,
+      uriHasLoginChallenge: true,
+      rawSearchHasLoginChallenge: false,
+      rawHrefHasLoginChallenge: false,
+    ).copyWith(value: uriValue);
+  }
+
+  final rawSearchValue = _normalizeChallenge(
+    _extractQueryParamFromRawQuery(rawSearch, 'login_challenge'),
+  );
+  if (rawSearchValue != null) {
+    return const LoginChallengeResolution(
+      value: null,
+      source: LoginChallengeSource.rawSearch,
+      uriHasLoginChallenge: false,
+      rawSearchHasLoginChallenge: true,
+      rawHrefHasLoginChallenge: false,
+    ).copyWith(value: rawSearchValue);
+  }
+
+  final rawHrefValue = _normalizeChallenge(
+    _extractQueryParamFromRawHref(rawHref, 'login_challenge'),
+  );
+  if (rawHrefValue != null) {
+    return const LoginChallengeResolution(
+      value: null,
+      source: LoginChallengeSource.rawHref,
+      uriHasLoginChallenge: false,
+      rawSearchHasLoginChallenge: false,
+      rawHrefHasLoginChallenge: true,
+    ).copyWith(value: rawHrefValue);
+  }
+
+  return const LoginChallengeResolution(
+    value: null,
+    source: LoginChallengeSource.missing,
+    uriHasLoginChallenge: false,
+    rawSearchHasLoginChallenge: false,
+    rawHrefHasLoginChallenge: false,
+  );
+}
+
+String? _normalizeChallenge(String? value) {
+  final trimmed = value?.trim();
+  if (trimmed == null || trimmed.isEmpty) {
+    return null;
+  }
+  return trimmed;
+}
+
+String? _extractQueryParamFromRawHref(String? rawHref, String key) {
+  final href = rawHref?.trim();
+  if (href == null || href.isEmpty) {
+    return null;
+  }
+
+  final parsed = Uri.tryParse(href);
+  final fromParsed = parsed?.queryParameters[key];
+  final normalizedParsed = _normalizeChallenge(fromParsed);
+  if (normalizedParsed != null) {
+    return normalizedParsed;
+  }
+
+  final question = href.indexOf('?');
+  if (question < 0) {
+    return null;
+  }
+  final hash = href.indexOf('#', question + 1);
+  final rawQuery = hash < 0
+      ? href.substring(question + 1)
+      : href.substring(question + 1, hash);
+  return _extractQueryParamFromRawQuery(rawQuery, key);
+}
+
+String? _extractQueryParamFromRawQuery(String? rawQuery, String key) {
+  final query = rawQuery?.trim();
+  if (query == null || query.isEmpty) {
+    return null;
+  }
+
+  final normalizedQuery = query.startsWith('?') ? query.substring(1) : query;
+  if (normalizedQuery.isEmpty) {
+    return null;
+  }
+
+  try {
+    final parsed = Uri.splitQueryString(normalizedQuery);
+    final value = _normalizeChallenge(parsed[key]);
+    if (value != null) {
+      return value;
+    }
+  } catch (_) {
+    // URI 파싱이 실패하면 수동 파싱으로 보완합니다.
+  }
+
+  for (final pair in normalizedQuery.split('&')) {
+    if (pair.isEmpty) {
+      continue;
+    }
+    final equalIndex = pair.indexOf('=');
+    final rawKey = equalIndex < 0 ? pair : pair.substring(0, equalIndex);
+    final decodedKey = _decodeQueryComponentSafe(rawKey);
+    if (decodedKey != key) {
+      continue;
+    }
+    if (equalIndex < 0) {
+      return null;
+    }
+    final rawValue = pair.substring(equalIndex + 1);
+    final decodedValue = _normalizeChallenge(
+      _decodeQueryComponentSafe(rawValue),
+    );
+    if (decodedValue != null) {
+      return decodedValue;
+    }
+  }
+  return null;
+}
+
+String _decodeQueryComponentSafe(String value) {
+  try {
+    return Uri.decodeQueryComponent(value);
+  } catch (_) {
+    return value;
+  }
+}
+
+extension on LoginChallengeResolution {
+  LoginChallengeResolution copyWith({
+    String? value,
+    LoginChallengeSource? source,
+    bool? uriHasLoginChallenge,
+    bool? rawSearchHasLoginChallenge,
+    bool? rawHrefHasLoginChallenge,
+  }) {
+    return LoginChallengeResolution(
+      value: value ?? this.value,
+      source: source ?? this.source,
+      uriHasLoginChallenge: uriHasLoginChallenge ?? this.uriHasLoginChallenge,
+      rawSearchHasLoginChallenge:
+          rawSearchHasLoginChallenge ?? this.rawSearchHasLoginChallenge,
+      rawHrefHasLoginChallenge:
+          rawHrefHasLoginChallenge ?? this.rawHrefHasLoginChallenge,
+    );
+  }
+}

