use regex + static method to centralize hashedfavicon URL behavior

This commit is contained in:
Nick Krecklow 2020-05-08 16:00:36 -05:00
parent 15814cf86b
commit 04d94a9461
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GPG Key ID: 5F149FDE156FFA94
2 changed files with 28 additions and 23 deletions

@ -1,4 +1,5 @@
const http = require('http')
const format = require('util').format
const WebSocket = require('ws')
const finalHttpHandler = require('finalhandler')
@ -6,14 +7,18 @@ const serveStatic = require('serve-static')
const logger = require('./logger')
const HASHED_FAVICON_URL = '/hashedfavicon_'
const HASHED_FAVICON_EXTENSION = '.png'
const HASHED_FAVICON_URL_REGEX = /hashedfavicon_([a-z0-9]{32}).png/g
function getRemoteAddr (req) {
return req.headers['cf-connecting-ip'] || req.headers['x-forwarded-for'] || req.connection.remoteAddress
}
class Server {
static getHashedFaviconUrl (hash) {
// Format must be compatible with HASHED_FAVICON_URL_REGEX
return format('/hashedfavicon_%s.png', hash)
}
constructor (app) {
this._app = app
@ -28,24 +33,26 @@ class Server {
this._http = http.createServer((req, res) => {
logger.log('info', '%s requested: %s', getRemoteAddr(req), req.url)
if (req.url.startsWith(HASHED_FAVICON_URL) && req.url.endsWith(HASHED_FAVICON_EXTENSION)) {
this.handleFaviconRequest(req, res)
} else {
// Attempt to handle req using distServeStatic, otherwise fail over to faviconServeStatic
// If faviconServeStatic fails, pass to finalHttpHandler to terminate
distServeStatic(req, res, () => {
faviconsServeStatic(req, res, finalHttpHandler(req, res))
})
// Test the URL against a regex for hashed favicon URLs
// Require only 1 match ([0]) and test its first captured group ([1])
// Any invalid value or hit miss will pass into static handlers below
const faviconHash = [...req.url.matchAll(HASHED_FAVICON_URL_REGEX)]
if (faviconHash.length === 1 && this.handleFaviconRequest(res, faviconHash[0][1])) {
return
}
// Attempt to handle req using distServeStatic, otherwise fail over to faviconServeStatic
// If faviconServeStatic fails, pass to finalHttpHandler to terminate
distServeStatic(req, res, () => {
faviconsServeStatic(req, res, finalHttpHandler(req, res))
})
})
}
handleFaviconRequest = (req, res) => {
let hash = req.url.substring(HASHED_FAVICON_URL.length)
hash = hash.substring(0, hash.length - HASHED_FAVICON_EXTENSION.length)
handleFaviconRequest = (res, faviconHash) => {
for (const serverRegistration of this._app.serverRegistrations) {
if (serverRegistration.faviconHash && serverRegistration.faviconHash === hash) {
if (serverRegistration.faviconHash && serverRegistration.faviconHash === faviconHash) {
const buf = Buffer.from(serverRegistration.lastFavicon.split(',')[1], 'base64')
res.writeHead(200, {
@ -54,13 +61,11 @@ class Server {
'Cache-Control': 'max-age=604800' // Cache hashed favicon for 7 days
}).end(buf)
return
return true
}
}
// Terminate request, no match
res.writeHead(404)
res.end()
return false
}
createWebSocketServer () {

@ -1,13 +1,11 @@
const crypto = require('crypto')
const TimeTracker = require('./time')
const Server = require('./server')
const config = require('../config')
const minecraftVersions = require('../minecraft_versions')
const HASHED_FAVICON_URL = '/hashedfavicon_'
const HASHED_FAVICON_EXTENSION = '.png'
class ServerRegistration {
serverId
lastFavicon
@ -233,16 +231,18 @@ class ServerRegistration {
if (!this._faviconHasher) {
this._faviconHasher = crypto.createHash('md5')
}
this.faviconHash = this._faviconHasher.update(favicon).digest('hex').toString()
return true
}
return false
}
getFaviconUrl () {
if (this.faviconHash) {
return HASHED_FAVICON_URL + this.faviconHash + HASHED_FAVICON_EXTENSION
return Server.getHashedFaviconUrl(this.faviconHash)
} else if (this.data.favicon) {
return this.data.favicon
}