added web challenge

bi0sctf23/web/src/index.js

@@ -0,0 +1,200 @@
+const express = require('express');
+const fs = require('fs');
+const protobuf = require('protobufjs');
+const glob = require('glob');
+const { healthCheck } = require('./bot');
+const app = express();
+const port = 3000;
+
+function generateNoteId(length) {
+  const characters = 'abcdefghijklmnopqrstuvwxyz0123456789';
+  let result = '';
+  for (let i = 0; i < length; i++) {
+    const randomIndex = Math.floor(Math.random() * characters.length);
+    result += characters.charAt(randomIndex);
+  }
+  return result;
+}
+
+let noteList = [];
+let flag = process.env.FLAG;
+if(!flag){
+  flag='{"title":"flag","content":"bi0sctf{fake_flag}"}';
+}
+else{
+  flag=`{"title":"flag","content":"${flag}"}`;
+}
+const flagid = generateNoteId(16);
+const healthCheckId='Healthcheck';
+fs.writeFileSync(`./notes/${flagid}.json`, flag);
+fs.writeFileSync(`./notes/${healthCheckId}.json`, '{"title":"Healthcheck","content":"success"}');
+
+app.use(express.json());
+
+app.set('view engine', 'ejs');
+app.set('views', __dirname + '/views');
+
+const restrictToLocalhost = (req, res, next) => {
+  const remoteAddress = req.connection.remoteAddress;
+  if (remoteAddress === '::1' || remoteAddress === '127.0.0.1' || remoteAddress === '::ffff:127.0.0.1') {
+    next();
+  } else {
+    res.status(403).json({ Message: 'Access denied' });
+  }
+};
+
+const cleanserver = () => {
+  Object.keys(require.cache).forEach(i => {
+    delete require.cache[i];
+  });
+};
+
+app.use('/search', restrictToLocalhost);
+
+app.get('/delete', (req,res) => {
+  cleanserver();
+  return res.json({Message: 'Notes deleted successfully!'});
+});
+
+app.get('/search/:noteId', (req, res) => {
+  const noteId = req.params.noteId;
+  const notes=glob.sync(`./notes/${noteId}*`);
+  if(notes.length === 0){
+    return res.json({Message: "Not found"});
+  }
+  else{
+    try{
+      fs.accessSync(`./notes/${noteId}.json`);
+      return res.json({Message: "Note found"});
+    }
+    catch(err){
+      return res.status(500).json({ Message: 'Internal server error' });
+    }
+  }
+
+})
+
+app.get('/customise', (req, res) => {
+  return res.render('customise');
+});
+
+app.post('/customise',(req, res) => {
+  try {
+    const { data } = req.body;
+
+    let author = data.pop()['author'];
+
+    let title = data.pop()['title'];
+
+    let protoContents = fs.readFileSync('./settings.proto', 'utf-8').split('\n');
+
+    if (author) {
+      protoContents[5] = `  ${author} string author = 3 [default="user"];`;
+    }
+
+    if (title) {
+      protoContents[3] = `  ${title} string title = 1 [default="user"];`;
+    }
+
+    fs.writeFileSync('./settings.proto', protoContents.join('\n'), 'utf-8');
+
+    return res.json({ Message: 'Settings changed' });
+  } catch (error) {
+    console.error(error);
+    res.status(500).json({ Message: 'Internal server error' });
+  }
+})
+
+app.get('/create', (req, res) => {
+  return res.render('create', { noteList, Message: false });
+});
+
+app.post('/create', (req, res) => {
+  requestBody=req.body
+  try{
+    schema = fs.readFileSync('./settings.proto', 'utf-8');
+    root = protobuf.parse(schema).root;
+    Note = root.lookupType('Note');
+    errMsg = Note.verify(requestBody);
+
+    if (errMsg){
+      return res.json({ Message: `Verification failed: ${errMsg}` });
+    }
+    buffer = Note.encode(Note.create(requestBody)).finish();
+    decodedData = Note.decode(buffer).toJSON();
+
+    const noteId = generateNoteId(16);
+    fs.writeFileSync(`./notes/${noteId}.json`, JSON.stringify(decodedData));
+    noteList.push(noteId);
+
+    return res.json({Message: 'Note created successfully!',Noteid: noteId });
+  }
+  catch (error) {
+    console.error(error);
+    res.status(500).json({Message: 'Internal server error' });
+  }
+});
+
+
+app.get('/view/:noteId', (req, res) => {
+  const noteId = req.params.noteId;
+
+  try {
+    let note=require.resolve(`./notes/${noteId}`);
+    if(!note.endsWith(".json")){
+      return res.status(500).json({ Message: 'Internal Server Error' });
+    }
+
+    let noteData = require(`./notes/${noteId}`);
+    for (var key in module.constructor._pathCache) {
+      if (key.startsWith("./notes/"+noteId)){
+        if (!module.constructor._pathCache[key].endsWith(noteId+".json")){
+          if (noteId===healthCheckId){
+            cleanserver();
+          }
+          delete module.constructor._pathCache[key];
+          return res.status(500).json({ Message: 'Internal Server Error' });
+        }
+      }
+    }
+    if(req.query.temp !== undefined){
+      fs.unlink(`./notes/${noteId}.json`, (unlinkError) => {
+        if (unlinkError) {
+          console.error('File missing');
+        }
+        noteList=noteList.filter((value)=>value!=noteId);
+      });
+    }
+    return res.render('view', { noteData });
+
+  } catch (error) {
+    console.log(error)
+    return res.status(500).json({ Message: 'Internal Server Error' });
+  }
+});
+
+
+app.get('/healthcheck',async(req,res)=>{
+  try {
+    await healthCheck();
+
+    return res.json({ Message: 'healthcheck successful' });
+  } catch (error) {
+    console.error(error);
+    return res.json({ Message: 'healthcheck failed' });
+  }
+});
+
+app.get('/', (req, res) => {
+  return res.redirect('/create');
+});
+
+
+app.use((err, req, res, next) => {
+  console.error(err.stack);
+  res.status(500).json({ error: 'Internal Server Error' });
+});
+
+app.listen(port, () => {
+  console.log(`Server running on port ${port}`);
+});