userfront/lib/features/auth/presentation/login_screen.dart

@@ -11,6 +11,7 @@ import '../../../core/services/auth_proxy_service.dart';
 import '../../../core/services/auth_token_store.dart';
 import '../../../core/services/oidc_redirect_guard.dart';
 import '../../../core/notifiers/auth_notifier.dart';
+import '../domain/login_challenge_resolver.dart';
 import '../domain/password_login_flow_policy.dart';
 import '../../profile/domain/notifiers/profile_notifier.dart';
 import '../../../core/services/web_window.dart';
@@ -99,8 +100,12 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
         }
       }
 
-      _loginChallenge =
-          widget.loginChallenge ?? uri.queryParameters['login_challenge'];
+      final challengeResolution = _resolveLoginChallenge(uri);
+      _loginChallenge = challengeResolution.value;
+      _logLoginChallengeDiagnostics(
+        phase: 'init',
+        resolution: challengeResolution,
+      );
       final loginIdParam = uri.queryParameters['loginId'];
       final codeParam = uri.queryParameters['code'];
       final pendingRefParam = uri.queryParameters['pendingRef'];
@@ -273,6 +278,32 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
   bool get _hasLoginChallenge =>
       _loginChallenge != null && _loginChallenge!.isNotEmpty;
 
+  LoginChallengeResolution _resolveLoginChallenge(Uri uri) {
+    return resolveLoginChallenge(
+      widgetLoginChallenge: widget.loginChallenge,
+      uri: uri,
+      rawSearch: webWindow.currentSearch(),
+      rawHref: webWindow.currentHref(),
+    );
+  }
+
+  void _logLoginChallengeDiagnostics({
+    required String phase,
+    required LoginChallengeResolution resolution,
+  }) {
+    final current = Uri.base;
+    final currentQueryKeys = current.queryParameters.keys.toList()..sort();
+    final payload = <String, Object?>{
+      'phase': phase,
+      'current_path': current.path,
+      'current_query_keys': currentQueryKeys,
+      'stored_has_login_challenge': _hasLoginChallenge,
+      'stored_login_challenge_len': _loginChallenge?.length ?? 0,
+      ...resolution.toDiagnostics(),
+    };
+    debugPrint("[Auth] login_challenge diagnostics: ${jsonEncode(payload)}");
+  }
+
   void _logOidcRedirectDiagnostics({
     required String source,
     required OidcRedirectCheckResult checked,
@@ -864,6 +895,15 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
     }
 
     try {
+      final challengeResolution = _resolveLoginChallenge(Uri.base);
+      if (!_hasLoginChallenge && challengeResolution.value != null) {
+        _loginChallenge = challengeResolution.value;
+      }
+      _logLoginChallengeDiagnostics(
+        phase: 'password_submit',
+        resolution: challengeResolution,
+      );
+
       final res = await AuthProxyService.loginWithPassword(
         loginId,
         password,
@@ -883,6 +923,11 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
       debugPrint(
         "[Auth] Password login outcome: has_login_challenge=$_hasLoginChallenge, next_action=$nextAction, has_jwt=$hasJwt",
       );
+      if (!_hasLoginChallenge) {
+        debugPrint(
+          "[Auth] WARNING: password login proceeded without login_challenge; treated as local login flow",
+        );
+      }
 
       switch (nextAction) {
         case PasswordLoginNextAction.redirectToOidc:

userfront/lib/main.dart

@@ -147,14 +147,17 @@ final _router = GoRouter(
             GoRoute(
               path: 'login',
               builder: (context, state) {
+                final loginChallenge =
+                    state.uri.queryParameters['login_challenge'];
                 final redirectUrl =
                     state.uri.queryParameters['redirect_uri'] ??
                     state.uri.queryParameters['redirect_url'];
                 _routerLogger.info(
-                  "Navigating to /login, redirect: $redirectUrl",
+                  "Navigating to /login with login_challenge: $loginChallenge, redirect: $redirectUrl",
                 );
                 return LoginScreen(
                   key: state.pageKey,
+                  loginChallenge: loginChallenge,
                   redirectUrl: redirectUrl,
                 );
               },

