feat: capture undergraduate pages with scoped evidence

2026-10-14 23:40:15 +08:00
parent ebe70e3eb2
commit d101ffbf85
4 changed files with 274 additions and 0 deletions
@@ -0,0 +1,22 @@
+import '../school_navigation_policy.dart';
+
+class UndergraduateNavigationPolicy {
+  static bool canNavigate(Uri uri, {required bool isMainFrame}) =>
+      uri.scheme == 'https' &&
+          uri.port == 443 &&
+          uri.userInfo.isEmpty &&
+          const {
+            'eams.uestc.edu.cn',
+            'idas.uestc.edu.cn',
+            'eportal.uestc.edu.cn',
+          }.contains(uri.host) ||
+      !isMainFrame && uri.toString() == 'about:blank';
+  static bool isDataPage(Uri uri) =>
+      canNavigate(uri, isMainFrame: true) &&
+      uri.host == 'eams.uestc.edu.cn' &&
+      uri.path.startsWith('/eams/');
+  static bool isLogout(Uri uri) =>
+      isDataPage(uri) && uri.path == '/eams/logout.action';
+  static Uri? secureIdentityRedirect(Uri uri) =>
+      SchoolNavigationPolicy.secureIdentityRedirect(uri);
+}
@@ -0,0 +1,121 @@
+import 'dart:convert';
+
+import 'navigation_policy.dart';
+
+const undergraduateProbeBase = r'''(() => {
+  const capture=__CAPTURE__;
+  const topUrl=location.href;
+  const result={topUrl,authenticated:false,pages:[]};
+  const trusted=value=>{try{const u=new URL(value);return u.protocol==='https:' && u.hostname==='eams.uestc.edu.cn' &&
+    (!u.port || u.port==='443') && !u.username && !u.password && u.pathname.startsWith('/eams/');}catch(_){return false;}};
+  if(!trusted(topUrl) || document.querySelector('input[type="password"]'))return JSON.stringify(result);
+  const origin=new URL(topUrl).origin,seen=new Set();let total=0;
+  const headers=['课程序号','课程名称','考试日期','考试安排','考试地点','座位号','考试情况','考试类型','其它说明'];
+  const add=(kind,url,body)=>{
+    total+=new TextEncoder().encode(body).byteLength;
+    if(total>2*1024*1024)throw new Error('capture_limit');
+    result.pages.push({kind,url,html:body});
+  };
+  const visit=(doc,depth)=>{
+    if(!doc || seen.has(doc))return;
+    let url;try{url=doc.location.href;}catch(_){return;}
+    if(!trusted(url) || new URL(url).origin!==origin || doc.querySelector('input[type="password"]'))return;
+    if(depth>4 || seen.size>=16)throw new Error('capture_limit');seen.add(doc);
+    const timetable=doc.querySelector('#manualArrangeCourseTable');
+    const exams=Array.from(doc.querySelectorAll('table')).filter(table=>{
+      const row=table.querySelector('tr');if(!row)return false;
+      const values=Array.from(row.children).map(c=>c.textContent.trim());
+      return values.length===9 && headers.every((v,i)=>values[i]===v);
+    });
+    const logout=Array.from(doc.querySelectorAll('a[href]')).some(a=>{try{return new URL(a.getAttribute('href'),url).pathname==='/eams/logout.action';}catch(_){return false;}});
+    result.authenticated=result.authenticated || Boolean(logout || timetable || exams.length);
+    if(capture && (timetable || exams.length)){
+      const fields=Array.from(doc.querySelectorAll('input[name="semester.id"],input[name="examType.id"],input[name="params"]')).map(input=>{
+        const clone=input.cloneNode(true);clone.setAttribute('value',input.value);return clone.outerHTML;
+      }).join('');
+      const scripts=Array.from(doc.querySelectorAll('script')).filter(s=>/new\s+TaskActivity|\bunitCount\s*=|\bvar\s+params\s*=/.test(s.textContent)).map(s=>s.outerHTML).join('');
+      if(timetable){
+        const roster=Array.from(doc.querySelectorAll('table')).filter(table=>{
+          const row=table.querySelector('tr');return row && Array.from(row.children).some(c=>c.textContent.trim()==='课程序号') &&
+            Array.from(row.children).some(c=>c.textContent.trim()==='课程代码');
+        }).map(t=>t.outerHTML).join('');
+        add('timetable',url,fields+timetable.outerHTML+roster+scripts);
+      }
+      for(const table of exams)add('exams',url,'<form id="stdExamTableForm">'+fields+'</form>'+table.outerHTML+scripts);
+    }
+    for(const frame of doc.querySelectorAll('iframe,frame')){
+      let child;try{child=frame.contentDocument;}catch(_){continue;}visit(child,depth+1);
+    }
+  };
+  try{visit(document,0);}catch(_){result.error='capture_limit';result.pages=[];}
+  return JSON.stringify(result);
+})()''';
+
+final undergraduateStatusProbeScript = undergraduateProbeBase.replaceAll(
+  '__CAPTURE__',
+  'false',
+);
+final undergraduateCaptureScript = undergraduateProbeBase.replaceAll(
+  '__CAPTURE__',
+  'true',
+);
+
+class UndergraduateFragment {
+  const UndergraduateFragment(this.kind, this.url, this.html);
+  final String kind, html;
+  final Uri url;
+}
+
+class UndergraduatePageEvidence {
+  const UndergraduatePageEvidence(this.authenticated, this.pages);
+  final bool authenticated;
+  final List<UndergraduateFragment> pages;
+  static UndergraduatePageEvidence decode(Object raw, Uri current) {
+    try {
+      dynamic value = raw;
+      for (var i = 0; i < 2 && value is String; i++) {
+        value = jsonDecode(value);
+      }
+      if (value is! Map ||
+          value['topUrl'] != current.toString() ||
+          value['error'] != null ||
+          !UndergraduateNavigationPolicy.canNavigate(
+            current,
+            isMainFrame: true,
+          ))
+        throw const FormatException('页面证据无效');
+      final pages = value['pages'];
+      if (pages is! List || pages.length > 32)
+        throw const FormatException('页面片段过多');
+      var bytes = 0;
+      final result = <UndergraduateFragment>[];
+      for (final page in pages) {
+        if (page is! Map ||
+            page['url'] is! String ||
+            page['html'] is! String ||
+            !const ['timetable', 'exams'].contains(page['kind']))
+          throw const FormatException('页面片段无效');
+        final uri = Uri.parse(page['url'] as String),
+            body = page['html'] as String;
+        bytes += utf8.encode(body).length;
+        if (bytes > 2 * 1024 * 1024 ||
+            !UndergraduateNavigationPolicy.isDataPage(current) ||
+            !UndergraduateNavigationPolicy.isDataPage(uri) ||
+            current.origin != uri.origin)
+          throw const FormatException('页面来源或大小无效');
+        result.add(UndergraduateFragment(page['kind'] as String, uri, body));
+      }
+      if (!UndergraduateNavigationPolicy.isDataPage(current) &&
+          (value['authenticated'] == true || result.isNotEmpty))
+        throw const FormatException('认证页面不能作为数据来源');
+      return UndergraduatePageEvidence(
+        value['authenticated'] == true,
+        List.unmodifiable(result),
+      );
+    } on FormatException {
+      rethrow;
+    } catch (_) {
+      throw const FormatException('学校页面读取未完成');
+    }
+  }
+}