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const crypto = require('crypto')
const http = require('http')
const mustache = require('mustache')
const getRawBody = require('raw-body')
const _ = require('lodash')
const flag = require('./flag')
const indexTemplate = `
<!doctype html>
<style>
body {
background: #172159;
}
* {
color: #fff;
}
</style>
<h1>your public blueprints!</h1>
<i>(in compliance with military-grade security, we only show the public ones. you must have the unique URL to access private blueprints.)</i>
<br>
{{#blueprints}}
{{#public}}
<div><br><a href="/blueprints/{{id}}">blueprint</a>: {{content}}<br></div>
{{/public}}
{{/blueprints}}
<br><a href="/make">make your own blueprint!</a>
`
const blueprintTemplate = `
<!doctype html>
<style>
body {
background: #172159;
color: #fff;
}
</style>
<h1>blueprint!</h1>
{{content}}
`
const notFoundPage = `
<!doctype html>
<style>
body {
background: #172159;
color: #fff;
}
</style>
<h1>404</h1>
`
const makePage = `
<!doctype html>
<style>
body {
background: #172159;
color: #fff;
}
</style>
<div>content:</div>
<textarea id="content"></textarea>
<br>
<span>public:</span>
<input type="checkbox" id="public">
<br><br>
<button id="submit">create blueprint!</button>
<script>
submit.addEventListener('click', () => {
fetch('/make', {
method: 'POST',
headers: {
'content-type': 'application/json',
},
body: JSON.stringify({
content: content.value,
public: public.checked,
})
}).then(res => res.text()).then(id => location='/blueprints/' + id)
})
</script>
`
// very janky, but it works
const parseUserId = (cookies) => {
if (cookies === undefined) { // 判断是否未定义
return null
}
const userIdCookie = cookies.split('; ').find(cookie => cookie.startsWith('user_id='))
// 使用;分割并且查找名为"user_id="的值
if (userIdCookie === undefined) { // 值为空返回null
return null
}
return decodeURIComponent(userIdCookie.replace('user_id=', '')) // url解码，替换值为空
}
const makeId = () => crypto.randomBytes(16).toString('hex') // 随机hash
// list of users and blueprints
const users = new Map()
http.createServer((req, res) => {
let userId = parseUserId(req.headers.cookie) // 获取请求cookie
let user = users.get(userId) // 存放cookie
if (userId === null || user === undefined) { // 没有Cookie
// create user if one doesnt exist
userId = makeId()
user = {
blueprints: {
[makeId()]: { // hash存储
content: flag,
},
},
}
users.set(userId, user) // 设置hash为索引存放content
}
// send back the user id
res.writeHead(200, {
'set-cookie': 'user_id=' + encodeURIComponent(userId) + '; Path=/', // url编码后的
})
if (req.url === '/' && req.method === 'GET') {
// 列出所有
res.end(mustache.render(indexTemplate, {
blueprints: Object.entries(user.blueprints).map(([k, v]) => ({
id: k,
content: v.content,
public: v.public,
})),
}))
} else if (req.url.startsWith('/blueprints/') && req.method === 'GET') {
// show an individual blueprint, including private ones
const blueprintId = req.url.replace('/blueprints/', '')
if (user.blueprints[blueprintId] === undefined) {
res.end(notFoundPage) // 判断是否有id
return
}
res.end(mustache.render(blueprintTemplate, {
content: user.blueprints[blueprintId].content, // 返回对应id的content
}))
} else if (req.url === '/make' && req.method === 'GET') {
// show the static blueprint creation page
res.end(makePage)
} else if (req.url === '/make' && req.method === 'POST') {
// API used by the creation page
getRawBody(req, {
limit: '1mb',
}, (err, body) => {
if (err) {
throw err
}
let parsedBody
try {
// default values are easier to do than proper input validation
parsedBody = _.defaultsDeep({ // 数组拷贝，json数据为可控的body
publiс: false, // default private
cоntent: '', // default no content
}, JSON.parse(body))
} catch (e) {
res.end('bad json')
return
}
// make the blueprint
const blueprintId = makeId()
user.blueprints[blueprintId] = {
content: parsedBody.content,
public: parsedBody.public,
}
res.end(blueprintId)
})
} else {
res.end(notFoundPage)
}
}).listen(80, () => {
console.log('listening on port 80')
})
|