userfront/test/login_challenge_resolver_test.dart

@@ -0,0 +1,69 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:userfront/features/auth/domain/login_challenge_resolver.dart';
+
+void main() {
+  group('login_challenge_resolver', () {
+    test('widget 값이 있으면 최우선으로 사용', () {
+      final resolved = resolveLoginChallenge(
+        widgetLoginChallenge: 'widget-challenge',
+        uri: Uri.parse('/ko/login'),
+        rawSearch: '?login_challenge=raw-search',
+        rawHref: 'https://sso-test.hmac.kr/ko/login?login_challenge=raw-href',
+      );
+
+      expect(resolved.value, 'widget-challenge');
+      expect(resolved.source, LoginChallengeSource.widget);
+    });
+
+    test('widget 값이 없으면 URI query에서 복구', () {
+      final resolved = resolveLoginChallenge(
+        widgetLoginChallenge: null,
+        uri: Uri.parse('/ko/login?login_challenge=uri-query'),
+        rawSearch: '',
+        rawHref: '',
+      );
+
+      expect(resolved.value, 'uri-query');
+      expect(resolved.source, LoginChallengeSource.uriQuery);
+    });
+
+    test('URI query가 비어 있으면 raw search에서 복구', () {
+      final resolved = resolveLoginChallenge(
+        widgetLoginChallenge: null,
+        uri: Uri.parse('/ko/login'),
+        rawSearch: '?login_challenge=raw-search-value&x=1',
+        rawHref: '',
+      );
+
+      expect(resolved.value, 'raw-search-value');
+      expect(resolved.source, LoginChallengeSource.rawSearch);
+      expect(resolved.rawSearchHasLoginChallenge, isTrue);
+    });
+
+    test('raw search도 비어 있으면 raw href에서 복구', () {
+      final resolved = resolveLoginChallenge(
+        widgetLoginChallenge: null,
+        uri: Uri.parse('/ko/login'),
+        rawSearch: '',
+        rawHref:
+            'https://sso-test.hmac.kr/ko/login?a=1&login_challenge=raw-href-value#fragment',
+      );
+
+      expect(resolved.value, 'raw-href-value');
+      expect(resolved.source, LoginChallengeSource.rawHref);
+      expect(resolved.rawHrefHasLoginChallenge, isTrue);
+    });
+
+    test('값이 전부 없으면 missing', () {
+      final resolved = resolveLoginChallenge(
+        widgetLoginChallenge: null,
+        uri: Uri.parse('/ko/login'),
+        rawSearch: '',
+        rawHref: 'https://sso-test.hmac.kr/ko/login?x=1',
+      );
+
+      expect(resolved.value, isNull);
+      expect(resolved.source, LoginChallengeSource.missing);
+    });
+  });
+}

userfront/test/router_redirect_widget_test.dart

@@ -28,6 +28,21 @@ Widget _buildTestApp(String initialLocation) {
               );
             },
           ),
+          GoRoute(
+            path: 'login',
+            builder: (context, state) {
+              final challenge = state.uri.queryParameters['login_challenge'];
+              final redirect =
+                  state.uri.queryParameters['redirect_uri'] ??
+                  state.uri.queryParameters['redirect_url'] ??
+                  '';
+              return Scaffold(
+                body: Text(
+                  'login|challenge=${challenge ?? ''}|redirect=$redirect',
+                ),
+              );
+            },
+          ),
           GoRoute(
             path: 'profile',
             builder: (context, state) =>
@@ -45,7 +60,7 @@ Widget _buildTestApp(String initialLocation) {
       final isLoggedIn =
           AuthTokenStore.getToken() != null || AuthTokenStore.usesCookie();
       final path = stripLocalePath(state.uri);
-      final isPublicPath = path == '/signin';
+      final isPublicPath = path == '/signin' || path == '/login';
       if (isPublicPath) {
         return null;
       }
@@ -70,6 +85,25 @@ void main() {
     LocaleRegistry.resetForTest();
   });
 
+  testWidgets('/login: login_challenge와 redirect_uri를 전달', (tester) async {
+    final encodedRedirectUri = Uri.encodeComponent(
+      'https://rp.example.com/callback?x=1',
+    );
+    await tester.pumpWidget(
+      _buildTestApp(
+        '/en/login?login_challenge=lc_999&redirect_uri=$encodedRedirectUri',
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    expect(
+      find.text(
+        'login|challenge=lc_999|redirect=https://rp.example.com/callback?x=1',
+      ),
+      findsOneWidget,
+    );
+  });
+
   testWidgets('비로그인: redirect_uri/login_challenge가 signin으로 전달', (
     tester,
   ) async {