const path = require("path"); const config = require("./config/config"); const WhiteboardServerSideInfo = require("./WhiteboardServerSideInfo"); function startBackendServer(port) { var fs = require("fs-extra"); var express = require("express"); var formidable = require("formidable"); //form upload processing const createDOMPurify = require("dompurify"); //Prevent xss const { JSDOM } = require("jsdom"); const window = new JSDOM("").window; const DOMPurify = createDOMPurify(window); const { createClient } = require("webdav"); var s_whiteboard = require("./s_whiteboard.js"); var app = express(); app.use(express.static(path.join(__dirname, "..", "dist"))); app.use("/uploads", express.static(path.join(__dirname, "..", "public", "uploads"))); var server = require("http").Server(app); server.listen(port); var io = require("socket.io")(server, { path: "/ws-api" }); console.log("Webserver & socketserver running on port:" + port); const { accessToken, enableWebdav } = config.backend; app.get("/api/loadwhiteboard", function (req, res) { var wid = req["query"]["wid"]; var at = req["query"]["at"]; //accesstoken if (accessToken === "" || accessToken == at) { var ret = s_whiteboard.loadStoredData(wid); res.send(ret); res.end(); } else { res.status(401); //Unauthorized res.end(); } }); app.post("/api/upload", function (req, res) { //File upload var form = new formidable.IncomingForm(); //Receive form var formData = { files: {}, fields: {}, }; form.on("file", function (name, file) { formData["files"][file.name] = file; }); form.on("field", function (name, value) { formData["fields"][name] = value; }); form.on("error", function (err) { console.log("File uplaod Error!"); }); form.on("end", function () { if (accessToken === "" || accessToken == formData["fields"]["at"]) { progressUploadFormData(formData, function (err) { if (err) { if (err == "403") { res.status(403); } else { res.status(500); } res.end(); } else { res.send("done"); } }); } else { res.status(401); //Unauthorized res.end(); } //End file upload }); form.parse(req); }); function progressUploadFormData(formData, callback) { console.log("Progress new Form Data"); var fields = escapeAllContentStrings(formData.fields); var files = formData.files; var whiteboardId = fields["whiteboardId"]; var name = fields["name"] || ""; var date = fields["date"] || +new Date(); var filename = whiteboardId + "_" + date + ".png"; var webdavaccess = fields["webdavaccess"] || false; try { webdavaccess = JSON.parse(webdavaccess); } catch (e) { webdavaccess = false; } fs.ensureDir("./public/uploads", function (err) { if (err) { console.log("Could not create upload folder!", err); return; } var imagedata = fields["imagedata"]; if (imagedata && imagedata != "") { //Save from base64 data imagedata = imagedata .replace(/^data:image\/png;base64,/, "") .replace(/^data:image\/jpeg;base64,/, ""); console.log(filename, "uploaded"); fs.writeFile("./public/uploads/" + filename, imagedata, "base64", function (err) { if (err) { console.log("error", err); callback(err); } else { if (webdavaccess) { //Save image to webdav if (enableWebdav) { saveImageToWebdav( "./public/uploads/" + filename, filename, webdavaccess, function (err) { if (err) { console.log("error", err); callback(err); } else { callback(); } } ); } else { callback("Webdav is not enabled on the server!"); } } else { callback(); } } }); } else { callback("no imagedata!"); console.log("No image Data found for this upload!", name); } }); } function saveImageToWebdav(imagepath, filename, webdavaccess, callback) { if (webdavaccess) { var webdavserver = webdavaccess["webdavserver"] || ""; var webdavpath = webdavaccess["webdavpath"] || "/"; var webdavusername = webdavaccess["webdavusername"] || ""; var webdavpassword = webdavaccess["webdavpassword"] || ""; const client = createClient(webdavserver, { username: webdavusername, password: webdavpassword, }); client .getDirectoryContents(webdavpath) .then((items) => { var cloudpath = webdavpath + "" + filename; console.log("webdav saving to:", cloudpath); fs.createReadStream(imagepath).pipe(client.createWriteStream(cloudpath)); callback(); }) .catch((error) => { callback("403"); console.log("Could not connect to webdav!"); }); } else { callback("Error: no access data!"); } } /** * @type {Map} */ const infoByWhiteboard = new Map(); setInterval(() => { infoByWhiteboard.forEach((info, whiteboardId) => { if (info.shouldSendInfo()) { io.sockets .in(whiteboardId) .compress(false) .emit("whiteboardInfoUpdate", info.asObject()); info.infoWasSent(); } }); }, (1 / config.backend.performance.whiteboardInfoBroadcastFreq) * 1000); io.on("connection", function (socket) { var whiteboardId = null; socket.on("disconnect", function () { if (infoByWhiteboard.has(whiteboardId)) { const whiteboardServerSideInfo = infoByWhiteboard.get(whiteboardId); if (socket && socket.id) { whiteboardServerSideInfo.deleteScreenResolutionOfClient(socket.id); } whiteboardServerSideInfo.decrementNbConnectedUsers(); if (whiteboardServerSideInfo.hasConnectedUser()) { socket.compress(false).broadcast.emit("refreshUserBadges", null); //Removes old user Badges } else { infoByWhiteboard.delete(whiteboardId); } } }); socket.on("drawToWhiteboard", function (content) { content = escapeAllContentStrings(content); if (accessToken === "" || accessToken == content["at"]) { socket.compress(false).broadcast.to(whiteboardId).emit("drawToWhiteboard", content); //Send to all users in the room (not own socket) s_whiteboard.handleEventsAndData(content); //save whiteboardchanges on the server } else { socket.emit("wrongAccessToken", true); } }); socket.on("joinWhiteboard", function (content) { content = escapeAllContentStrings(content); if (accessToken === "" || accessToken == content["at"]) { socket.emit("whiteboardConfig", { common: config.frontend }); whiteboardId = content["wid"]; socket.join(whiteboardId); //Joins room name=wid if (!infoByWhiteboard.has(whiteboardId)) { infoByWhiteboard.set(whiteboardId, new WhiteboardServerSideInfo()); } const whiteboardServerSideInfo = infoByWhiteboard.get(whiteboardId); whiteboardServerSideInfo.incrementNbConnectedUsers(); whiteboardServerSideInfo.setScreenResolutionForClient( socket.id, content["windowWidthHeight"] || WhiteboardServerSideInfo.defaultScreenResolution ); } else { socket.emit("wrongAccessToken", true); } }); socket.on("updateScreenResolution", function (content) { content = escapeAllContentStrings(content); if (accessToken === "" || accessToken == content["at"]) { const whiteboardServerSideInfo = infoByWhiteboard.get(whiteboardId); whiteboardServerSideInfo.setScreenResolutionForClient( socket.id, content["windowWidthHeight"] || WhiteboardServerSideInfo.defaultScreenResolution ); } }); }); //Prevent cross site scripting (xss) function escapeAllContentStrings(content, cnt) { if (!cnt) cnt = 0; if (typeof content === "string") { return DOMPurify.sanitize(content); } for (var i in content) { if (typeof content[i] === "string") { content[i] = DOMPurify.sanitize(content[i]); } if (typeof content[i] === "object" && cnt < 10) { content[i] = escapeAllContentStrings(content[i], ++cnt); } } return content; } process.on("unhandledRejection", (error) => { // Will print "unhandledRejection err is not defined" console.log("unhandledRejection", error.message); }); } module.exports = startBackendServer;